34839005 - water droplets falling into the hand

Rain is the primary source of most of the fresh water in the world. It plays an important role for life on Earth as part of the hydrologic cycle. When the moisture from the oceans evaporates into the sky, condenses into droplets, and precipitates from the sky over the Earth's surface, water is distributed throughout the globe. It is thanks to this form of precipitation that we have suitable conditions for diverse ecosystems, power sources, and crop irrigation. 

All plants need at least some water to survive, and rain is the most effective means of watering. A regular watering pattern is vital to healthy plants. Too little or too much rainfall can be detrimental, or even devastating to crops. A drought can be drastic, killing numerous crops, while extremely wet weather can cause disease and fungus. Some plants, such as cacti, are able to thrive in areas with limited precipitation. Tropical plants, however, need hundreds of inches of rain per year to survive.

Excessive rain, especially in the wake of long dry spells that harden the soil such that it cannot absorb water, can cause flooding. Many people find the scent of the rain — during, or immediately after a storm — pleasing and distinctive. The source of this scent is the oils produced by plants which are released first into rocks or soil, and later into the air during rainfall.
<h3>Statistics of Rainfall Around the World</h3>
Precipitation is measured by the rate at which it falls using a rain gauge. It is considered very light rain when the gauge measures less than 0.01 inches per hour. The classifications continue with light, moderate, heavy, very heavy, and extreme rain with amounts of 2 inches per hour or more.
<h4>Europe</h4>
<ul>
 	<li>In the United Kingdom, most rain is driven into the country by south-western tradewinds along the warm gulf stream currents. The western coastal regions can receive up to 40 inches of rain per year at sea level, and up to 100 inches in the mountains.</li>
</ul>
<h4>North America</h4>
<ul>
 	<li>Seattle, Washington in the U.S is well known for its rainy climate. However, despite the renown, Seattle experiences less rainfall (37 inches per year on average) than New York City (46 inches per year). Seattle does have more cloudy days (201 per year) than New York City (152).</li>
</ul>
<ul>
 	<li>The wettest city in the 48 contiguous United States is Mobile, Alabama, with an average rainfall of 67 inches per year.</li>
</ul>
<ul>
 	<li>Alaska’s temperate rainforests get an average of 160 inches per year.</li>
</ul>
<h4>Australia</h4>
<ul>
 	<li>Although Australia is the world’s driest continent, more than 300 inches of rain falls on Mount Bellendon Ker each year. 472 inches were recorded in the year 2000. Melbourne’s climate is similar to that of Seattle, Washington, but only gets about 25 inches per year. Sydney receives an average of 48 inches of rain per year. </li>
</ul>
<h4>Asia</h4>
<ul>
 	<li>Cherrapunji, a town on the southern slopes of the Himalayas in Shillong, India is one of the wettest places on Earth. Their average annual rainfall is about 450 inches per year. The highest recorded rainfall was 904.9 inches in 1861. Most of the rainfall in Cherrapunji occurs during the monsoon seasons (between April and September).</li>
</ul>
<h4>South America</h4>
<ul>
 	<li>Llor, in Choc, Colombia, is considered the place with the most rainfall, averaging 523.6 inches per year. In 1974, the town recorded 86.3 feet of rainfall, the largest annual rainfall measured in Colombia. Some storms in Choc have been known to drop as much as 20 inches of rain in one day. Unlike Cherrapunji, Tutunendo receives rain throughout the year, averaging 280 rainy days, 68% of which falls at night.</li>
</ul>
<h3>The Characteristics of a Raindrop</h3>
Raindrops are often depicted as being teardrop-shaped, but this is not entirely correct; only drops of water falling from certain objects appear this way at the moment of formation. Small raindrops are more spherical in shape, and larger raindrops become flattened on the bottom, much like a hamburger bun.

Some of the largest raindrops (0.20 inches or more in diameter) become unstable, and fragment. The average raindrop is about 0.05 inches in diameter. Two regions hold the Guinness world record for the largest raindrops: Brazil (in 1995), and the Marshall Islands (1999). Laser image equipment employed by researchers from the University of Washington measured raindrops with a diameter of at least 0.338 inches.
<h3>The Formation of Raindrops</h3>
After evaporating, water vapor rises into the upper atmosphere where it is cool enough for the vapor to condense. The droplets fall towards the Earth once the water becomes heavy enough to be released from the clouds. Not all of the rain that falls reaches the surface, though; sometimes rain evaporates as it falls, especially through dry air. This type of rainfall is known as virga, or ‘phantom rain’, and often encountered in hot desert regions. The Bergeron process is a scientific explanation of how water vapor turns into rainfall.
<h3>Other Types of Rainfall</h3>
Both nature and human activities produce some rain that contains more than water alone. Industrial emissions can cause pollutants to react with the water vapor, producing clouds of acid rain. The fumes from various mechanical sources can cause the build up of gases such as sulfur dioxide or nitrogen oxide in the atmosphere in as little as seven days. Acid rain-bearing clouds can be formed and distributed throughout the atmosphere after only five days of build up.

Normally, rain has a pH level just under 6 on the scale. This is due to atmospheric carbon dioxide that dissolves in the droplet and forms extremely small quantities of carbonic acid. In some regions, airborne dust particles contain enough calcium carbonate to counter the acidity levels in precipitation, making it neutral or alkaline. It is considered acid rain if the pH is 5.5 or lower.

There are also efforts to increase the rainfall on several parts of the planet. Many countries are experimenting with cloud seeding — a process inducing rain by releasing salt particles into the air around the clouds. The particles combine with the water vapor to draw more water out of the clouds than normal.

The phenomenon of rain is not isolated to planet Earth; Titan, Saturn’s largest moon, has many channels on its surface that are hypothesized to have been carved by methane rain. The sulfuric acid saturating Venus’ atmosphere evaporates 15 miles above the surface. The gas giants — Jupiter, Neptune, Uranus, and Saturn — also likely have precipitation of various compositions in their upper atmospheres.

What is Rain?

Rain is the primary source of most of the fresh...

36609665 - cold weather low temperature concept

A snow gauge is an instrument used in meteorology to gather and measure the amount of solid precipitation (as opposed to liquid precipitation that is measured by a rain gauge) over a period of time.
<h2>A snow gauge has two parts:</h2>
<ol>
 	<li>the copper catchment container</li>
 	<li>the funnel shaped gauge itself</li>
</ol>
The actual gauge is mounted on a pipe that is about 4 ft. 11 in. high. The gauge itself is about 20.25 inches long.
Snowfall is measured by how much falls into the gauge. When snow has fallen, the container is removed and replaced by a spare.

The snow is then melted while still in the container, then poured into a glass measuring beaker. While snow is normally measured in centimeters, melted snow is measured in millimeters. The estimate of the snow depth is obtained by multiplying the water equivalent by ten. Measuring snow depth accurately can be hindered when wind is prevalent. If the wind is strong enough, it may blow the snow across the gauge and the measurements will be inaccurate.
<h2>The problems of snow gauge</h2>
However, due to the shape of the funnel gauge, this is usually a minor problem. Another problem with measuring snow is when rain falls with snow and the gauge is not changed accordingly.

Some gauges that are in areas that aren’t always readily accessible, have specialized features that allow the measure of snow to be recorded accurately. These gauges collect snow to a certain point and when the weight limit is reached, the gauge tips over and dumps the snow. This dumping trips a switch and sends a signal. The collection then repeats itself. If the catch basin has a heater in it, it can measure the snow weight accurately. Some gauges can be set to tip based on volume rather than weight.

A snow pillow is another type of gauge that looks like a round bag lying on the ground. Inside the pillow is a liquid that resembles antifreeze yet is safe for the environment. The snow pillow is often connected to a manometer (a device that measures pressure) that measures how much snow is sitting on the pillow.
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What is Snow Gauge?

A snow gauge is an instrument used in meteorology to...

Soft rime is a type of ice that forms when water droplets from fog freeze to the outer surfaces of objects. This formation usually occurs with light winds and cold conditions. The rime forms to the windward (facing the wind) side of solid objects. Soft rime is very similar in appearance to hoarfrost, but is formed differently.

Rime can produce shapes like needles or scales. It is a milky white color and can be easily shaken off branches or other objects with ease. Conditions for the formation of rime include small water droplet size, slow accumulation of water particles, high rate of super-cooling, or rapid heat loss.

Hoarfrost and rime have many of the same characteristics, but are told apart by the process in which they form. Hoarfrost happens on cold, humid nights under clear skies, and the water vapor is directly deposited onto solid ice. It is only when the cause is fog freezing over a surface that it is considered soft rime.

The formation of soft rime and hoarfrost also differ by the process the water droplets go through. For soft rime, water vapor is first condensed into a liquid (such as in fog or mist) before attaching to a surface. Hoarfrost is a result of the deposition of water vapor directly into ice, or solid form.

&nbsp;

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What is Soft Rime?

Soft rime is a type of ice that forms when...

Heat lightning is simply faint flashes of light reflecting outward from distant thunderstorms. The light is actually regular lightning that is seen from over the horizon. These flashes are too far away (10+ miles) to hear the sound that is normally produced by thunderstorms. The reason for the term ‘heat lightning’ is said to be because they often occur on hot summer nights.

Heat lightning being so clearly visible from so far away is a matter of reflection, as well as magnification. Due to light reflecting off of water particles in the moist, humid air, the light is able to spread throughout the upper atmosphere. Over flat terrain, the lightning flashes can be seen up to 100 miles away.

Heat lightning is sometimes an early warning sign of an approaching storm. While lightning normally produces thunder, the sound of thunder rarely travels more than 10 miles. Other factors contributing to the quiet nature of heat lightning are:
<ul>
 	<li>Refraction of the sound over changing densities of air</li>
 	<li>Temperature differences overhead refracting the sound upward</li>
 	<li>Airborne matter muffling the sound of thunder, such as heavy snow during a winter storm. Dust and sand storms are also capable of muffling the sound of thunder</li>
</ul>
Lightning itself is a discharge of electrical energy reaching temperatures of up to 25,000°C — hotter than the surface of the sun. The friction from ice and water particles rubbing together cause positive and negative charges to distribute within storm clouds, producing sparks. What we see during a flash of lightning are streams of plasma that the positive and negatively charged particles can travel through.

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What is Heat Lightning?

Heat lightning is simply faint flashes of light reflecting outward...

For astronomers, the day that the sun’s path and the Earth’s celestial equator intersect signifies the Autumnal Equinox. During the Equinox, the entire planet receives about 12 hours of sunlight and darkness over the 24 hour period. The name is derived from the Latin words ‘aequi’ (equal), and ‘nox’ (night).

The Autumn, or Fall Equinox occurs between September 21 and 24 in the Northern Hemisphere. The date varies slightly each year due to factors such as the precession of the Equinoxes, the Earth’s axial precession, and the cycle of leap years in the Gregorian Calendar. In the Southern Hemisphere, the Spring Equinox occurs around the same date, marking the beginning of Spring.
<h3>How To Recognize the Equinox</h3>
<ul>
 	<li>During the Equinox, the sun rises directly in the east and sets directly in the west. </li>
 	<li>The position of the sun at 12:00 noon changes day by day. Following the sun's path throughout the year at it’s high point reveals what astronomers call the analemma — an augmented figure-8 shape. The Equinox occurs when the sun is at the center point of the anelemma.</li>
 	<li>Leading up to the day of the Equinox, the sun rises and sets increasingly to the north (in relation to the Equator), and afterwards, rises and sets increasingly to the south. </li>
</ul>
<h3>Cultural Equinox Celebrations</h3>
The start of the Fall season is when the Neopagan Sabbat of Mabon is celebrated. Also, Autumnal Equinox Day is an official national holiday in Japan, and is spent visiting family graves, and holding family reunions. Some civilizations also celebrate the Harvest Moon, which is the full moon closest to the Autumn Equinox.

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What is the Autumnal Equinox?

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47375900 - ice floe and sun on winter baikal lake

Clear ice is a natural weather event that occurs when air temperatures are 0°C (32°F) — 3°C (38°F). Air moisture must be rapidly, or 'super-cooled' (such as in freezing fog) in order for the ice to be transparent. A similar phenomenon called glaze occurs when freezing rain or drizzle hits a solid surface.

Clear ice build up typically occurs because of the absence of air bubbles in the area where the water freezes. If the freezing happens without any impurities or foreign particles trapped in the water at the time the liquid turns solid, the ice will be see-through. The color in ice from household freezers, for example, is essentially from trace amounts of particles dissolved in the water.

Clear ice is denser and more homogeneous than hard rime. However, similar to rime, icicles can accumulate on branches and overhead lines, which can become particularly dangerous. Also referred to as black ice due to its transparency against roads and other surfaces, clear ice causes some of the most hazardous conditions for driving. Many times, a patch of black ice appears to be merely a wet spot on the road, making it difficult for motorists to recognize the danger until it’s too late. Slip-and-slide accidents can be common wherever the temperatures allow clear ice to form.

What is Clear Ice?

Clear ice is a natural weather event that occurs when air...

Condensation is the change of a substance from a gaseous into a liquid form. It is the opposite of evaporation, which is another major steps in the Earth’s water cycle. 

One example of condensation is the formation of dew. When the air temperature cools to what is called the dew point, water vapor can collect in liquid form and settle on cold surfaces. Water vapor will only condense on a surface when the temperature of the surface is cooler than the water vapor’s temperature.

Water molecules carry a little heat energy and, as they condense, transfer this energy to the atmosphere. When water vapor condenses into liquid water, hydrogen forms and releases latent heat. This increases the sensible heat, and therefore causes the temperature of the air to rise. The sensible heat is removed from the air and the temperature drops when evaporation occurs. This process continues, causing air temperature to rise and fall again as water vapor forms and condenses.

The process of condensation is often utilized to generate large quantities of water for human usage. Many structures — including fog fences, air wells, dew ponds, and distillation equipment — are made solely for the purpose of collecting water formed by condensation. Sometimes these manmade structures and systems can be used to retain soil moisture in more arid, desert areas.

Psychrometry is a science related to condensation. It is the study of thermodynamic properties of moisture in air and the changes of conditions of this moisture. Many times, weather reporters mention relative humidity values and high/low pressure systems — information gathered using psychrometric equipment (such as the sling psychrometer).

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What is Condensation?

Condensation is the change of a substance from a gaseous...

Hard rime is a white colored ice caused by water droplets in fog freezing to the outer surfaces of objects. It occurs when low clouds cause freezing fog, and can be found on trees, atop mountains and high ridges in winter. This fog freezes along the windward (facing the wind) sides of trees, buildings, and other solid objects. High winds are usually an accompaniment to its formation. The air temperature required is typically between 17°F and 29ºF.
<h2>Characteristics of Hard Rime</h2>
Hard rime has a comb-like appearance, unlike soft rime which looks more feathery or spiky. Hard rime is also very dense and less milky in color than soft rime. Typically, the quantity of water droplets that have super-cooled (when a liquid's temperature is brought below 0ºC without solidifying or crystallizing) determines the type of ice that forms. The more water droplets found in ice, the denser it becomes. Hard rime often has less water droplets and more ice crystals.

In some extreme weather regions such as Mount Washington in New Hampshire, scientists at the meteorological observatory often break huge chunks of hard rime off of their equipment to keep them from malfunctioning. Rime ice also accumulates on the leading edges of aircrafts as they fly through extremely cold weather conditions. Hard rime build up is said to be the cause of the Continental Connection (flight 3407) plane crash on February 12th, 2009.

In some atmospheric conditions, descending snow crystals may pass through super-cooled cloud droplets. Contact between the snow crystals and the cloud droplets results in freezing of the liquid droplets onto the crystal's surface. This freezing process is known as accretion. The crystals that have frozen droplets on their surfaces are considered 'rimed'. If this continues to the point that the original snow crystal is no longer identifiable, the crystal becomes known as graupel. The graupel can become five times greater in mass than the original snow crystal. As the riming process continues, snow crystals become increasingly obscure.

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What is Hard Rime?

Hard rime is a white colored ice caused by water...

Haze is an atmospheric phenomenon where dust, smoke, and dry particles in the air obscure the sky’s clarity. When seen from afar, and depending upon the direction of view, haze can have a bluish or brownish tint. Various activities such as farming, vehicle traffic, and wildfires can create a pollutant-clouded atmosphere. The World Meteorological Organization (WMO) categorizes atmospheric obscuration by a list of different types. These include: haze, fog, ice fog, steam fog, mist, smoke, volcanic ash, dust, sand, and snow.

Although haze is mostly a dry air phenomenon, some of its particles tend to create condensation, subsequently giving form to mist droplets. This phenomenon is known as wet haze, or visibility-reducing aerosols of the wet type. The process of aerosol creation occurs due to the chemical reactions between the atmosphere and the sulfur dioxide gas emissions, which create small droplets of sulfuric acid. Sunlight, high humidity, and stagnant airflow may enhance this process. 

Wet haze tends to favor warm weather. It can cover large areas and reach thousands of square miles in the favorable summer conditions. It most often occurs when dust and smoke particles accumulate in relatively dry air. When the natural dispersal methods of smoke and other pollutants are hindered, the build-up creates a low-hanging, cloud-like blanket that impairs visibility. The compound isoprene (C5H8), a hydrocarbon emitted from many deciduous trees, share some characteristics with wet haze/aerosols.
<h2>What Causes Haze?</h2>
Some of the sources of atmospheric haze include:
<h3>Volcanic Activity </h3>
In the aftermath of major volcanic eruptions, sulfur dioxide (SO2), hydrochloric acid (HCl), and ashes are distributed into the atmosphere. The haze of sulfur dioxide droplets created by volcanic gases can have a lasting affect; hanging aerosols became a headlining problem in Southeast Asia following the eruption of Mt. Pinatubo in 1991. The Royal Meteorlogical Society notes that the average global temperature dropped as much as 0.5 degrees Celsius for 1992 and 1993. 
<h3>Windy Weather</h3>
Desert dust blown into the atmosphere by the wind is another form of naturally-occurring haze. The minerals contained in the dust and dirt allow sunlight to be absorbed, warming the area. The dusts can be blown over many miles; dust from the Sahara Desert is sometimes carried over to other parts of the world, including the United States and the Amazon Rainforest. 

Wind also lifts water from the oceans, causing the salts to be evaporated into the air — accounting for some atmospheric haze. The sea salt acts as cloud condensation nuclei, which accelerates cloud formation. Clouds produced in this fashion stay in the sky for long periods of time. Due to the chemical reactions between the air and water molecules and the pollutants, some clouds are unable to release the built-up water they contain and can float around in the sky for any number of years. Some of these pollutant-rich clouds are also responsible for acid rain. 
<h3>Human Practices</h3>
Human activities like forest burning, factory emissions, automobile traffic pollution, and the burning of coal and other fossil fuels are said to outweigh natural sources in the production of hazes. According to NASA, the industrial revolution (spanning the 18th and 19th centuries) generated a rapid growth in the concentration of sulfate aerosols in the atmosphere. The global temperature is said to have risen by 0.8º C since 1880 — a small change that has a very dramatic influence on the workings of the entire planet. NASA confirms that over 60% of the temperature increase has occurred since 1975 — about 0.15-0.20°C per decade.
<h2>Environmental Issues Involving Haze</h2>
The greenhouse effect, a theory for global climate change, was first proposed in 1896 by Swedish scientist Svante Arrhenius (1859-1927). Arrhenius suggested that an increase in carbon dioxide (CO2) would in fact lead to a rise in temperature. His theory wasn’t widely accepted until the 1940’s, when the technology to measure long-wave radiation became available. By the 1980’s, the greenhouse gas argument gained popularity with the steep rising of the global mean temperature. In 1988, the greenhouse effect theory was named, and  the Intergovernmental Panel on Climate Change was founded by the United Nations Environmental Programme and the World Meteorological Organization.

The greenhouse gases said to be responsible for much of the global temperature increase, aside from water vapor, are concentrations of four principle gases: carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and what are called halocarbons or CFC’s — gases containing fluorine (F), chlorine (Cl) and bromine (Br). While some of these gases are naturally produced by the Earth, over-concentrations can mean drastic changes to the atmosphere. 

Some of the aerosols, however, like those produced by Mt. Pinatubo’s eruption — which blasted 20 million tons of sulfur dioxide into the atmosphere — reflect the sun’s light outward, cooling the area beneath.

Hazy skies can also cause issues with terrestrial photography. The filtering of large quantities of dense atmosphere is sometimes necessary to make accurate detailed images of distant objects. Light scattering from haze particles can cause visual disturbances that interfere with measuring equipment. On hazy days, sunrise and sunset colors appear subdued, and stars may become obscured at night. In some cases, the effects of haze can be so great that, toward sunset, the sun disappears altogether before reaching the horizon.

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What is Haze?

Haze is an atmospheric phenomenon where dust, smoke, and dry...

Mountain peak from clouds at Arctic Ocean

Arctic haze is a phenomenon that occurs in the atmosphere at the higher latitudes due to air pollution. What distinguishes Arctic haze from atmospheric haze found elsewhere is the ability of its chemical ingredients to endure in the atmosphere for longer periods of time compared to other pollutants. Limited snowfall, rain, or turbulent air to displace pollutants from the polar air in the spring leads to Arctic haze remaining in the air for more than 30 days in the Northern atmosphere.

Researchers from The University of Utah state that Arctic haze was first discovered in 1750, at the beginning of the Industrial Revolution. Whalers of the region noticed the pollution, which the Inuit referred to as “poo-juk”. Norwegian explorer and national hero Fridtjof Nansen, on one of his excursions in the Arctic latitudes, found dark stains on the ice surface — an indication of pollution. The actual term “Arctic haze” wasn’t coined until 1956 by Murray Mitchell Jr., a U.S. Air Force officer stationed in Alaska. He used the term to describe an unusual and persisting reduction in visibility during his observations on weather reconnaissance missions called the Ptarmigan flights. During these missions, the haze was reported to have covered distances as much as 3200 km across the horizon.

Components and Characteristics of Arctic Haze

Atmospheric haze in the Arctic is seasonal, peaking in the late winter and spring. Researchers from the University of Alaska have noted polluted air masses over the Arctic circle, and two great lobes that extend over Eurasia and North America. The mass of polluted air is said to be as large as the African Continent. 

Researchers from the University of Rhode Island have found that the majority of Arctic haze is formed by pollutants coming from coal burning by cities in the mid-northern latitudes. The concentrations of these aerosols contain about 90% sulfur (S) and 10% carbon (C), giving the haze a reddish color. The Western nations’ burning of petroleum products also releases traces of vanadium (V) and manganese (Mn) into the air, adding what is known as black carbon to the atmosphere.

Studies have shown greenhouse gas pollution to be the main cause of the warming in the Arctic region, which is happening a rate greater than any other place on Earth. The particles in the haze act as a trap for sunlight, holding infrared radiation and thus warming the surface and atmosphere.

Arctic haze sources

There are many contributors to atmospheric haze, and the subsequent warming of the Arctic region. Besides greenhouse gases and pollution from industry, Arctic pollution sources include:
<ol>
 	<li>Boat/Ship emissions</li>
 	<li>Smoke from forest fires</li>
 	<li>Atmospheric aerosols (nitrous oxide (NOx), sulfur dioxide (SO₂), </li>
 	<li>O-zone pollutants (mercury, aluminum, vanadium, manganese).</li>
 	<li>Volcanic eruptions</li>
</ol>
Many people perceive the Arctic as a frozen, pure, and clean region of Earth. The pure and clean landscapes may soon become a memory as pollution travels more pollution leaks into the Arctic regions. The haze in the arctic creates a residual effect due to the depletion of ice which creates a reduction in the albedo effect — the process by which the thermal energy from the sun is reflected back out into space from the polar regions. The entire planet is drastically changed as a result, with the addition of a trillion tons of carbon dioxide (CO₂) added to the Earth’s atmosphere if the current trends continue.

Many environmentalists predict that by the end of the 21st century, the Arctic temperatures may rise by an average of 5 degrees Fahrenheit. The summer sea ice of the Arctic may also disappear completely by 2040 if warming continues. This will be due to many factors including Arctic oil drilling which causes more pollution and sparks more severe climate changes. Because of global warming, the Arctic region is seeing a rise in rainfall that freezes soon after falling. This process is putting a huge strain on the wildlife of this region and with the continued effects of Arctic haze, the global environment is at serious risk.

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What is Arctic Haze?

Arctic haze is a phenomenon that occurs in the atmosphere...

<h2>Terraforming</h2>
Terraforming (literally, “Earth-shaping”) is the process of modifying a planet, moon or other body to a more habitable atmosphere, temperature or ecology.

Jack Williamson used the term in a science fiction novel, ‘Seetee Shock’ (1940?), but the concept is older than that. An example in fiction is ‘First and Last Men’ by Olaf Stapledon. In which Venus is modified, after a long and destructive war with the original inhabitants.

Early fictional accounts of the process are frequently handicapped by the inaccurate contemporary knowledge of the actual conditions, as in the Stapledon example, which had Venus covered in oceans.

A more recent example, using the actual conditions on Mars as revealed by planetary probes to that time, is the Mars trilogy by Kim Stanley Robinson. The three volumes are a lengthy description of the fictional terraforming of Mars. They are very evidently the result of a massive amount of research by the author.

In the 1960s astronomer and popularizer of science Carl Sagan proposed terraforming the planet Venus by seeding its atmosphere with algae, which would remove carbon dioxide and reduce the greenhouse effect until surface temperatures dropped to comfortable levels.
<h2>Venus discoveries</h2>
Later discoveries about the conditions on Venus made this particular approach impossible, however; there is simply too much atmosphere to process and sequester. Even if atmospheric algae were able to thrive in the hostile and arid environment of Venus’ upper atmosphere, any carbon that was fixed in organic form would be liberated as carbon dioxide again as soon as it fell into the hot lower regions.

Today the most feasible planet for terraforming appears to be Mars. A well elaborated plan was presented by Robert Zubrin, the founder of the Mars Society. He wants to start with a Mars return mission called Mars Direct.

The reason given to pursue terraforming is creating suitable worlds for habitation by human beings. However, some researchers believe that space habitats will be a more economical means for supporting space colonization.

If (nanotechnology and advanced chemical processes) researches continues, it may become feasible to terraform planets in centuries rather than millennia. On the other hand, it may become reasonable to modify humans so that they don’t require an oxygen/nitrogen atmosphere in a 1G gravity field to live comfortably. That would then reduce the need to terraform worlds, or at least the degree to which other worlds’ environments would need to be altered.

(this needs a lot more yet, including non-fictional research – and the aspect that the whole problem of greenhouse gases is that we are inadvertantly engaged in the terraforming project of returning atmospheric carbon dioxide to the levels of millions of years ago).
<h2>Paraterraforming</h2>
Also known as the “worldhouse” concept. Paraterraforming involves a habitable construction enclosure on a planet which eventually grows to encompass most of the planet’s useable area. The enclosure would consist of :
<ul>
 	<li>A transparent roof held one or more kilometers above the surface</li>
 	<li>pressurized with a breathable atmosphere, and anchored with tension towers and cables at regular intervals.</li>
</ul>
A worldhouse can be constructed with technology known since the 1960s.

Paraterraforming has several advantages over the traditional approach to terraforming. For example, it provides an immediate payback to investors; the worldhouse starts out small in area, but those areas are habitable from the start.

The paraterraforming approach also allows for a modular approach that can be tailored to the needs of the planet’s population, growing only as fast and only in those areas where it is required.
Finally, paraterraforming reduces the atmosphere amount that will added to planets to provide Earthlike atmospheric pressures. By using a solid envelope in this manner, even bodies which would otherwise be unable to retain an atmosphere at all (such as asteroids) could be given a habitable environment.
<h2>Geoengineering</h2>
Geoengineering is the deliberate modification of Earth’s environment on a large scale, in a sense “terraforming” Earth itself. There is currently a great deal of debate over the notion that human civilization has already been inadvertantly modifying Earth’s climate through the industrial emission of greenhouse gases, and proposals have been made to counter any such effects through further deliberate geoengineering.

For example, Scientists proposed that putting large mirrors in orbit which would modify the insolation recieved by Earth. Either increasing or decreasing it, as the need arises.

other examples which have been seriously considered are:
<ul>
 	<li>Large-scale sequestration of carbon dioxide inside geological formations or ocean sediment</li>
 	<li>Modification of Earth’s albedo with reflective or absorbtive materials spread over portions of its surface</li>
 	<li>The alteration of rainfall patterns through the creation of artificial seas</li>
</ul>
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What is Terraforming?

Terraforming Terraforming (literally, “Earth-shaping”) is the process of modifying a...

Digital,Illustration,Of,The,Earth's,Magnetosphere,Deflecting,Solar,Wind,And

Earth's Magnetic Field: Origin, Structure, and Impact on Humanity

Earth's magnetic field, also known as the geomagnetic field, is...

Boat in mysterious fog

The occurrence of mist is simply a collection of small droplets of water suspended in the air. The suspended water droplets cause light to be refracted and reflected differently in the area where a mist dwells. Often, there is a bluish-gray coloration when seen from a distance.

A mist, or light fog, is many times produced as part of a natural weather event —  such as volcanic activity or radiation fog (the cool ground interacting with moisture in the air causing a fog just before sunrise). Mist is also commonly found in the cold air above warm water. 

During the hydrologic process, evaporated water particles rise to the sky and condense again to form clouds. When the air close to the Earth’s surface is cool enough, the water vapors hang and condense. It can be said that mists and fogs are really just sparse clouds. 

Mistiness also occurs when we exhale air in cold temperatures, and when steam is formed in a sauna. Aerosol spray cans also create artificial hanging mist when the humidity levels are just right. Although most common near shorelines, the phenomenon can also occur as high as mountain tops when the temperatures are low; the warm air moving over snow and ice causes a smoke-like mist to float over the cold surfaces.
<h4>What's The Difference Between Mist and Fog?</h4>
One major difference between mist and fog is visibility. If less than 1 kilometer (0.62 miles) of distance is visible, the conditions are referred to as fog. The thinner the veil of water vapor, the closer it is to being considered mist. Another notable difference between the two is that mist moves through the air and dissipates fairly quickly, but a fog can tend to stay in the air for hours at a time. 

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What is Mist?

The occurrence of mist is simply a collection of small...

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Nushagak Bay, a large estuary in southwest Alaska. Nushagak runs mainly north to south and exits in Bristol Bay, a large body of water in the Bering Sea.



"The bay is primarily fed by the Nushagak River, which begins in the Alaska Range and flows southwest approximately 450 km. The bay is also fed by several additional rivers including the Wood, Igushik, Snake and Weary rivers," says ESA.



"The dark colors of the Nushagak River are most likely due to tannins or lignins (chemical substances found in plants). Tannins and lignins from roots, leaves, seeds, bark and soil can leach into the water and give it a brown or even black colour. The sediments then flow southwards where it is mixed with the bluer waters of the bay."



Video/ Image Credit: ESA



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Nushagak Bay in southwest Alaska

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Today's Video of the Day from the <a href="https://www.acs.org/">American Chemical Society</a> (ACS) reveals that proteins on flu viruses are actually flexible, tilting and waving in a “breath-like” motion. According to the experts, these proteins could be used to better defend against the flu.



"The main antigenic targets of influenza virus are two surface glycoproteins, hemagglutinin (HA) and neuraminidase (NA). Whereas the structural and dynamical properties of both glycoproteins have been studied previously, the understanding of their plasticity in the whole-virion context is fragmented," wrote the researchers.



To investigate, the team conducted detailed simulations of the influenza A H1N1 virion, or the swine flu. The experts concluded that the visualizations show many new vulnerable states of flu viruses, which could improve future vaccines and antiviral drugs.



Video/ Image Credit: American Chemical Society&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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Flu viruses are more flexible than expected

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Lake Trasimeno, which is located west of Perugia in central Italy. It is the fourth largest lake in the country. While Trasimeno’s water level varies, it has a maximum depth of approximately six meters.&nbsp;



"In this Copernicus Sentinel-2 image, captured on 6 August 2022, the lake’s emerald green colour is likely due to the presence of phytoplankton. Streaks in the water, particularly visible in the west, indicate the presence of soil and sediments which have been stirred up by winds. Dark colored waters in the southern part of the lake indicate a presence of submerged and floating macrophytes (aquatic plants) as well as algae," says ESA.



"Surrounded by hills on three sides, Trasimeno is subject to heavy storms created by winds, especially from the north and west. There are three islets in the lake: Maggiore, Minore and Polvese (the largest). The lake’s shores are sparsely inhabited with only two popular villages: Castiglione del Lago and Passignano sul Trasimeno."



"Italy is experiencing its worst drought in 70 years which has affected drinking water supplies, hydroelectric power and agricultural production. High temperatures, hot winds and lack of rainfall are the main causes of drought in the Umbrian region which saw Lake Trasimeno’s drop 1.3 m, reaching the limit of the hydrometric zero in July 2022."



Video/Image Credit: ESA&nbsp;



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Lake Trasimeno in Central Italy

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Today's Video of the Day from the <a href="https://www.acs.org/">American Chemical Society</a> describes a new self-powered nanosensor that can instantly detect mercury contamination with the tap of a finger.&nbsp;



The oxidized form of mercury can be harmful when it is ingested through contaminated water or food. This makes it necessary for experts to develop sensors that can quickly and accurately detect the presence of mercury.&nbsp;



Zong-Hong Lin and colleagues have now created a triboelectric nanosensor (TENS) that can detect mercury by simply by touching a sample. According to the researchers, their TENS could serve as the basis for similar devices to safely and remotely monitor other pollutants.



Video Credit: American Chemical Society&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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Detecting mercury contamination with the tap of a finger

[sendtonews key="LvS8v8bp9z-2564889-12187" type="single"] Today's Video of the Day from the...

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Today’s Video of the Day from the <a href="https://www.acs.org/">American Chemical Society</a> explores the ability of salt to transform the way that foods and beverages taste. Salt is known to cover up undesirable flavors, such as bitterness in coffee or beer, but how exactly does sodium chloride change the taste of other compounds?



One previous study showed that, not only does salt suppress bitterness, but also enhances sweetness and sourness. Another study revealed that bitterness reduction by salt seems to be happening at the tongue receptor level as well as in the brain.&nbsp;



While it is known that salt taste is mediated by the presence of sodium channels in the form of taste buds, experts believe that there is also an unknown receptor responsible for how we taste salt that has not yet been identified.&nbsp;



Video Credit: ACS Reactions



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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How does salt makes things taste better?

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Santiago, the capital city of Chile. The city is located in the center of the Santiago Metropolitan Region, which has a population of about eight million people.&nbsp;



'The weather of Santiago resembles the Mediterranean climate with dry and warm summers with temperatures reaching up to 35°C (from October to March) and cool and humid winters that can drop to 0°C (from April to September)."



"The city lies in the centre of the country’s central valley around 80 km from the Pacific Ocean to the west and borders Argentina to the east. A tiny part of Argentina is visible in the top-right corner of the image where the mountain crest of the Andes Mountains acts as a divider between the two countries," says ESA.



Video/ Image Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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Santiago, Chile in South America

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Spiral,Galaxy,,Illustration,Of,Milky,Way

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Astronomers at <a href="https://www.jhu.edu/">Johns Hopkins University</a> have created an interactive map of the universe, including the actual position and real colors of 200,000 galaxies. The map allows the public to access data that was previously only available to scientists.



The map was developed using data collected by the Sloan Digital Sky Survey. For over two decades, a telescope in New Mexico was aimed at slightly different locations to capture the night sky.&nbsp;



"Growing up I was very inspired by astronomy pictures, stars, nebulae and galaxies, and now it's our time to create a new type of picture to inspire people," said map creator Brice Ménard, a professor at Johns Hopkins. "Astrophysicists around the world have been analyzing this data for years, leading to thousands of scientific papers and discoveries. But nobody took the time to create a map that is beautiful, scientifically accurate, and accessible to people who are not scientists. Our goal here is to show everybody what the universe really looks like."



"In this map, we are just a speck at the very bottom, just one pixel. And when I say we, I mean our galaxy, the Milky Way which has billions of stars and planets. We are used to seeing astronomical pictures showing one galaxy here, one galaxy there or perhaps a group of galaxies. But what this map shows is a very, very different scale."



"From this speck at the bottom, we are able to map out galaxies across the entire universe, and that says something about the power of science."



The <a href="https://mapoftheuniverse.net/">interactive map</a> is available online, where it can be downloaded for free.



Video Credit: Johns Hopkins&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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Interactive map of the universe includes 200,000 galaxies

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Lesotho: Africa's "Kingdom in the Sky" Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features northwest Lesotho in South Africa.



According to ESA, Lesotho is the only nation in the world that lies completely above 1,000 m in elevation. The country is famous for its tall mountains and narrow valleys, and is known as Africa's "Kingdom in the Sky."



Out of a population of around two million people, about 80 percent live in rural areas. More than 75 percent of these people are engaged in <a href="https://www.earth.com/news/climate-change-will-have-a-global-impact-on-agriculture/">agriculture</a>, including rainfed cereal production and animal grazing.&nbsp;



ESA reports that the country’s agricultural system faces a growing number of issues, with climate-related vulnerabilities such as drought, floods and extreme temperatures occurring more frequently. 



Diamonds are amongst the minerals found in the mountains. Indeed, Lesotho can truly be called the Kingdom in the Sky. Beautiful, culturally rich, safe, affordable, and easily accessible from Durban and Johannesburg, mountainous Lesotho is a vastly underrated travel destination. the Kingdom of Lesotho (Sotho: 'Muso oa Lesotho) is an enclaved country in southern Africa. It is just over 30,000 km2 (11,583 sq mi) in size and has a population of around 2 million.



Video Credit: ESA&nbsp;&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer 



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Lesotho: Africa's "Kingdom in the Sky"

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Today's Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Dublin, the capital and largest city of Ireland. Beyond its pub culture, Dublin is known as a modern culinary destination and a UNESCO City of Literature.



"Dublin is located near the midpoint of Ireland’s east coast in the province of Leinster. The city, which covers an area of around 115 square kilometers, is bordered by the Dublin Mountains, a low mountain range to the south, and is surrounded by flat farmland to the north and west," says ESA.



"The city straddles the River Liffey, which rises in the Wicklow Mountains and flows around 80 kilometers eastwards through the city of Dublin, in which it is canalised and bordered with quays. It then empties into Dublin Bay, an arm of the Irish Sea."



Dublin has an abundance of green spaces, including one of the largest enclosed public parks in any European capital city. Phoenix Park, which was originally formed as a royal hunting park in the 1660s, includes 707 hectares of green space.



Video Credit: ESA&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The city of Dublin on Ireland's east coast

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Today's Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features the province of Zaragoza in northeast Spain. The image was captured by the Copernicus Sentinel-2 mission.



"Together with the provinces of Huesca and Teruel, Zaragoza formed the old kingdom of Aragon. Its capital, also called Zaragoza (not visible in this image) is home to around half of Aragon’s population," says ESA.



"The Ebro River can be seen winding its way through the province from west to east in this image. Between its source in the Cantabrian Mountains in the northwest and its delta on the Mediterranean coast, the Ebro River is fed by more than 200 tributaries as it flows 910 km across much of northern Spain."



Since rainfall is very scarce in this region, irrigation in the Ebro basin is critically important. In the valleys surrounding the Ebro River, many fields are used for growing crops such as corn, wheat, and barley.



Video/ Image Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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The province of Zaragoza in northeast Spain

[sendtonews key="oL4FnPTGCV-2384527-12187" type="single"] Today's Video of the Day from the...

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Today’s Video of the Day from <a href="https://earthobservatory.nasa.gov/">NASA Earth Observatory</a> reveals the evolution of the Columbia Glacier in southeastern Alaska. Columbia is among the fastest shrinking glaciers in the world, and the video documents its rapid retreat over the years.&nbsp;



Columbia Glacier is a large, multi-branched calving glacier that flows out of the Chugach Mountains to the Prince William Sound.&nbsp;



According to USGS, Columbia had a long history of stability prior to 1980, with a length 41 miles, and small, short-lived advances or retreats.



In the years since 1980, however, satellite images have captured Columbia’s alarming retreat. By using false-color images, scientists can distinguish between snow and ice, open water, vegetation, and rocky debris on the glacier’s surface.



The series of false-color images featured in today's video were acquired over the span of 35 years. You can see that by 2021, the glacier’s main branch had retreated about 15 miles from its initial position.



The Columbia Glacier has also lost more than 50 percent of its volume, mostly due to calving. <a href="https://www.earth.com/video/nasa-reveals-3d-visual-of-an-atmospheric-river/">NASA</a> reports that while climate change likely started the retreat, mechanical processes kept the disintegration going.



The NASA images are provided by Jesse Allen, Robert Simmon, Joshua Stevens, and Lauren Dauphin using data from Landsat satellites, from the U.S. Geological Survey, and data from MODIS on NASA’s Terra satellite. The structure of Columbia’s moraine played a large role in the stability of the glacier before 1980. 



Like other tidewater glaciers, the Columbia built up a moraine over time, and the mixture of ice and rock functioned like a dam keeping out the sea. It was supported on one end by the shoreline and by the underwater terminal moraine at the other.



Video Credit: NASA Earth Observatory/&nbsp; NASA’s Scientific Visualization Studio



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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The rapid retreat of the Columbia Glacier

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features the Pyrenees Mountains, which form a natural boundary between France and Spain in southwest Europe.



The mountain range is 430 kilometers in length. It stretches from the Mediterranean Sea on the east to the Atlantic Ocean on the west.



At an elevation of 3404 meters, Pico de Aneto is the highest mountain peak in the Pyrenees, and the third-highest peak in Spain. Pico de Aneto is located in the Posets-Maladeta Natural Park, which spans more than 82,000 acres.&nbsp;



"Geological studies have revealed that the Pyrenees Mountains have been around for longer than the Alps, with their sediments first deposited in coastal basins during the Paleozoic and Mesozoic eras," reports ESA.



"The entire mountain range formed due to the upwelling of large sedimentary rocks by the collision of the Iberian and the Eurasian plate around 100 to 150 million years ago, followed by intense erosion from ice and water."



The western Pyrenees receive more precipitation due to moisture blowing in from the Atlantic Ocean. The mountain range contains many lakes, several small glaciers, and some of the highest waterfalls in Europe.



Video &amp; Image Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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The Pyrenees Mountains in southwest Europe

[sendtonews key="6HyfrAJTBI-1831843-12187" type="single"] Today’s Video of the Day from the...

Earth,Like,Exoplanet,3d,Render

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Today's Video of the Day from <a href="https://www.nasa.gov/goddard">NASA Goddard</a> describes two exoplanets that are orbiting a star 218 light-years away. A team of researchers led by the University of Montreal has found evidence that these planets are "water worlds."



The experts used data from NASA’s Hubble and Spitzer Space Telescopes. They discovered that exoplanets Kepler-138 c and Kepler-138 could be composed largely of water.



"We previously thought that planets that were a bit larger than Earth were big balls of metal and rock, like scaled-up versions of Earth, and that's why we called them super-Earths," explained study co-author Björn Benneke.&nbsp;



"However, we have now shown that these two planets, Kepler-138 c and d, are quite different in nature and that a big fraction of their entire volume is likely composed of water. It is the best evidence yet for water worlds, a type of planet that was theorized by astronomers to exist for a long time."



Video Credit: NASA Goddard



Image Credit: NASA, ESA, and Leah Hustak (STScI)



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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Two distant planets may be "water worlds"

[sendtonews key="QIoVYJqRBi-2434608-12187" type="single"] Today's Video of the Day from NASA...

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Satellites reveal how Earth's systems are interconnected Today’s Video of the Day from <a href="https://www.nasa.gov/goddard">NASA Goddard</a> describes Earth’s interconnected systems, and how this network is affected by rising temperatures.&nbsp;



During 2020, average global temperatures matched the hottest year on record. The hurricane season was also record-breaking, with many of the storms intensifying at extraordinary speeds. Hot water in the ocean is fuel for hurricanes. The satellite data shows that it's all one interconnected system showing how Satellites reveal how Earth's systems are interconnected.



According to NASA, dust swept up from Northern Africa plays a major role in the formation of hurricanes, and is also a key source of fertilization in the Amazon rainforest. As a result of<a href="https://www.earth.com/news/seagrass-wasting-disease-is-fueled-by-climate-change/"> climate</a> change, dust plumes are expected to decline, which will have an effect on vegetation far away.&nbsp;



Images from Earth-observing satellites show how the world’s plant life is affected by natural disasters, fires, and deforestation. Satellites also reveal how widespread changes in vegetation impact waterways,&nbsp; the climate, air quality. Satellites communicate by using radio waves to send signals to the antennas on the Earth. "Earth From Space" is a groundbreaking two-hour special that reveals a spectacular new space-based vision of our planet. 



Video Credit: NASA Goddard&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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Satellites reveal how Earth's systems are interconnected

[sendtonews key="JbW4VsY53O-1632195-12187" type="single"] Satellites reveal how Earth's systems are interconnected...

Today’s Video of the Day from the <a href="https://welcome.miami.edu/">University of Miami</a> Rosenstiel School of Marine and Atmospheric Science explores how changes in water temperatures have affected tiger shark habitats and movements in the North Atlantic Ocean. The study reveals that rising temperatures have caused the sharks to shift toward the poles over the past 40 years.



“Tiger shark annual migrations have expanded poleward, paralleling rising water temperatures,” explained study lead author Neil Hammerschlag. “These results have consequences for tiger shark conservation, since shifts in their movements outside of marine protected areas may leave them more vulnerable to commercial fishing.”



The researchers analyzed nine years of tracking data from satellite-tagged tiger sharks, combined with four decades of conventional tag and recapture data provided by National Oceanic and Atmospheric Administration (NOAA) Cooperative Shark Tagging Program.



The experts found that during the last decade of record heat, for every one-degree Celsius increase in water temperatures, tiger sharks migrated further poleward by over 400 kilometers. They also migrated two weeks earlier than usual to waters off the northeastern coast of the United States.



“Given their role as apex predators, these changes to tiger shark movements may alter predator-prey interactions, leading to ecological imbalances, and more frequent encounters with humans,” concluded Professor Hammerschlag.



Video Credit: University of Miami Rosenstiel School of Marine and Atmospheric Science



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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Tiger sharks are shifting poleward as temperatures rise

Today’s Video of the Day from the University of Miami...

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> is focused on the melt ponds that emerge during the spring and summer on the Greenland Ice Sheet, which is the largest ice mass in the northern hemisphere.



"Melt ponds are vast pools of open water that form on both sea ice and ice sheets and are visible as turquoise-blue pools of water in this Copernicus Sentinel-2 image," says ESA.



"When snow and ice melts atop glaciers, water flows in channels and streams and collects in depressions on the surface. These melt ponds can speed up the melting of the surrounding ice since they greatly reduce the ice’s ability to reflect sunlight."



"This can create a positive feedback where an increasing number of melt ponds absorb more heat which causes ice cover to melt even faster."



According to ESA, Greenland has been hit with a late-season heatwave that began in early September. This caused the type of melt event that usually occurs in the middle of summer.



"In a recent paper published in Nature Climate Change, scientists found that major sea-level rise from the melting of the Greenland ice cap is now ‘inevitable’ even if the burning of fossil fuels were to halt overnight," says ESA. "Using satellite observations of Greenland ice loss and ice cap from 2000 to 2019, the team found the losses will lead to a minimum rise of 27 cm regardless of climate change."



Video Credit: ESA&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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Melt ponds on the Greenland Ice Sheet

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> describes a new map of Mars that is providing insight into the planet’s watery past. The map also reveals where future missions could safely land on Mars.&nbsp;



The map has been created over the last decade using observations of water-rich rocks and mineral deposits. The images were captured by ESA’s Mars Express and NASA’s Mars Reconnaissance Orbiter.



"A big surprise is the prevalence of these minerals, with the map revealing hundreds of thousands of water-affected locations in the oldest parts of the planet," says ESA. "The new data will help answer exciting questions about Mars’ climate history, whether water was globally persistent or confined to short, intense episodes, and whether the conditions were ever suitable for life."



"Specifically, the map shows the locations and abundances of aqueous minerals. These are from rocks that have been chemically altered by the action of water in the past, and have typically been transformed into clays and salts."



According to John Carter of the Institut d’Astrophysique Spatiale (IAS), our collective understanding of Mars has been oversimplified. He explained that planetary scientists have tended to think that only a few types of clay minerals on Mars were created during its wet period, then as the water gradually dried up, salts were produced across the planet.



The new map shows that the composition of Mars is much more complicated than what we thought. For example, while many salts formed after Martian clays, there are some salts that are presumed to be older than some of the clays.&nbsp;



“The evolution from lots of water to no water is not as clear cut as we thought, the water didn’t just stop overnight. We see a huge diversity of geological contexts, so that no one process or simple timeline can explain the evolution of the mineralogy of Mars. That’s the first result of our study. The second is that if you exclude life processes on Earth, Mars exhibits a diversity of mineralogy in geological settings just as Earth does,” said Carter.



Video Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The history of Mars is much more complex than we thought

[sendtonews key="qas3EhyI0Y-2220951-12187" type="single"] Today’s Video of the Day from the...

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Today's Video of the Day from the <a href="https://www.stowers.org/">Stowers Institute for Medical Research</a> describes how cavefish adapted to a sedentary lifestyle over tens of thousands of years. 



The experts found that the muscle metabolism of cavefish has been genetically reprogrammed over time. As a result, the animals have experienced major changes in their morphology and behavior. Despite these changes, however, the cavefish remain healthy and fit.



The research may provide new clues about the evolutionary consequences of prolonged physical inactivity in humans.&nbsp;



“It’s no surprise that people are moving less and less as technology has advanced,” said Rohner. “With cavefish, we have a unique system where we can study what might happen if people remained couch potatoes over very, very long periods of time.”



Video Credit: Stowers Institute for Medical Research



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Cavefish are healthy despite their sedentary lifestyle

[sendtonews key="vpljfR2VBX-2560867-12187" type="single"] Today's Video of the Day from the...

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Today’s Video of the Day from <a href="https://earthobservatory.nasa.gov/">NASA Earth Observatory</a> some of the most incredible waves in the world, as seen by Landsat satellites.



"With more than 370,000 miles of coastline on Earth, there are plenty of places where epic waves build up, curl over, and hurtle toward the shore.- much to the thrill of surfers," says NASA. "There are some places where these waves are so magnificent that they can be seen from space."



"With the broad perspective of satellites, we can see how these iconic waves develop into the world’s tallest, longest, fastest, and heaviest."



Video Credit: NASA Earth Observatory&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Satellites capture the world's biggest and fastest waves

[sendtonews key="MHyhtebibJ-2200368-12187" type="single"] Today’s Video of the Day from NASA...

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> describes why satellite images and measurements of our planet have become "essential to our survival, offering a new outlook of our world."&nbsp;



Rising sea levels pose one of the biggest societal threats associated with climate change. According to ESA, satellite altimeter missions such as Copernicus Sentinel-6 are essential in monitoring global and regional changes in sea level.



"Unbeknown to many, the island of Crete, Greece, plays an important role in the Copernicus satellite altimetry constellation and on an international stage," reports ESA.



"Satellite altimetry data have to be continuously monitored at the ESA’s Permanent Facility for Altimetry Calibration where different techniques have pioneered the use of transponders to provide the best measurements to validate satellite altimeters in space soon after launch."



Dr. Craig Donlon explains that, by understanding planet Earth through satellite measurements, we are able to find evidence of change.&nbsp;



Video Credit: European Space Agency&nbsp;



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Satellites have become essential to our survival

[sendtonews key="761m2QQvR1-2035772-12187" type="single"] Today’s Video of the Day from the...