LIFE on Other Planets

Life as we know it on earth is carbon based and requires a certain environment to survive. Even so, there are creatures on earth which seem to be able to survive in harsh environments, where the temperatures are very cold, or where there is little water or oxygen. It is environments like these which are similar to those found on other planets.

Sophisticated life forms are relative newcomers on Earth compared to bacteria and archaea. They arrived later because the Earth proved to be a healthy environment over a long period of time. Because the environment of other planets is more primitive, life on other planets (if it exists) may be primitive. If not, then life would have developed the ability to withstand otherworldly environments as well as finding material for food. We might have to imagine what suchcreatures would be like.

Primitive life forms may have an easier time in a harsh environment. All life will leave behind certain signs that it has been there. Scientists recently thought that they had found some of these signs on a Martian meteorite, but it turned out to be untrue. No concrete evidence of life anywhere other than life has been found.

Can there be Life in the Environment of Venus?

This is an artist’s rendition of a column of clouds on Venus. The temperature of the different layers is shown at the left.
Click on image for full size version (183K JPG)
Windows Original

Venus is very hot, almost 800 degrees (Fahrenheit) at the surface. Venus also has a very heavy atmosphere. With a heavy atmosphere, there is a lot of pressure (about 91-94 times sea level pressure on Earth). A sophisticated life form such as a human-being would need a heavy shell for protection, just as humans going to great pressures under the sea need a submarine. Venus also has corrosive clouds of sulfuric acid.

We know, however, that there are life forms on earth which can survive in very harsh environments. Bacteria and very simple plant life can survive in unexpected places.

Because of the very high temperature, pressure, and corrosive atmosphere the environment of Venus seems unfriendly toward life as we know it on earth. More exploration of Venus is needed to determine if life was once present there.

Can there be Life in the Environment of Mars?

This is an image of the surface of Mars.
Click on image for full size version (80K JPG)
Image from: NASA

In spite of the fact that Mars has an atmosphere, the environment of Mars seems unfriendly toward life as we know it on earth.

Mars is small, so there is not much gravity. For this reason, much of the atmosphere of Mars has drifted away. With little atmosphere, and no ozone layer, there is less protection from the ultraviolet radiation of the sun, which is very harmful to life.

With little atmosphere, there is a only a small buffer between the surface and space itself. This means that the temperature above the surface is cold. With little atmosphere, there is only a little pressure, which sophisticated life forms such as humans need to keep blood from boiling. (Remember what happened to the characters of the movie “Total Recall” when they encountered the surface of Mars)!

We know, however, that there are life forms on earth which can survive in very harsh environments.

In the past, liquid water flowed on the surface of Mars. With a liquid water habitat and a thicker atmosphere, life may have once thrived. More exploration of Mars is needed to determine if life was once present there.

Can there be Life in the Environment of Jupiter?

This is a drawing of the Galileo probe exploring the environment of Jupiter.
Click on image for full size version (92K GIF)
Image from: The Jet Propulsion Laboratory

Jupiter’s atmospheric environment is one of strong gravity, high pressure, strong winds, from 225 miles per hour to 1000 miles per hour, and cold temperatures of -270 degrees to +32 degrees (freezing temperature). These winds make it hard for life forms to have “peace and quiet”.

The region where it is 32 degrees sounds OK, but where the temperature is 32 degrees, the pressure is about the same as it would be if you were a couple miles below the sea on Earth. This region is probably within Jupiter’s liquid region. The air of Jupiter is definitely a region that is well below freezing temperatures!

In the atmosphere there are at least three known cloud decks of ammonia, ammonia-combined-with-sulfur, and water, perhaps even made of huge droplets.

There is energy in the environment from lightning, ultraviolet light, and charged particles.

Jupiter’s interior possesses an environment of pressures as great as three million times the sea-level pressure on earth, and temperatures as high as 10,000 degrees.

Overall, this environment sounds very unfriendly to life as we know it on earth.

Can there be Life in the Environment of Io?

This is an image of the surface of Io.
Click on image for full size version (80K JPG)
Image from: NASA

In spite of the fact that Io has an atmosphere, the environment of Io seems pretty unfriendly toward life as we know it on earth.

Io is very small, so there is not much gravity. For this reason, the atmosphere of Io is constantly drifting away. If it were not for the volcanic eruptions, there would be no atmosphere at all.

Io is inside the enormously powerful magnetosphere of Jupiter. With very little atmosphere, there is little protection from the radiation of the charged particles of the magnetosphere.

With little atmosphere, there is hardly a buffer between the surface and space itself. This means that the temperature above the surface is very cold. On the other hand, with all the volcanos, the surface of Io is frequently molten, therefore the surface itself is sometimes super-hot!

All together these things add up to a very hostile environment for life as we know it.

Can there be Life in the Environment of Europa?

This is an image of Europa.
Click on image for full size version (136K JPG)
Image from: NASA

At first glance Europa may seem unfriendly to life as we know it on earth.

Like other icy moons, Europa is small, with no air to breathe, with direct exposure to space and the charged particle environment of Jupiter’s magnetosphere. On the surface, the temperature is very very cold.

Nevertheless, the interior of Europa may have been warm enough at one time to contain a liquid layer just under the surface. On Earth, we know that there are some creatures which can survive in an environment of very cold water, such as under the ice of the north pole.

This means that, if the conditions are just right, there may be living creatures on Europa under the icy surface!

The Environment of Saturn

This is an image of Saturn.
Click on image for full size version (92K GIF)
Image from: NASA

Saturn’s atmospheric environment is one of strong gravity, high pressure, strong winds, from 225 miles per hour to 1000 miles per hour, and cold temperatures of -270 degrees to +80 degrees. With winds like these, it is hard to have peace and quiet.The region where it is 80 degrees sounds pretty friendly, but where the temperature is 80 degrees, the pressure is about the same as it would be if you were a couple miles below the sea on Earth!

In the atmosphere there are at least three known cloud decks of ammonia, ammonia hydrosulfide, and water, perhaps made of huge droplets.

There is energy in the environment from lightning, ultraviolet light, and charged particles.

Saturn’s interior possesses an environment of pressures as great as three million times the sea-level pressure on earth, and temperatures as high as 10,000 degrees.

Overall, this environment sounds very unfriendly to life as we know it on earth.

Can there be Life in the Environment of Titan?

This is an image showing the clouds of Titan.
Image from: NASA

Titan’s atmosphere is a lot like the Earth’s, except that it is very cold, from -330 degrees to -290 degrees! Like the Earth, there is a lot of Nitrogen and other complex molecules. There also may be an ocean of methane, or perhaps a liquid water layer inside the moon. Except for the cold, these signs would be favorable for some sort of life. Some creatures on Earth are known to live in an environment of very cold water.In the atmosphere there are layers of clouds composed of complex molecules such as methane. Moreover there is energy from ultraviolet light, and the charged particles of the magnetosphere. This type of environment, aside from the cold, is the kind of environment in which scientists think life began.

Overall, the environment sounds unfriendly to life as we know it on earth, because of the cold. Since not much is known about the moon Titan, up close exploration of this moon, with a probe, as shown in this drawing, would help scientists better understand if life could survive there.

The Environment of Moons

This is a composite image of the small moons of Saturn
Click on image for full size version (92K GIF)
Image from: NASA

The environment of the moons, with the exception of Io, and Titan, is one of little or no atmosphere, which means there is nothing to even out the warming of the surface by the sun. It is either burning hot, or freezing cold. It also means there is no pressure, which most terrestrial life forms require to hold their bodies intact (recall the movie Total Recall ). Without an atmosphere, the lunar surfaces are also exposed to extreme ultraviolet light and energetic charged particles. These materials have a tendency to break down biological cells in life as we know it.

The Environment of Uranus

This is an image of Uranus.
Click on image for full size version (92K GIF)
Image from: NASA

Uranus’ has strong gravity and extremely cold temperatures (-270 degrees F to -380 degrees F). There is also energy from lightning and ultraviolet light.Uranus is made of methane, ethane and other sophisticated gases. These materials, combined with the energy from lightning, ultraviolet light, and charged particles, constitute the essential elements of conditions under which scientists believe life began. But life on Earth grew and changed, and now these conditions are no longer suitable for life as we know it.

This environment sounds very unfriendly to life as we know it on earth.

The Environment of Neptune

This is an image of Neptune.
Click on image for full size version (32K GIF)
Image from: NASA

The air of Neptune is extremely cold, with temperatures of -270 degrees to -380 degrees. The air is made of complex molecules, the same sort of molecules that we see coming out of cars on earth in the form of smog. Energy in the atmosphere comes from lightning, ultraviolet light, and charged particles.

This kind of atmosphere is very similar to the kind of environment in which scientists believe life began. But from prehistoric times until today, life on Earth changed, and now these conditions are no longer friendly for life as we know it.

The inside of Neptune is very hot and liquid-like, but the temperature is as high as 10,000 degrees.

Overall, the environment of Neptune sounds very unfriendly to life as we know it on earth.

Life on Triton?

This is an image of Triton.
Click on image for full size version (168K JPG)
Image from: NASA

Triton is most like Jupiter’s moon Europa. Like Europa, the interior of Triton may have been warm enough at one time to contain a liquid layer just under the surface. On Earth, we know that there are some creatures which can survive in an environment of very cold water, such as under the ice of the north pole.

It is very cold on Triton, about -300 degrees. There is almost no atmosphere, but what there is is like Saturn’s moon Titan because there is Nitrogen. Nitrogen is one of the waste products left behind by life forms.

Unfortunately Triton is inside the magnetosphere of Neptune, which is very harmful to life.

Overall, the environment sounds unfriendly to life as we know it on earth, because of the magnetosphere and the cold. However, if the interior is warm enough, and if the conditions are just right, there may be living creatures on Triton under the icy surface.

source:http://www.windows.ucar.edu

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About Rashid Faridi

I am Rashid Aziz Faridi ,Writer, Teacher and a Voracious Reader.
This entry was posted in Solar System and tagged , , , , , , . Bookmark the permalink.

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