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.

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.

Mars has little atmosphere . 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.