Water is one of the most common substances in the universe, and ...

[Haya94]

Water is one of the most common substances in the universe, and vital to us on Earth. What happened to it on Mars?
 
  What will be an ideal response?

Question 2

The center of the Milky Way lies in the direction of the constellation
 
  A) Cygnus. B) Orion. C) Andromeda. D) Sagittarius. E) Virgo.

[chem1s3]

Answer to Question 1

At first, while erupting volcanoes thickened it, Mars' atmosphere was dense enough to stay warm enough for liquid water to flow over much of Mars' ancient surface. But as the core of Mars cooled down, volcanism declined, and Mars' atmosphere lost much of its initial water to space, due to its less surface gravity then our own. Today there is still much water frozen in the polar caps and tundra, and on some occasions it melts fast enough to erupt as small mud flows imaged by the Mars Global Surveyor recently.

Answer to Question 2

D

[Haya94]

Excellent

[epscape]

Gracias!