Life on Mars

Question 1

Is there life on Mars?

Answer 1

No

Question 2

Why are we interested in this question?

Answer 2

Mars is most like Earth in our Solar SystemThe other planets are too hot, or too cold, or too extreme in their environments
What are the origins of life? If the building blocks are all there; can life form in places other than Earth?

Question 3

Early ideas

Answer 3

Late 18th century: William Herschel characterized ice caps
Mid 19th century: color changes thought to be land and oceans
Late 19th century: Apparent observations of Martian channels, or canals
These channels turned out to be an optical illusion, and not actually evidence of civilization

Question 4

Mars: a colder rock

Answer 4

Lack of a large molten core means that there is no global magnetic field on MarsThe global magnetic field on Earth protects us from ionizing radiation.
No tectonic activity.
Very this atmosphere.

Question 5

Water on Mars

Answer 5

There doesn’t appear to be any liquid water on Mars, although there are ice caps on each pole.