MARS & COMETS |
COMETS
are giant snowballs in space
made of ice, frozen gases, rocks, and dust. Image Credit: NASA/MSFC/Aaron Kingery Image Credit: NASA/JPL-Caltech About 4 billion years ago
in a newly formed solar system, icy comets
often crashed into a newly formed planet Mars. Comets likely brought
trillions of pounds
of new material to Mars each year.
Add that up over
millions of years
and that's quite a lot of incoming material!
During this ancient time, some
scientists think that comets likely
brought an enormous amount of
water
to Mars (and Earth!).
That's because comets
contain a lot of
water ice
along with other simple compounds
(e.g., ammonia, methanol, and carbon dioxide).
Image Credit: NASA/JPL-Caltech
Comets may have seeded Mars and Earth
with carbon-based molecules called
organics
- the chemical building blocks of life as we know it.
Many comets we see today contain
dark, organic material.
When comets impacted ancient Mars, the force
of their impact and resulting shockwaves likely
provided an enormous supply of
energy
(not to mention high temperatures!).
Image Credit: Tim Wetherell - Australian National University
It's possible that these extreme conditions
sparked numerous
chemical reactions
among organic and other compounds,
creating the pre-conditions necessary for life.
|