Transcript Mars - Evidence for Past (and maybe Present) Water

There’s lots of evidence for water
on Mars…in the past
• River beds and teardrop-shaped “perched”
craters.
• Lake beds
• Minerals have been found that only form under
water.
• Outflow Channels
• Sedimentary layers in the walls of the Valles
Marineris and many craters.
• Gusev Crater!
1
88
2
3
90
4
91
This is the shore of
an ancient lake.
Notice the layering
in the rocks!
5
92
The blueberries
were found near
Meridiani Planum,
the landing site of
NASA’s Mars
Exploration Rover
Opportunity.
Image credit: NASA
These little nodules, “blueberries”, are made
of the mineral hematite that usually forms
only under water.
6
93
7
94
Similar hematite nodules
here on earth.
8
95
Obvious layering
in the rocks
near the landing
site of NASA’s
Opportunity
Rover.
Image Credit: NASA
9
96
10
97
Finally…Gusev Crater
In 2004, NASA’s rover
Spirit landed inside Gusev
Crater. This crater quickly
showed that it had once
been full of water.
It’s connected by a valley
to an outflow channel, and
was probably filled with
water and sediment during
the catastrophic flooding. 11
98
What about recent water on Mars?
• There is some
possible evidence
for recent water on
Mars:
– Gullies in the walls
of some craters
might
have been formed
when water ran
down the crater
walls under layers
of frost or ice.
Credit: Malin Space Science Systems, MGS, JPL, NASA
12
99
Newton Basin
13
100
Where Did the Water Go?
• Today, liquid water can’t exist long on the
surface of Mars due to the low
temperature and low atmospheric
pressure.
• Loss of magnetic field ... atmospheric
erosion … water lost to space.
• Some water is still in the polar ice caps
and may still exist in permafrost.
14
101