Download Chapter 8: Section 4 * Life in the Solar System

Chapter 8:
Section 4 – Life
in the Solar
System
What is life?
 All
living things have
the following traits:
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Made of cells
Use energy
Respond to their
environment
Grow
Reproduce
 Life
on Earth is VERY
diverse.
Exotic Life on Earth
 Conditions
on other planets and moons
are very extreme
 It does not seem that life could exist in
these harsh environments
 However, there are extreme environments
on earth that support life
Yellowstone
National Park –
Bacteria live in
pools of water that
are boiling !
Exotic Life on Earth
 Extremophile
– an organism that lives in an
environment that is very harsh; very hot; very cold;
dark; salty; etc.
 Volcanic Vents – locations on the ocean bottom
without sunlight where water is heated by magma.
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Crabs, shrimp, worms, and clams survive in water so
scalding it would kill other creatures.
http://www.youtube.com/watch?v=cSaTMaCctNk
Exotic Life on Earth
 Other
extremophiles:
 Moss in Siberia can remain frozen and dormant for
40,000 years and come back to life
 Three species of bacteria found in Mono Lake in
California survive in an environment without light
and oxygen and very high levels of lye and salt.
Can Life Exist on Other Worlds?
 High
temperatures, toxic gases, and
exposure to solar radiation make life on
other worlds unlikely BUT not impossible.
 Extraterrestrial Life: Life on other worlds.
 Scientists are currently searching for life on
several moons and planets in our solar
system.
Mars
 During
much of Earth’s
history, the only living
creatures were single celled
bacteria.
 Scientists are looking for proof
that Mars currently or once
had single-celled life.
 A meteorite thought to have
come from Mars, found in
Antarctica, may have
fossilized bacteria that are
millions of years old.
Europa
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Data from the Galileo space
probe indicates that three
of the Galilean Moons have
ice covered oceans.
Europa’s ocean may be 25
m below its icy surface.
The pull of Jupiter’s gravity
on Europa may even keep
this water warm.
If life is found at the bottom
of Earth’s oceans where
there is no sunlight, then life
might too exist on Europa.
Europa is thought to be the
most promising location for
extraterrestrial life.
Titan
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Moon of Saturn
Larger than Mercury
Atmosphere composed of nitrogen
with some argon and methane
Has both pure water ice and ice
mixed with hydrocarbons.
Hydrocarbons are chemicals that
contain the element carbon, which is
the building block for all life on Earth.
Titan may also have internal geologic
activity which could provide the
energy needed for carbon to link up
with other elements and make the
building blocks of life, such as oils and
nucleic acids.
End of Ch. 8 Notes