Search for Life on Mars

Evidence of Past Life on Mars

• The problem with Mars is not that it is too far from the Sun, the main problem is that it is too small to resist evaporation of atmospheric gases.

• In the past, Mars may have had an atmospheric like the Earth’s but 99% was lost.

•About 3.5 billion years ago on Mars, conditions would have been favorable. At this time, life was certainly producing fossils on Earth.• The main challenge is to see if live arose briefly at some point in the past.

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VIKING VIKING LANDINGS LANDINGS ON MARSON MARS

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Life

No long chains of atoms!

Mass spectrometer

No Life

The planet-wide dust storms that periodically cloak Mars in a mantle of red may be generating a snow of corrosive chemicals, including hydrogen peroxide (H2O2) , that would be toxic to life

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The accumulated peroxide in the soil could have fooled the Viking experiments looking for life. These results are more indicative of a chemical reaction than the presence of life, Delory said.

Why was there no evidence?

The Viking tests were inconclusive because gases were produced only briefly, and other instruments found no traces of organic materials that would be expected if life were present.

Present Exploration of Mars

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Nasa has launch a spacecraft on a nine-month journey to Mars, where it will dig below the surface for clues to the existence of past or present life. If everything goes to plan, Phoenix should arrive at Mars in late May 2008.

On the northern plains, water ice is thought to lie just a few tens of centimetres below the surface, within reach of the lander's 2.4m (7.5ft) robotic arm. Scientists estimate the ice content of the upper metre of soil in this region could be as high as 50-70%.

Phoenix will land in the northern polar regions of the planet Mars, whose low temperatures and relatively high atmospheric water vapor should provide better growing conditions for such microbes than the more tropical region visited by Viking.

Its purpose is to look for and study the water ice that is expected to be found there. The mission will launch in August of 2007, and land on Mars in May, 2008.

Phoenix lander, 2008

Phoenix mission will land a robot in the polar region of Mars in May 2008. On the northern plains, water ice is thought to lie just a few tens of centimetres below the surface. The lander is capable of digging a 0.5 meter trench in the soil.

The craft has a mass spectrometer capable of detecting organic volatiles, an optical microscope and an atomic force microscope.

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The solar-powered craft will deploy its robotic arm to dig down vertically through the soil towards the icy crust.

The arm will deliver samples of soil to the lander's deck for analysis by a powerful suite of instruments.

These will check the samples for water and organics, characterise the physical properties of the soil, determine abundances of different minerals, and subject dust grains to microscopic examination.

http://www.astrobio.net/news/Archives.html

Can detect key molecules associated with life at a sensitivity roughly a million times greater than previous instrumentation

Can distinguish "left-handed" and "right-handed” amino acids.

ExoMars rover planned for launch in 2013

Can detect amino acidsat concentrations as low as a few parts per trillion.

to help answer questions about life on Mars. Its primary mission is to last for about one Martian year objective would be to specifically looki for life and the signs of life.

http://en.wikipedia.org/wiki/Exploration_of_Neptune

An Astrobiology Field Laboratory (AFL) is planned for launch in 2016,

Martian Meteorites

Picture credit: NASA GSFC

• Antarctic meteorite finds, due to analysis of trapped gases.

• The meteorite in questions, ALH 84001 is shown (left). This meteorite is 4 billion years old, dating from a time when liquid water was present, causing some sedimentary deposits.

• purported ‘microfossils’ - minute structures 1/100 the width of a human hair.

• The main problem with these structures is the size: about the size of a virus on Earth, which cannot survive without access to the DNA of a bacterium.

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Dislodged from Mars 16 Ma years ago

Fell to Earth 13,000 years ago, time is determined from the exposure to radioactive nuclei in space

Discovered Alan Hills ( Antarctica ice field) in 1984

10 years later scientists found it and indentified it as coming from mars

announcement in 1996 of possible microfossils inside a Martian meteorite

In the 19th century, many astronomers were convinced the Moon was inhabited by intelligent aliens. We now know that this isn't true. The Moon has no atmosphere, so life couldn't survive there.

Even so, the Apollo astronauts were held in quarantine after their trips to the Moon - just in case they had picked up any space bugs.

The Moon

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Return to the Moon ---- United States, Russia, India, Japan and China ---have all announced plans to send astronauts back to

the Moon around the year 2020

AST121,Fall 2005Robert ZimmermanUniversity of OregonSec 4

The End