Atmosphere vs.

Atmosphere

Links for different Landing Methods

http://www.youtube.com/watch?v=ggjD3i7efKU Viking (1976) 4:01http://www.youtube.com/watch?v=Q8uhzlJ5tws Pathfinder (1997) 2:43http://www.youtube.com/watch?v=tma2pt0k6UQ Spirit/Opportunity (2004) 4:41http://www.youtube.com/watch?v=FD4_3KqqG9k Phoenix (2008) 2:44http://www.youtube.com/watch?v=gwinFP8_qIM Curiosity (2012) 5:12 http://www.jpl.nasa.gov/news/news.php?release=2014-271 LDSD “Flying Saucer” Idea (2014) 2:08

Atmosphere of EarthSubstance Abundance (%) Notes

Nitrogen 78.08 Mostly inert

Oxygen 20.94 Pretty important

Argon 0.93 Inert

Water vapor Variable (~1%) Greenhouse gas

Carbon dioxide 0.040 Greenhouse gas

Neon 0.0018 Inert

Helium 0.0005 Inert

Methane 0.0002 Potent greenhouse gas

Surface pressure: ~1014 millibars

Atmosphere of MarsSubstance Abundance (%) Notes

Carbon dioxide 95.32 It’s what plants crave!

Nitrogen 2.7 So much less than Earth.

Argon 1.6 Inert.

Oxygen 0.13 Frowny face.

Carbon monoxide 0.08 Deadly at higher concentrations.

Water 0.00021 No, you can’t go to the school store.Surface pressure: ~6.6 millibars

Where’d it go?• In July 2013, NASA reported that its Curiosity

rover had found evidence that Mars lost the bulk of its atmosphere in a catastrophic event 4 billion years ago.

• For you chemistry kids, the ratio of two isotopes of argon on Mars is very different to that on Earth, suggesting that some unpleasant event changed the original composition of Mars’ atmosphere.

• As with every other major planetary event, it was either a giant impact or volcanic activity. We don’t know yet.

Where’d it go?• Of course, Mars also lacks a planetary

magnetic field, and that is the traditional explanation for the thin atmosphere.

• Outgassing from the Martian interior is in equilibrium with the thinning of the atmosphere by the solar wind.

Earth Magnetic Field vs Mars/Venus

An artist's impression of the magnetic fields of Venus, Earth and Mars interacting with charged particles streaming from the sun. Earth's magnetic field protects it from these atmosphere-stripping particles

Solar Wind on Mars• Earth has a fairly strong magnetic field

(compared to other planets.• Solar wind is charged particles (mostly

protons) that escape the Sun’s gravity and travels out into space in all directions.

• These particles are a form of radiation which can cause damage to eyes and skin and cause cancer.

• Since Mars has no magnetic field, humans on Mars would need shielding from the radiation in order to live safely. (For building, spacesuits, vehicles, etc.)

Solar Radiation• Is energy radiated from the sun in the form of

electromagnetic waves, including visible and ultraviolet light and infrared radiation.

• Earth’s atmosphere protects us from UV radiation (solar radiation))

Radiation on our journey to Mars

• http://www.space.com/21561-space-exploration-radiation-protection-plastic.html