Q & A – Mars on Earth

Mini-Science logo At the conclusion of each Mini-Science lecture, audience members submit their questions to the evening’s presenter, who answers as many as possible on the spot. Three of the unanswered questions are sent to the presenter for posting here. Here are questions from Prof. Wayne Pollard’s lecture “Exploring Mars on Earth: The Arctic as an Analogue for Mars” (May 13, 2009).

Q: Magnetic fields play an important role in Earth’s Arctic and Antarctic radiation exposure. Does Mars have similar magnetic fields and is this an important analogue consideration?

A: The Earth’s magnetic field is due to its complex internal structure and rotation. The layered nature of the Earth’s Core and Mantle and its fluid outer core containing iron and nickel produces a dynamo effect that turns the planet into a big bar magnet with its north magnetic pole located in the high Arctic and south magnetic pole in the Antarctic. The magnetic poles do not correspond with the Earth’s rotational pole. The Earth’s magnetic field creates the magnetosphere, a zone of charge plasma that extends into space and envelopes the Earth. The magnetosphere helps protect the Earth from the Sun’s solar winds, which could be quite harmful to life and the environment. The shape of the Earth’s magnetic field and its dipole nature means that the field is nearly vertical and somewhat thinner over the poles, which together with a thinner atmosphere has implications for UV radiation.

Mars does not have a structure that produces the sort of magnetic field that occurs on Earth. In fact it has little or no magnetic field. This means that Mars is extremely vulnerable to Solar winds which are believed to be responsible, at least in part, for the planet’s loss of its former oceans and atmosphere to space. This loss was caused, at least in part, by the direct impact of the solar wind on Mars’ upper atmosphere.

Q: Why is it important to study the Antarctic as an analogue for Mars, in addition to the Arctic?

A: Both the Arctic and Antarctic have valuable analogue attributes. The unglaciated parts of Antarctica (~2% of the continent) are extremely dry and cold; hence Antarctica is an ideal environment to study the limits of life on Earth and thus a possible model for the last life forms that may have existed on Mars.

Q: Where can I get more information in this field? Can you suggest some websites?

A: Analogue studies are an important part of Astrobiology. Astrobiology is a rapidly evolving science concerned with the search for life and the study for limits of life.

A good website is http://astrobiology.nasa.gov/nai/ which defines “Astrobiology as the study of the origins, evolution, distribution, and future of life in the universe. An interdisciplinary field requiring a comprehensive, integrated understanding of biological, planetary, and cosmic phenomena. Astrobiology encompasses the search for habitable environments in our Solar System and on planets around other stars… Astrobiologists address three fundamental questions: How does life begin and evolve? Is there life elsewhere in the universe? What is the future of life on Earth and beyond?”

Other websites include:
http://www.astrobiology.com/
http://www.astrobiology.com/extreme.html
http://www.astrobio.net/news/

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