Mars does not have an atmosphere and does not have a magnetic field today, so the planet doesn't have the protection from radiation that our atmosphere and magnetic fields provide us on Earth.

Next quotes

• David Grinspoon:

  What I wonder most about the Anthropocene is not when did it start - but when, and how, will it end

• David Grinspoon:

  Now, humans have become a dominant force of planetary change and, thus, we may have entered an eon

• David Grinspoon:

  The story of our species is one of overcoming existential risk through new forms of cooperation and

• David Grinspoon:

  We need to have a vision of the world we want to create so that we can see ourselves as collaborato

• David Grinspoon:

  You cannot study other planets without referring to Earth and without applying the techniques and t

• David Grinspoon:

  We're going to stop looking at Earth from orbit because we don't like what we are seeing and the co

• David Grinspoon:

  If we gutted NASA Earth Science, it wouldn't be NOAA or some other agency that would take the lead.

• David Grinspoon:

  I will defend the NASA Earth Science Division with everything I've got.

• David Grinspoon:

  There are other planets besides the Earth and Mars. I'd like to remind you that studying Venus is v

• David Grinspoon:

  There was a long history of people believing there was life on Venus. It was about the same size as