NASA: National Aeronautics and Space Administration


Ask an Astrobiologist
"Has the grinders on spirit and opportunity turned up anything that vaguely look like small fossils?"
  1. Special Note


    Ask an Astrobiologist has received nearly a thousand questions about Nibiru and 2012, with more than 200 answers posted. Please read a summary of the answers that have already been posted, use the search feature and read the FAQ’s before submitting questions on these topics.

  1. Question

    When Mars is at its closest point to Earth, could its gravity have an effect on us, or is it still too far away?

    The gravity of Mars has negligible effect on the Earth, although, of course, all the planets influence each other's orbits in subtle ways that are of interest only to planetary dynamics experts. But at a distance of more than 50 million kilometers, the gravity of Mars is extremely weak, and there are no other effects anticipated. For example, the gravitational tidal force exerted on you by Mars at its closest is less than that from any of the other people around you in your home, or from major pieces of furniture such as a refrigerator or washing machine.

    David Morrison
    NAI Senior Scientist

    August 18, 2003