2
votes
2answers
97 views

What mechanism causes oscillations of the solar system's orbit about the galactic plane?

In a recent paper (news release here) Lisa Randall and Matthew Reece propose that a dark matter disk coinciding with the galactic plane together with the solar system's oscillations through the ...
4
votes
1answer
126 views

What distance has the moon been from earth at the closest?

For every year, the moon is orbiting further away from earth. What distance has the moon been from earth at the closest?