2016 marks the 25th anniversary of the creation of what has become one of the primary venues for the publication of research in planetary science: the Journal of Geophysical Research: Planets. This occasion is a good opportunity to look back at what we have learned in this era of expanded exploration and to try to take a peek at the future.
The third entry in my series of blog posts about Favorite Astro Plots contains one of the biggest discoveries from the Apollo program -- as well as one of the biggest questions in planetary science. The chart was nominated by planetary scientist Barbara Cohen. It has to do with the ages of surfaces on the Moon.