Showing posts with label tsunami. Show all posts
Showing posts with label tsunami. Show all posts

Saturday, May 21, 2016

Mars: Close and Easy to See (And Wet Long Ago)


Tonight, if you look southeast, you can see Mars as a bright red dot next to the full Moon. Mars is in one of its closer positions, about 48 million miles away. Mars is in what astronomers call "opposition" right now (which is not a term related to the Bernie and Hilary situation!)
When Mars is in opposition, it is on the opposite side of the Earth from the Sun. This means that when the Sun goes down, Mars comes up in our skies, and Mars will be up all night long. (Looking at our diagram from Sky & Telescope magazine, you should also be able to find Saturn this evening or tomorrow night, lower toward the horizon than Mars.)
In recent weeks, even more evidence has been accumulating that ancient Mars, billions of years ago, had a much thicker atmosphere and water was therefore liquid on its surface. Astronomers now believe that there were once lakes and even perhaps seas on the red planet. Recently, planetary scientists even found what seems like evidence of two episodes of tsunamis that happened on Mars a long time ago, when a big chunk of rock or ice from space hit a larger body of water.
For details of this investigation, see: http://www.psi.edu/news/marstsunami
(Also check out a great new Hubble image of Mars at:
http://www.spacetelescope.org/news/heic1609/ )