Monday, October 09, 2017

"Good Night, Moon"

The waning gibbous

18.3 days old 

86.6 percent lit

October 5, 2017

A new study (click here) shows that an atmosphere was produced around the ancient Moon, 3 to 4 billion years ago, when intense volcanic eruptions spewed gases above the surface faster than they could escape to space.  The study was published in Earth and Planetary Science Letters.
When one looks up at the Moon, dark surfaces of volcanic basalt can be easily seen to fill large impact basins.  Those seas of basalt, known as maria, erupted while the interior of the Moon was still hot and generating magmatic plumes that sometimes breached the lunar surface and flowed for hundreds of kilometers.  Analyses of Apollo samples indicate those magmas carried gas components, such as carbon monoxide, the ingredients for water, sulfur, and other volatile species.
To right: Map of basaltic lavas that emitted gases on the lunar nearside
In new work, Dr. Debra H. Needham, Research Scientist of NASA Marshall Space Flight Center, and Dr. David A. Kring, Senior Staff Scientist, at the Lunar and Planetary Institute, calculated the amounts of gases that rose from the erupting lavas as they flowed over the surface and showed that those gases accumulated around the Moon to form a transient atmosphere.  The atmosphere was thickest during the peak in volcanic activity about 3.5 billion years ago and, when created, would have persisted for about 70 million years before being lost to space....