By Michael Summers
New Horizons Co-Investigator
"Professor Michael Summers Michael E. Summers is a professor of Planetary Science and Astronomy at George Mason University, and specializes in the study of the chemistry and dynamics of planetary atmospheres. He is a New Horizons co-investigator and member of the atmospheres science theme team."
"But now consider Pluto. Its atmosphere has a near-surface equivalent thickness of about 40 kilometers, which is almost 4% of its 1,200- kilometer (or so) radius. But the “outer limit” of Pluto’s atmosphere is very difficult to define, although we know that it is very far from the surface. If one defines it similar to the way we define the exobase of Earth’s atmosphere, then Pluto’s atmosphere has an outer limit of at least seven times Pluto’s radius above it surface. This means that the volume of Pluto’s atmosphere is over 350 times the volume of Pluto itself! This illustrates what a strange and wonderful new kind of world we are about to visit and explore.
And this estimate is conservative. As I noted, the outer limit for Pluto’s atmosphere is ill-defined because of the gradual way that the atmosphere merges with the vacuum of space. It could in fact be farther than seven Pluto radii from its surface, and thus its volume would be even larger."
Read entire article: http://pluto.jhuapl.edu/News-Center/Science-Shorts.php?page=ScienceShorts_02_24_2015
#Pluto #space #nasa #plutoflyby