[meteorite-list] Early Earth temperatures

[E.P. Grondine]

Hi Ron, all - 

The easy solution to this problem is that the Earth has been loosing atmosphere to space for a long time - blown away by the solar wind. 

(That process will continue, and there's a sobering thought: when does our air run out?)

By the way, someone needs to tell the WISE team that just because an asteroid or dead comet fragment is below their limit of detection, that does not it does not exist. 

Thus when they announce that they did not find as many asteroids or dead comet fragments as they expected in one class size, its most likely because they have fragmented into smaller pieces below their level of detection, not that there's less mass out there.

How are NASA's 73P tracking efforts going? How much dust has been generated? Enough to cause a nuclear winter in 2022?

E.P.