[jumper]

Supersonic? In reference to what? I smell a hyped up headline... The article doesn't seem to mention the reference but it seems likely they're assuming standard sea level Earth conditions for things like temperature\pressure\etc.

[bd]

It's 2,189 kilometres per hour (1,360 miles per hour):

http://en.wikipedia.org/wiki/Enceladus_%28moon%29%23Possible...