YEEE-HAAAAWW
Ready to take a ride on the X-43A Scramjet - at 7,000 miles per hour (Mach 9.8)?
For reference, that's about two miles a second.
Ride 'em cowboy
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Of course, speed (and time, don't forget) is relative. For example, back in 1998 Voyager 1 was traveling at about 10.8 miles per second.
That's an advantage of space - no pesky air molecules to contend with.
Read about that here, or a little more recently here. Second site has other fast stuff listed too.