[meteorite-list] Asteroid 2004 MN4: A Really Near Miss!

From: Sterling K. Webb <kelly_at_meteoritecentral.com>
Date: Fri Feb 4 22:37:14 2005
Message-ID: <42043F0B.F9CD07B9_at_bhil.com>

     Hi,

         Whoa, Darren! True, the asteroid will be closer than a geosynchronous satellite, but
     since it's not gravitationally bound to the Earth's g-field, the local speed limits will not
     apply! You're going to have to really hop up your police interceptor rocket if you're going
     to get close enough to even slap it on the ass on its way by!
         I don't know what its geocentric velocity will be when it gets here, but the figure of
     42 degrees per hour apparent movement through the sky field contrasted with the 15 degrees
     per hour of a geosynchronous satellite orbit, suggests it'll really be bookin'!
         The delta-V required to match up with it would probably be, you'll pardon the
     expression, astronomical. And, then, after you've had the space walk, the flag planting,
     the call from the President, etc., you still have to get back before you, too, disappear
     into the Wild Black Yonder. Another big hunk of delta-V.
         There's another problem unique to high speed close approach missions: not only do you
     have to execute a high delta-V maneuver, you have to do it in a big hurry. That thing is
     movin'! That means you will have to accelerate at very high gee's. Either that, or you have
     to go out to meet the thing well in advance and accelerate at a slower rate, matching
     velocities after a long "bow chase," as the sailors say.
         In fact, the only feasible mission plan would be a long voyage to the asteroid long
     before the Earth encounter, ride it by the Earth and back out to the best point for the
     Earth Return leg. Much less delta-V but a lot more time to play solitaire in the capsule.
         As for nudging, hey! You'd better practice on some asteroids that aren't going to pass
     near the Earth first, before you try nudging anything that is. In fact, I wouldn't mind if
     you skipped that nudging part altogether. :-]


     Sterling K. Webb

----------------------------------------------------------------------
Darren Garrison wrote:

> On Fri, 4 Feb 2005 16:32:42 -0800 (PST), Ron Baalke <baalke_at_zagami.jpl.nasa.gov> wrote:
>
> >Paul Chodas, Steve Chesley, Jon Giorgini and Don Yeomans of NASA's Near
> >Earth Object Program calculate that the asteroid will pass 4.7 Earth
> >radii (30,000 kilometers, or 18,600 miles) from Earth's surface. This is
>
> Wow. Plenty of time to plan a (relatively) easy visit and sample recovery mission. That's lower
> than geosynchronous orbit!
>
> Of course, if you wanted to be a bit more ambitious, given 24 years we could probably even throw
> together a project to nudge it into Earth orbit, but I think that would get some pretty bad press.
>
> Maybe we could nudge it into the moon and watch it hit!
Received on Fri 04 Feb 2005 10:35:39 PM PST