[meteorite-list] Asteroid Radar

[Richard Kowalski]

--- On Sat, 8/29/09, Meteorites USA <eric at meteoritesusa.com> wrote:

 > From: Meteorites USA <eric at meteoritesusa.com>
 > Subject: [meteorite-list] Asteroid Radar
 > To: "meteorite-list at meteoritecentral.com" 
<meteorite-list at meteoritecentral.com>
 > Date: Saturday, August 29, 2009, 3:46 AM
 > Hi Listees,
 >
 > I've a question that I've been wondering about... All the
 > fireball chasing, and meteorite hunting aside. Is there any
 > network of space based asteroid detection using radar
 > satelites? And if so how does that or would that work? Would
 > you be able to effectively "see" asteroids with radar in
 > space?
 >
 > Just curious...
 >
 > Regards,
 > Eric
 > ________


Hi Eric,

I'm not sure what you mean by "radar satellites". I'll assume you mean 
satellites that use radar to detect other objects in which case the 
short answer is no.

Planetary radar is extremely energy intensive and has an extremely 
narrow beam. Radar astronomers regularly make requests for astrometry of 
target asteroids on the Minor Planet Mailing List so their can refine 
their targeting so as to not waste precious, expensive time finding the 
objects and actually observing them

Also remember that you have to both transmit and receive for radar to 
work, and yoour targets are usually extremely small, so beside the 
narrow beam, you have to contend with the inverse square law. Your 
transmitted signal has to be extremely powerful to get a tiny signal back.

Planetary radar requires huge radio telescopes such as Goldstone & 
Arecibo to be effective, so the power requirements, beam angle and the 
size of the antennas needed eliminates any possibility for a satellite 
base radar detection system.

For more informtion, see the Asteroid Radar Research page at JPL here:

http://echo.jpl.nasa.gov/

Cheers

-- 
Richard Kowalski
Catalina Sky Survey
Lunar and Planetary Laboratory
University of Arizona
Tucson, AZ  85721