[meteorite-list] When I'm 64 ... Part1 of 2

From: bernd.pauli_at_paulinet.de <bernd.pauli_at_meteoritecentral.com>
Date: Mon Mar 28 06:02:41 2005
Message-ID: <DIIE.00000034000035EC_at_paulinet.de>

No, that was a song by the Beatles. I had better say:

When I'm 84 (and if I am still around, ...)


Alan MacRobert (2005) Asteroid 2004 MN4: A Really
Near Miss (Sky & Telescope, May 2005, pp. 16-17):

This big an asteroid should whiz this close by Earth only once in 1,300 years.

If you expect to be alive on April 13, 2029, you can look forward to an asteroid-
watching party across three continents like nothing the world has ever seen.
In late January, Lance Benner (Jet Propulsion Laboratory) and three other radar
astronomers used the giant Arecibo dish in Puerto Rico to ping the near-Earth
asteroid 2004 MN4 and refine its orbit. This object briefly made headlines last
December when astronomers estimated that it had a 1-in-38 chance of hitting Earth
in 2029. The threat quickly passed when old images were found that pinned down the
asteroid's orbit well enough to guarantee that it will miss us (see last month's
issue, page 20). The radar measurements confirm that the asteroid will miss Earth
- but by only about half the distance calculated before. As a result, we're going
to get a once-in-a-millennium naked-eye asteroid show.

Paul Chodas, Steve Chesley, Jon Giorgini, and Don Yeomans of NASA's Near Earth Object
Program find that the asteroid will pass 4.7 Earth radii (30,000 kilometers, or 18,600
miles) from Earth's surface. It should brighten to magnitude 3.3, similar to the faint-
est star of the Big Dipper, while moving northwest across Sextans and Cancer at a speed
reaching 42? per hour. Europe, Africa, and Asia will have ringside seats. With a newly
estimated diameter of 320 meters (1,050 feet), 2004 MN4 will appear up to 2 arcseconds
wide, making it barely resolvable in amateur telescopes. Skywatchers in North and South
America will get their best view hours earlier, while the asteroid is still on its
approach and only 7th magnitude.


Best regards,

Bernd
Received on Mon 28 Mar 2005 06:02:39 AM PST