[NormsRevenge]

Don Yeomans
NASA/JPL Near-Earth Object Program Office
January 22, 2008

Asteroid 2007 TU24, discovered by the Catalina Sky Survey on October 11, 2007 will closely approach the Earth to within 1.4 lunar distances (334,000 miles) on 2008 Jan. 29 08:33 UT. This object, between 150 and 600 meters in diameter, will reach an approximate apparent magnitude 10.3 on Jan. 29-30 before quickly becoming fainter as it moves further from Earth. For a brief time the asteroid will be observable in dark and clear skies with amateur telescopes of 3 inch apertures or larger.

For an interactive illustration of this object's orbit see: http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2007+TU24&orb=1

The illustration below is courtesy of amateur astronomer Dr. Dale Ireland from Silverdale, WA. The illustration shows the asteroid's track on the sky for 3 days near the time of the close Earth approach as seen from the city of Philadelphia. Since the object's parallax will be a significant fraction of a degree, observers are encouraged to use our on-line Horizons ephemeris generation service for their specific locations. These personalized ephemeris tables can be generated at: http://ssd.jpl.nasa.gov/horizons.cgi?find_body=1&body_group=sb&sstr=2007%20TU24

Given the estimated number of near-Earth asteroids of this size (about 7,000 discovered and undiscovered objects), an object of this size would be expected to pass this close to Earth, on average, about every 5 years or so. The average interval between actual Earth impacts for an object of this size would be about 37,000 years. For the January 29th encounter, near Earth asteroid 2007 TU24 has no chance of hitting, or affecting, Earth.

2007 TU24 will be the closest currently known approach by a potentially hazardous asteroid of this size or larger until 2027. Plans have been made for the Goldstone planetary radar to observe this object Jan 23-24 and for the Arecibo radar to observe it Jan 27-28 and then Feb 1-4. High resolution radar imaging is expected, which may permit later 3-D shape reconstruction.

[Zuben Elgenubi]

Nice map. Easy way to remember the brightest point is finding the north star and look 10 degrees south of that star on the evening of Jan 29. If you extend your fist out at the object, the width of your fist is about 10-15 degrees, as a reference.