NASA scientists get first images of Earth flyby asteroid
It has been determined that there is no possibility of an impact with Earth.
January 28, 2008
Provided by the Jet Propulsion Laboratory, Pasadena, California
January 28, 2008
This image shows asteroid 2007 TU24 and was taken by the Catalina Sky Survey, October 12, 2007.
Photo by Steve Larson and Ed Beshore, Catalina Sky Survey
Scientists at NASA's Jet Propulsion Laboratory in Pasadena, California, have obtained the first images of asteroid 2007 TU24 using high-resolution radar data. The data indicate the asteroid is somewhat asymmetrical in shape, with a diameter roughly 800 feet (250 meters) in size. Asteroid 2007 TU24 will pass within 1.4 lunar distances, or 334,000 miles (538,000 kilometers), of Earth on January 29 at 12:33 a.m. Pacific time (3:33 a.m. Eastern time).
"With these first radar observations finished, we can guarantee that next week's 1.4-lunar-distance approach is the closest until at least the end of the next century," says Steve Ostro, JPL astronomer and principal investigator for the project. "It is also the asteroid's closest Earth approach for more than 2,000 years."
Scientists at NASA's Near-Earth Object Program Office at JPL have determined that there is no possibility of an impact with Earth in the foreseeable future.
Asteroid 2007 TU24 was discovered by the NASA-sponsored Catalina Sky Survey on October 11, 2007. The first radar detection of the asteroid was acquired on January 23 using the Goldstone 230-foot (70-meter) antenna. The Goldstone antenna is part of NASA's Deep Space Network Goldstone station in Southern California's Mojave Desert. Goldstone's 230-foot (70-meter diameter) antenna is capable of tracking a spacecraft traveling more than 10 billion miles (16 billion kilometers) from Earth. The surface of the 230-foot reflector must remain accurate within a fraction of the signal wavelength, meaning that the precision across the 41,400-square-foot (3,850-square-meter) surface is maintained within 0.4 inch (1 centimeter).
These low-resolution radar images of asteroid 2007 TU24 were taken over a few hours by the Goldstone Solar System Radar Telescope in California's Mojave Desert. Image resolution is approximately 20-meters per pixel. Next week, the plan is to have a combination of several telescopes provide higher resolution images.
Photo by NASA/JPL-Caltech
Ostro and his team plan further radar observations of asteroid 2007 TU24 using the National Science Foundation's Arecibo Observatory in Puerto Rico on January 27-28 and February 1-4.
The asteroid will reach an approximate apparent magnitude 10.3 on January 29-30 before quickly becoming fainter as it moves farther from Earth. On that night, the asteroid will be observable in dark and clear skies through amateur telescopes with apertures of at least 3 inches (7.6 centimeters). An object with a magnitude of 10.3 is about 50 times fainter than an object just visible to the naked eye in a clear, dark sky.
NASA detects and tracks asteroids and comets passing close to Earth. The Near Earth Object Observation Program, commonly called "Spaceguard," discovers, characterizes and computes trajectories for these objects to determine if any could be potentially hazardous to our planet.