Arecibo astronomers prepare to obtain close images of a near-Earth asteroid
The Arecibo Observatory in Arecibo, Puerto Rico will observe a newly discovered asteroid on Jan. 27-28, as the object called 2007 TU24 passes within 1.4 lunar distances, or 334,000 miles, from Earth.
The asteroid, estimated at between 150 and 600 meters in diameter 鈥� about 500 feet to 1,900 feet, or the size of a football field, at 360 feet, to the size of Chicago鈥檚 110-story Sears Tower, at 1,454 feet 鈥� was discovered by the University of Arizona鈥檚 Catalina Sky Survey in October 2007. It poses no threat to Earth, but its near approach gives Arecibo astronomers a golden opportunity to learn more about potentially hazardous near-Earth objects.
鈥淲e don鈥檛 yet know anything about this asteroid,鈥� said Mike Nolan, head of radar astronomy at the Puerto Rico observatory. Such objects pass near Earth with relative frequency, he said 鈥� approximately one every five years or so 鈥� but it鈥檚 rare that astronomers have enough advance notice to plan for rigorous observing.
鈥淏ecause it鈥檚 coming so close, we鈥檒l get our highest quality imaging,鈥� said Nolan.
Using Arecibo鈥檚 powerful radar, which is the most sensitive in the world, researchers will gauge the object鈥檚 size, observe its speed and measure its spin. Switching then to imaging mode, which will offer resolution to 7.5 meters 鈥� three times more precise than NASA鈥檚 Goldstone telescope, the only other radar telescope in the world 鈥� the researchers hope to map the object鈥檚 surface in detail. The Robert C. Byrd Green Bank Telescope, Green Bank, W.Va., will receive Arecibo鈥檚 echo from the asteroid and transmit its data back to Arecibo.
TU2 is one of an estimated 7,000 near-Earth objects, its size or larger 鈥� most have never been closely studied.
鈥淲e have good images of a couple dozen objects like this, and for about one in 10, we see something we鈥榲e never seen before,鈥� said Nolan. 鈥淲e really haven鈥檛 sampled the population enough to know what鈥檚 out there.鈥�
Arecibo鈥檚 radar is vital for continuing to classify and understand such objects, said Cornell University assistant professor of astronomy Jean-Luc Margot. 鈥淎recibo does a fantastic job at getting images, discovering the shape, spin and reflection properties of such an object . . . all these things that are important to know.鈥�
The telescope will be trained on TU24 Jan. 27-28 and again Feb. 1-4. Goldstone鈥檚 planetary radar observed it Jan. 23-24.
Source: Cornell University
