Close Encounter
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- Scientific consulting by:
- Stefan Immler
- View full credits
On November 9, 2011, asteroid 2005 YU55 blazed past Earth at nearly 25,000 miles per hour. Overshooting our planet by more than 200,000 miles, the asteroid didn't pose a threat of a catastrophic collision. However, the quarter-mile-wide tumbling space rock did dip below the moon's orbit, making it one of the closest asteroid approaches of its size identified to date. As ground-based telescopes tracked the asteroid using radar, infrared and optical light, NASA's Swift satellite imaged it at ultraviolet wavelengths. Observing the asteroid using ultraviolet light gave insight into the makeup of its surface—information astronomers can use to predict its future trajectory. Researchers estimate the asteroid, which is locked in orbit around the sun, will pass safely by our planet in 2041 and 2075. Watch the video to see satellite footage of asteroid 2005 YU55 hurtling through space.
For More Information
See NASA.gov
Credits
Please give credit for this item to:
NASA's Goddard Space Flight Center
Swift footage and images courtesy of NASA/Swift/Stefan Immler and DSS
Goldstone radar images courtesy of NASA/JPL-Caltech
Near-Earth asteroid image courtesy of NASA/JPL-Caltech
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Writer
- Francis Reddy (University of Maryland College Park)
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Video editor
- Scott Wiessinger (KBR Wyle Services, LLC)
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Scientist
- Stefan Immler (UMCP) [Lead]
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Producer
- Scott Wiessinger (KBR Wyle Services, LLC)
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ID: 10871 Produced Video
Swift Captures Flyby of Asteroid 2005 YU55
Read moreAs asteroid 2005 YU55 swept past Earth in the early morning hours of Wednesday, Nov. 9, telescopes aboard NASA's Swift satellite joined professional and amateur astronomers around the globe in monitoring the fast-moving space rock. The unique ultraviolet data will aid scientists in understanding the asteroid's surface composition.The challenge with 2005 YU55 was its rapid motion across the sky, which was much too fast for Swift to track. Instead, the team trained the spacecraft's optics at two locations along the asteroid's predicted path and let it streak through the field. The first exposure began a few hours after the asteroid's closest approach and fastest sky motion — near 9 p.m. EST on Nov. 8 — but failed to detect it.Six hours later, around 3 a.m. EST on Nov. 9, Swift began an exposure that captured the asteroid sweeping through the Great Square of the constellation Pegasus. The 11th- magnitude rock was then 333,000 miles away and moving at 24,300 mph, about an hour from its closest approach to the Moon. That exposure gave the Swift team more than a streak through the stars. "A novel feature of Swift is the ability to go into a mode tracking the arrival of every photon captured by the instrument. With that information, we can reconstruct the asteroid as a point source moving through the Ultraviolet/Optical Telescope's field of view," said Neil Gehrels, lead scientist for Swift at NASA's Goddard Space Flight Center in Greenbelt, Md.The 27-minute-long image was effectively sliced into short 10-second-long exposures, which then were combined into a movie. This allows scientists to study short-term brightness variations caused by the object's rotation.The result is a movie of 2005 YU55 at ultraviolet wavelengths unobtainable from ground-based telescopes. For planetary scientists, this movie is a treasure trove of data that will help them better understand how this asteroid is put together, information that may help make predictions of its motion more secure for centuries to come. The press release on NASA.gov is here. ||
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