Several years ago, near-Earth asteroid 2005 YU55 was “imaged” by the Arecibo Radar Telescope in Puerto Rico. In early November, this large space rock will zip by planet Earth and be surveyed by radar, visual and infrared equipment. Image credit: NASA/Cornell/Arecibo.
An animation prepared by Jon Giorgini of the Jet Propulsion Laboratory shows the motion of asteroid 2005 YU55 in the vicinity of the Earth and Moon during the flyby.
Circle the day November 8 on your calendars. One of the largest and potentially most perilous space rocks in the heavens will zoom by Earth. The unique event will become the object de jour for an armada of ground observers. An extensive campaign of radar, visual and infrared observations has been ordered to survey the cosmic intruder.
Asteroid 2005 YU55 is a mini-world that’s roughly 1,300 feet (400 meters) in diameter. In early November, this asteroid will approach Earth within a scant 0.85 lunar distance. A lunar distance is the distance from the Earth to the Moon or about 240,000 miles.
In many ways, the chunk of rock serves as yet another wake-up call. It is a reminder about life here on our sitting duck of a planet. This will be the closest approach to date by an object this large that we know about in advance.
But don’t worry…too much. Although classified as a potentially hazardous object, 2005 YU55 poses no threat of an Earth collision – for at least the next 100 years!
The 2005 YU55 is unusual since it is close and big, explains Don Yeomans, Manager of NASA’s Near-Earth Object (NEO) Program Office and the Jet Propulsion Laboratory (JPL) in Pasadena, California. “On average, one wouldn’t expect an object this big to pass this close but every 30 years.”
Yeomans told Imaging Notes that scientists see a great opportunity coming, given the close flyby. On call are ground-based optical and near-infrared equipment, as well as high-powered radar. Collectively, the observations should paint a fairly complete picture of a large, potentially hazardous asteroid.
The observations should define the object’s rotation characteristics, as well as the asteroid’s surface roughness and even mineral makeup.
It’s a truly extraordinary flyby that we hope will reveal considerably more information than we currently have about this 400-meter sized, round, dark, and mysterious little world.
Lance Benner is a research scientist at JPL and a specialist on radar imaging of near-Earth objects. He said radar scanning of the asteroid will be done using the huge Arecibo dish in Puerto Rico and equipment at Goldstone, California. “In a real sense, this will provide imaging resolution compar-able to or even better than a spacecraft mission flyby,” he points out. “It’s a truly extraordinary flyby that we hope will reveal considerably more information than we currently have about this 400-meter sized, round, dark, and mysterious little world.”
Using the Goldstone radar operating in a relatively new “chirp” mode, the November radar opportunity could result in a shape model reconstruction of the object with a resolution as fine as 4 meters.
Early on, the asteroid will be too close to the Sun and too faint for optical observers. However, late in the day on November 8 into the following day, the object could reach about 11th magnitude for several hours before it fades as its distance from Earth rapidly increases.
But what won’t fade is interest in keeping an eye on asteroids that may well have Earth’s address on their space routes.
The havoc stemming from an NEO plowing into the Earth depends on its size and trajectory. Damage could range from destruction of an area the size of a city, to creation of tsunamis, to the extinction of almost all life on Earth.
In the making is a Planetary Defense strategy, one that includes finding these potentially hazardous objects, predicting their future locations, and providing warning about future impacts with the Earth. It also includes missions to deflect impacting asteroids by changing their orbit, and disaster preparedness, management, and recovery on Earth to mitigate their consequences.
The Secure World Foundation has focused on how the world might organize to meet the challenge of mitigating possible effects of an incoming NEO. Doing so poses significant policy and legal challenges, many of which are common to space situational awareness, data sharing, collective security, and shared decision making.
Hence, the Foundation has partnered with the Association of Space Explorers and other organizations to assist the U.N. Committee on the Peaceful Uses of Outer Space to develop an appropriate international agreement for responding to the NEO threat.
By the way, put in your memory bank the year 2028. That’s when asteroid 2001 WN5 will pass to within 0.6 lunar distance!
“There are definitely small near-Earth asteroids in our future, and we must make sure that when we encounter one, it is on our terms, not its,” points out David Morrison, Director of the Carl Sagan Center for the Study of Life in the Universe at the SETI Institute in Mountain View, California.
See an animation prepared by Jon Giorgini of the Jet Propulsion Laboratory that shows the motion of asteroid 2005 YU55 in the vicinity of the Earth and Moon during the flyby.