Huge Asteroid 2005 YU55 Approaches Earth : Discovery News
The quarter-mile wide space rock will miss us tomorrow... but astronomically, it's a near-miss.
The 400-meter wide asteroid will pass inside the orbit of the moon.
2005 YU55 is the closest a known object this large has ever gotten to a collision with Earth.
Observatories are on high alert worldwide in the hope of glimpsing the space rock as it flies past on Tuesday at 7:30 p.m. ET.
On Tuesday, Nov. 8, an asteroid deemed "potentially hazardous" by the Minor Planet Center in Cambridge, Ma. will approach Earth's atmosphere.
Fortunately for us, Asteroid 2005 YU55 will miss an Earthly encounter by 0.85 lunar distance, or approximately 208,000 miles (335,000 kilometers).
With a diameter of 400 meters, the approach will mark the closest a known object this large has ever gotten to a collision with Earth and will continue to hold that record until Asteroid 2001 WN5 gets within 0.6 lunar distance in 2028. 2005 YU55 was only discovered 6 years ago, so there is still the possibility that Space Watch may find other monstrous floating rocks in the run-up to 2028.
The approach will be closest at around 7:30 p.m. ET and viewable in both the Northern and Southern Hemispheres with a visual brightness of the 11th magnitude, but will not be easily spotted according to Robert McMillan of the Space Watch Program in Tucson, Ariz.
"You will be able to see nothing with the naked eye or even a small telescope with an eyepiece. The object will approach Earth this time from the direction of the sun and departs our vicinity toward the bright moon," McMillan told Discovery News. "It will be dim and only visible with imaging detectors."
It was McMillan who originally discovered the dark, spherical asteroid on Dec. 28, 2005.
Originally thought to be another blasé rock to add to the thousands he had already discovered and the 900 near-Earth objects that the program as a whole had found, scientists now anxiously await the approach of the C-Type -- or carbon-bearing -- asteroid.
Thanks to its 20-hour rotation period, the Goldstone Observatory, based in California's Mojave Desert, may be able to capture 8-hour radar tracks from Nov. 3 through Nov. 11 in the hope of measuring rotation characteristics, surface roughness and mineral composition.
The Goldstone radar will also utilize a new method of transmitting radar signals to the target asteroid. Known as "chirp" mode, this advanced radar may allow for a shape model reconstruction that allows features as small as 4 meters wide to be resolved.
Many other observatories worldwide -- including the twin infrared Keck telescopes atop Mauna Kea, Hawaii -- will be tracking the large space rock.
Not thought to be a threat to Earth for at least the next few centuries, Asteroid 2005 YU55 may still be a threat for future generations.
"2005 YU55 cannot hit Earth at least over the interval that we can compute the motion reliably, which extends for several hundred years," said Lance Benner, NASA Jet Propulsion Laboratory research scientist, in a recent NASA video.
"It made close approach to Earth about 18 months ago," added Benner. "In April of 2010, colleagues of ours at Arecibo Observatory were able to observe this asteroid using their radar facility at Arecibo and they were able to obtain radar images that showed that this object is about 400 meters across."
Luckily, with the advancement of radar and the knowledge scientists will gain as it makes its next pass, we will be given more than six years notice when it comes around again, gleaning possible insights as to how to avoid catastrophe later this millennium.