Earth's has survived a near miss with an asteroid, after its closest fly-by in 200 years. Passing our planet by just a mere 350 miles, the 400-metre-wide rock was invisible to the naked eye.
AFP - A big asteroid made its closest fly-by of Earth in 200 years on Tuesday, but there was never a chance of a crash landing as it zipped past our planet, NASA said.
Astronomers around the world aimed their telescopes to catch a glimpse of the 2005 YU55 asteroid, which is the size of an aircraft carrier but was not visible to the naked eye when it passed by at its closest point at 2328 GMT.
"This is going to be really hard to see. This is 100 times more dim than what the human eye can see. You need a good telescope," NASA spokeswoman Veronica McGregor said before the fly-by.
The near-spherical asteroid, 1,300 feet (400 meters) in diameter, often travels in the vicinity of Earth, Mars and Venus, but NASA said this fly-by was the closest the asteroid had come to Earth in at least 200 years.
Other asteroids of this size pass by Earth frequently, though the last such event happened in 1976 and the next will not take place until 2028, when an asteroid called 2001 WN5 will skim about halfway between the Moon and Earth.
NASA said at the point of closest approach Tuesday, the 2005 YU55 asteroid "was no closer than 201,700 miles (324,600 kilometers), as measured from the center of Earth" -- roughly .85 times the distance of the Moon to the Earth.
The space rock drew closest to earth at 3:28 pm (2328 GMT), when it soared by some 350 miles (560 kilometers) southwest of Guatemala City, over the Pacific, said DC Agle, a spokesman at NASA's Jet Propulsion Laboratory.
The asteroid "is one of the potentially hazardous asteroids that make close approaches from time to time because their orbits either approach or intersect the orbit of the Earth," said Robert McMillan, an associate research scientist at the University of Arizona.
McMillan discovered the asteroid in 2005 as part of the university's Spacewatch Project, a solar system-scanning group of scientists near Tucson, Arizona.
However, astronomers knew from analyzing the trajectory of the asteroid that it would not hit Earth this time.
The asteroid's next closest pass is set to take place in 2094, at a distance of 167,000 miles, according to forecasts.
"The observations will give us a piece of the puzzle, one we don't get many chances to see," said Don Yeomans of NASA's Jet Propulsion Laboratory.
"At one time, we thought these were the asteroids that delivered carbon and other elements to the early Earth, so they are pretty important."
NASA said the Arecibo Planetary Radar Facility in Puerto Rico tracked the asteroid as it closed in.
Astronomers at the Clay Center Observatory in Brookline, Massachusetts also trained their 25-inch (64-centimeter) telescope to track the asteroid and capture images of it.
NASA's Deep Space Network antenna in Goldstone, California grabbed radar images of the asteroid looking like a large gray egg, which were posted on NASA's website late Monday.
While the charcoal-colored asteroid's visit saw eager scientists striving for a closer look, most people on Earth probably did not notice it.
"The gravitational influence of the asteroid will have no detectable effect on Earth, including tides and tectonic plates," NASA said.
Date created : 2011-11-09