The 500-meter-wide rock may seem apocalyptic in size, but thankfully it will pass no closer than 1.2 million kilometers of our planet — about three times the distance between Earth and the moon. The agency says it will provide a rare opportunity to get a good look at a near-Earth asteroid. The next chance will come in 2027, when asteroid 1999 AN10 will fly past Earth.
Due to its orbit around the sun, the asteroid is currently only visible by astronomers with large telescopes who are located in the southern hemisphere.
However, by January 26, its changing position will make it visible to in the northern hemisphere.
"Monday, January 26 will be the closest asteroid 2004 BL86 will get to Earth for at least the next 200 years," Don Yeomans, who is retiring as manager of NASA's Near Earth Object Program Office at the Jet Propulsion Laboratory (JPL) in Pasadena, California is quoted as saying in a statement on NASA’s website.
"And while it poses no threat to Earth for the foreseeable future, it's a relatively close approach by a relatively large asteroid, so it provides us a unique opportunity to observe and learn more."
The scientists plan to track the fast-moving space rock using the 230-foot (70 m) dish-shaped Goldstone antenna at NASA's Deep Space Network in California, as well as the 1,000-foot (305 m) Arecibo Observatory in Puerto Rico. These radio dishes will beam microwave signals at the asteroid, which will then bounce off the target and return to Earth.
"When we get our radar data back the day after the flyby, we will have the first detailed images," said radar astronomer Lance Benner of the JPL, the principal investigator handling the Goldstone radar observations of the asteroid. "At present, we know almost nothing about the asteroid, so there are bound to be surprises."
Asteroid 2004 BL86 was initially discovered on January 30, 2004 by a telescope from the Lincoln Near-Earth Asteroid Research (LINEAR) survey in White Sands, New Mexico.
The asteroid is expected to be observable to amateur astronomers with small telescopes and strong binoculars.