Asteroids are one of the most hazardous objects in the solar system. The NASA keeps close eye on potentially hazardous objects and allows us to know about asteroids coming towards Earth. This time, asteroid named as 2004 BL86, will be safely pass Earth on 26 January, 2015. The size of the asteroid is estimated to be around 650 m by studying reflected brightness of the asteroid. The asteroid of this size is categorized as Potentially Hazardous Asteroid.

The asteroid of size larger than 35 meters across can pose a threat to a town or city. The asteroid of diameter 100 to 150 m is big enough to cause regional devastation to human settlements unprecedented in human history in the case of a land impact, or a major tsunami in the case of an ocean impact. Such events occur on an average once per 10000 year.

Although it is potentially hazardous asteroid but you don’t need to worry as this will pass Earth safely. The closest distance between the asteroid and the Earth will around 1.2 million km (745,000 miles) on 26 January which is about 3.1 times the distance between moon and Earth.

It will be the closest known asteroid this large to pass near Earth until 2027, that’s when an asteroid called 1999 AN10 flies by us.

“Monday, January 26 will be the closest asteroid 2004 BL86 will get to Earth for at least the next 200 years,” said Don Yeomans, who is retiring as manager of NASA’s Near Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, California, after 16 years in the position. “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 at NASA are planning to observe this asteroid with microwave. NASA’s Deep Space Network antenna at Goldstone, California, and the Arecibo Observatory in Puerto Rico will try to obtain the scientific data and radar generated image of the asteroid 2004 BL86.

“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 JPL, the principal investigator for the Goldstone radar observations of the asteroid. “At present, we know almost nothing about the asteroid, so there is bound to be surprises.”

The asteroid was discovered by a telescope of the Lincoln Near-Earth Asteroid Research (LINEAR) survey in White Sands, New Mexico in January 2004.

The brightness of the asteroid 2004 BL86 will be around magnitude 9.5 so it can be easily viewed by the small telescopes and binoculars. So this will be good opportunity for amateur astronomers to enjoy the view of large asteroid from such a close distance.

“I may grab my favorite binoculars and give it a shot myself,” said Yeomans. “Asteroids are something special. Not only did asteroids provide Earth with the building blocks of life and much of its water, but in the future, they will become valuable resources for mineral ores and other vital natural resources. They will also become the fuelling stops for humanity as we continue to explore our solar system. There is something about asteroids that makes me want to look up.”

If you don’t have telescope or binocular then don’t be upset. You can watch the closest approach of asteroid online on “The Virtual Telescope Project 2.0”. This will provide the live images of closest approach of asteroid 2004 BL86 with live commentary by their scientific staff.

NASA detects tracks and categorizes asteroids and comets using their Earth based and satellite telescope. The Near Earth Object Program, often referred as “safeguard”, tries to identify the asteroids which could be potentially Hazardous to our planet. The asteroid hit in Siberia in 2013 clearly proves the requirement of this type of programs to save us from the Potentially Hazardous Objects. By 2014, NASA has listed 1458 known Potentially Hazardous Asteroids which are studied by various means including optical, radar and infrared to determine various characteristics of asteroid like size, composition, rotation rate and to more accurately determine its orbit. Both professional and amateur astronomers participate in detection of Potentially Hazardous Asteroids.

Reference:

http://www.jpl.nasa.gov/news/news.php?release=2015-015