Two comets in similar orbits are approaching Earth. One of them – comet P/2016 BA14 (Pan-STARRS) – will be the closest comet in 246 years!
A pair of comets showing very similar orbits are approaching Earth. While both will pass at a safe distance, one of them will have a record-breakingly close flyby. Comet 252P/LINEAR 12 was already known to be passing by Earth on March 21, 2016 at a distance of 3,290,000 miles (5.3 million km). This is about 14 times the Earth-Moon distance, and, taken by itself, sets no record.But recently astronomers learned that this comet has company. On January 22, 2016, the Pan-STARRS observatory in Hawaii detected an object with a similar orbit that was preliminary designated as asteroid 2016 BA14. Further observations showed a cometary tail, suggesting the object is a comet and not an asteroid. Did comet 252P split in two? We may find out soon.Comet P/2016 BA14 (Pan-STARRS) will safely pass Earth on March 22,2016, passing even closer than comet 252P. Comet P/2016 BA14 flyby will be at just 2,199,933 miles (3.5 million km) or about 9 lunar distances, which is very close for a comet. In fact, this comet – P/2016 BA14 – will set a record as the third-closest known comet to pass our planet in recorded history.Astronomers have seen a lot of asteroids coming even closer to Earth, but … comets are different. No, there is absolutely no danger to planet Earth, because 9 lunar distances is a very safe distance.
Read more - http://earthsky.org/space/twin-comets-approach-closely-in-march