When you can see the asteroid passing close to Earth
The asteroid called 2004 BL86 came closest to Earth at 10:19 a.m. Central time Monday, January 26, 2015, but the best viewing was actually expected to be nine to thirteen hours later. The asteroid was about 745,000 miles from Earth; that’s about three times as far away as the moon.
It’s a big chance for scientists and enthusiasts to get a relatively close view of a large asteroid. Although 2004 BL86 is about one-third of a mile in diameter, not much was expected to be visible when it came closest to Earth. It was dim because only part of the illuminated side was visible.
The good news for skywatchers: More of the illuminated side would be visible later, when the sun was behind us, so the asteroid was expected to get brighter as it gets farther from Earth. That makes the best chance for viewing 2004 BL86 in the eastern sky between 7 p.m. and midnight Central time Monday evening, January 26.
You’ll still need a telescope to see 2004 BL86; some say binoculars might work but Sky & Telescope magazine recommended a three- or four-inch diameter telescope.
Before that time, Gianluca Masi’s Virtual Telescope site planned to live stream the asteroid starting at 1:30 p.m. Central time. To watch that stream, click here. Slooh Observatory teamed up with NASA to offer a special webcast about the asteroid on their website – click here.
2004 BL86, which was discovered January 30, 2004, won’t get that close to Earth for at least the next 200 years according to NASA.