Friday, January 27, 2012

2012 BX34 - Close Approach

Today, January 27, 2012 at about 15:25 UT, the asteroid designated 2012 BX34 will pass only 59,044 km (36,750 miles) or about ~0.2 lunar distance (or 0.0004 AU) above the Earth's surface. The asteroid was discovered by Catalina Sky Survey with a 0.68-m Schmidt + CCD on January 25, 2012 at magnitude ~20.

According to its absolute magnitude (H=27.6) this asteroid has an estimated diameter of roughly 8-18 meters, so it is very small. We have been able to follow-up this object few hours ago remotely from the GRAS Observatory (near Mayhill, NM) through a 0.10-m f/5 reflector + CCD. 

At the moment of our images from New Mexico on January 27, 11:04UT, "2012 BX34" was moving at about ~318.86 "/min and its magnitude was ~15. At the moment of its close approach around 15UT of today, 2012 BX34 will be bright as magnitude ~13.8 and moving at ~1810 "/min.

Below you can see a single 120-seconds exposure showing the object as a ~11-arcminutes trail (due to its fast speed). Click on the thumbnail to see a bigger version:


While this is an animation showing the object moving among the field stars. Each image was a 120-second exposure. Click on the thumbnail to see a bigger version:




While there is no cause for concern, this is one of the closest approaches recorded. The table below shows the top 20 closest approaches by NEOs (Near-Earth Objects) sorted by nominal distance. The table has been computed on the NASA/Neo-JPL website (the event that took 2008 TC3 into the earth's atmosphere is not included). Click on the thumbnail to see a bigger version:



by Ernesto Guido, Giovanni Sostero & Nick Howes

9 comments:

Robert T. said...

Just because I don't know, why isn't an object this small and passing this close captured by Earth's gravitational field?

NickAstronomer said...

Velocity and trajectory are not ones which would permit orbital capture

Matthew Nuckolls said...

Gravity alone doesn't actually capture objects in free fall. This guy is close enough that our gravity is bending his path, but a capture would require other factors.

Anonymous said...

Speed. It is moving too fast relative to the Earth to be caught by the gravitational field.

dhughes said...

The escape velocity of earth is only 11 km / s at the surface and decreases with the square of distance. The moon orbits at 1 km/s for example. Anything faster than the escape velocity doesn't get captured.

Eric Fleet said...

Because it is moving way too fast. Our gravity will change its trajectory, but not enough to capture it.

Anonymous said...

@Robert T. It is because of it's speed. Without getting into physic formulas, since it comes real fast, it got too much kinetic energy and simply gets slingshotted in another direction.

Robert T. said...

Thanks, that all makes sense (and that was my best guess). I'm an author, not an astronomer as you can figure out by that question. Keep up the good work, I like reading this blog

questorthews said...

I am wondering, if i am seeing things correctly. As i was studying the short clips, i noticed two other objects moving in the slides. Not moving like the astroid but on and off and shifting. The first is just off the left side of the bright object on the left. (if you zoom in, look just past the 3 little stars on its left and you can see it moving) the Second is directly above the larger bright spot by the top of the frame) both seem to be moving to me. Maybe more astroids?