The Night Sky Guy

Two Meteors Make Close Approach

Earlier Monday (May 28) a 26 meter wide, newly discovered asteroid dubbed 2012 Kp24 safely zipped by Earth at about 14,000 miles distance.  At its closest point it was more than one full diameter of Earth away from us. Earlier in the day backyard astronomers managed to snag an image of the interloper while it was still 350,000 km from Earth using his telescope and CCD imager.

Hot on the heels is a fresh discovery made in the early hours of Monday that is even a closer call,  a smaller asteroid 2012 KT42. While the orbital data is still preliminary it looks like this mini-van sized space rock will pass unusually close to Earth – about 8,700 miles above our atmosphere. This puts it at about 5% the distance of the Moon and makes it the 6th closest approach of an asteroid ever recorded by NASA.

Check out the full table of close calls here.

At its closest approach to Earth at about 3 am ET May 29th it will become about 12th Magnitude and be in the constellation Pisces , putting it in the range of backyard telescopes and an easy target for scopes with CCD imagers.  For those interested in plotting it on sky charts here are its orbital elements. Also fro more images and animation of the meteor click here. Its moving so fast – at about 2 arc-minutes per second – that you should be able to detects movement at the telescope eyepiece.

Here are two wide-angle star charts to give an idea where in the sky it will be traveling . Viewing Tip: Best chance to catch this small asteroid is to use a medium to large telescope (8 to 16 inches) at peak brightness. Which means that the Pisces constellation needs to be above your local horizon at 3 am Eastern Time (12 am Pacific Time)…

UPDATE:  forgetaboutit.. updated orbital data makes transit unviewable as disk is 0.006″ not 6″!  Also reports indicate that the asteroid will transit in front of the sun at 10:10 UT May 29th. It’s silhouette would be teeny-tiny at only 6 arc-seconds…about as small as the disk of planet Mars can appear through a telescope.

Here is where it would be visible:

credit: Aldo Vitagliano

While this all sounds scary to some folks, there is really not much to worry about with this rock. Even if the orbital data does end up being tweaked such that it is on a collision course – it’s way to small to cause any damage as it would probably break up in the atmosphere before it makes it to the ground. Observers would mostly likely only experience a super-bright meteor- that’s it.

Also this two back to back findings may seem odd at first glance but the reason we are hearing more about these close call asteroids is that our telescope surveys are becoming more sensitive to smaller objects farther out than ever before and are able to hunt down those that are only the size of cars to houses- which there are many, many more of than the larger, potentially dangerous ones.

While we did not get much warning about this asteroid , just remember it’s too small to hurt us.  But today is a great proof of concept for these telescopic surveys that catalog potentially hazardous asteroids – they do in fact work. And when there is the ‘big one’ heading our way – the idea is that they find it in time for us to do something about it.

You can think of today’s close call as target practice for asteroid hunters.

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