[meteorite-list] 'Tiny' Asteroid to Give Us a Close Shave Today (2014 DX110 AND 2014 EC)

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Wed, 5 Mar 2014 10:06:36 -0800 (PST)
Message-ID: <201403051806.s25I6a1K010450_at_zagami.jpl.nasa.gov>

http://www.slate.com/blogs/bad_astronomy/2014/03/05/asteroid_2014_dx110_tiny_rock_will_pass_the_earth_today.html

'Tiny' Asteroid to Give Us a Close Shave Today
By Phil Plait
March 5, 2014

The near-Earth asteroid 2014 DX110 will pass closer than the Moon today.
You can see it marked in the picture just below center and to the right.


[Image]
Photo by Gianluca Masi, Virtual Telescope Project. Used by permission

[Note the update at the bottom of this post about a second asteroid that
will pass us today.]

At about 21:00 UTC (4:00 p.m. Eastern time) today, the 25-30 meter-wide
asteroid 2014 DX110 will pass just 350,000 km from the Earth - closer
than the Moon!

[Graphic]
An orbital diagram for the asteroid shows it passing so close the labels
for it and Earth overlap. Space is big - that's why it's called "space"
- so in fact it will miss us by a decent margin.
diagram by NASA / JPL

We're in no danger from this rock on this go-round, which is nice; it's
somewhat bigger than the one that exploded over Russia in 2013 so I prefer
it keeps its distance. But you can watch the pass live using the Virtual
Telescope Project, an observatory that will follow the asteroid and send
images out on the web. The picture at the top of this post was taken yesterday,
Mar. 4, 2014, when DX110 was still about 1.5 million km (900,000 miles)
from Earth. It's far too faint to see with the unaided eye even during
this close encounter, so your best chance is to see it online.

You should know that rocks this size pass close to the Earth fairly often,
but rarely hit us - a circle 350,000 km in radius has 3,000 times the
area of the Earth! So we're a pretty small target as things go. Averaged
over time, a 25 meter asteroid is expected to hit us very roughly every
50 years or so, and would generally do so over the ocean and uninhabited
territory. But rocks this size do hit us and eventually one will if we
don't do anything about it. That's why it's something we should be aware
of and working on.

[UPDATE (Mar. 5, 2014 at 17:00 UTC): An asteroid called 2014 EC that was
discovered only last night will pass the Earth just after midnight UTC
tonight, sliding past us at a distance of just 56,000 km (35,000 miles)
above Earth's surface! This rock is roughly 10 meters across - half the
diameter of the Chelyabinsk asteroid. A miss is as good as a mile, as
they say, but it shows that there are lots of these things passing us
all the time. There's aren't more now than there were; we're just getting
better at finding them. Thanks to Ron Baalke for the alert.]

[UPDATE 2 (Mar. 5, 2014 at 17:05 UTC): ...and no sooner do I write the
above update that I find out that 2014 EC has a very, very tiny chance
of hitting the Earth in 2025. I do mean tiny: the chance is only about
1 in 2.7 million. Almost certainly, as more observations of this small
rock are made, the chance of an impact will drop even farther; I explain
how this works in an earlier post. No need to panic over this one.]
Received on Wed 05 Mar 2014 01:06:36 PM PST