Swing and a miss!

http://www.universetoday.com/2009/11/09/su...d-buzzed-earth/

We will apparently be seeing 2009 VA again in the 2020s and 2030s. Also, here's the orbital diagram.

Sorry, but we will probably never be seeing it again, ever. It was poorly observed near closest approach. Unless someone has observations they have not yet turned in (a possiblility), then we're stuck with an orbit with large error margins. It is too close now to the sun to be observed, and will be too faint to see (25th magnitude) when it is back in view. And its sky location is already uncertain by a degree.

There is a 4% chance it will come within 0.2 AU of earth in 2026, and 3% in 2030. It will have to get a lot closer than that, and in the right part of the sky, to be bright enough for a survey to stumble on it again. That's even if PanSTARRS is up and running. 2009 VA is a tiny object.

I googled around and looked for info in NASA NEO site, but couldn't find any statistical data, so I'm asking it here:
how much part of the sky, and for how long in a day is monitored for approaching NEOs? I was quite surprised by the asteroid passed half the GEO orbit near Earth some days ago, being spotted only a few hours before it reached minimum distance, as I thought the sky was constantly monitored for such events.
Is it not?

Although there are constantly people looking at some part of the sky, the entire sky is not photographed continuously, and faint objects can (and, most often, do) slip by unobserved, or are only seen within hours of their closest approach. And don't forget that we basically have no hope of spotting previously undiscovered things that are coming at us from the dayside of Earth! But these faintest objects that are only discovered within hours of their closest approach are also the smallest and, if they were to hit us, would explode in the atmosphere on their way down; any damage on the ground is caused by direct hits from flying debris, rather than from impact effects. Larger objects are brighter and therefore discovered earlier. Only one asteroid has ever been discovered before it became an impactor -- 2008 TC3.

Far as I know, it is not.

Although Pan-STARRS would do it, if it actually gets built.

http://pan-starrs.ifa.hawaii.edu/public/as...oid_threat.html

WISE, which should launch next month, ought to give us a MUCH better picture of what we're up against, at least.

http://wise.ssl.berkeley.edu/mission.html

--Greg

Sky Coverage from the IAU Minor Planet Center

Another nice meteor trail:
http://www.ksl.com/?nid=148&sid=8714738
and
http://www.heliotown.com/FB20091118_0707utAshcraft.mp4

I see we have a couple of new units of measure.

Microwave (Sojourner) and Washing Machine (Deep Imapct Impactor) are already on the official (but non existent) NASA scale of size objects list

Others I know of...
Golf Cart ( MER )
Mini Cooper ( MSL )
School Bus ( Cassini )
Squash Court ( Eagle Crater )
Utah ( Hematite & Meridiani )

Thrust should be expressed in the weight of a piece of paper, or multiples of Jumbo Jets.

All rocks, described in terms of the closest representing piece of fruit.

Also any extremely elongated asteroid is described in multiples of "Manhattan" with Eros being the most commonly mentioned body as "twice the size of Manhattan".

The amount of propane in the atmosphere of Titan is measured in Labor Day Barbecues.

I wonder how many Labor Day Barbecues of fuel are needed to provide enough Jumbo Jets of thrust to propel a Washing Machine to Ludicrous speed.

As soon as Spirit is making progress extracting herself from Troy, I don't mind new references been invented.
In France a very little distance is said as been "1/4th of a fly ass hair" (sorry for the rude reference)

That's OK, we're used to rude Frenchmen.

Excuse me, but on the ships I sailed the proper term for a small quantity was 'half a gnat's cock'.