Greetings fellow astrophiles!
The Voyager delivery accuracy at Neptune of 100 km (62 mi), divided by the trip distance or arc length traveled of 7,128,603,456 km (4,429,508,700 mi), is equivalent to the feat of sinking a 3630 km (2260 mi) golf putt, assuming that the golfer can make a few illegal fine adjustments while the ball is rolling across this incredibly long green.
I include this piece of historical content to put into context any discussion about a 2012 DA14 impact (which, at this point, falls clearly into the conspiracy theory regime). The world has a very good handle on Newtonian Mechanics and, when it is reported by NASA physicists that something is going to miss the planet by 27,000 km (OK, fine. 27,000 km from the Earth’s center. As the point on the Earth’s surface farthest from the Earth’s center is 6,384 km away, DA14 will miss by “only” 20,616 km), you can believe it. If we can be off by 100 km after 12 YEARS in space, be assured we can be within that same 100 km with a year’s worth of data collection.
With the good news out of the way…
As the newest reports about 2012 DA14’s path make clear, its passing within geosynchronous orbit will be a treat for observers in Indonesia and an otherwise great view for Europe, Asia, and Africa. And by great, I mean that the predicted apparent magnitude will not reach smaller than 7.4 (smaller = brighter. Naked Eye viewing trails off rapidly after magnitude 4, making 2012 DA14 a “big binocular” object even at its closest approach. The Sun, on the other hand, is at magnitude –26.74 from Earth), so it will be great with the aid of optics. CNY, and the Americas in general, will only be able to observe 2012 DA14 on its “way out,” after closest approach. As it will be moving at quite a clip away from us, it will be quite a difficult object in CNY to find for anyone outside on the night of the 15th. Reports seems to indicate it will be at magnitude 11 by the time the East Coast could see it, which is a heroic magnitude for most any amateur telescope).
CAPTION: Path of 2012 DA14 (in Universal Time (UT) and as viewed from the Earth’s Center) on February 15/16. Click for a full-sized version. From www.virtualtelescope.eu.
And, if you’re still freaked out about impact, note that we (CNY) will STILL be on the wrong piece of Terran real estate. That said, its trajectory is even wrong for colliding with geosynchronous satellites, so your cell phone service won’t be impacted, either.
I am pleased to report that the best 4 minute discussion of 2012 DA14 has been put together by an organization I’ve been a member of for over 15 years – The Planetary Society (co-founded by Carl Sagan, currently CEO’ed over by Bill Nye, the list of activities in space science and public outreach is considerable). Bruce Bett’s youtube video is provided below. If Snow Storm Nemo has anything to say about it, you’ll have plenty of time this weekend to watch and take notes.
CAPTION: Planetary Society Director of Projects Bruce Betts reassures us in this brief and fascinating explanation of what will happen–and what WON’T happen–when this big asteroid comes closer to Earth than many satellites.
You can read a full article about 2012 DA14 at the Planetary Society website: www.planetary.org/explore/projects/neo-grants/2012da14.html. A thorough FAQ can be found at www.planetary.org/explore/projects/neo-grants/2012-da14-faq.html.