Thursday, January 31, 2013

We're All Gonna ... Nevermind: Feb. 15, 2013 Edition

Looks like we're in for another close pass by a big chunk of space debris:

Talk about a close shave. On Feb. 15th an asteroid about half the size of a football field will fly past Earth only 17,200 miles above our planet's surface. There's no danger of a collision, but the space rock, designated 2012 DA14, has NASA's attention.

"This is a record-setting close approach," says Don Yeomans of NASA's Near Earth Object Program at JPL. "Since regular sky surveys began in the 1990s, we've never seen an object this big get so close to Earth."

Record Setting Asteroid Flyby

The new, digital NASA even has an online video to talk about it, which is where this diagram of 2012-DA14's close approach to earth came from:

Image credit: Screenshot of this NASA video by Cujo359

So, yes, once again we will not get to see earth-shattering explosions happen, unless, of course, we like what passes for science fiction cinema these days. As the graphic shows, the asteroid will pass closer than geosynchronous satellites, but well above the International Space Station (ISS) or the Hubble Space Telescope, so there's not much danger there, either. (Well, maybe not "shows" as "implies. See UPDATE/NOTE1.)

What would have happened had this asteroid hit the Earth? It would have been extremely unpleasant for some of us:

The impact of a 50-meter asteroid is not cataclysmic--unless you happen to be underneath it. Yeomans points out that a similar-sized object formed the mile wide Meteor Crater in Arizona when it struck about 50,000 years ago. "That asteroid was made of iron," he says, "which made it an especially potent impactor." Also, in 1908, something about the size of 2012 DA14 exploded in the atmosphere above Siberia, leveling hundreds of square miles of forest. Researchers are still studying the "Tunguska Event" for clues to the impacting object.

"2012 DA14 will definitely not hit Earth," emphasizes Yeomans. "The orbit of the asteroid is known well enough to rule out an impact."

Record Setting Asteroid Flyby

As this photo I took of the meteor that hit Meteor Crater, shows, that was, indeed, made of metal, which made it a more formidable projectile. 2012 DA14 is made of stone, so probably would break up more before reaching the surface.

The main reason I mention this is that, for some reason, the article on this subject is "embargoed", to use their terminology from the front page. I'm not sure why that is, but it doesn't appear to be the work of some doomsday cult.

UPDATE/NOTE 1: Well, actually, the graphic doesn't show low earth orbit, largely because it's so near the Earth on that scale that you probably couldn't see it. The ISS is roughly 200 miles (let's say roughly 300 kilometers) above the Earth's surface. That's well below where the asteroid will be passing us.


Paul Sunstone said...

I wonder if there will be a panic about the asteroid even though NASA assures us it will not hit the earth? People have a strange desire for stories of doom.

Cujo359 said...

I suspect it's some copyright issue, but who knows? It might also be that there was some related information in the article that, on second thought, they weren't sure was properly sourced.

Expat said...

Doesn't the prevalence of innumeracy just leave you just shaking with confidence?
Like that silly screw thingy on the Hubble telescope.
First thing I'd like to know if the folks making these calculations have balanced checkbooks.
Thanks for the heads up.

Cujo359 said...

As Henry Patrowski wrote once upon a time, To Engineer Is Human. Engineers and scientists miscommunicate requirements, and make other mistakes, just like everyone else. When it's not possible to discover and fix those mistakes until the machine is in orbit, it's just a whole lot more obvious that you screwed up.

Thorough design review and testing are the ways to avoid these problems. Unfortunately, when budgets get tight, these are usually the first things to see cutbacks.

NASA has an amazing record, when you compare it to other space agencies' achievements, and when you consider the environment it works in.

Expat said...

My bad, target was not engineers or scientists being human. Target was those calculating orbits, particularly orbits that guarantee a MISS. Something about a false-positive isn't as reassuring as it would sound.

A few years ago IIRC another situation about orbits had 'Houston' calculations being corrected by Russian mathematics which introduced some doubt into the π (Honestly don't recall the details but that was the gist). The state of the nation's education leaves little reassurance as do reports of cheating at Harvard.

NASA is a treasure, no disputation.

Expat said...

Serendipitously found in the bookshelves:
Lucifer's Hammer
by Larry Niven and Jerry Pournelle
(ISBN 0-449-23599-8)
and wondered if you have experienced the book.
Best read before 15/02/2013

Cujo359 said...

I read that one a long time ago. It's scary, yet it might be optimistic compared to what would actually happen.

Another science fiction treatment of the idea is Micheal Flynn's Firestar series. It's not about an asteroid hitting the Earth, but rather, an attempt to prevent such things from happening. While I'm not big on the libertarian solutions proposed, he shows a pretty thorough understanding of the situation, and why we're here.