By now everyone has either seen, or is at least aware of, the 1998 motion picture Armageddon.
To quickly recap: after a massive meteor shower bombards Finland & New York City…
(why is it that New York City always gets the short end of the stick relative to major disasters? I Am Legend? Planet Of The Apes? 1,000 other movies? But I digress),
…NASA discovers that a rogue comet passing through the asteroid belt pushed forward a large amount of space debris, including a Texas-sized asteroid that will collide with Earth in 18 days, creating worldwide extinction.
What is NASA’s solution to this situation, you ask?
They decide a team of blue-collar, ragtag oil drillers (led by Bruce Willis and the dreamy Ben Affleck) will fly into space, land on the asteroid, drill a massive hole in the asteroid, proceed to drop a nuclear bomb in the hole and then fly back to Earth but not before detonating the bomb before it passes ‘zero barrier’, sparing the Earth from complete and total Armageddon!
Even as far-fetched as that may sound, the mission is somehow a success. The catch, however, is Bruce Willis must detonate the bomb from the asteroid because the bomb’s remote detonator was destroyed as the team of oil drillers were in the process of landing on the asteroid after having to ‘slingshot’ around the moon in order to properly land on the giant space rock.
So this being Hollywood, Bruce Willis gets to save the world (literally) and his soon to be son-in-law (the aforementioned dreamboat himself Ben Affleck) from peril as his daughter Grace (played by Liv Tyler) tearfully watches from the NASA control room (but not before perishing in the explosion after pressing the button on the detonator with what appears to be no more than 2 seconds left before the asteroid passes ‘zero barrier’).
Whew! My astronomy professor here at UA did not have the best opinion on the movie. This YouTube clip, pointing out the literally thousands of mistakes in the movie, speaks to the larger point he was making
But, what if this scenario actually came to fruition?
In a way, it almost did last week.
On Thursday night, the 14th of Feb., a meteor was seen streaking through the sky above the town of Yekaterinberg in Russia. It hit the ground (possibly landing in a lake) near another city, Chelyablinsk. It is thought to be the biggest meteor to hit Earth in more than a century. The shock wave it caused as it passed overhead blew out windows and injured hundreds of people.
Moreover, at the same time, a 50 meter-wide asteroid called 2012 DA14 was zipping past Earth inside the orbit of some man-made satellites, marking the closest shave on record for an asteroid of that size. To put it in perspective, this asteroid was 150 feet wide, while the one Bruce Willis blew up was 1,382,288,793 feet wide (the actual square footage of Texas).
All joking aside, this brings up a serious issue.
This pair of unrelated events should focus minds, and not just among the small group of astronomers who have been worrying about asteroid strikes for many years. The first line of defense, as always, is knowing your enemy.
To that end NASA has been watching the sky since 1998, trying to detect any chunks of rock whose orbits bring them close to Earth. These rocks are known as near-Earth objects (NEOs).
A recent article published by The Economist takes a look at what counter measures are being considered if this Armageddon scenario did in fact play out.
NASA reckons it has now tracked down around 90% of the very biggest NEOs, the “planet killers” a kilometer or more across. (The asteroid that wiped out the dinosaurs is estimated to have been 7-10 km across.) These heavyweights account for around 10% of the 10,000 or so known NEOs. Most, like 2012 DA14, are smaller. This makes them less dangerous, though they would still do a lot of damage if they were to hit a town or city. It also makes them harder to spot.
As the article points out, the movie Armageddon has the pleasing symmetry of using one doomsday scenario to avert another, i.e. – using a nuclear weapon to actually avoid complete human extinction.
But as the research indicates, this approach would be problematic. A nuclear explosion might simply fracture a large asteroid into several smaller ones, which could still hit Earth. Legal pedants might also point out that the 1996 Comprehensive Test Ban Treaty bans nuclear explosions in space.