One bad day is all it takes for an asteroid to set off a mass extinction. But Asteroid Day – which falls on Thursday this year – is set aside as one good day to focus on the effort to head off future bad days, and even take advantage of the riches that near-Earth objects can offer.
“Our goal with Asteroid Day is to dedicate one day each year to learn about asteroids, the origins of our universe, and to support the resources necessary to see, track and deflect dangerous asteroids from Earth’s orbital path,” Brian May, the guitarist/astrophysicist who co-founded the Asteroid Day campaign, said in a news release marking the occasion.
Hundreds of museums and science centers around the globe, including Seattle’s Museum of Flight, are joining in the campaign. The museum will be live-streaming Asteroid Day video presentations and offering family activities to raise awareness about asteroids on Thursday.
This year, Asteroid Day’s organizers also have rolled out a seven-part YouTube video series that explains the threat – and the solutions that are within our reach.
The Slooh online observatory will also present a four-hour video marathon starting at 4 p.m. PT, in cooperation with the Science Channel. (You can watch the show via YouTube if that’s your preference.)
Asteroid Day made its debut last year, and the plan is to hold commemorations every year from now on to mark the anniversary of the 1908 Tunguska explosion, when a meteor blasted half a million acres’ worth of Siberian forest.
More recently, an asteroid blew up over the Russian city of Chelyabinsk in 2013, causing hundreds of injuries – but thankfully, no deaths.
Asteroids are known to have been death-dealers in the past. Sixty-five million years ago, an asteroid strike just off the Yucatan Peninsula did in the dinosaurs and most of Earth’s other species, clearing a path for the rise of mammals like us.
Scientists now estimate that asteroids capable of destroying a city may run into our planet once every century or two, on average. Many of those impacts occur in out-of-the-way places and don’t attract much notice at the time, like the Tunguska event. But experts say it’s only a matter of time before a near-Earth object targets a populated area.
What is to be done? Assessments of the asteroid threat have recently been the subject of a debate sparked by Seattle tech pioneer Nathan Myhrvold, but no one questions that the threat should be addressed.
The first step is detection: Telescopes on Earth and in space already have spotted thousands of near-Earth objects. So far, none of them appear to be on a threatening course, but more capable instruments will be required to detect asteroids toward the lower end of the threat scale.
Next-generation asteroid detectors include the Pan-STARRS telescope system in Hawaii and the Large Synoptic Survey Telescope in Chile, currently under construction. One of the organizers of the Asteroid Day proceedings, the B612 Foundation, has been trying to raise money for a Sentinel Space Telescope to detect asteroids. Meanwhile, NASA is considering an asteroid-hunting space mission known as NEOCam.
Diverting potentially threatening asteroids is another matter entirely: Experts are still debating the best way to do it. One strategy involves sending up a massive spacecraft to just hang out near the asteroid, serving as a “gravity tractor” to move the object out of harm’s way. Another strategy would slam a projectile into the asteroid. The European Space Agency is considering a project called the Asteroid Impact Mission, or AIM, to test the concept.
NASA’s Asteroid Redirect Mission, currently slated for the mid-2020s, could provide additional insight into how to divert an asteroid to save the world. And if it came to an “Armageddon” scenario, some scientists have acknowledged that nukes might be needed.
Near-Earth objects needn’t always be seen as a threat. Another NASA mission called OSIRIS-REx, due for launch in September, will land on an asteroid and send a sample back to Earth for study. OSIRIS-REx’s scientists are expected to learn more about what asteroids are made of, and how that relates to the origins of the solar system.
Commercial ventures such as Planetary Resources (based in Redmond, Wash.) and Deep Space Industries plan to capitalize on the resources available on asteroids for deep-space mining. The most valuable resource may well be water ice: That H2O can be converted into drinkable water, breathable air and the rocket fuel that space travelers will need when they push farther out into the solar system – perhaps to keep an eye out for future threats, or opportunities, in the skies.