Today marks the third annual celebration of Asteroid Day, a holiday created by filmmaker Grigorij Richters, astrophysicist Rusty Schweickart and Queen guitarist and big-haired astrophysicist Brian May to raise awareness about the awesomeness of asteroids and the threat they pose to the planet. As Stuart Clark at The Guardian reports, this year the celebration is being presented by the United Nations, and will include about 1,000 local asteroid-themed events around the world. Even if there’s no asteroid party nearby, everyone can celebrate with a 24-hour livestream that began broadcasting last night.
According to Matthew Reynolds at Wired, the livestream originates from Broadcasting Center Europe in Luxembourg includes talks by popular physicist and author Brian Cox, NASA astronaut Nicole Scott along with many other leading scientists and space nuts. There are funny clips on how to survive an asteroid strike as well as YouTube hosts showing their reactions to a virtual reality asteroid collision.
NASA has also contributed a two-hour show about its missions to study asteroids and other Near Earth Objects (NEOs). “At NASA, every day is an asteroid day,” NASA planetary defense officer Lindley Johnson tells Reynolds. “But we value the international collaboration for a designated day to call attention to the importance of detecting and tracking hazardous asteroids.”
The threat isn’t some far-fetched Hollywood scenario. The organizers chose June 30 for Asteroid Day because it’s the date of the Tunguska Event, which took place in Russia in 1908. On that day, something exploded over remote forests with an atomic-bomb-sized blast, knocking down and scorching 60 million trees over an 800-square-mile area. While there are fringe theories that it was aliens (isn’t it always?), a mini-black hole or anti-matter, most scientists believe the event was caused by a tiny comet or asteroid about a third the size of a football field hitting Earth’s atmosphere.
According to the Asteroid Day site, NEOs, including asteroids and comets, are all around us and bombard the Earth every single day. While most asteroids in the solar system orbit the sun in a rocky ring between Mars and Jupiter and in the Kuiper Belt, a jumble of ice, rock and minor planets (hello, Pluto and DeeDee!) beyond Neptune, there is also a swarm of NEOs left over from the Solar System’s formation that orbit the sun and occasionally cross Earth's path. These range from grains of dust to asteroids that are miles across.
Statistically, a 30,000-foot-diameter, civilization-ending asteroid hits the Earth every 100 million years. One the size of the Tunguska meteorite hits once every 150. But the asteroids aren’t on an exact timetable, and the big one could come at any time. That’s why in recent years the idea of Planetary Defense has become a big deal. In 2016 NASA established its first Planetary Defense Coordination Office to pull together and sync efforts around the globe to find and track potentially harmful asteroids. Finding a threatening asteroid years before it hits could give humanity time to prepare for the strike or even to stop the impact.
Currently, we have no technology available to prevent a strike. Last December, NASA researcher Joseph Nuth and colleagues suggested that humanity build two spacecraft and keep them at the ready in case we detect a planet killer. The first spacecraft would be used to get a closer look at the comet or asteroid. The second would carry some sort of technology to redirect the space rock away from Earth. Nuth says having the rockets on hand could cut humanity's preparation time down from five years to 12 months.
And we might need something soon. According to NASA there are around 1,648 NEOs classified as Potentially Hazardous Asteroids, which have the potential to hit Earth in the future. Not all such space rocks will strike the planet, but they orbit closely enough to warrant monitoring. Just this week, astronomers revealed they cannot rule out an eventual impact with the asteroid Apophis. In 2029 and 2036 the asteroid will make close approaches to Earth, but will not hit us. But because of the chaotic orbit of this 1,000-foot diameter rock, they cannot rule out potential impacts in the future.
Never fear: NASA is on the case. And hopefully by the time one of these space rocks make their approach, we will be ready and waiting.
Happy Asteroid Day!