Asteroid Day

June 30 the 108th anniversary of the Tunguska Event, a large explosion which flattened almost 200,000 hectares of Siberian forest. For many years, the cause of the event was controversial, but is now generally agreed to have been a small meteor exploding as it grazed Earth’s atmosphere.

In February of 2013 a similar event occurred, this time near the Russian city of Chelyabinsk. Instead of exploding over uninhabited forest, it injured 1500 people and caused severe economic damage to many, many more. Despite a century of warning, humanity didn’t learn.

Today, I’m asking you to change that.

Meteor explosions release as much energy as atomic bombs. In fact, they are frequently detected by the systems used to watch for illegal nuclear testing above Earth’s surface. Here are the explosions detected during my lifetime, up to the Chelyabinsk event:

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Only one of these asteroids exploded sufficiently close to population centers to cause significant damage, but it was only a matter of time until one hit a city. Three years later, we’re no closer to preventing this from happening again.

Asteroid impacts are neither the most damaging nor the most frequent natural disasters. They are, however, the only one which can be prevented by entirely technological means. Given sufficient time and warning, we can deflect an asteroid of any size from its Earth-impacting trajectory. The technical problems are not particularly difficult–such a mission would be simpler to design and execute than some of our more complicated science probes.

No, technology is not the problem. Social will, is. Planetary defense is no ones jurisdiction, and few are willing to take up responsibility for it. The B612 Foundation launched Asteroid Day in 2014  to remind the world that it’s only a matter of time before another Chelyabinsk. Will your city be next?

I’d rather not find out. The more we learn about the asteroid population of the inner Solar System, the more obvious it becomes that humanity is living on borrowed time.

Planetary defense is a species-level concern, and so far there’s been very little effort on the part of governments or the private sector to deal with it. The most promising project to date is the B612 Foundation’s Sentinel Space Telescope, now tentatively scheduled to launch in 2019. Without adequate funding, it will be delayed yet again, leaving Earth vulnerable to sunward asteroids yet another year. You can donate to the project here.

If you live in a democracy, consider writing your legislators about the importance of planetary defense. Protecting Earth from external threats is one of the few things governments should unambiguously be concerned with, but so far very little action has been taken.

Finally, think about joining the thousands of scientists, astronauts, and private citizens who have signed 100X Declaration. To date, we’ve observed about 1% of the estimated Near Earth Asteroids. This petition calls for us to find the rest, quantifying the threat once and for all.