Nuclear explosion detection system tells us how many big asteroids hit the Earth (it's a bit scary)
The B612 Foundation was created by astronauts Ed Lu and Rusty Schweickart to find a way to stop dangerous asteroids from impacting Earth. They saw our fragile blue planet from space, and they knew of the grave dangers of asteroid impacts (just look at the craters in the moon). While the dinosaurs couldn't do anything to prevent their demise from space rocks, we can do something... If only we put some resources into detecting all potentially dangerous asteroids long-enough in advance and develop the capacity to deflect them if necessary. Right now even if we knew a big one was coming, it would take us years to launch a mission, and that might not be fast enough.
If you're wondering about the name of the foundation, it's the home asteroid of the hero of Antoine de Saint-Exupéry's The Little Prince.
Little Prince book cover/Promo image
Asteroid strikes that are as big as nuclear bombs are not particularly rare, as you can see on the map above. Using a system that was designed to detect nuclear explosions and triangulate their size and location, we can know how many big asteroids have hit the Earth since 2000. Thankfully, really big impacts are much rarer, but given enough time, one will take place somewhere densely populated, that's guaranteed. Just last year we had a warning when a meteor exploded above a Russian city...
You can see the full-size version of the map above here.
This video gives a good explanation of the recent asteroid impacts:
How can we protect ourselves (and other living creatures on Earth by the same token)? The B612 Foundation wants to launch an infrared space telescope called Sentinel that would give us early warning and give us enough time to deflect the incoming rock. Here's Sentinel:
Sentinel is a mission of mapping and discovery. Mapping the great unknown of the inner solar system is the first step in protecting the Earth from asteroid impacts and in opening up this next frontier. By observing in infrared, Sentinel will discover more than 20,000 asteroids in just the first month of operation – more discoveries than all other telescopes combined have managed to discover in the last 30 years – and over 6.5 years will locate and follow the trajectories of more than 90% of asteroids larger than 140 meters.
The Sentinel Space Telescope will take about four years to build and test, with a scheduled launch in 2017-18, aboard a Falcon 9 rocket. After 6.5 years of operation, Sentinel will discover about 500,000 NEAs. Sentinel will compile the definitive catalog of NEAs, and within a few years nearly all NEAs known to humanity will have been discovered by Sentinel (more than 98% after 6.5 years).
Here's a view of asteroids in our solar system (kind of crowded in there, no?):
Obviously, the goal is to avoid something like this:
Here's a list of all the impacts between 2000 and 2013. Note how powerful each explosion was (a kiloton is equivalent to 1,000 tons of TNT explosives - note that the nuclear bomb that was dropped on Hiroshima during WWII had a power of about 16 kilotons of TNT):
8/25/2000 (1-9 kilotons) North Pacific Ocean
4/23/2001 (1-9 kilotons) North Pacific Ocean
3/9/2002 (1-9 kilotons) North Pacific Ocean
6/6/2002 (20+ kilotons) Mediterranean Sea
11/10/2002 (1-9 kilotons) North Pacific Ocean
9/3/2004 (20+ kilotons) Southern Ocean
10/7/2004 (10-20 kilotons) Indian Ocean
10/26/2005 (1-9 kilotons) South Pacific Ocean
11/9/2005 (1-9 kilotons) New South Wales, Australia
2/6/2006 (1-9 kilotons) South Atlantic Ocean
5/21/2006 (1-9 kilotons) South Atlantic Ocean
6/7/2007 (1-9 kilotons) Finland
8/9/2006 (1-9 kilotons) Indian Ocean
9/2/2006 (1-9 kilotons) Indian Ocean
10/2/2006 (1-9 kilotons) Arabian Sea
12/9/2006 (10-20 kilotons) Egypt
9/22/2007 (1-9 kilotons) Indian Ocean
12/26/2007 (1-9 kilotons) South Pacific Ocean
10/7/2008 (1-9 kilotons) Sudan
10/8/2009 (20+ kilotons) South Sulawesi, Indonesia
9/3/2010 (10-20 kilotons) South Pacific Ocean
12/25/2010 (1-9 kilotons) Tasman Sea
4/22/2012 (1-9 kilotons) California, USA
2/15/2013, (20+ kilotons) Chelyabinsk Oblast, Russia
4/21/2013 (1-9 kilotons) Santiago del Estero, Argentina
4/30/2013 (10-20 kilotons) North Atlantic Ocean
So what can you do? Well, B612 is a non-profit, so if you want to give them your spare change to help defend Earth against space rock, you can do so here.
Via B612 Foundation