The chance of a city-killing asteroid striking Earth is
higher than scientists previously believed, a non-profit
group building an asteroid-hunting telescope said today.
A global network that listens for nuclear weapons detonations
detected 26 asteroids that exploded in Earth's atmosphere
from 2000 to 2013, data collected by the Comprehensive
Nuclear Test Ban Treaty Organization shows.
include the February 15, 2013, impact over Chelyabinsk,
Russia, which left more than 1,000 people injured by flying
glass and debris.
"There is a popular misconception that asteroid impacts are
extraordinarily rare ... that's incorrect," said former
astronaut Ed Lu, who now heads the California-based B612
The foundation today released a video visualization of the
asteroid strikes in an attempt to raise public awareness of
Asteroids as small as 40m- less than half the size of a
football field - have the potential to level a city, Lu told
reporters on a conference call
"Picture a large apartment building - moving at Mach 50," Lu
Mach 50 is 50 times the speed of sound, or roughly 61,250
NASA already has a program in place that tracks asteroids
larger than 1 km. An object of this size, roughly equivalent
to a small mountain, would have global consequences if it
An asteroid about 10 km in diameter hit Earth some 65 million
years ago, triggering climate changes that are believed to
have caused the dinosaurs - and most other life on Earth at
the time - to die off.
"Chelyabinsk taught us that asteroids of even 20-metre size
can have substantial effect," Lu said.
City-killer asteroids are forecast to strike about once every
100 years, but the prediction is not based on hard evidence.
B612 intends to address that issue with a privately funded,
infrared space telescope called Sentinel that will be tasked
to find potentially dangerous asteroids near Earth. The
telescope, which will cost about $250 million, is targeted
for launch in 2018.
B612 takes its name from the fictional planet in the book
"The Little Prince," by French author and aviator Antoine de