There it goes.
That small spot moving in front of background stars in the
above video is a
potentially dangerous asteroid passing above the Earth's atmosphere.
This past Friday, the 50-meter wide asteroid
2012 DA14 just missed the Earth,
passing not only inside the orbit of the Moon, which is
for an asteroid of this size, but also inside the orbit of
Unfortunately, asteroids this big or
strike the Earth
every 1000 years or so.
Were 2012 DA14
to have hit the Earth, it could have devastated a
or stuck an ocean and raised
Although finding and tracking potentially dangerous asteroids is a primary concern of modern astronomy,
these small bodies or ice and rock are typically so dim that only a
few percent of them have been found, so far.
Even smaller chunks of ice and rock, like the (unrelated) spectacular meteors that
streaked over Russia and
California over the past few days, are even harder to find --
but pose less danger.