This miss might have been a big hit

Supporting Hawking’s theory, the Earth has had a near miss this week when a huge asteroid whizzed past on Monday, less than 50,000 miles away. The asteroid – about the size of a 10-storey building – flew past the Earth at roughly twice the distance of the highest Earth-orbiting satellites, according to website space.com.

It is similar in size to a rock that exploded above Siberia in 1908, flattening 80 million trees across an 800 square mile area.

Asteroid 2009 DD45 was closest to the earth on Monday at around 8.30am, at just under 45,000 miles above the surface of the planet. Astronomers knew it was coming after it was spotted last Saturday as a faint dot showing up in pictures at the Siding Spring Observatory in Australia (image right). There was never any risk of collision, experts said, but anything flying within 50,000 miles of the Earth is taken very seriously.

The closest listed “flyby” to Earth by an asteroid happened in March 2004 when a small one – 2004 FU162 – measuring about 20 feet across came within about 4,000 miles of the earth..

It is thought the collision of a rather smaller body with the Earth, about 70 million years ago, was responsible for the extinction of the dinosaurs. A few small early mammals survived, but anything as large as a human, would have almost certainly been wiped out.

Through Earth’s history such collisions occur, on the average every one million years. If this figure is correct, it would mean that intelligent life on Earth has developed only because of the lucky chance that there have been no major collisions in the last 70 million years. Other planets in the galaxy, Hawking believes, on which life has developed, may not have had a long enough collision-free period to evolve intelligent beings.

Impact rates depend on how many comets and asteroids exist in a particular planetary system. In general there is one major impact every million years -— a mere blink of the eye in geological time.

SOURCE: Daily Galaxy