Artist's concept of a catastrophic asteroid impact with the early Earth. An impact with a 500-km-diameter asteroid would effectively sterilize the planet. Russia is considering sending a spacecraft to a large asteroid set to fly near Earth in 2029, to knock the space rock off its path and prevent a possible collision with Earth, the head of the country's space agency said Wednesday.
NASA scientists recalculated the path asteroid Apophis, seen here, in early October. The refined path indicates a significantly reduced likelihood of a hazardous encounter with Earth in 2036.
The Apophis asteroid is approximately the size of two-and-a-half football fields. It's still too far away to see clearly, but up close would probably look like this this, a color image of Eros taken by NASA on February 12, 2000, at a range of 1100 miles. The image shows approximately the color that Eros would appear to the unaided human eye. Its subtle butterscotch hue is typical of a wide variety of minerals thought to be the major components of many asteroids.
Initially, Apophis was thought to have a 2.7 percent chance of impacting Earth in 2029. Additional observations of the asteroid in October ruled out any possibility of an impact in 2029. Nevertheless, Russia is considering sending a spacecraft to a large asteroid to knock it off its path and prevent a possible collision with Earth. The asteroid is expected to make a record-setting approach to Earth on Friday, April 13, 2029, when it comes no closer than 18,300 miles above Earth's surface.
An artist's impression of a major impact event. The collision between Earth and an asteroid a few kilometres in diameter releases as much energy as the simultaneous detonation of several million nuclear bombs.
So how could Earth's scientists prevent such an impact?
One way scientists have proposed to deal with an asteroid impact: a space tractor. Here, an artist's concept of such a tractor towing an Apophis-like asteroid away from a collision course with Earth.
Another theory on how to deal with potential near earth impacts: Send a satellite out to plant explosives, as graphically illustrated in movies like Deep Impact. Here, a NASA illustration of what such a mission might look like.
Another potential way to mitigate the potential risk of an asteroid impact: Attach a large enough solar sail directly to the cosmic rock, using the pressure of the sun to shift the object's orbit.
Russia is considering sending a spacecraft to a large asteroid to knock it off its path and prevent a possible collision with Earth. Just how would we prevent asteroids from colliding with Earth?