Asteroid 'can be deflected'
2006-10-21 17:03
Johannesburg - If an asteroid does embark on a collision course for Earth, it could be deflected, a scientist from the European Space Agency (ESA) said at the Johannesburg Planetarium on Saturday.
Apophis, the destroyer, was detected in 2004 and was initially thought to impact Earth in 2029 with globally catastrophic results. This is no longer a certainty though, said ESA's Dr Sima Adhya.
The asteroid, currently moving at a speed of 30km a second would have to pass through a 400m-wide region in space, called a gravitational keyhole, in 2029. If this happens, it will collide with Earth seven years later, in 2036, said Adhya.
Meanwhile, in the last year, Adhya has been working on the first phase of an asteroid-deflection project called Don Quixote.
This projects involves two spacecrafts being sent into space to deflect another 300m-wide asteroid.
The first spacecraft will launch in 2011 and will orbit the asteroid to get accurate measurements about it and its exact positioning in space.
The second spacecraft, about the size of a fridge, will be launched afterwards and will impact the asteroid at a relative velocity of 10km per second, deflecting its course.
"It will act as a ballistic missile," she said.
The first spacecraft will remain in orbit to measure the deflection.
According to Adhya, a mere 100m deflection will be sufficient to change an asteroid's course.
Adhya is touring the country as part a two-week Sasol SciFest roadshow that aims to bring the flavour of the festival, which takes place in Grahamstown in March, to the rest of the country.
- SAPA