Could A Gravity-Style Disaster Actually Strike Earth's Satellites?
The terrifying events depicted in Alfonso Cuaron's Gravity were all started by one explosion on a satellite orbiting Earth, which caused a dramatic chain reaction through the hundreds of high speed objects orbiting our planet. But could it be that an event as catastrophic as the one detailed in Gravity is not just limited to the cameras of Hollywood fiction? A team from the University of Leicester believe that such an event is not outside the realms of reality and they've even identified a potential culprit that could trigger it all.
In 2012 the Envisat satellite lost contact with Earth after 10 years in orbit and is now circling our planet with no form of human control. It is this 9 meter giant that final year Physics and Astronomy students believe could cause a horrific chain reaction as seen in Cuaron's 'Movie of the Year'.
The paper, entitled 'De-Orbiting Envisat' highlights the possibility, albeit a small one, that the ESA's $3billion satellite could collide with another spacecraft at some point during its remaining years in orbit if it is not removed. It is the high cost associated with moving such a large object that has led to its being left in orbit, and the students estimate that such a procedure would require around 2.7billion joules of energy, which is equivalent to over 140kg of extra fuel.
Every year Envisat is projected to come within 200 meters of at least 2 spacecraft, but despite these close calls, the team of students admit that the chances of the space behemoth causing a chain reaction are thankfully quite slim.
"In the film, the cloud of space debris is caused by a missile which was supposed to destroy a non-operational satellite and sparks a chain reaction which eventually collides with Clooney and Bullock's spacecraft," said student Katie Raymer. "In real life this is very unlikely to happen. It is even more unlikely that ESA's Envisat could cause one of these chain reactions. However, each year two objects are expected to pass Envisat within about 200m and other spacecraft have had to manoeuvre themselves out of Envisat's path. Also Envisat orbits at an altitude where the space debris is greatest. So although it is unlikely to happen, de-orbiting is certainly worth considering."
Indeed, should Envisat defy the odds and collide with another spacecraft, the implications could be hugely significant back here on Earth. One area that was not explored by Cuaron's movie was how the loss of so many communications satellites would be felt on the ground. We are a species that has, for the most part, become extremely reliant on satellite communications for everything from entertainment to connectivity. It's safe to say that such events back here on Earth would be more than worthy of an Alfonso Cuaron sequel!
For now at least, it would seem that we can focus on worrying about whether or not Gravity gets the Oscar haul it deserves and not about fiction becoming fact.
Read more on this at Phys.org: