5 Scientific Inaccuracies In Alfonso Cuaron's Gravity

By John Wesley Dickson / October 28, 2013

1. The Theme From Jaws Should Have Played Every Time The Wave Of Satellite Debris Came Sweeping Around

In other words, the wave of debris, the result of one Russian satellite exploding and causing a chain reaction that destroys other satellites and produces even more debris, is the Big Bad Monster of the movie. Clooney's character has even calculated how quickly the debris is orbiting the earth and sets a 90-minute timer to alert the astronauts to its arrival. The wave of debris devours the space shuttle, the Hubble, the International Space Station (ISS), and the Chinese space station, along with seemingly wiping out all communications satellites. I would like to think that Gravity could have put the astronauts into situations not quite so apocalyptic and had it be just as interesting. The idea of a survival film set in the void of space is certainly an intriguing one, and I don't think it required some monstrous force akin to the destabilization of the earth's core in Roland Emmerich's 2012 or the instantly freezing cold of Emmerich's The Day After Tomorrow. In other words, Gravity could have been a simple survival story without having the high-level destruction of an over-the-top disaster film. Overall, this wave of debris is the exploitation of artistic license which most tried my suspension of disbelief and tended to take me out of the film. First, if a satellite explodes in space, why would the debris all begin moving in one direction? Most likely, the debris would radiate in all directions. I suppose it's possible that the individual pieces of debris could be gravitationally attracted to one another, causing them to clump together in one heinous and vindictive wave of destruction. But, I suspect such an occurrence is much more implausible than not. Second, what really bothered me is the fact that - going back to the notion of orbital planes (the distance above the Earth - many communication satellites are in extremely high orbits, far far away from each other and even farther from low-Earth-orbit (LEO) structures such as the Hubble and the ISS.

I'm not sure what most of this chart means, but I do know that MEO (medium earth orbit) satellites, which include most GPS satellites as well as many communications satellites, are about 20 megameters (12,427 miles) above the earth. There are some communications satellites in low earth orbit, the Iridium network, but even these are over 650 km (403 mi) above sea level, still quite a stretch of distance from the Hubble orbiting at 370 km up (230 mi). And there are only about 70 satellites in the Iridium network.

For an explosion of one of them to cause a debris storm that wipes out another one would be like a telephone booth in France exploding and projecting debris to a phone booth in Cuba. Also, many of the MEO satellites are those used for Internet service as well as those used by NASA itself. So, a chain reaction involving LEO objects would have caused no outage of Facebook across North America, no inability to communicate with Mission Control.

Ultimately, space is big. Very big. Even if it were one of the MEO satellites that was destroyed by the Russians in Gravity, it would be virtually impossible for it to impact other satellites and cause a chain reaction. The other satellites would just be too damn far away. And for the debris from such an explosion to reach the Hubble would be an even larger leap in probability. Going back to our analogy about strolling from Zimbabwe to Pakistan, an MEO satellite explosion impinging upon the Hubble's integrity would be like throwing a rock from Pakistan and hoping to hit a target not just in Zimbabwe, but in a Zimbabwe that exists a whole other Earth away! Look at that picture above again. You could practically fit two entire Earths between LEO and MEO.

So the "antagonist" in Gravity, the giant shark which hunts our valiant astronauts down, following them across multiple orbital planes and orbital paths, is a huge implausibility. This villainous debris wave practically ruined the movie for me, sucking out the enjoyment. It was only later that I realized the entire movie is not about astronauts at all. It's actually an allegorical tale about the grieving process of a mother who has lost her child. Perhaps that's an article for another day.

Like this article? Let us know in the comments section below.