By Doug Norrie | 15 seconds ago
Have you ever been able to see a moon collide with a planet before? Me neither, but one day people might have that same opportunity. Although it will take a while. Scientists believe it will happen on Mars with the prediction that a moon, Phobos, is on track to eventually spiral towards the planet if it maintains its current orbital path. It should be quite a sight once it finally happens, descend to the red planet and disappear. The whole scenario sounds like something out of a science fiction movie.
NASA released a statement this week (via Futurism) that discussed the ongoing exploration of Mars by the Perseverance rover, as well as the gravitational aspects Phobos has on Mars. The oddly shaped satellite had been part of a solar eclipse earlier in the month and NASA scientists took the time to remind people that Phobos was “doomed” in its current orbital path. While this collision with Mars isn’t likely to happen anytime soon — the current prediction is something like 30 million years — there seems to be a consensus that the moon’s fate is already pretty much set, even if it’s well into the future.
While most agree that Phobos doesn’t have “time” for this solar system in terms of its lifetime, there is some disagreement about what will eventually happen to the moon. Some think that on its current orbital path, it will eventually crash into Mars with the moon breaking apart and pieces hitting the surface. But there is another idea that as it gets closer and closer to Mars, it will eventually break apart. And then those pieces will form an interplanetary ring around the planet. Only pieces of the moon with very strong cohesion will be strong enough to enter the atmosphere of Mars and eventually impact the planet.
Some of the reasons why Phobos has been studied intensively is that it has an unusual orbital path around Mars with its composition and origin not yet 100% confirmed. It’s oddly shaped, looking almost like a potato, and it’s actually moving around Mars in what appears to be below the synchronous orbit radius. This means that it has the strange trajectory of moving around Mars faster than the planet actually rotates. This has the effect of moving across the sky (if you’re standing on Mars) twice a day instead of, say, our moon, which completes that cycle only once a day.
With the time of Phobos’ demise still very (very, very) far in the future, there’s a chance that humans may be able to observe Mars’ moon for themselves at some point while standing on the planet. NASA has said it thinks there’s a chance the first human could go to Mars sometime in the 2030s. That might be ambitious all things considered, but there’s no doubt it will happen eventually. And there is still time to take a look at Phobos with its strange path and shape. It’s going to crash into Mars, but not for millions of years.