28 October 2010
Bradbury on Martian Moonrise
Posted by Ryan Anderson
A friend of mine sent me this Ray Bradbury quote:
A few years back, one dreadful boy ran up to me and said, “Mr. Bradbury?”
“Yes?” I said.
“That book of yours, The Martian Chronicles?” he said.
“Yes,” I said.
“On page 92 where you have the moons of Mars rising in the east?”
“Yeah,” I said.
“Nah,” he said.
So I hit him. I’ll be damned if I’ll be bullied by bright children.
Now, I don’t condone hitting bright children, but this made me laugh, because the kid is right. Okay, half right: Deimos does rise in the east, but it is really sluggish. Phobos on the other hand has a true retrograde (a.k.a. backwards) orbit: it orbits faster than the planet spins, so it rises in the west and sets in the east. In fact, because it orbits opposite the direction that the planet spins, the tides that it raises in Mars are gradually stealing its orbital energy, causing it to spiral closer and closer to the planet. In about 8 million years, Phobos will be close enough to Mars that gravity will tear it apart, forming a lovely ring:
That is so cool
I thought that Phobos was prograde, but below the geosynchronous height (which makes it rise in the west because it orbits faster than the planets spin, and means that tidal braking pulls it down, not up).
D’oh, you’re right. That’s what I get for not double-checking my explanations before posting. The post has been duly edited. Thanks for catching that!
what if we install a mass drive on Phobos , and use matter on Phobos as fuel to change the fate of Phobos. At the end, we will have a hallowed Phobos orbiting the Mars. And always, we can use Phobos as the Customs station of the Mars (since it is easier to get on/off the Phobos).
[…] Re: Historical realism vs fantasy I have come to accept that some critics are so polemical that they aren't really interested in debate or getting their facts straight. In those cases, the best advice is to ignore them. Engaging them means presenting your facts and hoping that they will be given fair consideration by someone intent on using you as an example of what's wrong with society. But, hey, there's this story about Ray Bradbury . . . https://blogs.agu.org/martianchronicl…tian-moonrise/ […]