Things I’ve learned: Phobos and Deimos

Mars has 2 moons Phobos and Deimos. Both were discovered in 1877 by Asaph Hall. Mars is the Roman god of war, called Ares by the Greeks. Ares had 2 sons by Aphrodite, named…you guessed it, Phobos and Deimos.

Phobos means panic/fear and Deimos means terror/dread. The sons were close companions of their father, always depicted as driving his chariot and assisting him on the battlefield. See for yourself:

“[Ares] ordered Phobos (Fear) and Deimos (Terror) to harness his horses, and himself got into his shining armour.” – Homer, Iliad 15.110

“Ares drove these [warriors] on … and Deimos (Terror) drove them, and Phobos (Fear), and Eris (Hate) whose wrath is relentless, she the sister and companion of murderous Ares.” – Homer, Iliad 4.436

It’s a little annoying that the planet has the Roman name and the moons the Greek…but I’m willing to let it slide, because I like the concept of naming the moons after the sons of the planet’s namesake. Moons are like the planet’s children, after all. And I like the poetry of it all, that in life and literature and astronomy, war is always accompanied by fear and terror.

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honestly, they have no clue what’s up there…

Apparently, since like yesterday, there is another new planet. Now that little contest winner girl is obsolete….

Actually, upon closer inspection, they don’t even say they found a new planet, they say, “If research is conducted on a wide scale, the planet is likely to be discovered in less than 10 years”.

Umm…so it’s an article announcing that they think there may be a new planet somewhere and they could possibly find it some time in the next decade or so? How is this news? That’s just random speculation. I’m so confused…

they really can’t decide what’s happening up there…

Umm…did you know there are 11 planets now? Yeah, not only did Pluto not get the boot (just a downgrade to “dwarf planet“) but he brought his friends Ceres and Eris with him. This also necessitated a new mnemonic. No longer did My Very Excellent Mother Just Serve Us Nine Pizzas. Instead, My Very Exciting Magic Carpet Just Sailed Under Nine Palace Elephants. Good to know…

Although, there are apparently as many as 42 other things floating around up there that could also be classified as dwarf planets. Good luck coming up with that mnemonic.

What the hell is going on up there?

So, this has been bugging me for a while. Did you know that the earth has another moon? Yeah, it’s a shocker. That’s like your parents suddenly revealing that they have another child. You know, one they just never really got around to ever mentioning to you…

So this moon, or rather “moon” since there’s some debate over the terminology—and I’ll get to that in an moment—is called Cruithne (also known as asteroid 3753). I don’t remember where I actually heard about this second moon, although it was probably on NPR since that is where the majority of my information seems to filter in from. Anyway, I thought I would look into it…

Here are the findings: First off, it seems that Cruithne is not really a moon, because Earth and Cruithne are not gravitationally bound. A moon would actually orbit the planet, while Cruithne just shares the Earth’s orbit around the Sun. It was discovered in 1986, although it took until the late nineties to figure out its orbit. Apparently, it’s up there careening around in some sort of crazy horseshoe pattern. Cruithne’s orbit will not cause it to crash into the earth. I find this reassuring.

So while I’m looking this up, I discover that there’s a bunch of other crap floating around up there. There are at least four Earth Coorbital Asteroids or “coorbitals” that share Earth’s orbit. They are certainly catchily named: 2003 YN107, 2002 AA29, 2004 GU9, and 2001 GO2. Poetic.

So the best part of the story is that that they thought they found another one called J002E3. Only then they discovered this:

“J002E3’s small size and unusual orbit suggest the object is no asteroid or other natural object, but a piece of man-made “space junk,” possibly a piece of one of the Saturn V rockets that launched American astronauts to the moon during the Apollo program.”

Nice. Yeah, we thought that might be a planet or something, but it turns out that’s its just some trash we didn’t dispose of properly…

So my real problem doesn’t actually have any thing to do with any of that. What I want to know is why do we call the moon the moon? Other planets have moons (and coorbitlas for that matter) and most of them have names. Pretty ones: Triton, Nereid, Phoebe, Titan, Calypso, Ganymede…Jupiter has 39 moons for goodness sake. In fact, as you may note above, even the other stuff orbiting the earth has a name (or at least a number).

So why do we call the big white one up there the moon. That’s like saying, “I have this cat, and we are going to call him ‘the cat’. Now, all these other cats—who you may note are also cats—will have names like Midnight and Socks and Nutmeg and Steve.” What’s that about? Makes no sense.