Water on the Moon? Eh, Not So Much

Another astro-map from Universe Today. This one's of the moon:



It's a topographical map, recently put together with data from Japan's Kaguya satellite. It shows the crests and dales of the moon's surface, from the Dirichlet-Jackson Basin near the equator (11 km high) to the Antoniadi crater near the south pole (9 km deep). (Is it official policy, by the way, that place names on the moon be unpronounceable?)

But besides mapping the moon's topography, the Japanese researchers did a neat trick. They measured the roughness of the moon's surface, which allowed them to figure out if there's water underground. See, if there is water there, then it would act as a sort of lubricant, and the surface would exhibit more flexibility. But if there's no water, then the surface will be more rigid, just like the rough, rigid surface of a desiccated fruit. And the moon? Turns out it's pretty rigid. So: no water. Bummer.

What's that, David Byrne? You have something to say on the topic of water underground? A-and the moon, too?


Thank you, David. Thank you for that.

Space Junk

A map of space debris from the European Space Operations Centre (via Universe Today):



From the New York Times, Feb. 11th, 2009:

Debris Spews Into Space After Satellites Collide

For decades, space experts have warned of orbits around the planet growing so crowded that two satellites might one day slam into one another, producing swarms of treacherous debris.

It happened Tuesday. And the whirling fragments could pose a threat to the International Space Station, orbiting 215 miles up with three astronauts on board, though officials said the risk was now small...

It happened some 490 miles above northern Siberia, at around noon Eastern time. Two communications satellites — one Russian, one American — cracked up in silent destruction. In the aftermath, military radars on the ground tracked large amounts of debris going into higher and lower orbits.

“Nothing to this extent” has ever happened before, Mr. Johnson said.

This is a serious and growing problem. You can imagine the worst-case scenario over the long term - that the swarm of junk surrounding Earth becomes so dense that it forms a sort of minefield such that no craft can go into orbit without a significant risk of collision; we will have encaged ourselves with our own debris. That's a remote possibility at this point, but if it came to pass, it wouldn't be the first time we managed to junk a pristine and seemingly limitless environment with our crap.