Science Made Cool

Music of the Spheres

I wasn't doing any blogging these past few days because I was a guest a Philcon in Cherry Hill, New Jersey. Most of my time at the con was spent doing panels -- I was at a total of eight events over the course of two nights and two days.

On Sunday I did manage to attend a panel as part of the audience -- I went to Dr. Patricia Boyd's presentation on the upcoming Kepler mission, and it sounds very exciting. The Kepler telescope will use very sensitive optics and massive computer processing to examine the light curves of some 150,000 stars in the sky near the Summer Triangle of Deneb, Altair, and Vega. What Kepler's looking for are regular, periodic dips in the light output of those stars. The slight variations in luminosity will indicate the presence of planets orbiting those stars. Kepler should be sensitive enough to detect worlds the size of Earth or even smaller. The goal is to see how common Earthlike planets are, and possibly identify some candidates for life.

Dr. Boyd's talk was interesting enough in itself for a space buff like me, but she enlivened the proceedings with some musical numbers. She is a member of the a capella singing group The Chromatics. As one might expect from a singing group founded by NASA employees, many of the Chromatics' original numbers have science and space exploration themes. They performed a couple of songs during the talk, bringing the audience musically up to speed on concepts like the Doppler Effect or the Life Zone of a star system.

Patricia Boyd and the Chromatics aren't the only connection between Kepler and music. The astronomer Johannes Kepler (who is of course the person after whom the mission is named) had his own theories about the harmonies of planetary motion. He even wrote out in musical notation what the "music of the spheres" might sound like if each planet had its own characteristic note. You can listen to it here.

I don't know if Dr. Boyd and the Chromatics have ever tried performing Kepler's music of the spheres themselves, but it would certainly be appropriate.

More Weirdness From Saturn

The weirdest planet in the Solar System keeps getting weirder. The latest finding from the Cassini probe orbiting Saturn is that the ringed planet has a mysterious bright aurora which physicists on Earth are still trying to puzzle out. The aurora covers the whole polar area of the planet and is very bright and energetic -- even though the Sun is going through an unusually quiet period right now.

Is there any connection between the anomalous aurora and Saturn's equally mysterious polar hexagon? Nobody knows. And those are two words dear to every scientist's heart.

Not-So-Giant Rock Alert!

Grab Aunt Nelly and head for the bomb shelter! A huge rock from space is . . .

Well, okay, not a huge rock, a rock about the size of a middle-aged game designer. But it's going to hit . . . er, pass really near the Earth! TODAY!

Space.com has the story.

Shiny Giant Rocks From Space!

In the past I've mentioned efforts to protect the Earth from the menace of large things falling on it. Former astronaut Harrison Schmidt and the United States Navy have all had their time in the spotlight here. Now we celebrate Mary D'Souza, who recently won the Space Generation Advisory Council's "Move an Asteroid" contest.

Her idea, summed up by scores of newspaper headline writers, is simple:  move asteroids by wrapping them in shiny Mylar. What none of the news stories, nor even the Council's own press release mentioned, was how wrapping up an asteroid would serve to deflect it.

The answer has to do with that old freshman physics standby, the mechanics of collisions. In an inelastic collision, when a small object hits a big one, it sticks and imparts all its energy to the big one. That's basically what happens when a photon strikes an asteroid -- the light gets absorbed, and the photon's momentum is imparted to the giant space rock.  Since the Sun is constantly pumping out photons at a steady rate, this constant outward "push" is already part of the motions of the various bodies in our Solar system.

If you (or a team of clever robots) wrap up an asteroid in shiny foil, the collisions between photons and giant rocks are no longer inelastic but elastic. The photons go bouncing off again, and being photons they do this at the speed of light. Momentum is conserved, which means that as the photons go speeding off in one direction, they give the asteroid a tiny push in the other -- more of a push than if the collision was inelastic.

That's the key to Mary D'Souza's asteroid deflection scheme. Making the asteroid shiny means you get more oomph (I believe that's the technical term) from the sunlight shining on it. If done suitably far in advance, it can shift the orbit of an Earth-grazing asteroid so it becomes a comfortably Earth-missing one.

SPACE MONSTER!!

There's a monster lurking in space -- and not just any monster, a monster galaxy! Galaxy NGC 1275 in the constellation Perseus is a highly active galaxy, emitting strong X-rays, probably generated by a massive black hole in the galaxy's heart. This image from the Chandra orbiting X-ray observatory even looks like a giant scary space monster. Who will save us?

Keeping Score

The successful landing of the Phoenix probe means that Earth has finally tied the  score with Mars in the interplanetary Expensive Hardware Lob contest. See the scorecard for details.

Phoenix Descending

The Phoenix lander is set to touch down on Mars today at 7:52 p.m. EDT. You can check out the mission home page, or the NASA/JPL mission page, which links to a bunch of other stuff. Let's all hope the Great Galactic Ghoul doesn't bag another Mars probe.

UPDATE:  Success! Phoenix is down in one piece and transmitting data. Congratulations to all the people who made it happen.

Messages To Space

From the redoubtable Pink Tentacle web log comes word of a message beamed into space by Japanese astronomers in 1983. It's instructive to compare it with the more well-known (to me, anyway) message transmitted from Arecibo in 1974.

The Arecibo message is certainly more stodgy. It has crude pixel-pictures of a human figure, the giant Arecibo antenna, DNA strands, atoms, and the Solar System. The Japanese one boasts a buxom female figure, the formula for ethanol, and a cheerful kanji toast.

I suspect neither one would make much sense to an alien civilization. You just can't convey much useful information in what amounts to a bathroom-tile mosaic. The chief datum carried by both signals is simply, "We're here!"

Will we get a reply to either one? Don't hold your breath. The Japanese message was sent toward Altair, which is a nice enough star if you like 'em bright and short-lived. To date nobody has even located any planets circling Altair, let alone anything capable of detecting a radio broadcast. Conversely, the Arecibo message was transmitted toward a star cluster 25,000 light-years away. Even if there is someone listening, it will be 50,000 years before we get an answer.

This doesn't mean we should quit looking. Contact with another intelligent species is so important it's worth the wait. And probably the most amusing topic to discuss at first will be their reaction to our weird little drawings beamed into space.
 

Good News For Saturn

In a move of startling good sense, NASA has decided to extend the Cassini probe's ongoing mission to study Saturn and its moons. The project was slated to end this summer, but since Cassini is still chugging along in good condition, sending back data and pictures, and dramatically improving our knowledge of the Saturnian system, they've decided to let it run until 2010.

This is one of those bits of space program budget card tricks I honestly don't understand. Shouldn't every mission like this include some sort of "automatic extension as long as the probe keeps running" clause in the appropriation? When the Federal government can find money for every Congressman's pet pork-barrel project, surely learning about a whole planet is worth some bucks? Especially given that they've already paid for the expensive part -- building and launching the probe. Extending the mission basically means finding some quarters under the seat cushions to keep the grad students running the thing in ramen noodles and Jolt for another semester.

True Giant Space Rock Bible Stories!

There's a news item circulating in the press right now about how Sodom and Gomorrah, the two cities toasted by Jehovah for their wickedness, may have actually been done in by a Giant Rock From Space.

I say it's nonsense.

The evidence seems to be an, ahem, rather liberal translation of a Sumerian clay tablet plus a possible impact site in the Austrian Alps. Let's all think about this for a moment, shall we?

A giant rock from space comes careening toward the Earth, moving at roughly Earth escape velocity if not faster. It passes Mesopotamia, inspiring a local scribe to jot down some garbled account on a clay disk. It passes low over Sodom and Gomorrah, destroying them both with shock waves (no fire and brimstone from heaven, as in the Biblical account). Then the giant rock flips on its turn signal and makes a hard right turn, climbs to a safe cruising altitude so that no early Greeks even notice its passage, weaves through the Balkans like a cruise missile, and finally slams into a mountainside in Austria.

I don't buy it. In the past I've complained about people (one hesitates to call them scientists) trying to come up with "scientific" explanations for events in mythology. It's idiotic, unscientific, and needlessly offensive. And frankly, the "scientific" accounts often wind up being more implausible than a straightforward miracle performed by an omnipotent being.

(The folks over at the Skeptics' Guide are also dubious.)