Monthly Archives: June 2006

Planetarium-related, space-age technology

Spaceports and Dome Futures

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Delta launch, June 21, 2006. By Carolyn Collins Petersen.
Delta launch, June 21, 2006. © 2006 Carolyn Collins Petersen.

We went to a planetarium meeting this past week. There are several each year in various parts of the world, and this one was in Florida in Cape Canaveral. As you might expect, the talk of the meeting was all about planetarium presentations and techniques, along with a good smattering of other topics. We also had a chance to see a Delta rocket launch, carrying a satellite into space. I do like seeing launches!

One of our guest speakers this past week (and our speaker list included people from KSC and JPL, as well), was Phil Plait, known to many as the Bad Astronomer. His website (Bad Astronomy) is a great place to read about astronomy, space science, and the crazy theories and ideas that people come up with and claim as “science.” Phil’s an old friend and I thoroughly enjoyed his talk on Friday night. If you ever get a chance to hear him, make the time.

Space shuttle Discovery on the pad, June 22, 2006 By Carolyn Collins Petersen.
Space shuttle Discovery on the pad, June 22, 2006. © 2006 Carolyn Collins Petersen.

I left the meeting wondering what our next steps in space will be. Interestingly the history of planetariums in the U.S. is tied quite closely to the rise of the Space Age. These unique round rooms are changing though, just as our space exploration is morphing into something possibly unrecognizable. Shrinking funding hampers the vision we need to continue space exploration at levels once promised by our first achievements in space. The same thing happens to planetariums, which are also morphing before our eyes. Sure, we’re still going to space, sort of. We’re exploring Mars with robots and learning amazing things with Hubble Space Telescope (although with the possible loss of the Advanced Camera for Surveys and the “who knows if we’ll ever send the last servicing mission to HST” attitude among some mission planners, it’s hard to tell what HST’s future is now, even though it is still equipped with other working instruments.)

And sure, we’re still building planetariums, sort of. But many are closing down, just as NASA is having to choose between funding science and building out the space stations. No easy choices, there, either. New theaters are coming equipped with fulldome video, which forces many other, new choices on planetarium professionals. It’s a changing world, and this week’s meetings brought the changes in two of my interests—planetarium facilities and the U.S. space agency—into sharp focus.

astronomy news, comet, x-ray astronomy
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Comet Schwassmann-Wachmann 3 in a new light, Courtesy NASA/SWIFT/XRT/U.Leicester/Richard Willingdale.
Comet Schwassmann-Wachmann 3 in a new light, Courtesy NASA/SWIFT/XRT/U.Leicester/Richard Willingdale.

As Comet Schwassmann-Wachmann 3 continues what may be its final trip around the Sun(breaking up along the way), astronomers are turning everything they have toward it. While it isn’t as bright to the naked eye as Hyakutake or Hale-Bopp were a few years back, S-W3 is turning out to be dazzler in other wavelengths, most notably x-rays. In fact, it’s the brightest x-ray comet ever. The folks using the Chandra Observatory, the XMM-Newton satellite, and the Suzaku satellite (all three in orbit around Earth) are all getting ready to study the x-rays streaming off the comet.

The image above is what the comet looks like in x-ray wavelengths. It was taken using the NASA Swift satellite, which studied the comet recently. The data showed that the comet is about 20 times brighter in x-ray wavelengths of light.

How can a comet produce x-rays? It seems somewhat counterintuitive that such a cold, icy object would glow in wavelengths more commonly associated with hot, active events and objects. Astronomers are still characterizing the interactions that occur that cause cometary x-rays, but the basic story is this: as the comet plows through the solar wind, something called “charge exchange” occurs. Okay, that sounds appropriately mysterious, but what does it mean?

The solar wind is a stream of particles (electrons and protons). The comet is a lump of ices and dust. As it moves through the solar wind, those particles and gases fly away from the comet, particularly as the ices are warmed by the Sun. Those cometary bits are usually particles of molecules of water, methane, and carbon dioxide. When they the high-speed, high-energy particles from the solar wind encounter these lower-energy particles from the comet, electrons get “stolen” from the cometary chemical particles. In the process, a tiny bit of charge is exchanged and the result is a spark of energy, which results in an x-ray. So, it’s a collisional process that depends on an interaction between the comet and the solar wind. It’s not just from something the comet itself is generating.

Now, if you know enough about the x-ray energies that are given off in these collisions, you can make some deductions about the content of the solar wind and the makeup of the gases and materials being emitted by the comet. And this is one of the results of studying x-rays (and other high-energy emisssions) from such events as comets plowing through the solar wind.