August 30, 2007 at 12:38 pm | Leave a Comment
Stars emit light (electromagnetic radiation) and heat. If you take the light from a star and send it through an instrument called a spectrograph, you can essentially break up the light into its component colors (wavelengths). You’ve seen one form of a spectrum in nature: it’s called a rainbow and it was created by light being broken up through a prism of raindrops.
The image above is a graph spectrum showing us the chemical elements that exist in a star called NGC1333-IRAS 4B. The infrared light was analyzed by an instrument aboard the Spitzer Space Telescope (which is sensitive to infrared wavelengths). The scientists compared it to a model of a water spectrum, and found water vapor in the region surrounding the star. What they think is happening is that ice particles in the surrounding environment are falling toward the star. When they hit the disk of gas and dust around the star, they heat up and melt, forming water vapor.
These details are in the spectrum, which tells us about the motion of the ice particles surrounding the star.
Spectra are a part of astrophysical research that can look pretty boring or confusing to people who don’t see them every day. Yet, if you know how to read them and what to look for, they can reveal details of an astronomical object that you just can’t see with the naked eye or in an image. Here’s another one, from a recent Gemini Observatory press release, that shows the evidence for water and ammonia ices on Pluto’s companion world, Charon. It is centered on infrared light radiating at 2.2 microns. The solid line is a model of a surface with ices called ammonia hydrates, along with water ices. Other dots are the data from the surface of Charon that represent ammonia hydrate ices. (You can read more about this one here.)
Now I don’t normally “do” spectra in my planetarium shows, mostly because they require more explanation than we often have time for. But, spectra ARE treasure troves of information, hidden right before our eyes.
August 24, 2007 at 13:33 pm | Leave a Comment
There’s another meteor shower coming up in a week, and if you didn’t get enough of them with the Perseids, you should check this one out. It’s called the Aurigids, and it’s supposed to be a flurry of bright and oddly colored meteors that seem to come from the direction of the constellation Auriga.
There’s quite a bit of interest in this year’s shower, which is the debris from Comet Kiess (C/1911 N1), because it’s a rare one. Comet Kiess has only visited this end of the solar system twice in the past couple of thousand years, and so Earth rarely encounters its debris tail. This year we’ll plow right through that trail on September 1. And if we’re lucky, there could (emphasis on the “could”) be a nice meteor shower, with perhaps a hundred meteors per hour or more, if the debris stream is thick. Or, if the debris stream is thin, the shower could be a bust.
The catch here is that the peak of the shower will be best seen by people living in the Rocky Mountains and further west. Earth will be smack in the middle of this stream at 11:36 UT (that’s 4:30 AM PDT). That’s the peak time; the shower (if there is one) begins well before that.(See here and here for more information.)
If you are planning to watch for Aurigids, there’s a unique project brewing that you might want to be involved with: the Aurigid Laptop Meteor Observation Project. Essentially, it’s another distributed computing project that will take observation info sent in by people in the observing range of the shower and turn it into a three-dimensional map of the debris stream from Comet Kiess. If you’ve got the time, you’re in the right place, and want to make a contribution to solar system science, here’s your chance
August 23, 2007 at 14:37 pm | Leave a Comment
Here’s a pet peeve of mine, but with a little background. I read a lot of science press releases each week, and many more science stories from various online (and tree-based) sources. At least one (and usually more) of those sources winds up saying something like, “Scientists believe that… ” in an effort to get across the idea that the scientists are describing a discovery or knowledge they have about a given topic of research.
What bugs me about that usage is that it isn’t correct, particularly when it gets applied to some facts that scientists (doctors, physicists, chemists, biologists, etc.) are trying to get across to the public. The writer should have said, “Scientists think… ” or “Scientists know… ” or something that indicates definite knowledge, not hopeful belief. (Unless, of course the scientist in question says, “We believe we can find the cure for cancer in this generation.” That IS a correct usage.)
What bugs me about “believe” vs. “think”? It’s sloppy language usage. Here’s the Dictionary.com definition for believe: “to have confidence in the truth, the existence, or the reliability of something, although without absolute proof that one is right in doing so: Only if one believes in something can one act purposefully.” (Italics mine.)
Here’s the definition for think: “to have a conscious mind, to some extent of reasoning, remembering experiences, making rational decisions, etc.; to employ one’s mind rationally and objectively in evaluating or dealing with a given situation.”
Using the word “believe” puts in an element of uncertainty that often is at direct odds with what the scientist actually said or has discovered. Using “think” or “know” expertly expresses exactly what the data support. Let’s explore that a bit.
Let’s say that a planetary scientist discovers a new planet in the outer solar system. That discovery is written up in a press release and the scientist says, “We know from our spectra that the surface of this world is made up largely of water ice.” It’s absolute fact, he or she knows it, and after we read the story, we know it. We can look at the spectra and the data is right there, telling us that the surface has water ice on it.
Yet, often enough, I’ll see the news stories based on the press release (and even interviews with the scientist), and somewhere in the story, the reporter writes, “The scientists believe that there’s water ice on the surface of this new world.” (Or something like that.)
No. No. No. There’s no “belief” about it. It’s a fact. Go back up and read that definition of “believe” again and think about it. Saying “believe” is simply the wrong language to describe a scientific certainty. Now, if you wanted to say something like “Bobby believed that the Big Dipper was his favorite constellation” or “The Elbonians believed in the myth of Atlantis” that would be entirely proper because then there IS confidence in some truth or reliability of some information but there’s no data or proof of the stated belief.
It’s a fine point, but one that we should all pay more attention to, because science does deal in precise language and measurements. “Belief” is not part of the scientific process, but having factual knowledge is.
Or here’s another way to think of it. I’m a science writer, I have a degree in journalism, I work as a freelance editor, and I have experience working at at a magazine and a newspaper. Therefore I know something of how these professions work. It is entirely right for me to say, “I know that newspapers work on deadlines” because I experienced it and it goes on to this day. I also know from my experience that editors change stories that reporters turn in for publication (or that they get from press releases). They do this for many reasons, but usually to tighten them up or replace repeated words, or to clarify something.
For example, a writer that I once edited used the word “that” as much as possible. However, it gets tiresome to see the same word over and over again, so as an editor, I looked for words to replace “that” to help the meaning along. So, if I see a story where the word “believe” is substituted for the words “think” or “know” when referring to something that scientists DO think and DO know, I would be absolutely correct in saying, “I believe that the editor substituted the word “believe” for the word “know” because the writer may have used the word “know” too many times.” I could also just as easily say “I believe the writer used the word “believe” because he or she didn’t know better.”
I can’t say that I “think” the editor or the writer did it because that would imply that I have direct knowledge of what that editor or writer did. But, I can say that I “believe” it happened, because while I don’t have direct knowledge, I do have a pretty high confidence level that it happened.
Pedantic, yes. Correct, yes. Science writing demands as much precision as the subject we’re writing about. I don’t believe that. I KNOW it.
August 22, 2007 at 14:21 pm | Leave a Comment
Just when you thought Google had covered just about everything here on Earth, they’ve come out with a cosmic exploration tool accessible through Google Earth. To get it you have to download and install the latest version of Google Earth 4.2 (available for PC, Mac, or Linux).
Laid out before you are stars, nebulae, and galaxies (including some of the most distant ones ever seen), all accessible through the same navigational tools as regular Google Earth. You also get constellations and a whole Backyard Astronomy layer, complete with images as seen by naked eye and telescopes. Hubble Space Telescope imagery, and two informative layers about the life of a star and the users guide to galaxies complete the opening set. I can imagine that once people get hold of this and play with it for a bit that there will be a blossoming of .kmz files (the overlays) out there for all kinds of tours and educational trips through the cosmos.
This is one of those times in the development of the internet and the World wide Web when I look back over how far we’ve come. The first computer I ever used was a mainframe that our high school had access to from a local research establishment. We programmed it in BASIC, although the advanced types could do FORTRAN or COBOL. The output? Paper printouts. The first computer I ever owned was an Osborne Executive that Mark and I bought in the early 1980s. My first modem followed shortly thereafter. The output? Paper printouts. On the screen it was all ASCII.
In record time we went from that tiny 128K machine to Kaypros and Dells, each one bringing us more and more capability for office apps, plus access to content on what was becoming the Internet. Today, almost a quarter century later, we’re reaching out to the cosmos with Google and other accessible tools. The other night I was watching movies on my computer and had to stop and marvel for a second about how commonplace it all is now. But, 25 years ago, not so much. If anybody had told me then that I’d be accessing images from an orbiting space telescope, using my computer and a network to send my work to clients around the world, and exploring the distant cosmos with a program that made it as easy as a mouse click—well, I wouldn’t have believed them.
For those of you who have grown up with the wonders of the Web and Internet at your fingertips, it’s all as new as today. I think it’s great and now I’m going to stop reminding myself about the distant past. The future’s here folks. Enjoy!
Now, go download the new Google Earth and get to work exploring!
August 19, 2007 at 21:49 pm | Leave a Comment
Back in August, 1981 I took a trip out to California to be at the Jet Propulsion Laboratory in Pasadena to watch and learn as the Voyager 2 spacecraft made its closest approach to Saturn (and various moons and rings). It was a pretty major event in my life; it’s what turned me toward a life of science writing. I was working at The Denver Post at the time, and had talked the managing editor into letting me go out and cover the event (even though I was a newly fledged editorial assistant at the time). I think I must have told him that I’d represent the paper well, because he handed me an accreditation letter, patted my hand (which was sort of the editorial equivalent of chucking me under the chin, I guess), and told me to go out and have a good time.
A week or so later, I landed in Los Angeles, and proceeded to have the time of my life. JPL was sort of a “Holy Grail” site for me. I remembered reading about it during the Moon and Mars missions, so I couldn’t wait to get there and start watching planetary scientists in action.
So, there I was at JPL’s von Karman Auditorium and press site, with a desk and phone and press credentials, watching as folks like Carl Sagan (one of the people who showed me that science writing could be fun) would walk by, visiting with the press or talking with fellow scientists about what they’d seen so far.
Many of the press folk attending the week’s press conferences were experienced science reporters. A few, like Kelly Beatty of Sky & Telescope, the folks from Astronomy Magazine, myself, and others, had some astronomy and/or planetary science background. In fact, some were SO experienced that they could make some initial science diagnoses about the pictures at about the same time the scientists themselves were figuring just what the heck we were seeing in the images. The image interpretations (called “instant science”) were flowing freely, and the many successful press attempts to figure out the images led one scientist to dub the science press as the “von Karman imaging team” as a sort of tribute to our interest and expertise.
One of the most enduring memories I have of that week (and there are many!) is the evening that images from the moon Enceladus were due to come in. It also happened to be the night that Ted Koppel was going to broadcast “Nightline” live from the von Karman Auditorium at JPL. The press rooms were crawling with several hundred print and TV journalists from around the world, and most of them worked diligently during the day to get their stories filed by late afternoon. By evening all of us who weren’t on TV would sit around and watch the TV folks from the east coast do their standups and live interviews. That is, when we weren’t glued to the closed-circuit TVs around the place that showed a constant stream of images from Voyager 2.
Anyway, that night, we were watching as Ted put on his makeup and his entourage of directors and camera people bustled around getting things set up. Just as Ted and the bunch were about to go live with their broadcast, images of Enceladus started streaming onto the monitors. Immediately we were all drawn to them, and a bunch of us were clustered around one of the monitors (the von Karman imaging team AND Voyager imaging scientists who happened to be nearby) arguing over just what the strange markings on the moon’s surface could mean. It was a free-for-all of image interpretation, planetary science “jousting” and pure astonishment at the amazing level of detail we could make out in the images. I remember standing next to Brad Smith, who was one of the Voyager planetary science team members, listening to him describe the processes that could have formed those strange cracks on the surface.
Well, we’d pretty much forgotten about the “Nightline” folks in our frenzy to look at the images. Not that they cared about us print folks. But, they DID care about having a quiet set, and apparently we were interfering pretty badly with Ted’s opening monologue. One of his assistants came over, huffy and waving papers and hissing at us to keep it down.
We did, for awhile. But, as the pictures kept streaming down, our excited discussions got pretty loud again. At one point, Ted chuckled and said that the excitement level was quite high, one of the major understatements in the history of press conferences.
It’s amazing to realize that 26 years have gone by since that wonderful, exciting week. I, of course, haven’t aged a bit, although my science writing has steadily improved over the years. That visit to JPL is, as I said, what launched me as “TheSpacewriter” (although, at the time, I wasn’t quite so audacious as to call myself that), and eventually sparked my interest in going back to school to study more astronomy and planetary science. And, another degree, a couple of major science research projects, some books, a magazine editorship, a bunch of planetarium shows and documentaries, a major science exhibit project, an upcoming vodcast series, and countless other projects later, here I am looking back with great fondness on the mission that set me on my way. So, here’s a tip of the ol’ scan platform to Voyager 2 and the planet Saturn for being there at the beginning of my own trajectory into astronomy and planetary science!
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Image of Horsehead Nebula: T.A.Rector (NOAO/AURA/NSF) and Hubble Heritage Team (STScI/AURA/NASA)
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