April 29, 2009 at 5:01 am | 3 Comments
An Introduction to Large-Scale Structure
One of the coolest exhibits I’ve ever seen is taking up a wall at the Griffith Observatory in Los Angeles, California. It’s called The Big Picture, and is a deep view of a very small region in the constellation Virgo. It was taken using the Samuel Oschin Telescope on Palomar Mountain in California.
What makes this picture amazing is that it is a single continuous digital sky image, portrayed in porcelain tiles. It has at least a million galaxies and thousands of quasars depicted in it, plus asteroids, and a comet. The galaxies are part of the Virgo Cluster, the nearest big cluster to our own Local Group of Galaxies. Beyond them are the other galaxies, all part of the large-scale structure of the universe.
The Big Picture is the focus of today’s 365 Days of Astronomy podcast — which Mark and I produced. So, go over and check it out. I’ve also got a related page about it and the large-scale structure of the cosmos, here.
You can also see a video I’ve produced about The Big Picture as part of Astrocast.TV starting on May 1. I’ve joined the crew of Astrocast.tv to produce a monthly segment called The Astronomer’s Universe. Either way, be sure and check out this amazing image–it’ll take your breath away.
April 28, 2009 at 11:32 am | 2 Comments
What’s it Like?
A bunch of years ago I was gifted (by Mr. SpaceWriter) with an all-expenses-paid trip to Space Camp for adults held in Huntsville, Alabama. The object was a week’s worth of training in shuttle operations, and it was one of the coolest things I had done in my life to that point. It wasn’t all kids’ play — we actually spent our days in classes learning about propulsion systems, life support systems, launch systems, etc. Some of our lecturers were actual NASA engineers, one of whom had come to NASA from Germany in the 50s. We spent hours in simulators and, no surprise to any of my readers, I suppose, I ended up as shuttle commander for my flight. I had a pilot, two mission specialists and two payload specialists. We trained together each day, and then at the end of the week, we “flew” a simulated 2-hour mission. We had been warned in advance that there would be some anomalies thrown at us, so we had to be prepared.
Our launch was great, we cast off our SRBs on the nominal, and the main tank went just fine. Shortly thereafter, we had a fuel cell failure, which my pilot and I diagnosed in about 30 seconds and managed to fix. Everything went fine until we got to orbit, and then one of our payload bay doors jammed. We figured that one out, but lost about two minutes in our timeline doing so. After that, things went fine until late in the mission, when we had a couple of electrical problems. Fixed those, deployed our payload, had some time for some tomfoolery, and then we deorbited and landed. Despite our problems, our crew won top ratings that week and we all went home with huge grins on our faces.
I hadn’t thought about that week in Huntsville much until today when I was reading a Twitter message from an engineer in Houston who works in Mission Control at the Johnson Space Flight Center in Houston, Texas. She goes by the monicker @absolutspacegirl. Today, apparently, she and her team are working their way through some simulations of similar problems (fuel cell issues, payload bay door issues) thrown at the team and she’s twittering about it. Very, very cool.
Speaking of teaching and learning, the NASA James Webb Space Telescope folks have launched an online game to teach about the telescope (and telescopes in general) and how such things work. James Webb Telescope will launch sometime after 2013 and will be an infrared-sensitive telescope.
This telescope is a successor to the Hubble Space Telescope. It will be able to peer through dusty clouds surrounding newborn stars, for example, and possibly see planetary systems forming around them. Wanna learn more? check out the Webb Telescope game site.
April 27, 2009 at 12:08 pm | Leave a Comment
Skynights, Discovery Days, SkyCamps and
the Mt. Lemmon SkyCenter
This is cool — for those of you who live in Arizona or may be vacationing there sometime soon, check out the University of Arizona’s Mt. Lemmon SkyCenter — a science learning project aimed at the general public. It’s located up at 9,157 feet atop Mt. Lemmon, near Tucson. It looks like a great place to go get some hands-on experience with stargazing, professional-grade telescopes, and much more.
Moreover, the center is hosting workshops and programs for amateur astronomers, teaching about astrophotography.
Participants and users of the SkyCenter’s 24-inch telescope are already turning out some magnificent images, like this one, of the galaxy M101.
The center’s mission statement says that they want to engage people of all ages in the process of scientific exploration in their “sky island” — and I think that’s a really great way to get people interested in the sky AND science all at once. It is very much needed now that the University has closed down Flandrau Planetarium, largely due to economics, but also because a “new” planetarium is supposed to anchor a planned development project in Tucson. Unfortunately, that won’t be opening for a while, which leaves Tucsonians without the venerable Flandrau facility. It looks like the center will be doing some outreach with a portable planetarium, however, so the community is not without a planetarium. And, with the Mt. Lemmon SkyCenter not far away, the chance to do some actual hands-on astronomy is one that shouldn’t be missed.
April 26, 2009 at 11:33 am | Leave a Comment
Have a Conjunction with the Night Sky
According to the folks over at Spaceweather.com (who ping me daily with cool and useful information), there’s going to be a neat conjunction in the western sky tonight (for those of you readers who haven’t experienced sunset yet). The crescent Moon, Mercury, and the Pleiades star cluster will be grouped together after sunset. So, go out after sunset, look west, and watch the western sky in the gathering gloom! Read more about this at the link above.
As much as I like spring and summer, I’m always a little triste to see the Pleiades disappear from our evening and early morning skies for a few months. They’ll reappear in the night sky in the mid-autumn (for Northern Hemisphere gazers, mid-spring for the folks south of the equator), and they’ll be a harbinger of brighter, glitterier things to come (like Orion, yah!!!). So, I’ll check it out tonight, provided it’s not cloudy.
April 25, 2009 at 12:49 pm | 4 Comments
All that Glitters
When you look at the night sky, of course you see stars glittering up there. And, planets. And, if you have a telescope, you can make out the blurry wisps of nebulae and galaxies. Nebulae are clouds of gas and dust that float in space. They can be starbirth regions, the outpouring of a star (or stars) dying, and a mixture of both.
As it turns out, when you look at the clouds of gas and dust (called circumstellar disks) surrounding some special types of stars, you are looking at something else that glitters: diamonds. In these regions, there are countless numbers of these tiny sparklers (and I do mean tiny — most are not even the width of a human hair) swarming around in those disks. Yet around some stars, there are enough diamond specks that if you packed them all together, they’d have enough mass to make a tiny moonlet.
How can diamonds form in space? It’s a detective story, really, and a group of scientists from Japan, Germany, and Denmark used Subaru telescope on Mauna Kea in Hawai’i, to study ayoung star called Elias 1 to solve the central riddle of that story: how can diamonds form in space?
When scientists look for diamonds in space, they are like detectives using fingerprints to trace a missing person or find the perpetrator of a crime. The fingerprints of diamond crystals take the form of lines in the infrared wavelength of light, outside the range of visible light. The first such signature was discovered in 1983 in the circumstellar disk of Elias 1, a young star located in the direction of Taurus. It is is one of many Herbig Ae/Be (HAEBE) stars?young, very bright stars that are about 1.5-10 times as massive as our Sun.
The research team began with clues from previous laboratory research into how diamonds are formed (carbon materials are subjected to great temperatures and pressures). They coupled this with observations of stars that are surrounded by dust, and have partner stars that emit tremendous bursts of hard x-ray emissions. X-rays are emitted under extremely energetic and hot conditions, so that supplies the necessary energy and pressure for a natural diamond factory in space.
The scientists knew from their research that diamonds are formed close to the stars where they exist. They aren’t floating in from random points in space. Also, diamond stars must have special ingredients: that disk full of carbon material, a hot central star and a companion emitting hard x-rays. The star must be of intermediate mass that can warm up the disk to a medium temperature. Then, carbon onions can form, providing the cradle for diamond creation. The need for such special conditions would explain why we see so few stars with diamond signatures in their disks.
The findings of this research (more details here) will raise even more questions and speculation about the formation of these fascinating crystals. It’s possible that there are tons of diamonds that astronomers cannot yet see because their emissions are hidden from view by shells of material surrounding the stars where they exist.
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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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