September 27, 2012 at 21:23 pm | Leave a Comment
Big News in Distant Galaxies
You know that saying about how time is the universe’s way of keeping everything from happening at once? Well, there’s a lot happening in astronomy news today, almost all at once. So, the universe is flinging cool new stuff at us.
First, take a gander at this image. It’s an artist’s concept of what galaxies in the early universe were doing about 13 or so billion years ago.
Yep, they were making stars at a prodigiously fast rate, more rapidly than many galaxies do today. By comparison, our Milky Way’s star birth factories create at an average rate of one new star a year. Ours is a pretty quiet galaxy in that regard. And, while we do have a black hole at the center of the galaxy, compared to other galaxies’ very busy black holes, ours is pretty tame. Only occasionally does it capture a star or gas cloud and gobble it up.
Now, if you look at more active galaxies, you see more star formation. And these busy galaxies were much more common in the early universe. So, it makes sense that astronomers would find galaxies at that time busily baking up stars. Quasars and radio galaxies are prime examples of these active galactic denizens. And, observing them is easy due to their bright radiation, which can be detected over huge distances. Essentially, these active galaxies are easily detected through their luminous radio, ultraviolet or x-ray radiation, which results from steady accretion on to their massive central black holes.
These exotic galaxies are getting a lot of attention from the Herschel Telescope, which is sensitive to far-infrared wavelengths of light (which indicate heat radiation). A group of astronomers in the Netherlands has used it to study star birth in distant galaxies. Basically, it looks for heat radiation generated by star and planet formation in our own galaxy, and also studies the same radiation from complete galaxies. If a distant object is emitting strong levels of far-infrared radiation, then it’s a sure bet that the galaxy is undergoing massive amounts of star formation. And, by massive, I mean creating hundreds of stars each year.
These busy galaxies also have strong signals in radio frequencies, emanating from their central black holes. The black holes are busy growing (accreting mass and perhaps even merging), at the same time their host galaxies are creating whole batches of hot young newborn stars. And all of it is happening billions of light-years away, showing us galaxies in some of the earliest epochs of the universe.
The take-home message here is that these kinds of active galaxies existed early in cosmic history. They’re among the largest, most distant, most powerful and most spectacular objects in the universe. And, they give astronomers a look at what massive normal galaxies may have looked like in their infancy as they balanced the action of growing black holes at their hearts with the demands of star birth in other regions. These are the kind of “baby pictures” of infant galaxies that give astronomers a deeper understanding of what happened “way back when” at a time when the universe was a baby.
September 26, 2012 at 7:00 am | Leave a Comment
Star Formation is Gorgeous!
When you look at a star, it’s hard to wrap your head around the idea that it came from a cold cloud of gas molecules and dust. Yet, that describes the nebulae where stars are born pretty well. Take the Seagull Nebula. It lies about 3,700 light-years away from us near the constellation Canis Major (the Big Dog) in the sky, and kind of looks like a sea gull with a bright spot or two in it. Those bright spots are newborn stars. The image you see here was taken with the MPG/European Southern Observatory 2.2-meter telescope, using its Wide Field Imager.
So, one part of this complex of gas and dust clouds makes up the head of the cosmic sea gull. It’s glowing brightly (in red, near the bottom of the image) . What causes it fluoresce like that? See the star in the center of the image? That’s a hot young star that formed in the nebula and its strong radiation is heating the gases and causing them to glow.
There are other hot young blue-white stars that hatched here in this stellar nursery, and their light bounces off of dust particles and shows up as a blue haze.
One of the reasons that I’m so taken with images of star birth regions is that they are always so beautiful. That beauty belies the fact that stellar nurseries are places of great destruction. The birth of a star eats up the cloud material. It carves out caverns and spaces, and sometimes the formation of a huge star chokes off the formation of smaller sibling stars that haven’t yet emerged from their nebular cocoons.
Our own Sun was born in a cloud of gas and dust some 4.5 billion years ago. It likely formed with other sibling stars, which have moved on and taken up new spots in the galaxy.
So, when you look at gorgeous images of star birth regions, you’re seeing something similar to the place where our own solar system formed, where the elements that make up our Sun, planets, moons, rings, comets, asteroids… and us… concentrated together in the distant past.
September 25, 2012 at 23:38 pm | Leave a Comment
It Begins Here at Home, Part II
One of the things I absolutely love about astronomy is that it’s just outside the door. You go out, you look up and you see things. During the day you know the Sun’s there, and part of the month you can also see the Moon. At night, the stars are there for your exploration, along with the planets, and an amazing array of deep-sky objects such as nebulae. What if you had such concentrated and perfect eyesight that you could look across more than thirteen billion light-years of space to some of the earliest galaxies and galaxy “seedlings” ever formed? Well, people right here on Earth can do that. They’re using a magnificent time machine called the Hubble Space Telescope to do it.
Over a period of ten years, astronomers have aimed the telescope at a patch of sky in the constellation Fornax and taken images of distant galaxies in that direction. They’ve essentially used HST as a big light bucket for a decade to collect faint light streaming from thousands of galaxies.
The resulting image is called the Hubble eXtreme Deep Field (XDF), and it has gorgeous spiral galaxies similar in shape to our Milky Way and the neighboring Andromeda Galaxy. There are also large, old fuzzy red galaxies where the formation of new stars has shut down.
If you look closely at the large version of this image, you’ll find tiny, faint, and extremely distant galaxies sprinkled across the image. Think of these as the “seedlings” from which today’s striking galaxies grew.
This whole image is basically a history of galaxy formation — from the first shreds of galaxies to the enormous and grand galaxies we see today in near-Milky Way space.
Hubble used two instruments to get this image. It took the Advanced Camera for Surveys and the Wide Field Camera 3 to get this level of detail from 2,000 images taken over a total exposure time of 2 million seconds spread out over ten years. Why take so long? The longer you look, the deeper you look, and the deeper you look, the further back in time you see. Thus, Hubble is really a time machine, showing us the distant universe — all the while orbiting Earth and sending back data and images to astronomers right here on the planet. It’s really pretty amazing when you think about it.
To learn more about this image, surf on over to the Hubble Space Telescope Web site, and feast your eyes on bigger versions of this image. It’s worth exploring!
September 24, 2012 at 9:39 am | Leave a Comment
It Begins Here at Home, Part I
Mars-like Places Here on Earth
Life here on Earth is pretty fascinating. There are so many different kinds of life, and so many different places it can thrive, from the oceans to the mountaintops to the deserts. We can probably be forgiven (us humans) for thinking that Earth is just about the only place where it can do so. That’s understandable… we once thought we were the pinnacle of creation and that Earth was ours to do with what we wanted. And, our planet bears the scars of activities engendered by that kind of thinking.
But, we’re wising up and figuring out that life can exist in all kinds of places and they don’t have to be on our planet. Take Mars, for example. If you’ve been following any of the Mars missions put on or near the planet by any of several countries over the past few decades, you can’t have missed how much some of its landscapes remind us of places here on Earth.
Places where life exists on our planet. Some of them are pretty darned inhospitable places to us as humans, but perfectly acceptable paradises for other forms of life. Take the Antarctic, for example, or the relentlessly hot salt pans in Tunisia, or the Rio Tinto where the environment is corrosively acidic. In all these places, life can be found. These, and other spots such as the Utah desert, Devon Island in the Arctic, and the volcanic slopes of Mauna Kea in Hawai’i are among the many places where scientists do research to understand the conditions where life can flourish.
For Mars, scientists visit all kinds of places to study “Mars analogs”, those places that seem Mars-like here on Earth. Groups such as the Centro de Astrobiologica in Madrid range around the planet doing cutting-edge research on life’s origins and ability to withstand conditions that would give humans second thoughts about living in such areas.
I’ve often flown over the deserts of the southwest U.S. and thought to myself, “take away the plants, chill down the atmosphere, and this place could be Mars”. Same with Hawai’i, where I did some graduate field study in Mars analog conditions. So, it’s natural to me that our home planet would help us understand more about places like Mars. And, in the reverse, that Mars may very well help us understand how life on our own planet evolved and adapted. It’s an ongoing planetary exploration story that’s going on right here on the home planet. Stay tuned!
Research Begins Here at Home, Too.
Final Day for Crowdsourcing Research Fund Drive
Speaking of research here at home, the final countdown has begun for Uwingu’s fundraising campaign over at Indiegogo. The deadline for contributions is midnight tonight (Monday, September 24th) Pacific Daylight Time.
This project is the brain-child of my friend Alan Stern and several well-known planetary scientists and outreach educators. They’ve banded together to create a cool project that will help fund ongoing science research that isn’t being funded today due to budget shortfalls in the U.S. They’ll also be funding outreach projects to help bring the next generation of scientists up to speed as they proceed through elementary, high school and college.
It’s an admirable effort and I’ve donated to the cause because I am a science outreach type myself and I can see what the Uwingu folks are trying to do is of great intrinsic value. Plus, the money’s spent right here on Earth, helping us grow our understanding of the cosmos.
If you’ve got the cost of a trip to your favorite coffee shop available, or can spare the equivalent of a couple of movie tickets or a computer game or even more, consider sending it to Uwingu. You’ll be eligible for some cool perks, although the best one will be simply the satisfaction of knowing you made a difference in science research. THAT’s seriously cool.
I heard from co-founder Alan Stern that he’s going to be on Coast-to-Coast from 10 p.m. to midnight (PDT) tonight during the final countdown to the campaign’s end, sharing his insights with everyone about science research and how important it is to all of us. So, it could get pretty exciting at the last moment!
September 23, 2012 at 21:53 pm | Leave a Comment
At Home in LA
I spent a few hours on Friday watching the space shuttle Endeavour fly from her final stop at Edwards Air Force Base in California up to Sacramento, San Francisco, and finally to Los Angeles. If I had any way to do it, I would have gone out to LA to watch her final landing. I was in Florida for her final launch last year, and it would have been a fitting way to celebrate her final flight.
But, I couldn’t get out there, so I did the next best thing: I watched on the Web. NASA TV wasn’t carrying all of the flight, so I tuned into local TV stations online and observed folks observing the shuttle as she swooped her way around the LA basin. It was a beautiful sight.
I’m one of those people who loves to watch planes land. There’s just something majestic about a huge airliner float to the ground and gently touch down. And, when you count the fact that NASA’s Astro 95 was carrying a shuttle on her back, and was being accompanied by two chase jets… well, it’s irresistable to watch!
The folks at Griffith Observatory had a huge crowd of people watching from their perch on the Hollywood Hills. I have a special affinity for Griffith (I wrote their exhibits), and it’s just one of my favorite places in LA. So, when their Deputy Director wrote me today and mentioned that they had some great video of the flyovers online, I indulged in a few pass-throughs of the show. It’s the ultimate air show folks. Never coming this way again.
So, here it is. Enjoy!
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This blog a wholly pwnd subsidiary of Carolyn Collins Petersen, a.k.a. TheSpacewriter.
Copyright 2013, Carolyn Collins Petersen
Image of Horsehead Nebula: T.A.Rector (NOAO/AURA/NSF) and Hubble Heritage Team (STScI/AURA/NASA)
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