Hello all and welcome to the round up of what’s been going on in the Universe this week. If you’d like to find out more, or get involved yourself, check out the Carnival’s homepage over at Universe Today.
Before we get started, an important request: Nicole at NoisyAstronomer.com is asking people to help the residents of Louisa County, Virginia, which was the epicenter of the 5.8 magnitude east cost earthquake that happened earlier this year.
Onto the stories, and let’s begin with some space-travel news. NASA Space Flight gives an update on the progress New Orleans engineers are making on the Orion Multi-Purpose Crew Vehicle. The current aim is for this vehicle to blast off into orbit in 2013, with later missions aiming for the moon and perhaps beyond.
In other NASA news, Next Big Future report on news that the Space Agency hid the cheaper cost of in-space fuel depots to get a heavy lift rocket. They also cover Robert Bigelow’s prediction that China will have claimed large parts of the moon as its territory before 2030.
If NASA’s taking too long for you, how about launching your own spacecraft? For a small donation you can, thanks to the Sprite project.
Time for some history now. Riofrio Spacetime has paid a visit to Enterprise, the test vehicle which made the Space Shuttle program possible, whilst I visited SCUBA, a groundbreaking astronomical instrument which opened up the far-infrared – a previously little-explored wavelength range. Finally Vintage Space tells the story of Apollo 10, the dress rehearsal for the moon landing, and Cheap Astro’s podcast reminisces about the STS127 shuttle mission.
There’s more distant thinking over at Universe Today, where Paul Spudis outlines his plan for an affordable lunar base. It includes a type of ‘transcontinental railroad’ which opens up cislunar space – the area between Earth and the Moon – for development.
Moving out into the Solar System, and Astroblog reports that the remnants of Comet C/2010 X1 Elenin, which disintegrated in August, have been found, whilst Dear Astronomer answers the question “Why isn’t Pluto a planet anymore?” On a related note, the Urban Astronomer writes about the swarms of comets which the Spitzer Space Telescope has detected in the solar system around the star Eta Corvi.
Next up are stories from two tweetups (an informal meeting of people brought together via twitter) that took place recently. Weather Chat and Galileo’s Pendulum share their experiences of meeting astronauts from the final shuttle flight at the STS 135 tweetup in Washington DC. There are some more photos of the event from NASA HQ here. Meanwhile open.NASA and Ian Kluft visited NASA Ames for a tweetup in honour of the Stratospheric Observatory for Infrared Astronomy, or SOFIA (or the aeroplane with a telescope in the back, that flies even though there’s a giant hole cut in the side, as I like to call it). Again, there’s more photos of the event here (including the one above) and here, as well as two videos from the day.
The re-entry of the ROSAT and UARS satellites recently has highlighted the growing problem of space debris. The Space Review revisits the legal implications of potential damage caused by this junk whilst I’ve been learning how lasers might provide the answer. For lots more information on this subject check out the new edition of The Orbital Debris Newsletter.
Nearly done now (it’s certainly been a busy astro-week!) Alice of Alice’s AstroInfo found a star in 2000 and last week it (may have) exploded. She talks about the thrill of discovery, and what the new X-ray observations might mean. Over at the Chandra Blog Jessica Brodsky has been sleuthing through the Chandra archives on a quest to tag the images.
Finally, if these stories have inspired you, here’s two competitions to get your imaginations going. The 2012 Jim Bean Memorial Writing Contest is looking for “science fiction writers who create positive stories about man’s future in space”. No pulp fiction about large-breasted alien ladies in distant galaxies please! If film’s more your thing enter the American Museum of Natural History’s Beyond Planet Earth contest. They’re looking for original, out-of-this-world ideas on the future of space exploration in 3 minutes or less – watch their introductory video to find out more:
Since the launch of Sputnik in 1957 we’ve launched tonnes of stuff (literally) into space. We’ve not kept things very tidy up there either, so we now have hundreds of thousands of pieces of junk orbiting around us, threatening to crash into important things like the International Space Station. Or the satellite that handles your TV signal. These range in size from entire defunct satellites, to tiny coin-sized bits (there was even an astronaut’s tool bag for a while). How should we deal with all this mess? Shoot it with a laser of course!
It’s actually a pretty simple idea – laser pulses fired at a piece of debris act as a force which slow it down, thus changing its orbit and eventually making it fall into the atmosphere and safely burn up. It was first proposed 15 years ago but it’s only recently that technology has advanced to a stage that it could be built. I’m imagining that it will look something like this:
(Image from Flash Gordon and borrowed from Thiel-A-Vision)
but the authors of a paper published on the astronomy arXiv today disappointingly have something more like this in mind:
They also note that a project like this would need international co-operation before it could be built. I thought that this was because it would be a complicated thing to construct, but on closer reading it turns out to be a more fundamental issue. It’s to
…avoid concerns that it is really a weapons system.
Probably another good reason not to go with a Flash Gordon inspired design. Still, however it ends up looking, it should be a major help in cleaning up our astronomical mess.
Claude R. Phipps, Kevin L. Baker, Brian Bradford, E. Victor George, Stephen B. Libby, Duane A. Liedahl, Bogdan Marcovici, Scot S. Olivier, Lyn D. Pleasance, James P. Reilly, Alexander Rubenchik, David N. Strafford, & Michael T. Valley (2011). Removing Orbital Debris with Lasers Advances in Space Research arXiv: 1110.3835v1
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So this post was supposed to be about the discovery of the most distant galaxy ever found, at a redshift of about 8.2 (13.1 billion light years from us, or, to put it another way, only about 630 million years after the Big Bang), but I didn’t get round to it yesterday and I’ve now been distracted by a paper out today on telescopes, laser beams and aeroplanes instead! (For more details on the distant galaxy see this post over at the always excellent In the Dark. There’s a lot of effort being put into this field at the moment, as already discussed here by Rita, so I expect there’ll be a new ‘most distant’ one that I can catch up with soon.)
One of the main problems astronomers face when trying to observe things in the sky is the turbulence in the Earth’s atmosphere, from clouds, wind etc (this is known as ‘seeing’ and is what causes the stars to twinkle). To get away from this telescopes are normally built high up on mountains, above as many of the clouds as possible, or, like the Hubble Space Telescope, put into orbit where there’s no atmosphere to worry about.
Putting a telescope on a mountain doesn’t completely avoid all the atmospheric distortions, but a technique called adaptive optics can help to correct it. This needs a nice bright star in the field of view, but when this isn’t available an artificial star can be created by shooting a laser beam into the sky, as shown for the Keck Telescope in the picture above. The telescope then observes this ‘star’, and uses its fluctuations in shape (due to the current patch of atmosphere overhead at the time) to correct the astronomical images as they are observed. I should add here that this isn’t the only time lasers are used alongside telescopes – for example they are also fired at the reflectors left on the moon by the Apollo missions, as I’ve blogged about before.
The only flaw in this telescopes-lasers-great corrected, pictures of the sky/laser ranging plan is aeroplanes. Laser beams can dazzle pilots so understandably they can’t be used at the telescopes when planes are in the vicinity. What this has meant in practice up till now is someone sitting outside all night, ready to close the laser-shutter when one comes too close. Not very practical and a pretty boring job! Well, now some researchers in California have come up with a solution. Aviation regulations require that all aircraft are fitted with transponders so that they can be tracked by air-traffic control. By measuring the ratio of transponder signal power from two antennae aligned with the laser, one broad and one narrow beam, the position of the aircraft can be found. An automated shutter can then be activated to turn the laser off, and the cold plane-watchman can go back inside.
W. A. Coles, T. W. Murphy Jr., J. F. Melser, J. K. Tu, G. A. White, K. H. Kassabian, K. Bales, & B. B. Baumgartner (2009). A Radio System for Avoiding Illuminating Aircraft with a Laser Beam submitted to PASP arXiv: 0910.5685v1