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:
Interesting fact of the day: examining the fossil record suggests that mass extinctions on Earth occur approximately once every 26 million years (Myr). One possible explanation for this is a companion dwarf star to the Sun on a 26 Myr orbit. Every time is passes by, the theory goes, it messes up the Oort cloud and throws comets our way, greatly increasing the possibility of a collision (and all the nasty effects that could go with it). This potential star was christened Nemesis for obvious reasons.
If Nemesis exists then its orbital period (the time it takes to complete one orbit) is predicted to vary by a few Myr every orbit, because of the influence of other stars in the Galaxy. Remember this – it will be important later!
The theory that the mass extinction periodicity is caused by the Nemesis companion star was first suggested in 1984. Since then the quality of the fossil record datasets has improved significantly which has led two scientists, Adrian Melott and Richard Bambach to re-examine the hypothesis using these new modern data. They found strong evidence that mass extinctions have been occurring every 26.8 Myr, stretching back over 500 Myr (interesting aside: that’s approximately as far back as they could go in the fossil record apparently, as that’s how long things with hard body parts, which make good fossils, have existed).
Their results seem at first glance to support the existence of Nemesis. However, the mass extinctions they see are too regular – if they were being triggered by the visits of Nemesis the gap between them should vary more, given the predicted variation in the length of the star’s orbit.
If Nemesis isn’t responsible for these apparently regular extinctions then what is? The alternative explanations range from oscillations in the galactic plane to geological instabilities in the Earth itself, and if someone publishes new research on any of them I’ll maybe try and explain them too. One final thing to note: if Nemesis is out there after all, the new all-sky surveys to be carried out by Pan-Starrs, WISE or the planned LSST should see it.
Adrian L. Melott, & Richard K. Bambach (2010). Nemesis Reconsidered MNRAS arXiv: 1007.0437v1