Universe Today

There's a number in the Universe which we humans call alpha - or the fine structure constant. It shows up in almost every mathematical formula dealing with magnetism and electricity. The very speed of light depends on it. If the value for alpha was even a little bit different, the Universe as we know it wouldn't exist - you, me and everyone on Earth wouldn't be here. Some physicists have recently reported that the value for alpha has been slowly changing since the Big Bang. Others, including Jeffrey Newman from the Lawrence Berkeley National Laboratory have good evidence that alpha has remained unchanged for at least 7 billion years.

Let's say you're browsing around the comic book store and happened to notice a perfect copy of Action Comics #1 on the rack mixed in with the current stuff. It's in mint condition, untouched since it was first printed almost 70 years ago. Now imagine the same situation... except with stars. Anna Frebel is a PhD student at the Research School of Astronomy and Astrophysics at the Australian National University. She's working with a team of astronomers who have found the oldest star ever seen - possibly untouched since shortly after the Big Bang.

In case you missed the news, NASA is headed back to the Moon in the next decade. A permanent lunar base could be down the road, so scientists are starting to consider where we should build. Ben Bussey, with Johns Hopkins University in Maryland likes the Moon's North Pole. It's got everything you might need for a long-term stay: permanent sunlight, relatively stable temperatures, and lots of lunar soil. And as an added bonus, there might be plenty of frozen water hiding in lunar craters.

Wolf-Rayet stars are big, violent and living on borrowed time. Put two of these stars destined to explode as supernovae in a binary system, and you've got an extreme environment, to say the least. Sean Dougherty, an astronomer at the Herzberg Institute for Astrophysics in Canada has used the Very Long Baseline Array radio telescope to track a binary Wolf-Rayet system. The two stars are blasting each other with ferocious stellar winds. This is one fight we're going to stay well away from.

Black holes... you know. Cosmic singularities that can contain the mass of billions of stars like our Sun. Where the pull of gravity is so strong, nothing, not even light can escape their fearsome grasp. They're the source of much discussion, indirect observation and science fiction speculation. But according to George Chapline from Lawrence Livermore National Laboratory in California, they don't exist. Instead we have dark energy stars, which are connected to that mysterious force accelerating the expansion of the Universe.

Remember Sedna? It's that icy object uncovered last year in the outer reaches of the Solar System. When it was first discovered, astronomers noticed it rotated once every 20 days. The only explanation that could explain this slow rotation was a moon, but a moon never showed up in any of their observations. Scott Gaudi is a researcher with the Harvard Smithsonian Centre for Astrophysics. He and his colleagues have been watching the rotation of Sedna with a skeptical eye, and think it's only rotating once every 10 hours or so. As for the moon? Easy come, easy go.

Universe Today is a daily summary of the latest space and astronomy - I've been publishing it daily since 1999. In this audio edition, I interview astronauts, astronomers, and scientists about their latest research. The podcasts are short (10-15 minutes long) and very focused.