The 134th Carnival of Space blog festival has been posted at Cumbrian Sky, and it’s the Christmas edition! So expect lots of cool blog posts collected about space and astronomy, just like usual, except now with 52% more Christmasy stuff. So it’ll give you something to do when things get a little too Yuley at home and you just need to get away for a few minutes.

Millions of years ago, a koala looked more like a possum. By studying rare skulls of the famous marsupial that date between 5 and 24 million years old, a team of Australian researchers propose how it got to looking like it does today, with findings published in the Journal of Vertebrate Paleontology.

Food was one driver, they say—millions of years ago koalas ate a variety of foods. The dietary switch to an exclusive eucalypt diet seems to have occurred during the late Miocene period, some 12 to five million years ago, when a drying climate made eucalyptus the dominant forest species [Canberra Times]. As a result, they lost their snouts and developed powerful jaw muscles.

But while koalas need to adapt to the changing food supply, they also needed to stay in communication, and began to develop the low-frequency calls that today can travel half a mile. The researchers hypothesize that the ancient koalas evolved their communication system at a time when the Australian continent was drying out and the koala habitat becoming less dense. By lowering the frequency of their calls, they were able to maintain communication in the sparser forests [Wired.com]. And to hear those low-frequency calls, koalas developed a middle ear with high volume compared to other marsupials.

“The unique cranial configuration of the modern koala is therefore the result of accommodating their masticatory adaptations without compromising their auditory system,” write the researchers [Wired.com]. In other words: you put those two things together and you get today’s adorable but strange marsupial.

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DISCOVER: One Marsupial Too Many

Image: flickr / tinyfroglet

This is simply too cool: the shadow of Saturn’s rings moving across the face of its tiny moon Janus.

This animation is made up of images taken by Cassini (of course) in August. At that time, it was the equinox on Saturn, so the Sun was shining straight down on Saturn’s equator… which happens to be the plane of the orbit for both the rings and the moons. In other words, the Sun was shining straight along the rings. During this brief time, twice per Saturn orbit of 29 years, the moons can cast long shadows across the rings, and the rings can cast shadows on the moons.

Janus really is dinky, just 179 km (111 miles) across, which is why it’s not really all that round. Its gravity isn’t strong enough to crush itself into a sphere. Other moons are bigger, of course, and the Cassini folks just released several other astonishing animations of them as well, showing the moons dancing and eclipsing each other, with Satrun’s rings as the backdrop. This one showing Rhea and Janus is particularly beautiful.

What more can I add? Cassini continues to deliver, over and again. Amazing.

Related posts:
Behold, Saturn
Ringless
Titan’s Shadow
Saturn’s rings do the wave

Photographer Alex Wild picks his favorite images of insects from the year. Bugilicious.

Some people are simply addicted to Facebook, even those that should keep a low profile, according to CNN:

Craig Lynch, 28, escaped Hollesley Bay open prison near Suffolk, eastern England, back in September, but has continued to update his Facebook status regularly — describing everything from his meals to who his next girlfriend will be.

On his Facebook page, Lynch, who was sentenced to seven years for aggravated burglary, is literally giving the finger to the law. The police have spoken with Facebook and are following his status updates like bread crumbs in an attempt to track him down. Then again, ”We’re taking what he’s saying on Facebook with a pinch of salt because he’s now aware that people may be reading what he’s writing,” says one cop.

Uh, not to tell you how to do your job, officers, but maybe you should try tracking the data packets back to the computer he’s using rather than just hoping he’ll make slip up and tell you where he’s hiding out.

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