Astrobiologists take heed of new discoveries about Earth's primordial past. Ice levels in the arctic fall alarmingly low. And the debate over Pluto's status continues. It's Earthy Thursday, our segment on science and Earth-related news. All this and more for the Pagan News Beagle!

At this point, biologists have a pretty good idea of how long life has been around on Earth. Nonetheless, the search for the world's earliest lifeforms in the form of microbial fossils continues. And as pedantic as such efforts may seem they could also teach us a lot about the possibilities of life elsewhere in the universe.

Carbon, oxygen, hydrogen. Those are the most important elements to life. But they're far from the only ones that are vital. Farmers are well-aware of the importance other elements play, like nitrogen or phosphorus. Nitrogen is common enough but cheap supplies of phosphorus are on the decline now, which could spell bad news for agriculture.

Last winter arctic ice levels finally reached a peak. But it was a smaller peak than the year before. Which was a smaller peak than the year before that. As global warming progresses the annual maximum of ice sheets is shrinking and shows little sign of stopping soon.

One of the most popular forms of alternative energy is solar energy, which captures sunlight and transforms it into usable electricity. It has a number of drawbacks: right now it's highly inefficient, is very space-intensive, and only works in certain parts of the world. But when it does work, it's often quite beautiful as these photos demonstrate.

More than 10 years ago, the International Astronomical Union redefined the word "planet" for the scientific community... and the debate has continued ever since. Still, for a number of years it had quieted down somewhat. But now that Pluto has been photographed up-close for the first time, people are questioning the IAU's redefinition as loudly as ever.

Top image by PDTillman