We’ve now discovered thousands of stars with planets. Is ours really unique?
Shores of Cosmic Oceans
Observations of a white dwarf finds evidence of a Ceres-sized asteroid comprised of one third water.
Body in Motion
[av_video src=’http://vimeo.com/114099764′ format=’16-9′ width=’16’ height=’9′] Standing upon the Earth, we feel at rest. The Sun rises and sets, the stars drift across the night sky. The very universe spins around us. But that’s only how it appears.
A Comet’s Tale
Results are starting to come in from the Rosetta mission, including a new article in Science on the composition of water on the comet 67P/C-G. The results support the idea that Earth’s water didn’t come from cometary bombardments.
Star Trekkin
You may have heard about a “Star Trek-like” shield that scientists have found surrounding the Earth. That’s because the University of Colorado Boulder shamefully stated as much in a press release, and websites all over the world would rather copy and paste than actually do science journalism. The press release was promoting a new paper in Nature which looks at properties of the Earth’s radiation belts.
Ancient Seas
Earth’s water is more ancient than you might suspect.
Thor’s Hammer
Imagine if a Tunguska event occurred every 5 years or so. Every few years, and some part of the planet gets a crater, or an airburst. Most would be in remote areas, but some wouldn’t. Of course we know that meteors follow a power law distribution in size distribution. So for every Tunguska event, there would be thousands of Chelyabinsks. So perhaps 200 of them every year. Then there are the larger ones. Big impacts creating 10km-wide craters every century or so. And the ever larger ones every millennia. Now imagine Earth gets pummeled at this rate for 200 million years.
Rare Earth
About 1.85 billion years ago, in what would come to be known as Sudbury Canada, a 10 kilometer wide asteroid struck with such energy that it created an impact crater 250 kilometers wide. Today the chief industry of Sudbury is mining, all because of that ancient impact. In fact much of the mining industry is possible because of asteroid impacts in Earth’s early history.
Land of Lakes
For the past week I’ve been in a remote part of northern Minnesota, vacationing at my Grandmother’s house. In that part of world you can pretty much throw a stick and hit a lake, which is part of the reason it is known as the Land of 10,000 lakes. Being in a region with so much water tends to give the impression that Earth is water-rich world.