by Caroline Morley | Feb 1, 2012 | Daily Paper Summaries
A very small rocky planet—close to the size of Mercury—is evaporating as it orbits the host star. The putative planet orbits the star in less than 16 hours, so the planet’s surface is highly irradiated. The planet would actually be hot enough to vaporize rocky material at the surface, which could escape the gravitational pull of the planet and form a comet-like tail trailing the orbit.
by Dan Gifford | Dec 28, 2011 | Current Events
Comets are thought to be the perfect specimens to study the primordial stuff that created our solar system. These icy objects can speed through the inner solar system at up to 150,000 miles per hour after making the long journey from the outer reaches of our Sun’s gravitational influence. As you might imagine, collecting samples from these fleeting visitors can be very difficult. Landing on one is probably out of the question considering their uneven surfaces; however, NASA scientists have come up with a clever idea to get around this difficulty. Instead of landing they will have a craft “hover” over the surface of the comet and fire a harpoon to rapidly collect samples from different locations around the comet.Currently in testing, the firing device is positioned to fire vertically downward into a bucket of target material. It cannot be positioned upward because if it accidentally fires, it could potentially launch a test harpoon tip about a mile! An mechanical winch pulls the bow back to generate enough force to fire the harpoons up to 100 feet per second. The test material is a mix of sand, salt, pebbles, but nobody is sure what they will encounter on the comet itself. It could be a combination of things like the test bed, or it could be mostly dust or even solid rock. This is the tricky part of the harpoon engineering. Most likely the comet will be composed differently in different areas, so the design must be capable of penetrating different types of materials.Also in testing, the harpoon tip must contain a hollow chamber to store the samples collected....
