Concluding 1 year of Astrobites
Astrobites looks back at its first year as the astro-ph reader’s digest.
Saving the World by Harpooning a Comet
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....Fingerprinting Galaxies with Stellar Population Models
Can we match models of galaxy evolution to multiwavelength galaxy observations in order to infer galactic properties? In this paper, the authors compare this method to others for a sample of z~1 galaxies.
If Santa goes Down Under
The moon is usually pictured in illustrations of Christmastime which show evening or night scenes. But, as Peter Barthel reveals in his study, illustrations of the partially lit moon are often astronomically incorrect, unless the scenes take place Down Under.
The Christmas Burst: GRB 101225A Explained?
Last year on Christmas day, scientists observed a unique gamma-ray burst, GRB 101225A. Two interesting and very different models have developed for the ‘Christmas burst:’ a tidal disruption of a comet by a neutron star somewhere in our Galaxy, or a neutron star consuming its companion star over 5 billion light years away.