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Domain: cometography.com
Stories and comments across the archive that link to cometography.com.
Stories · 4
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Comets Probably Seeded Earth's Nitrogen Atmosphere
KentuckyFC writes "One of the biggest puzzles of astrobiology is the origin of the Earth's oceans and atmosphere. One favored theory is that our water is the leftovers from a bombardment of comets early in Earth's history. But the ratio of hydrogen and deuterium in the oceans doesn't match the ratio in the four comets measured so far (Halley's, Hyakutake, Hale-Bopp and C/2002 T7 LINEAR). Now a new analysis of the ratio of nitrogen-14 and 15 isotopes in these comets and on Earth places new limits on how much of our environment could have come from comets. On the one hand, the astronomers who did the work say that no more than a few percent of Earth's water could have come from comets. But on the other, they say that the ratio of nitrogen isotopes in these comets almost exactly matches the ratio in Earth's atmosphere. That suggests that while Earth's oceans must have come from somewhere else, Earth's early atmosphere was probably seeded by comets." -
Mission to Harpoon Comet is Back on Track
An anonymous reader writes "The Rosetta mission planners have announced today that after an indefinite launch delay earlier this year, their goal of landing on a comet is back on track. Their new baseline target is a rendezvous with the comet, Churyumov-Gerasimenko, in November 2014. En route to the comet, Rosetta will inspect two asteroids (Otawara and Siwa) at close quarters." -
Comet Kudo-Fujikawa Reaches Perihelion
MagnetarJones writes "Cruising through the inner Solar System, new Comet Kudo-Fujikawa reached perihelion, its closest approach to the Sun, yesterday, January 29. Passing within 28.4 million kilometers of the Sun, this comet came much closer than innermost planet Mercury. The space-based SOHO observatory captured these views of the comet as it neared perihelion by using a coronograph's occulting disk to block the overwhelming sunlight. Though fading on its outbound journey, Kudo-Fujikawa should soon be visible to southern hemisphere comet-watchers in February's evening skies." -
One Meteor Shower Coming Up
Jens Lönn writes: "The annual Giacobinid meteor shower (also known as the Draconids) peaks on October 9th and 10th. Most years the shower produces no more than a few shooting stars per hour for northern sky watchers. But there have been some impressive Giacobinid outbursts - most recently in 1998 where the maximum rate was over 500 per hour. The shower's parent comet is far away, so this year's display will probably be modest. You can see the comets orbit simulated here."
