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Geminid Meteor Shower Coming On December 13–14

December 9, 2012 Leave a comment

If it’s clear late Thursday night, December 13th, 2012, keep a lookout high overhead for the shooting stars of the Geminid meteor shower. “The Geminids are usually one of the two best meteor showers of the year,” says Alan MacRobert, senior editor at Sky & Telescope magazine. “They may beat out the Perseids of August.” This year’s showing has the added benefit of reduced celestial competition — thanks to the new Moon, no moonlight will interfere with meteor counting.

Under a clear, dark sky, you may see a shooting star every minute from 10 p.m. local time Thursday until dawn Friday morning. If you live under the artificial skyglow of light pollution the numbers will be less, but the brightest meteors will still shine through.

Full Stoty: http://www.skyandtelescope.com/about/pressreleases/Geminid-Meteor-Shower-December-13-14-182064841.html

NGC 922: Searching For The Best Black Hole Recipe

December 9, 2012 Leave a comment

In this holiday season of home cooking and carefully-honed recipes, some astronomers are asking: what is the best mix of ingredients for stars to make the largest number of plump black holes?

NGC 922 Credit: X-ray (NASA/CXC/SAO/A.Prestwich et al); Optical (NASA/STScI)

NGC 922 Credit: X-ray (NASA/CXC/SAO/
A.Prestwich et al); Optical (NASA/STScI)

They are tackling this problem by studying the number of black holes in galaxies with different compositions. One of these galaxies, the ring galaxy NGC 922, is seen in this composite image containing X-rays from NASA’s Chandra X-ray Observatory (red) and optical data from the Hubble Space Telescope (appearing as pink, yellow and blue).

NGC 922 was formed by the collision between two galaxies – one seen in this image and another located outside the field of view. This collision triggered the formation of new stars in the shape of a ring. Some of these were massive stars that evolved and collapsed to form black holes.

Most of the bright X-ray sources in Chandra’s image of NGC 922 are black holes pulling material in from the winds of massive companion stars. Seven of these are what astronomers classify as “ultraluminous X-ray sources” (ULXs). These are thought to contain stellar-mass black holes that are at least ten times more massive than the sun, which places them in the upper range for this class of black hole. They are a different class from the supermassive black holes found at the centers of galaxies, which are millions to billions of times the mass of the sun.

Full Story: http://www.chandra.harvard.edu/photo/2012/ngc922/

Charitum Montes: A Cratered Winter Wonderland

December 9, 2012 Leave a comment

Credits: ESA/DLR/FU Berlin (G. Neukum)

Credits: ESA/DLR/FU Berlin (G. Neukum)

The high-resolution stereo camera on ESA’s Mars Express imaged the Charitum Montes region of the Red Planet on 18 June, near to Gale crater and the Argyre basin featured in our October and November image releases.

The brighter features, giving the image an ethereal winter-like feel in the colour images, are surfaces covered with seasonal carbon dioxide frost.

Charitum Montes are a large group of rugged mountains extending over almost 1000 km and bounding the southernmost rim of the Argyre impact basin.

They can be seen from Earth through larger telescope and were named by Eugène Michel Antoniadi (1870–1944) in his 1929 work La Planète Mars.

Full Story: http://www.esa.int/esaSC/SEMH7W2ABAH_index_0.html

NASA’s GRAIL Creates Most Accurate Moon Gravity Map

December 9, 2012 Leave a comment

Lunar gravity field. Image credit: NASA/JPL-Caltech/MIT/GSFC

Lunar gravity field. Image credit: NASA/JPL-Caltech/MIT/GSFC

The new map, created by the Gravity Recovery and Interior Laboratory (GRAIL) mission, is allowing scientists to learn about the moon’s internal structure and composition in unprecedented detail. Data from the two washing machine-sized spacecraft also will provide a better understanding of how Earth and other rocky planets in the solar system formed and evolved.

The gravity field map reveals an abundance of features never before seen in detail, such as tectonic structures, volcanic landforms, basin rings, crater central peaks and numerous simple, bowl-shaped craters. Data also show the moon’s gravity field is unlike that of any terrestrial planet in our solar system.

“What this map tells us is that more than any other celestial body we know of, the moon wears its gravity field on its sleeve,” said GRAIL Principal Investigator Maria Zuber of the Massachusetts Institute of Technology in Cambridge. “When we see a notable change in the gravity field, we can sync up this change with surface topography features such as craters, rilles or mountains.”

Full Story: http://www.jpl.nasa.gov/news/news.php?release=2012-385#1

NASA-NOAA Satellite Reveals New Views Of Earth At Night

December 9, 2012 Leave a comment

Continental United States at night. Credit: NASA Earth Observatory/NOAA NGDC

Continental United States at night. Credit: NASA Earth Observatory/NOAA NGDC

Scientists unveiled today an unprecedented new look at our planet at night. A global composite image, constructed using cloud-free night images from a new NASA and National Oceanic and Atmospheric Administration (NOAA) satellite, shows the glow of natural and human-built phenomena across the planet in greater detail than ever before.

Many satellites are equipped to look at Earth during the day, when they can observe our planet fully illuminated by the sun. With a new sensor aboard the NASA-NOAA Suomi National Polar-orbiting Partnership (NPP) satellite launched last year, scientists now can observe Earth’s atmosphere and surface during nighttime hours.

The new sensor, the day-night band of the Visible Infrared Imaging Radiometer Suite (VIIRS), is sensitive enough to detect the nocturnal glow produced by Earth’s atmosphere and the light from a single ship in the sea. Satellites in the U.S. Defense Meteorological Satellite Program have been making observations with low-light sensors for 40 years. But the VIIRS day-night band can better detect and resolve Earth’s night lights.

Full Story: http://www.nasa.gov/mission_pages/NPP/news/earth-at-night.html
Realated International Dark-Sky Association Story: http://www.darksky.org/night-sky-conservation/266