Hearts Of Galaxies Close In For Cosmic Train Wreck

The galactic cores are in a single, tangled galaxy called NGC 6240, located 400-million light years away in the constellation Ophiuchus. Millions of years ago, each core was the dense center of its own galaxy before the two galaxies collided and ripped each other apart. Now, these cores are approaching each other at tremendous speeds and preparing for the final cataclysmic collision. They will crash into each other in a few million years, a relatively short period on a galactic timescale.
The spectacular image combines visible light from NASA's Hubble Space Telescope and infrared light from Spitzer. It catches the two galaxies during a rare, short-lived phase of their evolution, when both cores of the interacting galaxies are still visible but closing in on each other fast.
"One of the most exciting things about the image is that this object is unique," said Stephanie Bush of the Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass., lead author of a new paper describing the observation in an upcoming issue of the Astrophysical Journal. "Merging is a quick process, especially when you get to the train wreck that is happening. There just aren't many galactic mergers at this stage in the nearby universe."
NGC 6240 is already putting out huge amounts of infrared light, an indication that a burst of star formation is underway. The extra infrared radiation is common in interacting galaxies; as the two galaxies interact, dust and gas swept up by the collision form a burst of new stars that give off infrared light. Such galaxies are called luminous infrared galaxies. Spitzer's infrared array camera can image the extra heat from newly formed stars, even though their visible light is obscured by thick dust clouds around them.
The blob-like shape of the galaxy is due to the sustained violence of the collision. Streams of millions of stars are being ripped off the galaxy, forming wispy "tidal tails" that lead off NGC 6240 in several directions. But things are about to get even more violent as the main event approaches and the two galactic cores meld into one.
In the center of NGC 6240, the two black holes in the cores will whip up a frenzy of radiation as they careen towards one another head-on, likely transforming the galaxy into a monster known as an ultra-luminous infrared galaxy, thousands of times as bright in infrared as our Milky Way.
Another fascinating aspect of this rare object is that no two galactic mergers are the same. "Not only are there few objects at this stage, but each object is unique because it came from different progenitor galaxies," said Bush. "These observations give us another layer of information about this galaxy, and galactic mergers in general."
Infrared light taken by Spitzer's infrared array camera at 3.6 and 8.8 microns (red) shows cold dust and radiation from star formation; visible light from Hubble (green and blue) shows hot gas and stars.
Other authors of this paper include Zhong Wang, Margarita Karovska and Giovanni Fazio, all of the Harvard-Smithsonian Center for Astrophysics.
NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology, also in Pasadena. Caltech manages JPL for NASA.

practical ways to combat climate change

How to Tackle Global Warming and Still Keep the Lights On.

It concerns practical solutions to the biggest global challenge of our generation, and in the pod we discuss the hypocrisy of some of the trendier and more high-profile greenies (Live Earth, anyone?) and ask: can technology solve everything? The book is co-authored by the former government chief scientist Sir David King and it's outnow.

Tsunami Video - Patong Beach, Thailand

Tsunami Video - Patong Beach, Thailand

Video Description:

Taken by a local resident who was about to film a marathon, the video captured the massive earthquake as it shook the town of Banda Aceh. Participants and spectators of the marathon could be seen holding onto the ground as they waited for the quake to subside. Cars were jolted from side to side by the 9.1-strong quake.

Residents soon rushed their way inland as they heard news about the tsunami. The cameraman also captured survivors climbing on the piles of debris gathered by the flowing river, some of whom managed to escape by reaching the river bank.

சுனாமி - கன்னியாகுமரி (Tsunami in Kanyakumari)

Maps of Moon's far side give new clues to its origin

Maps of Moon's far side give new clues to its origin :
BRISBANE: Astronomers have gained new insight into how the Moon formed by combining a new topographical map with knowledge about the Moon's gravity.

The map is the first to cover the Moon from pole to pole and shows craters never before seen, researchers report today in a trio of papers in the U.S. journal Science.

The experts also reveal the first direct observations of gravitational anomalies on the satellite's far side, which, combined with the topographic data, suggest that the Moon has very little water – a key clue to understanding its origin and evolution.

Two-faced Moon
"The surface can tell us a lot about what's happening inside the Moon, but until now mapping has been very limited," said C.K Shum an earth scientist at Ohio State University in the U.S. and co-author of one of the studies. "With this new high-resolution map, we can confirm that there is very little water on the Moon today, even deep in the interior. And we can use that information to think about water on other planets, including Mars."
The data was collected by SELENE, a Japanese satellite that has subsidiary satellites that relay information from the main craft back to Earth, while it is out of sight on the far side of the Moon. That allows the researchers to track the satellite's movements accurately and be certain of the quality of the data, said study co-author Noriyuki Namiki, of Kyushu University in Fukuoka, Japan.
Using a laser altimeter, SELENE has mapped the Moon's entire surface to a resolution of 15 km (meaning that objects as small as 15-km-wide can be seen). This is up from the previous resolution of 20 to 60 km provided by NASA's 1994 Clementine mission, which only mapped part of the surface.

Rigid crust
From Earth we always see the same side of the Moon (the near side) as its rotation is tidally locked with ours.
The new map shows the substantial differences between the Moon's near and far sides. The side of the Moon that faces Earth is covered with low-lying, smooth, dark volcanic rock, while the on the far side there are older, heavily cratered highlands.
The map also gives hints about the Moon's interior, because it doesn't show the surface crust bending over areas of unusually high gravity on the far side. The rigidity of the crust suggests that there is very little water even deep inside the Moon, the researchers said, because water would make the Moon's crust more flexible.

"The abundance of water is a key parameter to understanding the formation and evolution of the Moon," said co-author of one study Araki Hiroshi, an astronomer at the National Astronomical Observatory of Japan in Tokyo.
The lack of water suggested by SELENE supports the theory that the Moon was formed in a giant collision between a still-molten Earth and a wandering proto-planet. Astronomers believe that such an impact would have heated the debris that became the Moon, evaporating off its water and explaining why the Moon is dry even though it is close to a watery Earth.
Astrophysicist Sarah Maddison, of Swinburne University in Melbourne, Australia, said that getting a good map of the whole Moon was an important step, because knowing the exact shape of the Moon gave researchers better information about its gravity.