This is why we take physics DJ
Black Holes Grow Big by Eating Stars
Cambridge, MA (SPX) Apr 10, 2012
” Most galaxies, including the Milky Way, have a supermassive black hole at their center weighing millions to billions of suns. But how do those black holes grow so hefty? Some theories suggest they were born large. Others claim they grew larger over time through black hole mergers, or by consuming huge amounts of gas.
New research by astronomers at the University of Utah and the Harvard-Smithsonian Center for Astrophysics (CfA) shows that supermassive black holes can grow big by ripping apart double-star systems and swallowing one of the stars.
“Black holes are very efficient eating machines,” said Scott Kenyon of the CfA. “They can double their mass in less than a billion years. That may seem long by human standards, but over the history of the Galaxy it’s pretty fast.” “
As two black holes spiral into each other, they produce gravity waves that contain energy 100 billion trillion times the power of our sun.
This discovery image provides the first evidence that Mercury has a small natural satellite or moon. Visible as a small bright spot in this image taken in March 31, 2012 by MESSENGER, the moon is approximately 70 meters in diameter and orbits Mercury at a mean distance of 14,300 km.
A proposal to name the moon “Caduceus,” after the staff carried by the Roman god Mercury, has been submitted by the MESSENGER team to the International Astronomical Union, the body responsible for assigning names to celestial objects.
This discovery presents an unprecedented opportunity for a return of samples from the Mercury system. In an emergency meeting yesterday evening The MESSENGER team took a unanimous decision to use the remaining propellant to crash MESSENGER into Caduceus. With the right timing and trajectory, MESSENGER will impart just enough momentum to the moon to break it free of Mercury’s gravity well and set it on an Earth-crossing trajectory suitable for recovery as a Mercury meteorite.
If Caduceus is successfully released from the pull of Mercury and placed on a course to reach Earth, we can expect the moon to arrive at Earth by 2014. The MESSENGER team have designed a trajectory that will bring the moon to Earth at a remote location on the Wilkes Land ice sheet in Antarctica within reach for retrieval by the scientific staff at the U.S.-operated McMurdo Station.
Organics Probably Formed Easily in Early Solar System. NASA’s Spitzer Space Telescope observed a fledgling solar system like the one depicted in this artist’s concept. New computer simulations at the University of Chicago show that turbulence lofts dust particles above the illuminated portion of the cloud, where they become exposed to high levels of ultraviolet light from nearby stars. UV irradiation was a key component in the production of complex organic molecules in the early solar system. Read more here. (Credit: Courtesy of NASA/JPL-Caltech)
by Randy Shivak
Sunspot group 1429 with large solar flare in progress. Taken with Daystar Quantum PE .5 Angstrom filter.
Photoset reblogged from with 719 notes
Geomagnetic storms aren’t just beautiful to look at — these disturbances in the Earth’s magnetic field could also be messing with your mind and body. There’s a ton of evidence suggesting that geomagnetic storms can cause everything from depression to cardiac problems — and may even be influencing the stock market.
A new paper suggests there’s a lot more evidence for this connection than anybody realizes.
The paper, published in the Proceedings of the Royal Society B, argues that there’s a large, disparate, and controversial body of scientific literature that links geomagnetic storms to a number of animal behaviors, including cardiovascular, psychiatric and behavioral changes in humans. And author Dr. James Close has the enormous literature review to back up his claims.
Images via NASA/Goddard
The globular cluster Messier 9 shines in this new photo from the Hubble Space Telescope. Credit: NASA & ESA
Hundreds of thousands of glittering stars shine in a cluster at the center of our galaxy in a new photograph from the Hubble Space Telescope.
The cluster is called Messier 9, and contains hordes of stars swarming in a spherical cloud about 25,000 light-years from Earth. The object is too faint to be seen with the naked eye, and when it was discovered by French astronomer Charles Messier in 1764, the scientist could only resolve it as a faint smudge that he classified as a nebula (“cloud” in Latin).
Now, though, the Hubble Space Telescope is powerful enough to make out more than 250,000 individual stars in Messier 9, in a new picture released today (March 16). The bluer points indicate hotter stars, while the redder stars are cooler.
Messier 9 is what’s known as a globular cluster, containing some of the oldest stars in the galaxy in a clump that is thought to have formed together when the universe was much younger. These stars, which are about twice as old as the sun, are made of different materials than our star. They tend to lack the sun’s heavier elements, such as oxygen, carbon and iron, which were only present in larger quantities when the universe was older.
M31, also known as the Andromeda galaxy, is one of the closest galaxies to our own at “only” 2.5 million light-years away. Experts believe Andromeda holds about a trillion stars and spans over 200,000 light-years.
8 images of galaxies far, far away
Page 1 of 2