Asteroid passing Earth will be closer than moon

http://news.msn.com/science-technology/ ... -than-moon

Astronomers witness mysterious, never-before-seen disintegration of asteroid
Astronomers have witnessed for the first time the breakup of an asteroid into as many as 10 smaller pieces. The discovery is published online March 6 in Astrophysical Journal Letters.

Though fragile comet nuclei have been seen falling apart as they near the sun, nothing resembling this type of breakup has been observed before in the asteroid belt. NASA's Hubble Space Telescope photographed the demolition.

"Seeing this rock fall apart before our eyes is pretty amazing," said David Jewitt, a professor in the UCLA Department of Earth, Planetary and Space Sciences and the UCLA Department of Physics and Astronomy, who led the astronomical forensics investigation.

The crumbling asteroid, designated P/2013 R3, was first noticed as an anomalous, fuzzy-looking object on Sept. 15, 2013, by the Catalina and Pan-STARRS sky-survey telescopes. A follow-up observation on Oct. 1 with the W.M. Keck telescope on Hawaii's Mauna Kea revealed three co-moving bodies embedded in a dusty envelope that is nearly the diameter of Earth.

"The Keck telescope showed us that this asteroid was worth looking at with Hubble," Jewitt said.

With its superior resolution, the Hubble telescope revealed that there were really 10 embedded objects, each with comet-like dust tails. The four largest rocky fragments are up to 200 yards in radius, about twice the length of a football field.

The Hubble data showed that the fragments are drifting away from each other at a leisurely pace of one mile per hour — slower than a strolling human. The asteroid began coming apart early last year, but new pieces continue to emerge in the most recent images.

NASA planning to send robotic mission to Europa, Jupiter's watery moon that may harbor life

NASA is plotting a daring robotic mission to Jupiter's watery moon Europa, a place where astronomers speculate there might be some form of life.

The space agency set aside $15 million in its 2015 budget proposal to start planning some kind of mission to Europa. No details have been decided yet, but NASA chief financial officer Elizabeth Robinson said Tuesday that it would be launched in the mid-2020s.

Robinson said the high radiation environment around Jupiter and distance from Earth would be a challenge. When NASA sent Galileo to Jupiter in 1989, it took the spacecraft six years to get to the fifth planet from the sun.

Rensselaer Polytechnic Institute astronomer Laurie Leshin said it could be "a daring mission to an extremely compelling object in our solar system."

Past NASA probes have flown by Europa, especially Galileo, but none have concentrated on the moon, one of dozens orbiting Jupiter. Astronomers have long lobbied for a mission to Europa, but proposals would have cost billions of dollars.

Last year, scientists discovered liquid plumes of water shooting up through Europa's ice. Flying through those watery jets could make Europa cheaper to explore than just circling it or landing on the ice, said NASA Europa scientist Robert Pappalardo.

NASA will look at many competing ideas for a Europa mission, so the agency doesn't know how big or how much it will cost, Robinson said. She said a major mission goal would be searching for life in the strange liquid water under the ice-covered surface.

Scientists Directly Measure Spin of Extremely Distant Supermassive Black Hole

Gravitational lensing by an intervening elliptical galaxy – in the middle of the image – has created four different images of RX J1131-1231.

Such lensing offers a rare opportunity to study regions close to the black hole in distant quasars, by acting as a natural telescope and magnifying the light from these sources.

The X-rays are produced when a swirling accretion disk of gas and dust that surrounds the black hole creates a multimillion-degree cloud, or corona near the black hole.

X-rays from this corona reflect off the inner edge of the accretion disk. The reflected X-ray spectrum is altered by the strong gravitational forces near the black hole. The larger the change in the spectrum, the closer the inner edge of the disk must be to the black hole.

The scientists, who reported their results in the journal Nature, found that the X-rays are coming from a region in the disk located only about three times the radius of the event horizon, the point of no return for infalling matter.

This implies that the black hole must be spinning extremely rapidly to allow a disk to survive at such a small radius.

. . . .

The discovery that the black hole in RX J1131-1231 is spinning at over half the speed of light suggests that this black hole has grown via mergers, rather than pulling material in from different directions.

Wow!

Another Asteroid! Third Space Rock Buzzes Past Earth

http://www.nbcnews.com/#/science/space/ ... rth-n46111

... A herd possibly being shards of one that has broken up n the past?