Archive
Asteroid To Fly By Earth Safely On January 26
Image credit: NASA/JPL-Caltech
An asteroid, designated 2004 BL86, will safely pass about three times the distance of Earth to the moon on January 26. From its reflected brightness, astronomers estimate that the asteroid is about a third of a mile (0.5 kilometers) in size. The flyby of 2004 BL86 will be the closest by any known space rock this large until asteroid 1999 AN10 flies past Earth in 2027.
At the time of its closest approach on January 26, the asteroid will be approximately 745,000 miles (1.2 million kilometers) from Earth.
“Monday, January 26 will be the closest asteroid 2004 BL86 will get to Earth for at least the next 200 years,” said Don Yeomans, who is retiring as manager of NASA’s Near Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, California, after 16 years in the position. “And while it poses no threat to Earth for the foreseeable future, it’s a relatively close approach by a relatively large asteroid, so it provides us a unique opportunity to observe and learn more.”
Spitzer Spies An Odd, Tiny Asteroid
Astronomers using NASA’s Spitzer Space Telescope have measured the size of an asteroid candidate for NASA’s Asteroid Redirect Mission (ARM), a proposed spacecraft concept to capture either a small asteroid, or a boulder from an asteroid. The near-Earth asteroid, called 2011 MD, was found to be roughly 20 feet (6 meters) in size, and its structure appears to contain a lot of empty space, perhaps resembling a pile of rubble. Spitzer’s infrared vision was key to sizing up the asteroid.
“From its perch up in space, Spitzer can use its heat-sensitive infrared vision to spy asteroids and get better estimates of their sizes,” said Michael Mommert of Northern Arizona University, Flagstaff, lead author of a new study appearing today, June 19, in the Astrophysical Journal Letters. David Trilling, also of Northern Arizona University, leads the team of astronomers.
Asteroid To Black Out A Bright Star
Credit: IOTA / Stellarium / Sky & Telescope
Millions of people around New York City and points north can plan to watch a faint asteroid dramatically black out a bright naked-eye star very late next Wednesday night (the night of March 19–20).
And if you’re anywhere from the Carolinas to Nova Scotia to Winnipeg, a citizen-science project is asking you to keep watch too!
Get ready for the best and brightest “asteroid occultation” ever predicted for North America. Late on the night of March 19–20, the faint asteroid Erigone (eh-RIG-uh-nee) will briefly eclipse the bright naked-eye star Regulus for more than 20 million people in the New York metropolitan area and parts of Long Island, New Jersey, Connecticut, upstate New York, and Ontario. The star will vanish from sight for up to 14 seconds around 2:06 a.m. EDT on the morning of the 20th for New Yorkers, and a minute or two later farther north.
If the sky is clear, Regulus will be a cinch for anyone to spot — no astronomy experience required! Around 2 a.m. or a bit before, go out and face the Moon. Extend your arms straight out to your sides. Regulus will be straight above your right hand, roughly as high as the Moon is. It’s the brightest star in that area.
“Regulus shines right through moonlight and light pollution that’s in the sky — even the light pollution over a city like New York,” says Alan MacRobert, a senior editor at Sky & Telescope magazine. “Just be sure to shield your eyes against any glary lights, and Regulus should be easy to find.”
Rocks Around The Clock: Asteroids Pound Tiny Star
Artist’s impression. Credit: NASA/JPL-Caltech
Scientists using CSIRO’s Parkes telescope and another telescope in South Africa have found evidence that a tiny star called PSR J0738-4042 is being pounded by asteroids — large lumps of rock from space.
“One of these rocks seems to have had a mass of about a billion tonnes,” CSIRO astronomer and member of the research team Dr Ryan Shannon said.
PSR J0738-4042 lies 37,000 light-years from Earth in the constellation of Puppis.
The environment around this star is especially harsh, full of radiation and violent winds of particles.
“If a large rocky object can form here, planets could form around any star. That’s exciting,” Dr Shannon said.
‘Rogue’ Asteroids May be The Norm
To get an idea of how the early solar system may have formed, scientists often look to asteroids. These relics of rock and dust represent what today’s planets may have been before they differentiated into bodies of core, mantle, and crust.
In the 1980s, scientists’ view of the solar system’s asteroids was essentially static: Asteroids that formed near the sun remained near the sun; those that formed farther out stayed on the outskirts. But in the last decade, astronomers have detected asteroids with compositions unexpected for their locations in space: Those that looked like they formed in warmer environments were found further out in the solar system, and vice versa. Scientists considered these objects to be anomalous “rogue” asteroids.
But now, a new map developed by researchers from MIT and the Paris Observatory charts the size, composition, and location of more than 100,000 asteroids throughout the solar system, and shows that rogue asteroids are actually more common than previously thought. Particularly in the solar system’s main asteroid belt — between Mars and Jupiter — the researchers found a compositionally diverse mix of asteroids.
Recently Reactivated NASA Spacecraft Spots Its First New Asteroid
NASA’s Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) spacecraft has spotted a never-before-seen asteroid — its first such discovery since coming out of hibernation last year.
NEOWISE originally was called the Wide-field Infrared Survey Explorer (WISE), which had made the most comprehensive survey to date of asteroids and comets. The spacecraft was shut down in 2011 after its primary mission was completed. But in September 2013, it was reactivated, renamed and given a new mission, which is to assist NASA’s efforts to identify the population of potentially hazardous near-Earth objects (NEOs). NEOWISE also can assist in characterizing previously detected asteroids that could be considered potential targets for future exploration missions
NEOWISE’s first discovery of its renewed mission came on Dec. 29 — a near-Earth asteroid designated 2013 YP139. The mission’s sophisticated software picked out the moving object against a background of stationary stars. As NEOWISE circled Earth scanning the sky, it observed the asteroid several times over half a day before the object moved beyond its view. Researchers at the University of Arizona used the Spacewatch telescope at the Kitt Peak National Observatory southwest of Tucson to confirm the discovery. Peter Birtwhistle, an amateur astronomer at the Great Shefford Observatory in West Berkshire, England, also contributed follow-up observations. NASA expects 2013 YP139 will be the first of hundreds of asteroid discoveries for NEOWISE.
NASA’s Asteroid Hunter Spacecraft Returns First Images After Reactivation
Image credit: NASA/JPL-Caltech
NASA’s Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE), a spacecraft that made the most comprehensive survey to date of asteroids and comets, has returned its first set of test images in preparation for a renewed mission.
NEOWISE discovered more than 34,000 asteroids and characterized 158,000 throughout the solar system during its prime mission in 2010 and early 2011. It was reactivated in September following 31 months in hibernation, to assist NASA’s efforts to identify the population of potentially hazardous near-Earth objects (NEOs). NEOWISE also can assist in characterizing previously detected asteroids that could be considered potential targets for future exploration missions.
“NEOWISE not only gives us a better understanding of the asteroids and comets we study directly, but it will help us refine our concepts and mission operation plans for future, space-based near-Earth object cataloging missions,” said Amy Mainzer, principal investigator for NEOWISE at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “The spacecraft is in excellent health, and the new images look just as good as they were before hibernation. Over the next weeks and months we will be gearing up our ground-based data processing and expect to get back into the asteroid hunting business, and acquire our first previously undiscovered space rock, in the next few months.”
‘Freakish’ Asteroid Discovered, Resembles Rotating Lawn Sprinkler
Credit: NASA, ESA, and D. Jewitt (UCLA)
Astronomers have discovered a “weird and freakish object” resembling a rotating lawn sprinkler in the asteroid belt between Mars and Jupiter. The find, reported online in the Nov. 7 issue of the Astrophysical Journal Letters, has left them scratching their heads and searching for an explanation for the strange asteroid’s out-of-this-world appearance.
Normal asteroids appear simply as tiny points of light. This bizarre asteroid has six comet-like tails of dust radiating from it like spokes on a wheel.
“It’s hard to believe we’re looking at an asteroid,” said lead investigator David Jewitt, a professor in the UCLA Department of Earth and Space Sciences and the UCLA Department of Physics and Astronomy. “We were dumbfounded when we saw it. Amazingly, its tail structures change dramatically in just 13 days as it belches out dust.”
One interpretation is that the asteroid’s rotation rate increased to the point where its surface started flying apart, ejecting dust in episodic eruptions, starting last spring. The team has ruled out a recent asteroid impact scenario because a large quantity of dust would have been blasted into space all at once. This object, designated P/2013 P5, has ejected dust for at least five months, Jewitt said.
Link To Full Story
Link To Another Story
Link To Another Story
NASA’s GRAIL Mission Puts A New Face On The Moon
Scientists using data from the lunar-orbiting twins of NASA’s Gravity Recovery and Interior Laboratory (GRAIL) mission are gaining new insight into how the face of the moon received its rugged good looks. A report on the asymmetric distribution of lunar impact basins is published in this week’s edition of the journal Science.
“Since time immemorial, humanity has looked up and wondered what made the man in the moon,” said Maria Zuber, GRAIL principal investigator from the Massachusetts Institute of Technology in Cambridge. “We know the dark splotches are large, lava-filled, impact basins that were created by asteroid impacts about four billion years ago. GRAIL data indicate that both the near side and the far side of the moon were bombarded by similarly large impactors, but they reacted to them much differently.”
Understanding lunar impact basins has been hampered by the simple fact that there is a lack of consensus on their size. Most of the largest impact basins on the near side of the moon (the moon’s face) have been filled with lava flows, which hide important clues about the shape of the land that could be used for determining their dimensions. The GRAIL mission measured the internal structure of the moon in unprecedented detail for nine months in 2012. With the data, GRAIL scientists have redefined the sizes of massive impact basins on the moon.
Astronomers Establish The Strength Of High-Inclination Asteroids
A team of astronomers from the National Astronomical Observatory of Japan and the University of Hyogo used the Subaru Prime Focus Camera (Suprime-Cam) mounted on the Subaru Telescope to observe faint asteroids with highly inclined orbits. They found that a smaller fraction of tiny bodies occur among high-inclination asteroids than those near the ecliptic plane. This means that large asteroids in high-velocity collisions between asteroids probably have a greater increase of strength in resisting disruption than those in the present mean-velocity collisions. Clarification of the relationship between collisional velocity and asteroids’ disruptive strength is helpful in understanding the collisional evolution of asteroids in the early Solar System.
AstroNews 