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.
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.
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.
A team of NASA and international scientists for the first time have gathered a detailed understanding of the effects on Earth from a small asteroid impact.
The unprecedented data obtained as the result of the airburst of a meteoroid over the Russian city of Chelyabinsk on Feb. 15, 2013, has revolutionized scientists’ understanding of this natural phenomenon.
The Chelyabinsk incident was well observed by citizen cameras and other assets. This provided a unique opportunity for researchers to calibrate the event, with implications for the study of near-Earth objects (NEOs) and developing hazard mitigation strategies for planetary defense. Scientists from nine countries have now established a new benchmark for future asteroid impact modeling.
“Our goal was to understand all circumstances that resulted in the shock wave,” said meteor expert Peter Jenniskens, co-lead author of a report published in the journal Science.
A team of astronomers from the University of Anitoquia, Medellin, Colombia, have discovered a graveyard of comets. The researchers, led by Antioquia astronomer Prof. Ignacio Ferrin, describe how some of these objects, inactive for millions of years, have returned to life leading them to name the group the ‘Lazarus comets’. The team publish their results in the Oxford University Press journal Monthly Notices of the Royal Astronomical Society.
The new work looked at a third and distinct region of the Solar System, the main belt of asteroids between the orbits of Mars and Jupiter. This volume of space contains more than 1 million objects ranging in size from 1 m to 800 km. The traditional explanation for asteroids is that they are the building blocks of a planet that never formed, as the movement of the pieces was disrupted by the strong gravitational field of Jupiter.
In the last decade 12 active comets have been discovered in the asteroid main belt region. This was something of a surprise and the Medellin team set out to investigate their origin. The team, made up of Prof. Ferrin and his colleagues Profs. Jorge Zuluaga and Pablo Cuartas, now think they have an explanation.
“We found a graveyard of comets”, exclaims Professor Ferrín. He adds: “Imagine all these asteroids going around the Sun for aeons, with no hint of activity. We have found that some of these are not dead rocks after all, but are dormant comets that may yet come back to life if the energy that they receive from the Sun increases by a few per cent.”
Data from NASA’s Wide-field Infrared Survey Explorer (WISE) have led to a new and improved family tree for asteroids in the main belt between Mars and Jupiter.
Astronomers used millions of infrared snapshots from the asteroid-hunting portion of the WISE all-sky survey, called NEOWISE, to identify 28 new asteroid families. The snapshots also helped place thousands of previously hidden and uncategorized asteroids into families for the first time. The findings are a critical step in understanding the origins of asteroid families, and the collisions thought to have created these rocky clans.
“NEOWISE has given us the data for a much more detailed look at the evolution of asteroids throughout the solar system,” said Lindley Johnson, the program executive for the Near-Earth Object Observation Program at NASA Headquarters in Washington. “This will help us trace the NEOs back to their sources and understand how some of them have migrated to orbits hazardous to the Earth.”
NASA is inviting members of the media and public to participate in online and television events May 30-31 with NASA officials and experts discussing the agency’s asteroid initiative and the Earth flyby of the 1.7-mile-long asteroid 1998 QE2.
At 4:59 p.m. EDT, Friday, May 31, 1998 QE2 will pass by Earth at a safe distance of about 3.6 million miles — its closest approach for at least the next two centuries. The asteroid was discovered Aug. 19, 1998, by the Massachusetts Institute of Technology’s Lincoln Near Earth Asteroid Research Program near Socorro, N.M.
Full Story, Times and Links: http://www.nasa.gov/home/hqnews/2013/may/HQ_M13-086_QE2_Asteriod_Events.html
On May 31, 2013, asteroid 1998 QE2 will sail serenely past Earth, getting no closer than about 3.6 million miles (5.8 million kilometers), or about 15 times the distance between Earth and the moon. And while QE2 is not of much interest to those astronomers and scientists on the lookout for hazardous asteroids, it is of interest to those who dabble in radar astronomy and have a 230-foot (70-meter) — or larger — radar telescope at their disposal.
“Asteroid 1998 QE2 will be an outstanding radar imaging target at Goldstone and Arecibo and we expect to obtain a series of high-resolution images that could reveal a wealth of surface features,” said radar astronomer Lance Benner, the principal investigator for the Goldstone radar observations from NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “Whenever an asteroid approaches this closely, it provides an important scientific opportunity to study it in detail to understand its size, shape, rotation, surface features, and what they can tell us about its origin. We will also use new radar measurements of the asteroid’s distance and velocity to improve our calculation of its orbit and compute its motion farther into the future than we could otherwise.”
The closest approach of the asteroid occurs on May 31 at 1:59 p.m. Pacific (4:59 p.m. Eastern / 20:59 UTC). This is the closest approach the asteroid will make to Earth for at least the next two centuries. Asteroid 1998 QE2 was discovered on Aug. 19, 1998, by the Massachusetts Institute of Technology Lincoln Near Earth Asteroid Research (LINEAR) program near Socorro, New Mexico.
The Japan Aerospace Exploration Agency (JAXA) is scheduled to launch the asteroid explorer “Hayabusa2”*1 on the H-IIA Launch Vehicle in 2014. The Hayabusa2 will arrive at an asteroid in 2018 to investigate it for one and half years, before returning to Earth in 2020.
JAXA will record and load your names, messages and illustrations on onboard devices (the target marker*2 and re-entry capsule*3) of the Hayabusa2. Through this campaign and Hayabusa2’s six-year space mission, we would like people to deepen their understanding of Japan’s space probe activities.
NASA and international researchers have discovered that Earth’s moon has more in common than previously thought with large asteroids roaming our solar system.
Scientists from NASA’s Lunar Science Institute (NLSI) in Moffett Field, Calif., discovered that the same population of high-speed projectiles that impacted our lunar neighbor four billion years ago, also hit the giant asteroid Vesta and perhaps other large asteroids.
The research unveils an unexpected link between Vesta and the moon, and provides new means for studying the early bombardment history of terrestrial planets. The findings are published in the March issue of Nature Geoscience.