Posted on by Elizabeth Howell

‘Freakish’ Asteroid Has Six Tails, Sheds Stuff Into Space

Pictures of asteroid P/2013 P5 taken by the Hubble Space Telescope. Credit: NASA, ESA, and D. Jewitt (UCLA)

A lawn sprinkler in space. That’s one of the descriptions NASA has for the curious P/2013 P5, which is spewing not one, not two, but six comet-like tails at the same time.

“We were literally dumbfounded when we saw it,” stated David Jewitt of the University of California at Los Angeles, who led the research. “Even more amazing, its tail structures change dramatically in just 13 days as it belches out dust. That also caught us by surprise. It’s hard to believe we’re looking at an asteroid.”

UCLA described the asteroid as a “weird and freakish object” in its own press release.

The mystery started when astronomers spotted a really blotchy thing in space Aug. 27 with the Pan-STARRS survey telescope in Hawaii. The Hubble Space Telescope then swung over to take a look on Sept. 10, revealing all these tails of debris flying off the asteroid.

Pan-STARRS PS1 Observatory just before sunrise on Haleakala, Maui. Credit: Harvard-Smithsonian Center for Astrophyiscs
Pan-STARRS PS1 Observatory just before sunrise on Haleakala, Maui. Credit: Harvard-Smithsonian Center for Astrophyiscs

It appears, scientists say, that the asteroid is rotating so quickly that it is ripping its very surface apart. They’ve ruled out a collision because the dust leaves in spurts; calculations by team member Jessica Agarwal of the Max Planck Institute for Solar System Research in Lindau, Germany estimated this happened on April 15, July 18, July 24, Aug. 8, Aug. 26 and Sept. 4.

Once the dust gets loose, the sun’s continuous stream of particles then pushes the debris into these extraordinary tails. It’s also possible that this “radiation pressure” contributed to the asteroid’s high spin rate. It appears the team is looking to find more of these objects to see if this is a way that smaller asteroids commonly fall apart.

“In astronomy, where you find one, you eventually find a whole bunch more,” Jewitt stated. “This is just an amazing object to us, and almost certainly the first of many more to come.”

The research appeared in Astrophysical Journal Letters and is also available in prepublished form on Arxiv.

Source: NASA

Posted on by Elizabeth Howell

Lovely Green Olivine On Vesta Paints A Different Formation History

The mineral olivine on Vesta, as seen from hyperspectral data received during the Dawn mission. Credit: Image generated by Alessandro Frigeri and Eleonora Ammannito using VIR data and Framing Camera images.

That ghoul-like sheen on the asteroid Vesta, as seen in the image above, is not some leftover of Hallowe’en. It’s evidence of the mineral olivine. Scientists have seen it before in “differentiated” bodies — those that have a crust and an inner core — but in this case, it’s turning up in an unexpected location.

Finding olivine is not that much of a surprise. Vesta is differentiated and also (likely) is the origin point of diogenite meteorites, which are sometimes olivine-rich. Researchers expected that the olivine would be close to the diogenite rocks, which in Vesta’s case are in areas of the south pole carved out from the mantle.

NASA’s Dawn mission to the asteroid did a search in areas around the south pole — “which are thought to be excavated mantle rocks”, the researchers wrote — but instead found olivine  in minerals close to the surface in the northern hemisphere. These minerals are called howardites and are normally not associated with olivine. So what is going on?

Artist's conception of the Dawn mission. Credit: NASA
Artist’s conception of the Dawn mission. Credit: NASA

Basically, it means that Vesta’s history was far more complex than we expected. This situation likely arose from a series of impacts that changed around the eucritic (stony meteorite) crust of Vesta:

“A generalized geologic history for these olivine-rich materials could be as follows: ancient large impacts excavated and incorporated large blocks of diogenite-rich and olivine-rich material into the eucritic crust, and subsequent impacts exposed this olivine-rich material,” the researchers wrote.

“This produced olivine-rich terrains in a howarditic background, with diogene-rich howardites filling nearby, eroded, older basins.”

Dawn, by the way, has completed its time at Vesta and is now en route to another large asteroid, Ceres. But there’s still plenty of data for analysis. This particular research paper was led by E. Ammannito from the Institute of Astrophysics and Space Planetology (Istituto di Astrofisica e Planetologia Spaziali) in Rome. The research appears in this week’s Nature and should be available shortly at this link.

Posted on by Elizabeth Howell

What If Earth Was Threatened by An Asteroid Strike? Astronaut Panel Brings Up Ideas To Search, Deflect These Threats

Computer generated simulation of an asteroid strike on the Earth. Credit: Don Davis/AFP/Getty Images

“If we get hit 20 years from now, that’s not bad luck. That’s stupidity.”

That’s what former NASA astronaut Ed Lu has to say about asteroids and our efforts to search for them. He delivered those comments at a panel discussion today at New York’s American Museum of Natural History. He and several other astronauts spoke on behalf of the Association of Space Explorers (which, as the name implies, consists of astronauts, cosmonauts and the like.)

We guess that as astute readers of our publication, you know that a planetary threat from asteroids (and comets) exists. And there’s certainly more we can do; when that 17-meter asteroid blasted Russia earlier this year, Lu said most space agencies learned about it from social media!

So what’s being done about these threats? Here’s a roundup of the panel discussion’s information and some related information.

Asteroid searching and deflection:
  • Since Lu is the CEO of the B612 Foundation, there was a heavy emphasis on the agency’s proposed Sentinel telescope. Intended to launch in 2018, it would survey the solar system in infrared and seek out potential hazards.
  • To date, NASA’s NEO Observations Program has found 95 per cent of near-Earth objects larger than one kilometer, Jet Propulsion Laboratory scientist Amy Mainzer told Universe Today in a separate conversation today.
  • Mainzer also brought us up to speed on the Near-Earth Object Camera (NEOCam) proposal, which she’s been working on since 2005. Her group received technology development funding in 2010 to improve their infrared detectors, which succeeded in passing recent tests. Their group will seek more funding for NASA in the next opportunity.
  • The WISE spacecraft’s NEOWISE mission, meanwhile, is going to restart early next year, Mainzer added. “While NEOWISE is not nearly as capable as NEOCam will be, it will improve our knowledge of the diameters and albedos of  about 2,000 NEOs and tens of thousands of main belt asteroids,” Mainzer wrote. “With the NEOWISE prime mission, we discovered more than 34,000 new asteroids and observed >158,000 in total. We have used our data from NEOWISE to set constraints on the number of NEOs and potentially hazardous asteroids.”
Former NASA astronaut Tom Jones shared this slide concerning ideas for asteroid defense. Credit: Tom Jones/Association for Space Explorers/AMNH/Ustream (screenshot)

Getting the United Nations involved:

 

  • This week, the United Nations Committee on the Peaceful Uses of Outer Space adopted several steps related to asteroids. It’s planning an International Asteroid Warning Group (to share detections and warn of potential impacts), an Impact Disaster Planning Advisory Group, and a Space Missions Planning and Advisory Group (which would look at deflection missions, options, costs, etc.)
  • Why go with the United Nations? In the panel, NASA Apollo astronaut Rusty Schweickart explained it this way: deciding how to deflect an asteroid posts risks. You might be moving the impact path past a country that would not have been at risk before the deflection. It’s best to make such moves internationally, rather than having (say) the United States make a decision that could increase Russia’s risk to an asteroid.
  • The problem? Working by committee is slow, says former Romanian astronaut Dumitru-Dorin Prunariu: “You would think with the United Nations that we started to think about asteroids only in 2007, 8 or 9, but the first input was done by 1999 at the Unispace conference, the United Nations International Conference in Space.” People have been working hard, to be sure, but making a good, inclusive plan just takes time. An action team was formed in 2001, a working group was in place by 2007, and the adoptions by UNCOPUOS (as we stated earlier) took place this week.
An artist's conception of a space exploration vehicle approaching an asteroid. Credit: NASA
An artist’s conception of a space exploration vehicle approaching an asteroid. Credit: NASA
 Cost of all of this:
  • Schweickart: “Money is hardly an issue in this. This is a very inexpensive thing to do. It’s organizational setting the actual criteria, thresholds whatever.” It would only cost 1% of the NASA budget for the next 10 years, and less than 0.5% after that. (The NASA budget request for 2014 was $17.7 billion, so 1% of that is $177 million.)
  • The panel members emphasized that it’s best to start the search early and find the threatening asteroids before things become an emergency. If a moderate-sized asteroid was discovered only a few months out, it might be better just to evacuate the affected area rather than try to pull together a last-minute mission to stop the asteroid.
Posted on by Nancy Atkinson

Watch Live: Defending Earth from Asteroids

Asteroid mining concept. Credit: NASA/Denise Watt



Live streaming video by Ustream

We know that hundreds of thousands of asteroids orbit the Sun, and a very few have a high risk of striking Earth. There are also asteroids that haven’t been discovered yet that can surprise us, as evidenced by the explosion over Chelyabinsk, Russia, last February. This event was confirmation that an asteroid strike is a risk we do face. But also, how do scientists counter the pseudo-scientific claims and fears that asteroids seem to generate? And what opportunities do asteroids provide for mining useful resources?

Watch live today (Friday, October 25, 2013) at 15:00 UTC (11 am EDT) as astrophysicist Neil deGrasse Tyson, astronauts Rusty Schweickart, Tom Jones, Ed Lu, Soichi Noguchi and others discuss the research and the steps that are being taken to avoid these potential natural disasters. With current space technology, scientists know how to deflect the majority of hazardous near-Earth objects, but these technologies have not yet been tested in space, and prevention is only possible if nations work together on detection and deflection.

This webcast is sponsored by the American Museum of Natural History. You can see their webpage about this event here.

Posted on by Elizabeth Howell

Japanese ‘Space Cannon’ On Track For Aiming At An Asteroid: Reports

Painting of Asteroid 2012 DA14. © David A. Hardy/www.astroart.org

Watch out, asteroid 1999 JU3: you’re being targeted. As several media reports reminded us, the Japan Aerospace Exploration Agency (JAXA)’s Hayabusa-2 asteroid exploration mission will carry a ‘space cannon’ on board — media-speak for the “collision device” that will create an artificial crater on the asteroid’s surface.

“An artificial crater that can be created by the device is expected to be a small one with a few meters in diameter, but still, by acquiring samples from the surface that is exposed by a collision, we can get fresh samples that are less weathered by the space environment or heat,” JAXA states on its website.

Reports indicate JAXA is on schedule to, er, shoot this thing into space for a 2018 rendezvous with an asteroid. The spacecraft will stick around the asteroid for about a year before heading back to Earth in 2020. The overall aim is to learn more about the origin of the solar system by looking at a C-type asteroid, considered to be a “primordial body” that gives us clues as to the early solar system’s makeup.

Check out more on Hayabusa-2 on JAXA’s website.

Posted on by Elizabeth Howell

Here’s Your Chance To Fund A New Asteroid Search

Painting of Asteroid 2012 DA14. © David A. Hardy/www.astroart.org

The crowdfunding campaign is off to a slow start, but the PHASST-1 telescope still has more than a month to reach its $88,816 (€65,000) goal of deploying telescopes devoted to searching for near-Earth asteroids.

The Potentially Hazardous Asteroid Search & Tracking Telescope, as the acronym stands for, will begin with two telescopes: an f/1 Baker-Nunn camera near Arequipa, Peru and a 50cm f/3.6 astrograph near Ager, Spain.

“Even though PHASTT-1 will have a large field of view compared to most telescopes (~5x) of a similar aperture, competing in the area of asteroid search is difficult due to a large number of teams doing similar work. Because of this, we are designing PHASTT-1 as not only a search telescope but also as a followup and characterization instrument — two key areas where we can make an impact,” the IndieGogo campaign page states.

“Follow-up observations are important as they help us refine the orbits of potentially hazardous objects and narrow the uncertainties around how close an asteroid will come to the Earth. Characterization of asteroids is also important as it helps us understand the physical properties of asteroids. This understanding critical if we want to know how to best deal with a ‘rogue’ asteroid that is on an impact course or if we just want to know which asteroids would make for interesting near-Earth exploration targets.”

The principles including astronomers, a technology consultant and a laser ranging specialist. You can read more technical details on the IndieGogo campaign page or the PHASTT-1 website. If they get the money they need, they aim to be operational by the middle of next year. The campaign completes Nov. 26.

Posted on by Elizabeth Howell

NASA: Less Than 1% Chance That Asteroid 2013 TV135 Will Hit Earth In 2032

Diagram of the orbit of orbit of asteroid 2013 TV135 (in blue), which scientists are 99.998% certain will not hit Earth. Calculations are based on one week of observations since the asteroid's discovery Oct. 8, and astronomers expect further observations will reduce or eliminate the observed impact probability. Credit: NASA/JPL-Caltech

We’ll skip straight to the good news: NASA says Earth is likely safe from Asteroid 2013 TV135. Calculations put the newly discovered asteroid’s chances of hitting the planet in 2032 at incredibly small — 1 in 63,000 — despite some alarmist news reports.

“To put it another way, that puts the current probability of no impact in 2032 at about 99.998 percent,” stated Don Yeomans, manager of NASA’s Near-Earth Object Program Office.

“This is a relatively new discovery. With more observations, I fully expect we will be able to significantly reduce, or rule out entirely, any impact probability for the foreseeable future.”

Asteroid 2013 TV135 in a series of images snapped by amateur astronomer Peter Lake.

The asteroid was first spotted on Oct. 8 by scientists at the Crimean Astrophysical Observatory in Ukraine. It’s 1,300 meters (400 feet) in diameter and cycles in an orbit that goes three-quarters of the way out to Jupiter, and then back again towards its closest approach near Earth’s orbit.

The asteroid came within 4.2 million miles (6.7 million kilometers) of Earth on Sept. 16. Amateur astronomer Peter Lake uploaded a video (which you can see above) based on a few pictures he took Oct. 17-18.

“Its important to remember that new asteroids (this one has only 9 days of arc) usually don’t stay on the Torino Scale (the risk register) for long, as further data updates increase the precision of the orbit, and usually quickly remove them as potential impactors,” Lake added in a blog post.

There are many, many international efforts to watch asteroid paths and disseminate the information to the public. One of them is NASA’s Asteroid Watch website, where you can get the latest information on nearby space rocks.

Posted on by Elizabeth Howell

Wet Asteroid’s Remains Found In Old Star That Could Have Hosted Habitable Planets

Artist's impression of a rocky and water-rich asteroid being torn apart by the strong gravity of the white dwarf star GD 61. Credit: Mark A. Garlick, space-art.co.uk, University of Warwick and University of Cambridge

Remains of a water-filled asteroid are circling a dying white dwarf star, right now, about 150 light-years from us. The new find is the first demonstration of water and a rocky surface in a spot beyond the solar system, researchers say.

The discovery is exciting to the astronomical team because, according to them, it’s likely that water on Earth came from asteroids, comets and other small bodies in the solar system. Finding a watery rocky body demonstrates that this theory has legs, they said. (There are, however, multiple explanations for water on Earth.)

“The finding of water in a large asteroid means the building blocks of habitable planets existed – and maybe still exist – in the GD 61 system, and likely also around substantial number of similar parent stars,” stated lead author Jay Farihi, from Cambridge’s Institute of Astronomy.

Earth’s oxygen and water as detected by Venus Express (ESA)
Earth’s oxygen and water as detected by Venus Express (ESA)

“These water-rich building blocks, and the terrestrial planets they build, may in fact be common – a system cannot create things as big as asteroids and avoid building planets, and GD 61 had the ingredients to deliver lots of water to their surfaces. Our results demonstrate that there was definitely potential for habitable planets in this exoplanetary system.”

More intriguing, however, is researchers found this evidence in a star system that is near the end of its life. So the team is framing this as a “look into our future”, when the Sun evolves into a white dwarf .

The water likely came from a “minor planet” that was at least 56 miles (90 kilometers) in diameter. Its debris was pulled into the atmosphere of the star, which was then examined by spectroscopy. This study revealed the ingredients of rocks inside the star, including magnesium, silicon and iron. Researchers then compared these elements to how abundant oxygen was, and found that there was in fact more oxygen than expected.

White Dwarf Star
White Dwarf Star

“This oxygen excess can be carried by either water or carbon, and in this star there is virtually no carbon – indicating there must have been substantial water,” stated co-author Boris Gänsicke, from the University of Warwick.

“This also rules out comets, which are rich in both water and carbon compounds, so we knew we were looking at a rocky asteroid with substantial water content – perhaps in the form of subsurface ice – like the asteroids we know in our solar system such as Ceres.”

The measurements were obtained in ultraviolet with the Hubble Space Telescope’s cosmic origins spectrograph. What’s more, the researchers suspect there are giant exoplanets in the area because it would take a huge push to move this object from the asteroid belt — a push that most likely came from big planet.

“This supports the idea that the star originally had a full complement of terrestrial planets, and probably gas giant planets, orbiting it – a complex system similar to our own,” Farihi added.

The discovery was recently published in Science.

Source: University of Cambridge

Posted on by Elizabeth Howell

Possible Huge Meteorite Fragment Recovered From Russian Fireball

Frame grab from a video of the Feb. 15, 2013 Russian fireball by Aleksandr Ivanov

A half-ton meteorite — presumably from the Russian fireball that broke up over Chelyabinsk in February — was dragged up from Lake Chebarkul in the Urals, Russian media reports said. Scientists estimate the chunk is about 1,260 pounds (570 kilograms), but couldn’t get a precise measurement in the field because the bulky bolide broke the scale, according to media reports.

“The preliminary examination… shows that this is really a fraction of the Chelyabinsk meteorite,” said Sergey Zamozdra, associate professor of Chelyabinsk State University, in reports from Interfax and RT.

A polished slice of one of Russian meteorite samples. You can see round grains called chondrules and shock veins lined with melted rock. The meteorite is probably non-uniform. The preliminary analysis showed that the meteorite belongs to chemical type L or LL, petrologic type 5.
A polished slice of one of Russian meteorite samples (different samples than what was reportedly recovered on Oct. 16). You can see round grains called chondrules and shock veins lined with melted rock. The meteorite is probably non-uniform. The preliminary analysis showed that the meteorite belongs to chemical type L or LL, petrologic type 5.

“It’s got thick burn-off, the rust is clearly seen and it’s got a big number of indents. This chunk is most probably one of the top ten biggest meteorite fragments ever found.”

The big rock was first spotted in September, but it’s taken several attempts to bring it to the surface. If scientists can confirm this came from the fireball, this would be the biggest piece recovered yet. The chunk is reportedly in a natural history museum, where a portion will be X-rayed to determine its origins.

More than 1,000 people were injured and millions of dollars in damage occurred when the meteor broke up in the atmosphere Feb. 15, shattering glass and causing booms.

Since then, there have been numerous papers concerning the meteor’s origins (from the Apollo class of asteroids — you can read this article if you’re unclear on the difference between an asteroid and a meteorite) and tracking the spread of dust through the atmosphere, among other items.

Posted on by Dan Majaess

Astronomers Stress the Need for Characterizing the Population of Nearby Potential Earth-Impactors

Frame grab from a video of the Feb. 15, 2013 Russian fireball by Aleksandr Ivanov

The meteor explosion over Russia in February 2013 raised concerns that even small asteroid impactors may wreak some havoc given our heavily populated cities.  A new study by NASA scientists aims to improve our understanding of such asteroids that are lurking in Earth’s vicinity.  The team, led by Amy Mainzer, noted that only a mere fraction of asteroids comparable in size to the object that exploded over Russia have been discovered, and their physical properties are poorly characterized.

The team derived fundamental properties for over a hundred near-Earth objects, and determined that many are smaller than 100 meters.  Indeed, the team notes that, “In general … [asteroids] smaller than 100-m are only detected when they are quite close … and the smallest … were detected when they were only 2-3 lunar distances away from Earth.”  

Essentially, a large fraction of these bodies may go undetected until they strike Earth, analogous to the case of the asteroid that exploded over Russia in February.

The team’s results rely partly on observations from the Wide-field Infrared Survey Explorer (WISE), which is a space-based telescope that mapped the entire sky in the mid-infrared. Observations taken in the infrared, in concert with those taken in the optical, can be used to infer the fundamental properties of asteroids (e.g., their diameter and chemical composition).

On a somewhat positive note, Mainzer remarks that 90% of near-Earth asteroids larger than 1-km are known, and those potential impactors are most worrisome as they may cause widespread fatalities.  The dinosaurs suffered a mass-extinction owing, at least in large part, to a 10-km impactor that struck Earth 65 million years ago.   However, Mainzer notes that the survey completeness drops to 25% for nearby 100-m asteroids, and it is likely to be less than 1% for 20-m asteroids like that which exploded over Russia (Chelyabinsk).  The Tunguska event (see the image below) is likewise speculated to have been on the order of that latter size.

In 1908 the Tunguska impactor toppled millions of trees in a rather remote part of Siberia. The new study by Mainzer and coauthors aimed to better characterize the population of Tunguska-sized asteroids lurking in the vicinity of the Earth.
In 1908 the Tunguska meteor explosion toppled millions of trees in a rather remote part of Siberia. A new study by Mainzer et al. 2013 characterized 100+ objects lurking in the vicinity of the Earth that are on the order of the Tunguska impactor.

The team highlights that approximately 10,000 near-Earth objects have been discovered to date, 900 of which are 1-km or larger, and 3500 objects appear to be 100-m or smaller.  “Because their small sizes usually make them undetectable until they are very nearby the Earth, it is often difficult for the current suite of asteroid surveys and follow-up telescopes to track them for very long.

Consequently, the fraction of the total population at small sizes that has been discovered to date remains very low,” noted Mainzer.

In closing, Mainzer emphasizes that, “It is, however, clear that much work remains to be done to discover and characterize the population of very small NEOs [near-Earth objects].”


The Mainzer et al. 2013 findings have been accepted for publication in the Astrophysical Journal (ApJ), and a preprint is available on arXiv.  Coauthors on the study are J. Bauer, T. Grav, J. Masiero, R. M. Cutri, E. L. Wright, C. R. Nugent, R. Stevenson, E. Clyne, G. Cukrov, and F. Masci.