Posted on by Elizabeth Howell

How A New Family Tree of Space Rocks Could Better Protect Earth

An artist's conception of an asteroid collision, which leads to how "families" of these space rocks are made in the belt between Mars and Jupiter. Credit: NASA/JPL-Caltech
An artist's conception of an asteroid collision, in the belt between Mars and Jupiter. Credit: NASA/JPL-Caltech

In perhaps the neatest astronomical application of geneology yet, astronomers found 28 “hidden” families of asteroids that could eventually show them how some rocks get into orbits that skirt the Earth’s path in space.

From scanning millions of snapshots of asteroid heat signatures in the infrared, these groups popped out in an all-sky survey of asteroids undertaken by NASA’s orbiting Wide-Field Infrared Survey Explorer. This survey took place in the belt of asteroids between Mars and Jupiter, where most near-Earth objects (NEOs) come from.

NEOs, to back up for a second, are asteroids and comets that approach Earth’s orbit from within 28 million miles (45 million kilometers). Sometimes, a gravitational push can send a previously unthreatening rock closer to the planet’s direction. The dinosaurs’ extinction roughly 65 million years ago, for example, is widely attributed to a massive rock collision on Earth.

Part of NASA’s job is to keep an eye out for potentially hazardous asteroids and consider approaches to lessen the threat.

Artist concept of the asteroid belt. Credit: NASA
Artist concept of the asteroid belt between Mars and Jupiter. Credit: NASA

There are about 600,000 known asteroids between Mars and Jupiter, and the survey looked at about 120,000 of them. Astronomers then attempted to group some of them into “families”, which are best determined by the mineral composition of an asteroid and how much light it reflects.

While it’s hard to measure reflectivity in visible light — a big, dark asteroid reflects a similar amount of light as a small shiny one — infrared observations are harder to fool. Bigger objects give off more heat.

This allowed astronomers to reclassify some previously studied asteroids (which were previously grouped by their orbits), and come up with 28 new families.

“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,” stated Lindley Johnson, NASA’s program executive for the Near-Earth Object Observation Program.

This diagram illustrates the differences between orbits of a typical near-Earth asteroid (blue) and a potentially hazardous asteroid, or PHA (orange). Image credit: NASA/JPL-Caltech
This diagram illustrates the differences between orbits of a typical near-Earth asteroid (blue) and a potentially hazardous asteroid, or PHA (orange). Image credit: NASA/JPL-Caltech

The astronomers next hope to study these different families to figure out their parent bodies. Astronomers believe that many asteroids we see today broke off from something much larger, most likely through a collision at some point in the past.

While Earthlings will be most interested in how NEOs came from these larger bodies and threaten the planet today, astronomers are also interested in learning how the asteroid belt formed and why the rocks did not coalesce into a planet.

The prevailing theory today says that was due to influences from giant Jupiter’s strong gravity, which to this day pulls many incoming comets and asteroids into different orbits if they swing too close. (Just look at what happened to Shoemaker-Levy 9 in 1994, for example.)

Source: NASA

Posted on by Nancy Atkinson

Early Images Coming in of Asteroid 1998 QE2’s Flyby

Asteroid 1998 QE2, taken on May 31, 2013 when it was 5.8 million km (3.6 million miles) from Earth and moving at around 21 arc mins per hour. The asteroid was quite bright at around magnitude 11. Credit and copyright: Damian Peach.

Will the flyby of Near Earth Asteroid 285263 (1998 QE2) reveal more surprises? NASA announced yesterday that radar images uncovered a previously unknown small moon orbiting the big asteroid. Now, observatories and amateurs around the world are taking a look at this big, dark space rock, which is about 2.7 kilometers (1.7 miles) in diameter. Here are some of the “early returns” just in!

This asteroid will pass 5.86 million km (3.64 million miles) from the Earth on Friday, May 31st at 20:59 Universal Time (UT) or 4:59PM EDT. That is about 15 times the distance between Earth and the Moon, so no worries. But it is not often an asteroid this big comes by within viewing range of observatories on Earth.

Asteroid (285263) 1998 QE2, on May 31, 2013, taken remotely from the H06 iTelescope Observatory in New Mexico. Credit and copyright: Ernesto Guido and Nick Howes, Remanzacco Observatory.
Asteroid (285263) 1998 QE2, on May 31, 2013, taken remotely from the H06 iTelescope Observatory in New Mexico. Credit and copyright: Ernesto Guido and Nick Howes, Remanzacco Observatory.

The Remanzacco Observatory team of Ernesto Guido and Nick Howes provided this image, above, and a great animation of the asteroid, as well:

Animation of (285263) 1998 QE2 on May 31, 2013 by E. Guido & N. Howes photo 1998QE2_May_31_H06_zps64069369.gif

Animation of (285263) 1998 QE2 on May 31, 2013 by E. Guido & N. Howes

Asteroid 1998 QE2 on May 28, 2013. Credit and copyright: Gianluca Masi, Ceccano, Italy; Virtual Telescope Project.
Asteroid 1998 QE2 on May 28, 2013. Credit and copyright: Gianluca Masi, Ceccano, Italy; Virtual Telescope Project.

Masi also provided a video from his May 30 observations:

Animation of Asteroid 1998 QE2, May 31, 2013 taken remotely with iTelescope T9. Credit and copyright: Ian Musgrave.
Animation of Asteroid 1998 QE2, May 31, 2013 taken remotely with iTelescope T9. Credit and copyright: Ian Musgrave.

Here’s one from Ian Musgrave. If the animation isn’t working in your browser, click on the image to animate. Ian also has provided this graphic made from Celestia software to show Asteroid 1998 QE2’s orbit:

Orbit of 1998 QE2 simulated in Celestia at closest approach on May 31 20:59 UT. Via Ian Musgrave.
Orbit of 1998 QE2 simulated in Celestia at closest approach on May 31 20:59 UT. Via Ian Musgrave.

Want to try and see this asteroid for yourself? Our very own David Dickinson has written a great “how-to” for this object, but you are going to need a fairly large backyard telescope, since it will be about 100 times fainter than what can be seen with the naked eye, even at closest approach.

The Slooh online telescope will have views of online tomorrow, which you can watch at their website. The webcast will start at 20:30 UTC (4:30 p.m. EDT) on Friday, May 31.

Also, starting at 20:00 UTC (4:00 p.m. EDT), astrophysicist Gianluca Masi will have a webcast from the Virtual Telescope Project in Italy.

Also, if you want more asteroids, on Friday May 31, the White House is hosting an asteroid-themed “We the Geeks” Google+ Hangout starting at 2 p.m. EDT.

The live video conference will feature Bill Nye the Science Guy, JL Galache from the Minor Planet Center, former astronaut Ed Lu, NASA Deputy Administrator Lori Garver, and Peter Diamandis, co-founder of asteroid mining company Planetary Resources. They will discuss identification, resource potential and threat of asteroids. Here’s the link the White House’s Google+ page.

We’ll be adding more images as they come in.

Posted on by Nancy Atkinson

Surprise! Earth Passing Asteroid 1998 QE2 Has a Moon

Radar images from May 30, 2012 of Asteroid 1998 QE2, showing its binary companion. Credit: NASA.

Late yesterday, NASA turned the 230-foot (70-meter) Deep Space Network antenna at Goldstone, California towards Asteroid 1998 QE2 as it was heading towards its closest approach to Earth, and they got a big surprise: the asteroid is a binary system. 1998 QE2 itself is 1.7 miles (2.7 kilometers) in diameter, and the newly found orbiting moon is about 600 meters in diameter.

The radar images were taken were taken on May 29, 2013, when the asteroid was about 3.75 million miles (6 million kilometers) from Earth.

“Radar really helps to pin down the orbit of an asteroid as well as the size of it,” said Paul Chodas of NASA’s Near-Earth Object Program office, speaking during a JPL webcast about this asteroid on May 30. “We now know our size estimates were pretty good, but finding it was a binary was surprising.”

NASA said that about 16 percent of asteroids are binary or even triple systems.

Each of the images above are snippets of about 5 minutes of radar data. You can watch a movie of the data, below:

Other surprises were several radar-dark features, which may be cavities or impact craters, said Marina Brozovic, a scientist at JPL. The asteroid is also rotating more slowly than originally thought.

Near Earth Asteroid (NEA) 285263 (1998 QE2) will pass 5.86 million km from the Earth on Friday, May 31st at 20:59 Universal Time (UT) or 4:59PM EDT. This is the closest approach of 1998 QE2 for this century, and it poses no threat – and there’s not any threat in the future – as it is passing over 15 times as distant as the Earth’s Moon. But the rather large size of this space rock makes it an object of interest for astronomers.

Chodas added that they will continue to take radar data of this asteroid while they can to improve its orbital parameters, and that the presence of the moonlet means they can get an even more precise mass estimate of the asteroid.

Want to try and see this asteroid for yourself? Our very own David Dickinson has written a great “how-to” for this object, but you are going to need a fairly large backyard telescope, since it will be about 100 times fainter than what can be seen with the naked eye, even at closest approach.

The Slooh online telescope will have views of online tomorrow, which you can watch at their website. The webcast will start at 20:30 UTC (4:30 p.m. EDT) on Friday, May 31.

Also, starting at 20:00 UTC (4:00 p.m. EDT), astrophysicist Gianluca Masi will have a webcast from the Virtual Telescope Project in Italy.

Additionally, if you want to have a Bruce Willis-type view of this asteroid, check out NASA’s Eyes on the Solar System. They have a special feature on this asteroid, and you can “ride along with it for the next few days,” said Doug Ellison, Visualization Producer at JPL, speaking during the webcast.

This amazing tool creates realistic simulated views based on real data, and allows you to travel to any planet, moon or spacecraft across time and space, in 3D and in real time — or speed up to see the future.

Just go to the Eyes on the Solar System website, and when the window opens, click on “Tours and Features” in the upper right hand corner, then click on “1998 QE2” in the dropdown box, and away you go. If you click on the “Live” button the left, you’ll see the current location; click on “Ride Along” and find yourself sitting on the asteroid heading towards Earth.

At the bottom control panel “dock” (click on the bottom box on the lower right side if the panel isn’t showing), you can speed up time and see how far from Earth this asteroid will get and where it will go in the future.

Ellison added that right now the imagery on Eyes on the Solar System doesn’t have the moonlet orbiting 1998 QE2, but they will be adding it soon to make the visualization as realistic as possible.

NASA’s @AsteroidWatch Twitter account shared the news about the moon:

Also, if you want more asteroids, on Friday May 31, the White House is hosting an asteroid-themed “We the Geeks” Google+ Hangout starting at 2 p.m. EDT.

The live video conference will feature Bill Nye the Science Guy, former astronaut Ed Lu, NASA Deputy Administrator Lori Garver, and Peter Diamandis, co-founder of asteroid mining company Planetary Resources. They will discuss identification, resource potential and threat of asteroids. Here’s the link the White House’s Google+ page.

Posted on by Nancy Atkinson

Planetary Resources Looks to Crowdfund a Space Telescope for the Public

Example of an orbital 'selfie' that Planetary Resources' ARKYD telescope could provide to anyone who donates to their new Kickstarter campaign. Credit: Planetary Resources.

How much would you donate to have access to a space telescope … or just to have an orbital “selfie”? Planetary Resources, Inc., the company that wants to mine asteroids, has launched a Kickstarter campaign for the world’s first crowdfunded space telescope. They say their Arkyd-100 telescope will provide unprecedented public access to space and place the most advanced exploration technology into the hands of students, scientists and a new generation of citizen explorers.

To make their campaign successful, they need to raise $1 million in Kickstarter pledges by the end of June 2013. Less than 2 hours into their campaign, they have raised over $100,000.

Last year, Planetary Resources revealed their plans to develop a series of small spacecraft to do a little ‘space prospecting’ which would eventually allow them to mine near Earth asteroids, extracting valuable resources.

Their announcement today of the crowdfunded Arkyd-100 space telescope will allow them to begin the search for asteroid they could mine, while involving the public and providing access to to the space telescope “for inspiration, exploration and research” or have a commemorative photo of those who donate displayed above the Earth, such as the image above.

During a webcast today to announce the Kickstarter campaign, Chris Lewicki, President and Chief Engineer for Planetary Resources said the telescope would have 1 arcsecond resolution, with the benefit of being above atmosphere.

A wide array of scientists, space enthusiasts and even Bill Nye the Science Guy have voiced their support for Planetary Resources’ new public space telescope.

Artist concept of the Arkyd telescope in space. Credit: Planetary Resources Inc.
Artist concept of the Arkyd telescope in space. Credit: Planetary Resources Inc.

“The ARKYD crowdfunding campaign is extraordinary,” said Sara Seager, Ph.D., Professor of Physics and Planetary Science at the Massachusetts Institute of Technology. “Not only does the telescope have the technical capability to increase our understanding of space, but it can be placed in orbit for an incredibly low cost. That is an economic breakthrough that will accelerate space-based research now and in the future.”

The space telescope is being built by Planetary Resources’ technical team, who worked on every recent U.S. Mars lander and rover.

“I’ve operated rovers and landers on Mars, and now I can share that incredible experience with everyone,” said Lewicki. “People of any age and background will be able to point the telescope outward to investigate our Solar System, deep space, or join us in our study of near-Earth asteroids.”

Planetary Resources will use the proceeds from the Kickstarter campaign to launch the telescope, fund the creation of the public interface, cover the fulfillment costs for all of the products and services listed in the pledge levels, and fund the immersive educational curriculum for students everywhere. Any proceeds raised beyond the goal will allow for more access to classrooms, museums and science centers, and additional use by individual Kickstarter backers.

However, if they fail to reach the $1 million goal, they receive none of the money. According to Jeff Foust at the NewSpace Journal quoted Lewicki as saying, if that happens, they’ll proceed with their current plans, including development of a small prototype satellite, called Arkyd 3, that is planned for launch next year.

Here are a few of the donation levels:

• Your Face in Space – the #SpaceSelfie: For US$25, the team will upload an image of the campaign backer’s choice to display on the ARKYD, snap a photo of it with the Earth in the background, and transmit it to the backer. This space ‘photo booth’ allows anyone to take (or gift) a unique Space Selfie image that connects a personal moment with the cosmos in an unprecedented, yet tangible way.

• Explore the Cosmos: Higher pledge levels provide students, astronomers and researchers with access to the ARKYD main optic for detailed observations of the cosmos, galaxies, asteroids and our Solar System.

• Support Education Worldwide: At the highest levels, pledgers can offer the K-12 school, science center, university, or any interested group of their choice access to the ARKYD for use in interactive educational programming to strengthen STEM education worldwide. The full pledge list and ARKYD technical specifications can be found here.

See all the levels at Planetary Resources’ Kickstarter Page.

“When we launched Planetary Resources last year, we had an extraordinary response from the general public,” said Peter Diamandis, Co-Founder and Co-Chairman of Planetary Resources, Inc.. “Tens of thousands of people contacted us and wanted to be involved. We are using this Kickstarter campaign as a mechanism to engage the community in a productive way.”

During a webcast today to make their Kickstarter announcement Diamandis said, “In the last 50 years, space exploration has been led by national governmental agencies with their own set of priorities. Imagine not having to wait for Congress to decide what missions will fly!”

ARKYD Infographic

Posted on by David Dickinson

How to Spot Near-Earth Asteroid 1998 QE2 This Week

1998 QE2 on closest approach to Earth this Friday on May 31st. (Credit: NASA/JPL-Caltech).

A large asteroid visits our fair corner of the solar system this week, and with a little planning you may just be able to spot it.

Near Earth Asteroid (NEA) 285263 (1998 QE2) will pass 5.8 million kilometres from the Earth on Friday, May 31st at 20:59 Universal Time (UT) or 4:59PM EDT. Discovered in 1998 during the LIncoln Near-Earth Asteroid Research (LINEAR) sky survey looking for such objects, 1998 QE2 will shine at magnitude +10 to +12 on closest approach. Estimates of its size vary from 1.3 to 2.9 kilometres, with observations by the Spitzer Space Telescope in 2010 placing the ballpark figure towards the high end of the scale at 2.7 kilometres in diameter.

1998 QE2 would fit nicely with room to spare in Oregon’s 8 kilometre-wide Crater Lake.

Though this passage is over 15 times as distant as the Earth’s Moon, the relative size of this space rock makes it of interest. This is the closest approach of 1998 QE2 for this century, and there are plans to study it with both the Arecibo and Goldstone radio telescopes to get a better description of its size and rotation as it sails by. Expect to see radar maps of 1998 QE2 by this weekend.

“Asteroid 1998 QE2 will be an outstanding radar imaging target… we expect to obtain a series of high-resolution images that could reveal a wealth of surface features,” said astronomer and principal JPL investigator Lance Benner.

A recent animation of 1998 QE2 from earlier this month. (Credit: Nick Howes & Ernesto Guido).
A recent animation of 1998 QE2 from earlier this month.
(Credit: Nick Howes & Ernesto Guido).

An Amor-class asteroid, 1998 QE2 has an orbit of 3.77 years that takes it from the asteroid belt between Mars and Jupiter to just exterior of the Earth’s orbit. 1998 QE2 currently comes back around to our vicinity roughly every 15 years, completing about 4 orbits as it does so. Its perihelion exterior to our own makes it no threat to the Earth. This week’s passage is the closest for 1998 QE2 until a slightly closer pass on 0.038 Astronomical Units on May 27th, 2221. Note that on both years, the Earth is just over a month from aphelion (its farthest point from the Sun) which falls in early July.

Of course, the “QE2” designation has resulted in the inevitable comparisons to the size of the asteroid in relation to the Queen Elizabeth II cruise liner. Asteroid designations are derived from the sequence in which they were discovered in a given year. 1998 QE2 was the 55th asteroid discovered in the period running from August 1st to 16th 1998.

Perhaps we could start measuring asteroids in new and creative units, such as “Death Stars” or “Battlestars?”

But the good news is, you can search for 1998 QE2 starting tonight. The asteroid is currently at +12th magnitude in the constellation Centaurus and will be cruising through Hydra on its way north into Libra Friday on May 31st. You’ll need a telescope to track the asteroid as it will never top +10th magnitude, which is the general threshold for binocular viewing under dark skies. Its relative southern declination at closest approach means that 1998 QE2 will be best observed from northern latitudes of +35° southward. The farther south you are, the higher it will be placed in the sky after dusk.

A wide field view of the passage of 1998 QE2 this week, from May 27th through June 2nd. (Created by the author in Starry Night).
A wide field view of the passage of 1998 QE2 this week, from May 27th through June 2nd. (Created by the author in Starry Night).

Still, if you can spot the constellation Libra, it’s worth a try. Many observers in the southern U.S. fail to realize that southern hemisphere sites like Omega Centauri in the constellation Centaurus are visible in the evening low to the south at this time of year. Libra sits on the meridian at local midnight due south for northern hemisphere observers, making it a good time to try for the tiny asteroid.

Visually, 1998 QE2 will look like a tiny, star-like point in the eye-piece of a telescope. Use low power and sketch or photograph the field of view and compare the positions of objects about 10 minutes apart. Has anything moved? We caught sight of asteroid 4179 Toutatis last year using this method.

A closeup look at the passage of 1998 QE2, covering a 48 hour span centered on closest approach on May 31st. (Created by the author in Starry Night).
A closeup look at the passage of 1998 QE2, covering a 48 hour span centered on closest approach on May 31st. (Created by the author in Starry Night).

1998 QE2 will also pass near some interesting objects that will serve as good “guideposts” to track its progress.

We find the asteroid about 5° north of the bright +2.5 magnitude star Iota Centauri on the night of May 28th. It then crosses the border into the constellation Hydra about 6° south of the +3 magnitude star Gamma Hydrae (Star Trek fans will recall that this star lies in the Neutral Zone) on May 29th. Keep a careful eye on 1998 QE2 as it passes within 30’ (about the diameter of a Full Moon) of the +8th magnitude galaxy Messier 83 centered on May 28th at 19:00 UT/3:00 PM EDT. This will provide a fine opportunity to construct a stop-motion animated .gif of the asteroid passing by the galaxy.

Another good opportunity to pinpoint the asteroid comes on the night on Thursday, May 30th as it passes within 30’ of the +3.3 magnitude star Pi  Hydrae.

From there, it’s on to closest approach day. 1998 QE2 crosses into the constellation Libra early on Friday May 31st. The Moon will be at Last Quarter phase and won’t rise until well past local midnight, aiding in your quest.

At its closest approach, 1998 QE2 have an apparent motion of about 1 angular degree every 3 hours, or about 2/3rds the diameter of a Full Moon every hour. This isn’t quite fast enough to see in real time like asteroid 2012 DA14 was earlier this year, but you should notice its motion after about 10 minutes at medium power. Passing at ~465 Earth diameters distant, 1998 QE2 will show a maximum parallax displacement of just a little over 7 arc minutes at closest approach.

For telescopes equipped with setting circles, knowing the asteroid’s precise position is crucial. This allows you to aim at a fixed position just ahead of its path and “ambush” it as it drifts by. For the most precise positions in right ascension and declination, be sure to check out JPL’s ephemeris generator for 1998 QE2.

After its closest passage, 1998 QE2 will pass between the +3.3 & +2.7 magnitude stars Brachium (Sigma Librae) and Zubenelgenubi (Alpha Librae) around 4:00 UT on June 1st. Dedicated observers can continue to follow its northeastward trek into early June.

Slooh will also be carrying the passage of 1998 QE2 on Friday, May 31st starting at 5:00 PM EDT/21:00 UT.

Of course, the hypothetical impact of a space rock the size of 1998 QE2 would spell a very bad day for the Earth. The Chicxulub impact basin off of the Yucatán Peninsula was formed by a 10 kilometre impactor about 4 times larger than 1998 QE2 about 65 million years ago. We can be thankful that 1998 QE2 isn’t headed our way as we watch it drift silently by this week. Hey, unlike the dinosaurs, WE have a space program…   perhaps, to paraphrase science fiction author Larry Niven, we can hear the asteroid whisper as we track its progress across the night sky, asking humanity “How’s that space program coming along?”

Posted on by Elizabeth Howell

With Russian Meteor Fresh In Everyone’s Memory, ESA Opens An Asteroid Monitoring Center

The two main smoke trails left by the Russian meteorite as it passed over the city of Chelyabinsk. Credit: AP Photo/Chelyabinsk.ru

It’s been about three months since that infamous meteor broke up over Chelyabinsk, Russia. In that time, there’s been a lot of conversation about how we can better protect ourselves against these space rocks with a potentially fatal (from humanity’s perspective) gravitational attraction to Earth.

This week, the European Space Agency officially inaugurated a “NEO Coordination Centre” that is intended to be asteroid warning central in the European Union. It will be the hub for early warnings on near-Earth objects (hence the ‘NEO’ in the name) under ESA’s space situational awareness program.

ESA estimates that of the 600,000 asteroids and comets that orbit the Sun, about 10,000 of them are NEOs. (They define NEOs as asteroids or comets with sizes of several feet up to several tens of miles.)

NASA, of course, is also gravely concerned about the threat NEOs present. Its administrator, Charles Bolden, talked about this at a Congressional hearing about asteroids in March.

Before delving into the threat, Bolden took a metaphorical deep breath to talk about the dozens of asteroids — a meter or larger — that slam into Earth’s atmosphere each year. Most of them burn up harmlessly, and further, 80 tons of dust-like material rain on Earth daily.

A notable meteor that did cause some damage took place about 100 years ago, in 1908, when an object broke up over an isolated area in Russia and flattened trees for miles. Bolden characterized that as a statistically one-in-a-thousand year event, but added that the “real catch” is this type of event could happen at any time.

NASA, however, is seeking out those that cause a threat. It is supposed to find 90 per cent of asteroids 140 meters or larger by 2020, and is making progress towards that goal. (By comparison, the Chelyabinsk object was estimated at 17 to 20 meters.)

Nine radar images of near-Earth asteroid 2007 PA8 obtained between by NASA's 230-foot-wide (70-meter) Deep Space Network antenna. The part of the asteroid closest to the antenna is at top. Credit: NASA/JPL-Caltech
Nine radar images of near-Earth asteroid 2007 PA8 obtained between by NASA’s 230-foot-wide (70-meter) Deep Space Network antenna. The part of the asteroid closest to the antenna is at top. Credit: NASA/JPL-Caltech

So how to best monitor the threat? Bolden outlined a few ideas: crowdsourcing, coordinating with other federal agencies and making use of automatic feeds from different telescopes throughout the world (as NASA does right now.)

Bolden emphasized that none of the asteroids we have found is on a collision course with the Earth. Still, NASA and other science experts are not complacent.

In the same hearing, John Holdren — the president’s assistant on science and technology — recommended following a National Academy of Sciences report to spend upwards of $100 million a year on asteroid detection and characterization. To mitigate the threat, Holdren further recommended a visit to an asteroid by 2025, which would perhaps cost $2 billion.

Posted on by Nancy Atkinson

Mars Gets Bombarded by 200 Small Asteroids and Comets Every Year

A relatively new cluster of impact craters on Mars as seen by the HiRISE camera on the Mars Reconnaissance Orbiter. Credit: NASA/JPL-Caltech/MSSS/Univ. of Arizona

One of the benefits of having a spacecraft in orbit around another planet for several years is the ability to make long-term observations and interpretations. The Mars Reconnaissance Orbiter has been orbiting Mars for over seven years now, and by studying before-and-after images from the High Resolution Imaging Science Experiment (HiRISE) camera, scientists have been able to estimate that the Red Planet gets womped by more than 200 small asteroids or bits of comets per year, forming craters at least 3.9 meters (12.8 feet) across.

“It’s exciting to find these new craters right after they form,” said Ingrid Daubar of the University of Arizona, Tucson, lead author of the paper published online this month by the journal Icarus. “It reminds you Mars is an active planet, and we can study processes that are happening today.”

New impact site on Mars formed between November 2005 and October 2010. Credit: NASA/JPL-Caltech/MSSS/Univ. of Arizona
New impact site on Mars formed between November 2005 and October 2010. Credit: NASA/JPL-Caltech/MSSS/Univ. of Arizona

Over the last decade, researchers have identified 248 new impact sites on parts of the Martian surface in the past decade from spacecraft images, determining when the craters appeared. The 200-per-year planetwide estimate is a calculation based on the number found in a systematic survey of a portion of the planet.

The orbiters took pictures of the fresh craters at sites where before-and-after images by other cameras helped figure out when the impacts occurred. This combination provided a new way to make direct measurements of the impact rate on Mars. This will lead to better age estimates of recent features on Mars.

Daubar and co-authors calculated a rate for how frequently new craters at least 3.9 meters in diameter are excavated. The rate is equivalent to an average of one each year on each area of the Martian surface roughly the size of the U.S. state of Texas. Earlier estimates pegged the cratering rate at three to 10 times more craters per year. They were based on studies of craters on the moon and the ages of lunar rocks collected during NASA’s Apollo missions in the late 1960s and early 1970s.

“Mars now has the best-known current rate of cratering in the solar system,” said HiRISE Principal Investigator Alfred McEwen of the University of Arizona, a co-author on the paper.

Examples of craters listed in the paper 'The Current Martian Cratering Rate.' Credit: NASA/JPL/Univ. of Arizona.
Examples of craters listed in the paper ‘The Current Martian Cratering Rate.’ Credit: NASA/JPL/Univ. of Arizona.

These asteroids, or comet fragments, typically are no more than 3 to 6 feet (1 to 2 meters) in diameter. Space rocks too small to reach the ground on Earth cause craters on Mars because the Red Planet has a much thinner atmosphere.

For comparison, the meteor over Chelyabinsk, Russia, in February was about 10 times bigger than the objects that dug the fresh Martian craters.

HiRISE targeted places where dark spots had appeared during the time between images taken by the spacecraft’s Context Camera (CTX) or cameras on other orbiters. The new estimate of cratering rate is based on a portion of the 248 new craters detected. It comes from a systematic check of a dusty fraction of the planet with CTX since late 2006. The impacts disturb the dust, creating noticeable blast zones. In this part of the research, 44 fresh impact sites were identified.

Estimates of the rate at which new craters appear serve as scientists’ best yardstick for estimating the ages of exposed landscape surfaces on Mars and other worlds.

One of many fresh impact craters spotted by the UA-led HiRISE camera, orbiting the Red Planet on board NASA's Mars Reconnaissance Orbiter since 2006. (Photo: NASA/JPL-Caltech/MSSS/UA).
One of many fresh impact craters spotted by the UA-led HiRISE camera, orbiting the Red Planet on board NASA’s Mars Reconnaissance Orbiter since 2006. (Photo: NASA/JPL-Caltech/MSSS/UA).

See the abstract and other information here.
Source: JPL

Posted on by Jason Major

Cosmic C.S.I.: Searching for the Origins of the Solar System in Two Grains of Sand

Composite Spitzer, Hubble, and Chandra image of supernova remnant Cassiopeia A. A new study shows that a supernova as far away as 50 light years could have devastating effects on life on Earth. (NASA/JPL-Caltech/STScI/CXC/SAO)
Composite Spitzer, Hubble, and Chandra image of supernova remnant Cassiopeia A. A new study shows that a supernova as far away as 50 light years could have devastating effects on life on Earth. (NASA/JPL-Caltech/STScI/CXC/SAO)

“The total number of stars in the Universe is larger than all the grains of sand on all the beaches of the planet Earth,” Carl Sagan famously said in his iconic TV series Cosmos. But when two of those grains are made of a silicon-and-oxygen compound called silica, and they were found hiding deep inside ancient meteorites recovered from Antarctica, they very well may be from a star… possibly even the one whose explosive collapse sparked the formation of the Solar System itself.

Researchers from Washington University in St. Louis with support from the McDonnell Center for the Space Sciences have announced the discovery of two microscopic grains of silica in primitive meteorites originating from two different sources. This discovery is surprising because silica — one of the main components of sand on Earth today — is not one of the minerals thought to have formed within the Sun’s early circumstellar disk of material.

Instead, it’s thought that the two silica grains were created by a single supernova that seeded the early solar system with its cast-off material and helped set into motion the eventual formation of the planets.

According to a news release by Washington University, “it’s a bit like learning the secrets of the family that lived in your house in the 1800s by examining dust particles they left behind in cracks in the floorboards.”

A 3.5-cm chondrite meteorite found in Antarctica in Nov. 1998. Dark meteorites show up well against the icy terrain of Antarctica. (Carnegie Mellon University)
A 3.5-cm chondrite meteorite found in Antarctica in Nov. 1998. Dark meteorites show up well against the icy terrain of Antarctica. (Carnegie Mellon University)

Until the 1960s most scientists believed the early Solar System got so hot that presolar material could not have survived. But in 1987 scientists at the University of Chicago discovered miniscule diamonds in a primitive meteorite (ones that had not been heated and reworked). Since then they’ve found grains of more than ten other minerals in primitive meteorites.

The scientists can tell these grains came from ancient stars because they have highly unusual isotopic signatures, and different stars produce different proportions of isotopes.

But the material from which our Solar System was fashioned was mixed and homogenized before the planets formed. So all of the planets and the Sun have the pretty much the same “solar” isotopic composition.

Meteorites, most of which are pieces of asteroids, have the solar composition as well, but trapped deep within the primitive ones are pure samples of stars, and the isotopic compositions of these presolar grains can provide clues to their complex nuclear and convective processes.

The layered structure of a star about to go supernova; different layers contain different elements (Wikimedia)
The layered structure of a star about to go supernova; different layers contain different elements (Wikimedia)

Some models of stellar evolution predict that silica could condense in the cooler outer atmospheres of stars, but others say silicon would be completely consumed by the formation of magnesium- or iron-rich silicates, leaving none to form silica.

“We didn’t know which model was right and which was not, because the models had so many parameters,” said Pierre Haenecour, a graduate student in Earth and Planetary Sciences at Washington University and the first author on a paper to be published in the May 1 issue of Astrophysical Journal Letters.

Under the guidance of physics professor Dr. Christine Floss, who found some of the first silica grains in a meteorite in 2009, Haenecour investigated slices of a primitive meteorite brought back from Antarctica and located a single grain of silica out of 138 presolar grains. The grain he found was rich in oxygen-18, signifying its source as from a core-collapse supernova.

Finding that along with another oxygen-18-enriched silica grain identified within another meteorite by graduate student Xuchao Zhao, Haenecour and his team set about figuring out how such silica grains could form within the collapsing layers of a dying star. They found they could reproduce the oxygen-18 enrichment of the two grains through the mixing of small amounts of material from a star’s oxygen-rich inner zones and the oxygen-18-rich helium/carbon zone with large amounts of material from the outer hydrogen envelope of the supernova.

In fact, Haenecour said, the mixing that produced the composition of the two grains was so similar, the grains might well have come from the same supernova — possibly the very same one that sparked the collapse of the molecular cloud that formed our Solar System.

“It’s a bit like learning the secrets of the family that lived in your house in the 1800s by examining dust particles they left behind in cracks in the floorboards.”

Ancient meteorites, a few microscopic grains of stellar sand, and a lot of lab work… it’s an example of cosmic forensics at its best!

Source: Washington University in St. Louis

Posted on by Nancy Atkinson

NASA Explains Their New Asteroid Retrieval Mission

Concept of asteroid capture in progress. Credit: NASA.

NASA’s FY2014 budget proposal includes a plan to robotically capture a small near-Earth asteroid and redirect it safely to a stable orbit in the Earth-moon system where astronauts can visit and explore it. A spacecraft would capture an asteroid — which hasn’t been chosen yet, but would be about 7 meters (25 feet) wide — in 2019. Then using an Orion space capsule, a crew of about four astronauts would station-keep with the space rock in 2021 to allow for EVAs for exploration.

NASA has released new images, a video and more information about the mission.

They say that performing all the elements for the proposed asteroid initiative “integrates the best of NASA’s science, technology and human exploration capabilities and draws on the innovation of America’s brightest scientists and engineers.” The mission will combine existing technology along with capabilities being developed to find both large asteroids that pose a hazard to Earth and small asteroids that could be candidates for the proposed mission. NASA says this initiative will help accelerate technology development activities in high-powered solar electric propulsion and take advantage the Space Launch System rocket and Orion spacecraft currently being built, “helping to keep NASA on target to reach the President’s goal of sending humans to Mars in the 2030s.”

Here’s more of NASA’s info:

When astronauts don their spacesuits and venture out for a spacewalk on the surface of an asteroid, how they move and take samples of it will be based on years of knowledge built by NASA scientists and engineers who have assembled and operated the International Space Station, evaluated exploration mission concepts, sent scientific spacecraft to characterize near-Earth objects and performed ground-based analog missions.

As early as the 1970s, NASA examined potential ways to use existing hardware to visit an asteroid to understand better its characteristics. On the International Space Station, scientific investigations and technology demonstrations are improving knowledge of how humans can live and work in space. The agency also has examined many possible mission concepts to help define what capabilities are needed to push the boundaries of space exploration.

During the early space shuttle flights and through assembly of the space station, NASA has relied on testing both in space and on Earth to try out ideas through a host of analog missions, or field tests, that simulate the complexity of endeavors in space.

Concept of Spacecraft with Asteroid Capture Mechanism Deployed. Credit: NASA.
Concept of Spacecraft with Asteroid Capture Mechanism Deployed. Credit: NASA.

Through 16 missions in the National Oceanic and Atmospheric Administration’s underwater Aquarius Reef Base off the coast of Key Largo, Fla., aquanauts have tested techniques for human space exploration. These underwater tests have been built upon the experience gained by training astronauts in the Neutral Buoyancy Laboratory at NASA’s Johnson Space Center in Houston to assemble and maintain the space station. The NASA Extreme Environment Mission Operations (NEEMO) 15 and 16 missions in 2011 and 2012, respectively, simulated several challenges explorers will face when visiting an asteroid, including how to anchor to and move around the surface of a near-Earth object and how to collect samples of it.

NASA also has simulated an asteroid mission as part of its 2012 Research and Technology Studies ground test at Johnson. During the simulation, a team evaluated how astronauts might do a spacewalk on an asteroid and accomplish other goals. While performing a spacewalk on a captured asteroid will involve different techniques than the activities performed during recent analog exercises, decisions made about ways to best sample an asteroid will be informed by the agency’s on-going concept development and past work.

Artist's Concept of a Solar Electric Propulsion System. Credit: NASA.
Artist’s Concept of a Solar Electric Propulsion System. Credit: NASA.

Scientific missions also have investigated the nature of asteroids to provide a glimpse of the origins of the solar system. From the Pioneer 10 spacecraft, which in 1972 was the first to venture into the Main Asteroid Belt, to the Dawn mission, which recently concluded its investigations of asteroid Vesta and is on its way to the dwarf planet Ceres, NASA’s forays help us understand the origins of the solar system and inform decisions about how to conduct missions to distant planetary bodies. Scientists both at NASA and across the world also continue to study asteroids to shed light on their unique characteristics.

As NASA ventures farther into the solar system, the agency continues to simulate and evaluate operations and technical concepts for visiting an asteroid.

Source: NASA

Posted on by Nancy Atkinson

Official Confirms NASA Plan to Capture an Asteroid

An artist's illustration of an asteroid retrieval spacecraft capturing a 7-meter-wide, 500-ton asteroid. Rick Sternbach/Keck Institute for Space Studies.

Rumors have been leaking out for over a week, but now according to Alan Boyle at NBC News’ Cosmic Log, a senior Obama administration official has confirmed that $100 million is being sought for NASA’s budget request for the coming fiscal year for work to allow a robotic spaceship to capture a small asteroid and park it near the Moon for astronauts to explore. The spacecraft would capture a 500-ton, 7- meter (25-foot) asteroid in 2019. Then using an Orion space capsule, a crew of about four astronauts would station-keep with the space rock in 2021 to allow for EVAs for exploration. This plan would accelerate NASA’s deep space missions with Orion and prepare crews for going to Mars.

NBC news quoted the official — who spoke on condition of anonymity because there was no authorization to discuss the plan publicly — as saying the mission would “accomplish the president’s challenge of sending humans to visit an asteroid by 2025 in a more cost-effective and potentially quicker time frame than under other scenarios.”

A week ago, Aviation Week reported that NASA was considering this asteroid mission, which was proposed by the Keck Institute for Space Studies last year. Keck’s proposal had a price tag of $2.6 billion, but no cost estimate for the space agency’s version has yet been released.

Then on April 5, the Associated Press quoted U.S. Sen. Bill Nelson, D-Florida, Nelson, chairman of the Senate science and space subcommittee, that President Obama is putting $100 million in planning money for the accelerated asteroid mission in the 2014 budget that comes out next week. The money would be used to find the right small asteroid.

“It really is a clever concept,” AP quoted Nelson said in a press conference in Orlando. “Go find your ideal candidate for an asteroid. Go get it robotically and bring it back.”

This would be the first time ever an object in space of this size would be manipulated in such a manner.

In depth: A Human Mission to an Asteroid: Why Should NASA Go?

Donald Yeomans, who heads NASA’s Near Earth Object program, was quoted that while there are thousands of asteroids around 25-feet, finding the right one that comes by Earth at just the right time to be captured will not be easy. And once a suitable rock is found it would be captured with the space equivalent of “a baggie with a drawstring. You bag it. You attach the solar propulsion module to de-spin it and bring it back to where you want it.”

A 7- meter (25-foot) asteroid is not a threat to Earth because asteroids of that size would burn up in Earth’s atmosphere.

The official quoted by NBC said the plan has been under discussion for months, but after February’s meteor blast over Russia, the plan gained traction. The asteroid’s entry into Earth’s atmosphere and subsequent airblast injured more than 1,000 people, and sparked discussions about asteroid threats, including a series of congressional hearings. Congressional officials said they would support more funding to counter asteroid threats.

“This plan would help us prove we’re smarter than the dinosaurs,” NBC quoted said the official, referring to the asteroid that wiped out the dinosaurs and many other species 65 million years ago.