Asteroids Archives

November 27, 2016 by Matt Williams

NASA Technology Used To Find Stone Age Structures

The Phoenix Mars Lander used a lidar device built by Teledyne Optech to detect snow in the Martian atmosphere in 2008. Credits: NASA

Oklahoma’s Beaver River is an incredibly historic place. Anthropologists estimate that as early as 10,500 years ago, human beings hunted bison in the region. Being without horses, the hunter-gatherers would funnel herds into narrow, dead-end gullies cut into the hillside by the river. Once there, they would kill them en masse, taking the meat and organs and leaving the skeletons behind.

Sadly, no visible trace of this history remains in the region today, thanks to weathering and erosion. But according to a recent story released by NASA, the same technology that powers the Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) mission has made the ancient history of this region visible for all to see.

Having launched back in September of 2016, the robotic spacecraft OSIRIS-REx is scheduled to rendezvous with the Near-Earth Asteroid Bennu in 2023. The purpose of the mission is to obtain samples of the carbonaceous object and return them to Earth, thus helping scientists to get a better understanding of the formation and evolution of the Solar System, as well as the source of organic compounds that led to the formation of life on Earth.

Once it reaches Bennu, it will rely on light-detection and ranging (aka. lidar) to map the asteroid and help the mission team select a landing site. This technology uses one or more lasers to send out short pulses that bounce off of nearby objects. The instrument then measures how long it takes for the signal to return to get an accurate assessment of distance and generate topographical information.

The OSIRIS-REx Laser Altimeter (OLA) instrument was designed by Teledyne Optech, a company that has worked with NASA many times in the past. Their work includes the laser instrument that was used by the Phoenix Lander to detect snow in the Martian atmosphere back in 2008. And more recently, it was used by an archeological research team in the Beaver River area to create a detailed picture of its past.

Using an airborne version of the Teledyne Optech lidar device, the team was able to create a 3-D model of the surface. They were also able to generate as a ‘bare-earth” version of the area that showed what the land looked like without all of the concealing features – i.e. rocks, trees and grass – that hide its past.

In so doing, they were able to figure out where they should dig to find evidence that the region was once a major hunting ground. As Paul LaRoque, vice president of special projects at Teledyne Optech, explained, this process allowed the archaeologists to “see structures or features that were so overgrown that they wouldn’t be obvious at all to someone on the ground.”

Aerial photograph of a forest in Connecticut (left), and bare-earth lidar image beneath the overgrown vegetation (right) showing the remnants of stone walls, building foundations, abandoned roads and what was once cleared farm land. Credits: NASA/Katharine Johnson — *Aerial photograph of a forest in Connecticut (left), and bare-earth lidar image beneath the vegetation (right) showing archaeological remains. Credits: UofConn/Katharine Johnson*

This sort of process has also been used by other archaeological teams to make major finds, like uncovering the lost “Ciudad Blanca” (aka. the “City of the Monkey God”) of Honduras. This ancient Mesoamerican settlement, which is believed to have been built between the 1st and 2nd millennium CE, had remained the stuff of legend for centuries. Despite multiple claims by explorers, no confirmed discovery was ever made.

But thanks to a joint effort by archaeologists from the University of Florida and the Houston-based National Center for Airborne Laser Mapping, an archaeological team was able to create images that stripped away the lush rainforest to revealed multiple structures – including pyramids, a plaza, a possible ball court, and many houses.

Lidar was also used by a research team from the University of Connecticut for the sake of studying the dynamics between human settlement and the historic landscape of New England. Using publicly available data, they were able to peer beneath all the current vegetation to detect the remnants of stone walls, building foundations, abandoned roads and what was once cleared farm land.

The revealing look at Beaver River is one of 50 stories that will be released on Dec. 5th, as part of a NASA Spinoff publication. Each year, Spinoff profiles about 50 NASA technologies that have transformed into commercial products and services, demonstrating the wider benefits of America’s investment in its space program. Spinoff is a publication of the Technology Transfer Program in NASA’s Space Technology Mission Directorate.

Further Reading: NASA

November 18, 2016November 26, 2016 by Nancy Atkinson

Soar Over Ceres With New Images From the Dawn Spacecraft

This image of the limb of dwarf planet Ceres shows a section of the northern hemisphere. Prominently featured is Occator Crater, home of Ceres' intriguing brightest areas. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

There’s one thing that could mean the end of the Dawn mission: if the hydrazine fuel for its maneuvering thruster system runs out. Now, engineers for the Dawn mission have figured out a way to save on this fuel while still sending Dawn to a new science orbit around the dwarf planet Ceres. They are effectively extending the mission while expanding on the science Dawn can do.

And in the meantime, Dawn’s cameras can take stunning new images, like the one above of Occator Crater on Ceres and its intriguing, mysterious bright regions.

“This image captures the wonder of soaring above this fascinating, unique world that Dawn is the first to explore,” said Marc Rayman, Dawn’s chief engineer and mission director at the Jet Propulsion Laboratory.

This image has the cameras on the Dawn spacecraft looking straight down at Occator Crater on Ceres, with its signature bright areas. Dawn scientists have found that the central bright spot, which harbors the brightest material on Ceres, contains a variety of salts. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Dawn started making its way to a sixth science orbit earlier this month, raising its orbital height to over 4,500 miles (7,200 kilometers) from Ceres. For previous changes in its orbit, Dawn needed to make several changes in direction while it spiraled either higher or lower. But Dawn’s ever-ingenious engineers have figured out a way for the spacecraft to arrive at this next orbit while the ion engine thrusts in the same direction that Dawn is already going. This uses less hydrazine and xenon fuel than Dawn’s normal spiral maneuvers.

Previously, Dawn’s engineers have done things nothing short of miraculous, such as figuring out how to operate the spacecraft with only two reaction wheels (when at least three are needed, normally), they have developed new, emergency flight paths on short notice, and they keep figuring out ways to conserve the hydrazine. Earlier in the mission, they analyzed more than 50 different options to figure out how to reduce their fuel usage by a whopping 65 percent.

Occator Crater, with its central bright region and other reflective areas, provides evidence of recent geologic activity. The latest research suggests that the bright material in this crater is comprised of salts left behind after a briny liquid emerged from below, froze and then sublimated, meaning it turned from ice into vapor.

The impact that formed the crater millions of years ago unearthed material that blanketed the area outside the crater, and may have triggered the upwelling of salty liquid.

Another new image from Dawn scientists at the German Aerospace Center in Berlin shows how the dwarf planet’s colors would appear to the human eye. The color was calculated based on the way Ceres reflects different wavelengths of light.

This image of Ceres approximates how the dwarf planet's colors would appear to the eye. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA — This image of Ceres approximates how the dwarf planet’s colors would appear to the eye. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Dawn scientists say that one goal of Dawn’s sixth science orbit is to refine previously collected measurements. The spacecraft’s gamma ray and neutron spectrometer, which has been investigating the composition of Ceres’ surface, will characterize the radiation from cosmic rays unrelated to Ceres. This will allow scientists to subtract “noise” from measurements of Ceres, making the information more precise.

This image of the limb of dwarf planet Ceres shows a section of the northern hemisphere. A shadowy portion of Occator Crater can be seen at the lower right -- its bright "spot" areas are outside of the frame of view. Part of Kaikara Crater (45 miles, 72 kilometers in diameter) is visible at top left. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA — This image of the limb of dwarf planet Ceres shows a section of the northern hemisphere. A shadowy portion of Occator Crater can be seen at the lower right — its bright “spot” areas are outside of the frame of view. Part of Kaikara Crater (45 miles, 72 kilometers in diameter) is visible at top left. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

The spacecraft has gathered tens of thousands of images and other information from Ceres since arriving in orbit on March 6, 2015. After spending more than eight months studying Ceres at an altitude of about 240 miles (385 kilometers), closer than the International Space Station is to Earth, Dawn headed for a higher vantage point in August. Then, in October, Dawn raised its orbit to about 920-mile (1,480 km) altitude, returning more images and other valuable data about Ceres.

Thanks to the ingenuity of Dawn’s engineers, we’ll have more time to study Ceres.

See all of Dawn’s latest images here.

Oxo Crater and its surroundings are featured in this image of Ceres' surface from NASA's Dawn spacecraft. Dawn took this image on Oct. 18, 2016, from its second extended-mission science orbit (XMO2), at a distance of about 920 miles (1,480 kilometers) above the surface. The image resolution is about 460 feet (140 meters) per pixel. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA — Oxo Crater and its surroundings are featured in this image of Ceres’ surface from NASA’s Dawn spacecraft. Dawn took this image on Oct. 18, 2016, from its second extended-mission science orbit (XMO2), at a distance of about 920 miles (1,480 kilometers) above the surface. The image resolution is about 460 feet (140 meters) per pixel. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

This view from NASA's Dawn spacecraft features a lobe-shaped flow feature in Ghanan Crater on Ceres. The flow feature is a place where a crater rim has collapse and material has flowed across the surface. Several small craters are visible on top of the flow; the number of craters can help scientists estimate the feature's age. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA — This view from NASA’s Dawn spacecraft features a lobe-shaped flow feature in Ghanan Crater on Ceres. The flow feature is a place where a crater rim has collapse and material has flowed across the surface. Several small craters are visible on top of the flow; the number of craters can help scientists estimate the feature’s age. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Source: JPL

November 10, 2016 by Mark Mortimer

Rock Legends – the Asteroids and Their Discoverers

Artist's concept of Trojan asteroids, small bodies that dominate our solar system. Credit: NASA

If we are indeed stardust, then what will our future hold? And what happened to all that other dust that isn’t in people or planets? These are pretty heady questions perhaps best left for late at night. Since the age of Galileo and perhaps even beforehand these inquisitive night goers have sought an understanding of “What’s out there?” Paul Murdin in his book “Rock Legends – the Asteroids and Their Discoverers” doesn’t answer the big questions directly but he does shed some capricious light upon what the night time reveals and what the future may hold.

We’re pretty confident that our solar system evolved from a concentration of dust. Let’s leave aside the question about where the dust came from and assume that, at a certain time and place, there was enough free dust that our Sun was made and so too all the planets. In a nice, orderly universe all the dust would have settled out. However, as we’ve discovered since at least the time of Galileo this didn’t happen. There are a plethora of space rocks — asteroids — out wandering through our solar system.

And this is where Murdin’s book steps up. Once people realized that there more than just a few asteroids out there, they took to identifying and classifying them. The book takes a loosely chronological look at this classification and at our increasing knowledge of the orbits, sizes, densities and composition of these space wanderers.

Fortunately this book doesn’t just simply list discovery dates and characteristics. Rather, it includes significant amounts of its contents on the juicy human story that tags along, especially with the naming. It shows that originally these objects were considered special and refined and thus deserved naming with as much aplomb as the planets; i.e. using Greek and Roman deities. Then the number of discovered asteroids outpaced the knowledge of ancient lore, so astronomers began using the names of royalty, friends and eventually pets. Today with well over a million asteroids identified setting a name to an asteroid doesn’t quite have the same lustre, as the author is quick to point out with his own asteroid (128562) Murdin. Yet perhaps there’s not much else to do while waiting for a computer program to identify a few hundred more accumulations of dust, so naming some of the million nameless asteroids could happily fill in some time.

With the identifying of the early asteroid discoverers and the fun names they chose, this part of the book is quite light and simple. It expands the fun by wandering a bit just like the asteroids. From it you learn of the discovery of palladium, the real spelling of Spock’s name and the meaning of YORP. Sometimes the wandering is quite far, as with the origins of the Palladium Theatre, the squabbling surrounding the naming of Ceres and the status of the Cubewanos. Yet it is this capriciousness that gives the book its flavour and makes it great for a budding astronomer or a reference for a generalist. The occasional bouts of reflection on the future of various asteroids and even of the Earth add a little seriousness to an otherwise pleasant prose.

So if you’re wondering about the next occultation of Eris or the real background of the name (3512) Eriepa then you’re into asteroids. And perhaps you’re learning how to survive on a few hours of sleep so you can search for one more faint orbiting mote. Whether that’s the case or you’re just interested in how such odd names came to represent these orbiting rocks then Paul Murdin’s book “Rock Legends – the Asteroids and Their Discoverers” will be a treat. Read it and maybe you can use it to place your own curve upon an asteroid’s name.

The book is available on Springer. Find out more about author Paul Murdin here.

November 2, 2016November 2, 2016 by Evan Gough

NASA’s New Asteroid Alert System Gives 5 Whole Days of Warning

An asteroid strike that could wreak some serious havoc against Earth may be statistically unlikely. But it's not like there's no precedent for one. Artist's Image: . Credit: NASA

Everyone knows it was a large asteroid striking Earth that led to the demise of the dinosaurs. But how many near misses were there? Modern humans have been around for about 225,000 years, so we must have come close to death by asteroid more than once in our time. We would have had no clue.

Of course, it’s the actual strikes that are cause for concern, not near misses. Efforts to predict asteroid strikes, and to catalogue asteroids that come close to Earth, have reached new levels. NASA’s newest tool in the fight against asteroids is called Scout. Scout is designed to detect asteroids approaching Earth, and it just passed an important test. Scout was able to give us 5 days notice of an approaching asteroid.

Here’s how Scout works. A telescope in Hawaii, the Panoramic Survey Telescope & Rapid Response System (Pan-STARRS) detected the asteroid, called 2016 UR36, and then alerted other ‘scopes. Three other telescopes confirmed 2016 UR36 and were able to narrow down its trajectory. They also learned its size, about 5 to 25 meters across.

The Pan STARRS telescope in Hawaii. Image: Institute for Astronomy, University of Hawaii.

After several hours, we knew that UR 36 would come close to us, but was not a threat to impact Earth. UR 36 would pass Earth at a distance of about 498,000 km. That’s about 1.3 times further away than the Moon.

The key part of this is that we had 5 days notice. And five days notice is a lot more than the few hours that we usually have. The approach of 2016 UR36 was the first test for the Scout system, and it passed the test.

Asteroids that come close to Earth are called Near Earth Objects (NEOs) and finding them and tracking them has become a growing concern for NASA. In fact NASA has about 15,000 NEOs catalogued, and they’re still finding about 5 more every night.

NASA is getting much better at discovering and detecting NEOs. Image: NASA/NEO Program.

Not only does NASA have the Scout system, whose primary role is to speed up the confirmation process for approaching asteroids, but they also have the Sentry program. Sentry’s role is a little different.

Sentry’s job is to focus on asteroids that are large enough to wipe out a city and cause widespread destruction. That means NEOs that are larger than about 140 metres. Sentry has over 600 large NEOs catalogued, and astronomers think there are a lot more of them out there.

NASA also has the Planetary Defense Coordination Office (PDCO), which has got to be the greatest name for an office ever. (Can you imagine having that on your business card?) Anyway, the PDCO has the over-arching role of preparing for asteroid impacts. The Office is there to make emergency plans to deal with the impact aftermath.

5 days notice for a small asteroid striking Earth is a huge step for preparedness. Resources can be mobilized, critical infrastructure can be protected, maybe things like atomic power plants can be shut down if necessary. And, of course, people can be evacuated.

We haven’t always had any notice for approaching asteroids. Look at the Chelyabinsk meteor from 2013. It was a 10,000 ton meteor that exploded over the Chelyabinsk Oblast, injuring 1500 people and damaging an estimated 3,000 building in 6 cities. If it had been a little bigger, and reached the surface of the Earth, the damage would have been widespread. 5 days notice would likely have saved a lot of lives.

Smaller asteroids may be too small to detect when they’re very far away. But larger ones can be detected when they’re still 10, 20, even 30 years away. That’s enough time to figure out how to stop them. And if you can reach them when they’re that far away, you only need to nudge them a little to deflect them away from Earth, and maybe to the Sun to be destroyed.

Large asteroids with the potential to cause widespread destruction are the attention-getters. Hollywood loves them. But it may be more likely that we face numerous impacts from smaller asteroids, and that they could cause more damage overall. Scout’s ability to detect these smaller asteroids, and give us several days notice of their approach, could be a life-saver.

November 2, 2016 by David Dickinson

Watch Asteroid 2016 VA Pass Through Earth’s Shadow

Mining asteroids might be necessary for humanity to expand into the Solar System. But what effect would asteroid mining have on the world's economy? Credit: ESA.

Holy low-flying space rocks, Batman.

Newly discovered asteroid 2016 VA snuck up on us last night, and crossed through the Earth’s shadow to boot.

Discovered just yesterday by the Mount Lemmon Sky Survey based outside of Tucson Arizona, 2016 VA passed just 58,600 miles (93,700 kilometers) from the surface of the Earth this morning at 00:42 Universal Time (UT). That’s a little over 20% of the distance from the Earth to the Moon, and just over twice the distance to the ring of geosynchronous and geostationary satellites around the Earth.

This sort of close pass of a newly discovered asteroid happens a few times a year. What made 2016 VA’s passage unusual, however, was its transit through the Earth’s shadow. The discovery was announced yesterday by the Minor Planet Center, and astronomer Gianluca Masi soon realized that the Virtual Telescope Project had a unique opportunity to capture the asteroid on closest approach.

The passage of asteroid 2016 VA. Image credit: The Virtual Telescope Project. — Asteroid 2016 VA. Image credit: The Virtual Telescope Project.

Gianluca Masi explained how the difficult capture was done:

“The image is a 60-second exposure, remotely taken with “Elena” (a PlaneWave 17” +Paramount ME+SBIG STL-6303E robotic unit) available at the Virtual Telescope project. The robotic mount tracked the extremely fast apparent motion of the asteroid, so stars are trailing. The asteroid is perfectly tracked; it is the sharp dot in the center, marked with two white segments. At imaging time, asteroid 2016 VA was at about 200,000 kilometers from us and approaching.”

Catching a fast-moving asteroid such as 2016 VA on closest approach isn’t easy. First off, there’s an amount of uncertainty surrounding the orbit of a newly discovered object until more observations can be made. 2016 VA passed close enough to the Earth that our planet’s gravity substantially altered the tiny asteroid’s future orbit. Also, a house-sized Earth-crosser like 2016 VA is really truckin’ across the sky on closest approach: 2016 VA was moving at 1500” a minute through Earth’s shadow – that’s 25” a second, fast enough to cross the apparent diameter of a Full Moon in just 72 seconds.

Masi also notes:

“During its flyby, asteroid 2016 VA was also eclipsed by the Earth. We covered the spectacular event, clearly capturing the penumbral effects. The movie is an amazing document showing the eclipse. Each frame comes from a 5-second integration.”

Watch as 2016 VA winks out as it hits Earth's shadow... Image credit: The Virtual Telescope Project. — Watch as 2016 VA winks out as it hits Earth’s shadow… Image credit: The Virtual Telescope Project.

At an estimated 16 to 19 meters in size, 2016 VA shined at 13^th magnitude as it crossed the southern hemisphere constellation of Sculptor on closest approach. It crossed through the Earth’s shadow for 11 minutes from 23:23 to 23:34 UT last night, just over an hour before closest approach. You can see the dimming effect of the Earth’s outer penumbral shadow in the video, just before the asteroid strikes the inner dark umbra and emerges back into eternal sunshine once again. Sitting on 2016 VA, and observer would have seen a total solar eclipse, as the bulk of the Earth passed between the asteroid and the Sun in an event not witnessed by the tiny world for thousands of years.

Such transits of asteroid through the Earth’s shadow have been observed before: 2012 XE54 crossed through the Earth’s shadow a few years back, and 2008 TC3 crossed through the Earth’s shadow before striking the Nubian desert in the early morning hours of October 7^th, 2008.

Satellites in geostationary orbit also pull a similar vanishing act right around either equinox as well.

The orbit of 2016 VA. Iimage credit: NASA/JPL. — The orbit of 2016 VA. Image credit: NASA/JPL.

2016 VA is also a similar size to another famous space rock: the 20 metre asteroid that exploded over the city of Chelyabinsk the day after Valentine’s Day in 2013. 2016 VA gave us a miss, and won’t make another pass as close to the Earth again for this century.

To our knowledge, such a video capture of an asteroid crossing through Earth’s shadow is a first, or at least the first that we’ve seen circulated on ye ole Web.

The light curve of 2016 as it passed through the Earth's shadow. Image credit: Peter Birtwhistle, Great Shefford Observatory. — The light curve of 2016 as it passed through the Earth’s shadow. Image credit: Peter Birtwhistle, Great Shefford Observatory.

Congrats to the good folks at the Virtual Telescope Project for swinging into action so quickly, and providing us with an amazing view!

-Catch the closest Full Moon of the year (and for many years to come!) on November 14^th live courtesy of the Virtual Telescope Project.

November 1, 2016November 2, 2016 by Nancy Atkinson

Pure Metal Asteroid Has Mysterious Water Deposits

An artist’s concept of the Psyche spacecraft, a proposed mission for NASA’s Discovery program that would explore the huge metal Psyche asteroid from orbit. Credit: NASA/JPL-Caltech.

Water has been showing up in all sorts of unexpected places in our Solar System, such as the Moon, Mercury and Jupiter’s moon Ganymede. Add one more place to the list: Asteroid 16 Psyche. This metal-rich asteroid may have traces of water molecules on its surface that shouldn’t be there, researchers say.

Psyche is thought to be the largest metallic asteroid in the Solar System, at 300 km (186 miles) across and likely consists of almost pure nickel-iron metal. Scientists had thought Psyche was made up of the leftover core of a protoplanet that was mostly destroyed by impacts billions of years ago, but they may now be rethinking that.

“The detection of a 3 micron hydration absorption band on Psyche suggests that this asteroid may not be metallic core, or it could be a metallic core that has been impacted by carbonaceous material over the past 4.5 Gyr,” the team said in their paper.

While previous observations of Psyche had shown no evidence for water on its surface, new observations with the NASA Infrared Telescope Facility found evidence for volatiles such as water or hydroxyl on the asteroid’s surface. Hydroxyl is a free radical consisting of one hydrogen atom bound to one oxygen atom.

“We did not expect a metallic asteroid like Psyche to be covered by water and/or hydroxyl,” said Vishnu Reddy, from the University of Arizona’s Lunar and Planetary Laboratory, a co-author of the new paper about Psyche. “Metal-rich asteroids like Psyche are thought to have formed under dry conditions without the presence of water or hydroxyl, so we were puzzled by our observations at first.”

Asteroids usually fall into two categories: those rich in silicates, and those rich in carbon and volatiles. Metallic asteroids like Psyche are extremely rare, making it a laboratory to study how planets formed.

he asteroid Psyche is one of the larger asteroids. Credit: Lindy T. Elkins-Tanton

For now, the source of the water on Psyche remains a mystery. But Redddy and his colleagues propose a few different explanations. One is, again, Psyche may not be as metallic as previously thought. Another option is that the water or hydroxyl could be the product of solar wind interacting with silicate minerals on Psyche’s surface, such as what is occurring on the Moon.

The most likely explanation, however is that the water seen on Psyche might have been delivered by carbonaceous asteroids that impacted Psyche in the distant past, as is thought to have occurred on early Earth.

“Our discovery of carbon and water on an asteroid that isn’t supposed to have those compounds supports the notion that these building blocks of life could have been delivered to our Earth early in the history of our solar system,” said Reddy.

If we’re lucky, we won’t have to wait too long to find out more about Psyche. A mission to Psyche is on the short list of mission proposals being considered by NASA, with a potential launch as early as 2020. Reddy and team said an orbiting spacecraft could explore this unique asteroid and determine if whether there is water or hydroxyl on the surface.

Sources: Europlanet, University of Arizona, paper: Detection of Water and/or Hydroxyl on Asteroid (16) Psyche.

October 21, 2016 by Bob King

Astronomers Think They Know Where Rosetta’s Comet Came From

In the distant past, the orbit of 67P/Churyumov-Gerasimenko extended far beyond Neptune into the refrigerated Kuiper Belt. Interactions with the gravitational giant Jupiter altered the comet's orbit over time, dragging it into the inner Solar System. Credit: Western University, Canada

Rosetta’s Comet hails from a cold, dark place. Using statistical analysis and scientific computing, astronomers at Western University in Canada have charted a path that most likely pinpoints comet 67P/Churyumov-Gerasimenko’s long-ago home in the far reaches of the Kuiper Belt, a vast region beyond Neptune home to icy asteroids and comets.

According to the new research, Rosetta’s Comet is relative newcomer to the inner parts of our Solar System, having only arrived about 10,000 years ago. Prior to that, it spent the last 4.5 billion years in cold storage in a rough-and-tumble region of the Kuiper Belt called the scattered disk.

The Kuiper Belt was named in honor of Dutch-American astronomer Gerard Kuiper, who postulated a reservoir of icy bodies beyond Neptune. The first Kuiper Belt object was discovered in 1992. We now know of more than a thousand objects there, and it's estimated it's home to more than 100,000 asteroids and comets there over 62 miles (100 km) across. Credit: JHUAPL — The Kuiper Belt was named in honor of Dutch-American astronomer Gerard Kuiper, who postulated a reservoir of icy bodies beyond Neptune. The first Kuiper Belt object was discovered in 1992. We now know of more than a thousand objects there, and it’s estimated it’s home to more than 100,000 asteroids and comets there over 62 miles (100 km) across. Credit: JHUAPL

In the Solar System’s youth, asteroids that strayed too close to Neptune were scattered by the encounter into the wild blue yonder of the disk. Their orbits still bear the scars of those long-ago encounters: they’re often highly-elongated (shaped like a cigar) and tilted willy-nilly from the ecliptic plane up to 40°. Because their orbits can take them hundreds of Earth-Sun distances into the deeps of space, scattered disk objects are among the coldest places in the Solar System with surface temperatures around 50° above absolute zero. Ices that glommed together to form 67P at its birth are little changed today. Primordial stuff.

Watch how Rosetta’s Comet’s orbit has evolved since the comet’s formation

There are two basic comet groups. Most comets reside in the cavernous Oort Cloud, a roughly spherical-shaped region of space between 10,000 and 100,000 AU (astronomical unit = one Earth-Sun distance) from the Sun. The other major group, the Jupiter-family comets, owes its allegiance to the powerful gravity of the giant planet Jupiter. These comets race around the Sun with periods of less than 20 years. It’s thought they originate from collisions betwixt rocky-icy asteroids in the Kuiper Belt.

Fragments flung from the collisions are perturbed by Neptune into long, cigar-shaped orbits that bring them near Jupiter, which ropes them like calves with its insatiable gravity and re-settles them into short-period orbits.

Comet 67P/Churyumov-Gerasimenko is a Jupiter-family comet. Its 6.5 year journey around the Sun takes it from just beyond the orbit of Jupiter at its most distant, to between the orbits of Earth and Mars at its closest. Credit: ESA with labels by the author — Comet 67P/Churyumov-Gerasimenko is a Jupiter-family comet. Its 6.5 year journey around the Sun takes it from just beyond the orbit of Jupiter at its most distant to between the orbits of Earth and Mars at its closest. Credit: ESA with labels by the author

Mattia Galiazzo and solar system expert Paul Wiegert, both at Western University, showed that in transit, Rosetta’s Comet likely spent millions of years in the scattered disk at about twice the distance of Neptune. The fact that it’s now a Jupiter family comet hints of a possible long-ago collision followed by gravitational interactions with Neptune and Jupiter before finally becoming an inner Solar System homebody going around the Sun every 6.45 years.

By such long paths do we arrive at our present circumstances.

October 15, 2016November 5, 2016 by Bob King

The Moon Is Getting Slammed Way More Than We Thought

A brand new crater on the Moon! This new 12 meter (39 foot) diameter impact crater formed between 25 October 2012 and 21 April 2013 Credit: NASA/GSFC/Arizona State University].

Animation of a temporal pair of the new 39-foot (12-meter) impact crater on the moon photographed by NASA's Lunar Reconnaissance Orbiter Credit: NASA/GSFC/Arizona State University — Animation of a temporal pair of the new 39-foot (12-meter) impact crater on the moon photographed by NASA’s Lunar Reconnaissance Orbiter Credit: NASA/GSFC/Arizona State University

We often hear how the Moon’s appearance hasn’t changed in millions or even billions of years. While micrometeorites, cosmic rays and the solar wind slowly grind down lunar rocks, the Moon lacks erosional processes such as water, wind and lurching tectonic plates that can get the job done in a hurry.

After taking the first boot print photo, Aldrin moved closer to the little rock and took this second shot. The dusty, sandy pebbly soil is also known as the lunar ‘regolith’. Click to enlarge. Credit: NASA — One of a series of photos Apollo 11 astronaut Edwin Aldrin made of his bootprint in the dusty, sandy lunar soil, called regolith. Based on a newy study, the impression may disappear in a few tens of thousands of years instead a few million. Credit: NASA

Remember Buzz Aldrin’s photo of his boot print in the lunar regolith? It was thought the impression would last up to 2 million years. Now it seems that estimate may have to be revised based on photos taken by the Lunar Reconnaissance Orbiter (LRO) that reveal that impacts are transforming the surface much faster than previously thought.

Distribution of new impact craters (yellow dots) discovered by analyzing 14,000 NAC temporal pairs. The two red dots mark the location of the 17 March 2013 and the 11 September 2013 impacts that were recorded by Earth-based video monitoring [NASA/GSFC/Arizona State University] — This map shows the distribution of new impact craters (yellow dots) discovered by analyzing 14,000 narrow-angle camera (NAC) temporal pairs. The two red dots mark the location of the March 17, 2013 and September 11, 2013 impacts that were recorded by Earth-based video monitoring. LRO’s mission was **recently extended** an addition two years through September 2018. Credit: NASA/GSFC/ASU

The LRO’s high resolution camera, which can resolve features down to about 3 feet (1-meter) across, has been peering down at the Moon from orbit since 2009. Taking before and after images, called temporal pairs, scientists have identified 222 impact craters that formed over the past 7 years. The new craters range from 10 feet up to 141 feet (3-43 meters) in diameter.

By analyzing the number of new craters and their size, and the time between each temporal pair, a team of scientists from Arizona State University and Cornell estimated the current cratering rate on the Moon. The result, published in Nature this week, was unexpected: 33% more new craters with diameters of at least 30 feet (10 meters) were found than anticipated by previous cratering models.

their brightest recorded flash occurred on 17 March 2013 with coordinates 20.7135°N, 335.6698°E. Since then LRO passed over the flash site and the NAC imaged the surrounding area; a new 18 meter (59 feet) diameter crater was found by comparing images taken before and after the March date. — LRO before and after images of an impact event on March 17, 2013. The newly formed crater is 59 feet (18 meters) in diameter. Subsurface regolith not exposed to sunlight forms a bright halo around the new crater. There also appears to be a larger nimbus of darker reflectance material visible much further beyond but centered on the impact. Credit: NASA/GSFC/Arizona State University

Similar to the crater that appeared on March 17, 2013 (above), the team also found that new impacts are surrounded by light and dark reflectance patterns related to material ejected during crater formation. Many of the larger impact craters show up to four distinct bright or dark reflectance zones. Nearest to the impact site, there are usually zone of both high and low reflectance. These two zones likely formed as a layer of material that was ejected from the crater during the impact shot outward to about 2½ crater diameters from the rim.

An artist's illustration of a meteoroid impact on the Moon. (Credit: NASA). — An artist’s illustration of a meteoroid impact on the Moon. Impacts dig up fresh material from below as well as send waves of hot rock vapor and molten rock across the lunar landscape, causing a much faster turnover of the moon soil than previously thought. Credit: NASA

From analyzing multiple impact sites, far flung ejecta patterns wrap around small obstacles like hills and crater rims, indicating the material was traveling nearly parallel to the ground. This kind of path is only possible if the material was ejected at very high speed around 10 miles per second or 36,000 miles per hour! The jet contains vaporized and molten rock that disturb the upper layer of lunar regolith, modifying its reflectance properties.

How LRO creates temporal pairs and scientists use them to discover changes on the moon’s surface.

In addition to discovering impact craters and their fascinating ejecta patterns, the scientists also observed a large number of small surface changes they call ‘splotches’ most likely caused by small, secondary impacts. Dense clusters of these splotches are found around new impact sites suggesting they may be secondary surface changes caused by material thrown out from a nearby primary impact. From 14,000 temporal pairs, the group identified over 47,000 splotches so far.

Example of a low reflectance (top) and high reflectance (bottom) splotch created either by a small impactor or more likely from secondary ejecta. In either case, the top few centimeters of the regolith (soil) was churned [NASA/GSFC/Arizona State University]. — Here are two examples of a low reflectance (top) and high reflectance (bottom) splotch created either by a small impactor or more likely from secondary ejecta. In either case, the top few inches of the regolith (soil) was churned Credit: NASA/GSFC/Arizona State University

Based on estimates of size, depth and frequency of formation, the group estimated that the relentless churning caused by meteoroid impacts will turn over 99% of the lunar surface after about 81,000 years. Keep in mind, we’re talking about the upper regolith, not whole craters and mountain ranges. That’s more than 100 times faster than previous models that only took micrometeorites into account. Instead of millions of years for those astronaut boot prints and rover tracks to disappear, it now appears that they’ll be wiped clean in just tens of thousands!

September 29, 2016September 30, 2016 by Ken Kremer

NASA’s Outbound OSIRIS-Rex Asteroid Sampler Snaps ‘First-Light’ Images

On Sept. 19, 2016 the OCAMS MapCam camera recorded a star field in Taurus, north of the constellation Orion as part of the OSIRIS-REx spacecraft’s post-launch instrument check. Credits: NASA/Goddard/University of Arizona

NASA’s newest planetary probe, the OSIRIS-REx asteroid sampling spacecraft, is merrily snapping its ‘First-Light’ images following the successful power up and health check of all of the probes science instruments, barely three weeks after a stunning sunset launch from the Florida Space Coast – as it is outbound to asteroid Bennu.

“The spacecraft has passed its initial instrument check with flying colors as it speeds toward a 2018 rendezvous with the asteroid Bennu,” NASA officials reported in a mission update.

All five of the Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) spacecraft science instruments and one of its navigational instruments were powered on, starting last week on September 19.

NASA says they are all fully healthy for the groundbreaking mission whose purpose is to visit the carbon rich asteroid Bennu, snatch samples from the black as coal surface and return them to Earth in 2023 inside a Sample Return Capsule that will soft land by parachute in the Utah desert.

The seven year roundtrip mission to Bennu and back could potentially bring back samples infused with the organic chemicals like amino acids that are the building blocks of life as we know it.

“The data received from the checkout indicate that the spacecraft and its instruments are all healthy.”

The ‘First-Light’ image shown above was taken on Sept. 19, 2016 by the probes OCAMS MapCam camera and recorded a star field in Taurus, north of the constellation Orion along with Orion’s bright red star Betelgeuse.

“MapCam’s first color image is a composite of three of its four color filters, roughly corresponding to blue, green, and red wavelengths. The three images are processed to remove noise, co-registered, and enhanced to emphasize dimmer stars,” researchers said.

The OSIRIS-REx Camera Suite (OCAMS) was the first of the five science instrument to be tested and checlked out perfectly with “no issues.” It was provided by the University of Arizona and is comprised of three cameras which will image and map Bennu in high resolution.

View of science instrument suite and TAGSAM robotic sample return arm on NASA’s OSIRIS-REx asteroid sampling spacecraft inside the Payloads Hazardous Servicing Facility at NASA's Kennedy Space Center. Probe is slated for Sep. 8, 2016 launch to asteroid Bennu from Cape Canaveral Air Force Station, FL. Credit: Ken Kremer/kenkremer.com — View of science instrument suite and TAGSAM robotic sample return arm on NASA’s OSIRIS-REx asteroid sampling spacecraft inside the Payloads Hazardous Servicing Facility at NASA’s Kennedy Space Center. Probe is slated for Sep. 8, 2016 launch to asteroid Bennu from Cape Canaveral Air Force Station, FL. Credit: Ken Kremer/kenkremer.com

All the other instruments were also powered on and checked out flawlessly – including the OSIRIS-REx Laser Altimeter (OLA) which fired its laser, the OSIRIS-REx Visible and Infrared Spectrometer (OVIRS), the OSIRIS-REx Thermal Emissions Spectrometer (OTES), and the student designed Regolith X-ray Imaging Spectrometer (REXIS).

Lastly, the Touch and Go Camera System (TAGCAMS) navigational camera was successfully powered on and tested.

Furthermore, TAGCAMS took a dramatic image of the spacecraft’s Sample Return Capsule (below) – which is designed to bring at least a 60-gram (2.1-ounce) sample of Bennu’s surface soil and rocks back to Earth in 2023 for study by scientists using the world’s most advanced research instruments.

Image of OSIRIS-Rex Sample Return Capsule taken by StowCam instrument on Sept. 22, 2016, two weeks after launch, during initial science instrument checkout at a distance of 3.9 million miles (6.17 million km) away from Earth. Credit: NASA

The capsule image was captured by the StowCam portion of TAGCAMS when it was 3.9 million miles (6.17 million km) away from Earth and traveling at a speed of 19 miles per second (30 km/s) around the Sun.

The StowCam image of the Sample Return Capsule shows it “is in perfect condition,” according to the science team.

Overhead view of NASA’s OSIRIS-REx asteroid sampling spacecraft with small white colored sample return canister atop, inside the Payloads Hazardous Servicing Facility high bay at NASA's Kennedy Space Center. Launch is slated for Sep. 8, 2016 to asteroid Bennu from Cape Canaveral Air Force Station, FL. Credit: Julian Leek — Overhead view of NASA’s OSIRIS-REx asteroid sampling spacecraft with small white colored sample return canister atop, inside the Payloads Hazardous Servicing Facility high bay at NASA’s Kennedy Space Center. Launch is slated for Sep. 8, 2016 to asteroid Bennu from Cape Canaveral Air Force Station, FL. Credit: Julian Leek

The OSIRIS-REx spacecraft departed Earth with an on time engine ignition of a United Launch Alliance Atlas V rocket under crystal clear skies on Thursday, September 8 at 7:05 p.m. EDT from Space Launch Complex 41 at Cape Canaveral Air Force Station.

The ULA Atlas V injected OSIRIS-Rex perfectly onto its desired trajectory.

“We got everything just exactly perfect,” said Dante Lauretta, the principal investigator for OSIRIS-REx at the University of Arizona, at the post launch briefing at the Kennedy Space Center. “We hit all our milestone within seconds of predicts.

United Launch Alliance Atlas V rocket lifts off from Space Launch Complex 41 at Cape Canaveral Air Force Station carrying NASA’s Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer, or OSIRIS-REx spacecraft on the first U.S. mission to sample an asteroid, retrieve at least two ounces of surface material and return it to Earth for study. Liftoff was at 7:05 p.m. EDT on September 8, 2016 in this remote camera view taken from inside the launch pad perimeter. Note the newly install crew access arm and white room for astronaut flights atop Atlas starting in early 2018. Credit: Ken Kremer/kenkremer.com

The space rock measures about the size of a small mountain at about a third of a mile in diameter.

“The primary objective of the OSIRIS-Rex mission is to bring back pristine material from the surface of the carbonaceous asteroid Bennu, OSIRIS-Rex Principal Investigator Dante Lauretta told Universe Today in a prelaunch interview in the KSC cleanroom with the spacecraft as the probe was undergoing final preparations for shipment to the launch pad.

“We are interested in that material because it is a time capsule from the earliest stages of solar system formation.”

“It records the very first material that formed from the earliest stages of solar system formation. And we are really interested in the evolution of carbon during that phase. Particularly the key prebiotic molecules like amino acids, nucleic acids, phosphates and sugars that build up. These are basically the biomolecules for all of life.”

The asteroid is 1,614-foot (500 m) in diameter and crosses Earth’s orbit around the sun every six years.

After a two year flight through space, including an Earth swing by for a gravity assisted speed boost in 2017, OSIRIS-REx will reach Bennu in Fall 2018 to begin about 2 years of study in orbit to determine the physical and chemical properties of the asteroid in extremely high resolution.

Watch my up close launch video captured directly at the pad with the sights and sounds of the fury of blastoff:

Video Caption: ULA Atlas V rocket lifts off on September 8, 2016 from Space Launch Complex 41 at Cape Canaveral Air Force Station carrying NASA’s OSIRIS-REx asteroid sampling spacecraft, in this remote camera view taken from inside the launch pad perimeter. Credit: Ken Kremer/kenkremer.com

Watch for Ken’s continuing OSIRIS-REx mission reporting. He reported on the spacecraft and launch from on site at the Kennedy Space Center and Cape Canaveral Air Force Station, FL.

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer

September 23, 2016October 5, 2016 by Matt Williams

Five New Neptunian Trojans Discovered

The Solar System is filled with what are known as Trojan Asteroids – objects that share the orbit of a planet or larger moon. Whereas the best-known Trojans orbit with Jupiter (over 6000), there are also well-known Trojans orbiting within Saturn’s systems of moons, around Earth, Mars, Uranus, and even Neptune.

Until recently, Neptune was thought to have 12 Trojans. But thanks to a new study by an international team of astronomers – led by Hsing-Wen Lin of the National Central University in Taiwan – five new Neptune Trojans (NTs) have been identified. In addition, the new discoveries raise some interesting questions about where Neptune’s Trojans may come from.

For the sake of their study – titled “The Pan-STARRS 1 Discoveries of Five New Neptune Trojans“- the team relied on data obtained by the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS). This wide-field imaging facility – which was founded by the University of Hawaii’s Institute for Astronomy – has spent the last decade searching the Solar System for asteroids, comets, and Centaurs.

PS1 at dawn. The mountain in the distance is Mauna Kea, about 130 kilometers southeast. Credit: pan-starrs.ifa.hawaii.edu — *The PS1 telescope at dawn, with the mountain of Mauna Kea visible in the distance. Credit: pan-starrs.ifa.hawaii.edu*

The team used data obtained by the PS-1 survey, which ran from 2010 to 2014 and utilized the first Pan-STARR telescope on Mount Haleakala, Hawaii. From this, they observed seven Trojan asteroids around Neptune, five of which were previously undiscovered. Four of the TNs were observed orbiting within Neptune’s L4 point, and one within its L5 point.

The newly detected objects have sizes ranging from 100 to 200 kilometers in diameter, and in the case of the L4 Trojans, the team concluded from the stability of their orbits that they were likely primordial in origin. Meanwhile, the lone L5 Trojan was more unstable than the other four, which led them to hypothesize that it was a recent addition.

As Professor Lin explained to Universe Today via email:

“The 2 of the 4 currently known L5 Neptune Trojans, included the one L5 we found in this work, are dynamically unstable and should be temporary captured into Trojan cloud. On the other hand, the known L4 Neptune Trojans are all stable. Does that mean the L5 has higher faction of temporary captured Trojans? It could be, but we need more evidence.”

In addition, the results of their simulation survey showed that the newly-discovered NT’s had unexpected orbital inclinations. In previous surveys, NTs typically had high inclinations of over 20 degrees. However, in the PS1 survey, only one of the newly discovered NTs did, whereas the others had average inclinations of about 10 degrees.

Animation showing the path of six of Neptune's L4 trojans in a rotating frame with a period equal to Neptune's orbital period.. Credit: Tony Dunn/Wikipedia Commons — Animation showing the path of six of Neptune’s L4 trojans in a rotating frame with a period equal to Neptune’s orbital period.. Credit: Tony Dunn/Wikipedia Commons

From this, said Lin, they derived two possible explanations:

“The L4 “Trojan Cloud” is wide in orbital inclination space. If it is not as wide as we thought before, the two observational results are statistically possible to generate from the same intrinsic inclination distribution. The previous study suggested >11 degrees width of inclination, and most likely is ~20 degrees. Our study suggested that it should be 7 to 27 degrees, and the most likely is ~ 10 degrees.”

“[Or], the previous surveys were used larger aperture telescopes and detected fainter NT than we found in PS1. If the fainter (smaller) NTs have wider inclination distribution than the larger ones, which means the smaller NTs are dynamically “hotter” than the larger NTs, the disagreement can be explained.”

According to Lin, this difference is significant because the inclination distribution of NTs is related to their formation mechanism and environment. Those that have low orbital inclinations could have formed at Neptune’s Lagrange Points and eventually grew large enough to become Trojans asteroids.

*Illustration of the Sun-Earth Lagrange Points. Credit: NASA*

On the other hand, wide inclinations would serve as an indication that the Trojans were captured into the Lagrange Points, most likely during Neptune’s planetary migration when it was still young. And as for those that have wide inclinations, the degree to which they are inclined could indicate how and where they would have been captured.

“If the width is ~ 10 degrees,” he said, “the Trojans can be captured from a thin (dynamically cold) planetesimal disk. On the other hand, if the Trojan cloud is very wide (~ 20 degrees), they have to be captured from a thick (dynamically hot) disk. Therefore, the inclination distribution give us an idea of how early Solar system looks like.”

In the meantime, Li and his research team hope to use the Pan-STARR facility to observe more NTs and hundreds of other Centaurs, Trans-Neptunian Objects (TNOs) and other distant Solar System objects. In time, they hope that further analysis of other Trojans will shed light on whether there truly are two families of Neptune Trojans.

This was all made possible thanks to the PS1 survey. Unlike most of the deep surveys, which are only ale to observe small areas of the sky, the PS1 is able to monitor the whole visible sky in the Northern Hemisphere, and with considerable depth. Because of this, it is expected to help astronomers spot objects that could teach us a great deal about the history of the early Solar System.

Further Reading: arXiv