Posted on by Ken Kremer

2011: Top Stories from the Best Year Ever for NASA Planetary Science!

Dawn Orbiting Vesta. NASA's Dawn spacecraft achieved orbit at the giant asteroid Vesta in July 2011. The depiction of Vesta is based on images obtained by Dawn's framing cameras. Dawn is an international collaboration of the US, Germany and Italy. Credit: NASA/JPL-Caltech

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A year ago, 2011 was proclaimed as the “Year of the Solar System” by NASA’s Planetary Science division. And what a year of excitement it was indeed for the planetary science community, amateur astronomers and the general public alike !

NASA successfully delivered astounding results on all fronts – On the Story of How We Came to Be.

“2011 was definitely the best year ever for NASA Planetary Science!” said Jim Green in an exclusive interview with Universe Today. Green is the Director of Planetary Science for the Science Mission Directorate at NASA HQ. “The Search for Life is a significant priority for NASA.”

This past year was without doubt simply breathtaking in scope in terms of new missions, new discoveries and extraordinary technical achievements. The comprehensive list of celestial targets investigated in 2011 spanned virtually every type of object in our solar system – from the innermost planet to the outermost reaches nearly touching interplanetary space.

There was even a stunningly evocative picture showing “All of Humanity” – especially appropriate now in this Holiday season !

You and all of Humanity are here !
-- Earth & Moon Portrait by Juno from 6 Million miles away --
First Photo transmitted from Jupiter Bound Juno shows Earth (on the left) and the Moon (on the right). Taken on Aug. 26, 2011 when spacecraft was about 6 million miles (9.66 million kilometers) away from Earth. Credit: NASA/JPL-Caltech

Three brand new missions were launched and ongoing missions orbited a planet and an asteroid and flew past a comet.

“NASA has never had the pace of so many planetary launches in such a short time,” said Green.

And three missions here were awarded ‘Best of 2011’ for innovation !

Mars Science Laboratory (MSL), Dawn and MESSENGER named “Best of What’s New” in 2011 by Popular Science magazine. 3 NASA Planetary Science missions received the innovation award for 2011 from Popular Science magazine. Artist concept shows mosaic of MESSENGER, Mars Science Laboratory and Dawn missions. Credit: NASA/JPL-Caltech

Here’s the Top NASA Planetary Science Stories of 2011 – ‘The Year of the Solar System’ – in chronological order

1. Stardust-NExT Fly By of Comet Tempel 1

Starting from the first moments of 2011 at the dawn of Jan. 1, hopes were already running high for planetary scientists and engineers busily engaged in setting up a romantic celestial date in space between a volatile icy comet and an aging, thrusting probe on Valentine’s Day.

The comet chasing Stardust-Next spacecraft successfully zoomed past Comet Tempel 1 on Feb. 14 at 10.9 km/sec (24,000 MPH) after flying over 6 Billion kilometers (3.5 Billion mi).

6 Views of Comet Tempel 1 and Deep Impact crater during Stardust-NExT flyby on Feb. 14, 2011
Arrows show location of man-made crater created in 2005 by NASA’s prior Deep Impact comet mission and newly imaged as Stardust-NExT zoomed past comet in 2011. The images progress in time during closest approach to comet beginning at upper left and moving clockwise to lower left. Credit: NASA/JPL-Caltech/University of Maryland. Post process and annotations by Marco Di Lorenzo & Kenneth Kremer

The craft approached within 178 km (111mi) and snapped 72 astonishingly detailed high resolution science images over barely 8 minutes. It also fulfilled the teams highest hopes by photographing the human-made crater created on Tempel 1 in 2005 by a cosmic collision with a penetrator hurled by NASA’s Deep Impact spacecraft. The probe previously flew by Comet Wild 2 in 2004 and returned cometary coma particles to Earth in 2006

Tempel 1 is the first comet to be visited by two spaceships from Earth and provided the first-ever opportunity to compare observations on two successive passages around the Sun.

Don Brownlee, the original Principal Investigator, summarized the results for Universe Today; “A great bonus of the mission was the ability to flyby two comets and take images and measurements. The wonderfully successful flyby of Comet Tempel 1 was a great cap to the 12 year mission and provided a great deal of new information to study the diversity among comets.”

“The new images of Tempel showed features that form a link between seemingly disparate surface features of the 4 comets imaged by spacecraft. Combining data on the same comet from the Deep Impact and Stardust missions has provided important new insights in to how comet surfaces evolve over time and how they release gas and dust into space”.

2. MESSENGER at Mercury

On March 18, the Mercury Surface, Space Environment, Geochemistry, and Ranging, or MESSENGER, spacecraft became the first spacecraft inserted into orbit around Mercury, the innermost planet.

So far MESSENGER has completed 1 solar day – 176 Earth days- circling above Mercury. The probe has collected a treasure trove of new data from the seven instruments onboard yielding a scientific bonanza; these include global imagery of most of the surface, measurements of the planet’s surface chemical composition, topographic evidence for significant amounts of water ice, magnetic field and interactions with the solar wind.

“MESSENGER discovered that Mercury has an enormous core, larger than Earth’s. We are trying to understand why that is and why Mercury’s density is similar to Earth’s,” Jim Green explained to Universe Today.

The First Solar Day
After its first Mercury solar day (176 Earth days) in orbit, MESSENGER has nearly completed two of its main global imaging campaigns: a monochrome map at 250 m/pixel and an eight-color, 1-km/pixel color map. Small gaps will be filled in during the next solar day. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

“The primary mission lasts 2 solar days, equivalent to 4 Mercury years.”

“NASA has granted a 1 year mission extension, for a total of 8 Mercury years. This will allow the team to understand the environment at Mercury during Solar Maximum for the first time. All prior spacecraft observations were closer to solar minimum,” said Green.

MESSENGER was launched in 2004 and the goal is to produce the first global scientific observations of Mercury and piece together the puzzle of how Mercury fits in with the origin and evolution of our solar system.

NASA’s Mariner 10 was the only previous robotic probe to explore Mercury, during three flyby’s back in the mid-1970’s early in the space age.

3. Dawn Asteroid Orbiter

The Dawn spacecraft achieved orbit around the giant asteroid Vesta in July 2011 after a four year interplanetary cruise and began transmitting the history making first ever close-up observations of the mysteriously diverse and alien world that is nothing short of a ‘Space Spectacular’.

“We do not have a good analog to Vesta anywhere else in the Solar System,” Chris Russell said to Universe Today. Russell, from UCLA, is the scientific Principal Investigator for Dawn.

Before Dawn, Vesta was just another fuzzy blob in the most powerful telescopes. Dawn has completely unveiled Vesta as a remarkably dichotomous, heavily battered and pockmarked world that’s littered with thousands of craters, mountains and landslides and ringed by mystifying grooves and troughs. It will unlock details about the elemental abundances, chemical composition and interior structure of this marvelously intriguing body.

Cataclysmic collisions eons ago excavated Vesta so it lacks a south pole. Dawn discovered that what unexpectedly remains is an enormous mountain some 16 miles (25 kilometers) high, twice the height of Mt. Everest.

Dawn is now about midway through its 1 year mission at Vesta which ends in July 2012 with a departure for Ceres, the largest asteroid. So far the framing cameras have snapped more than 10,000 never-before-seen images.

“What can be more exciting than to explore an alien world that until recently was virtually unknown!. ” Dr. Marc Rayman said to Universe Today. Rayman is Dawn’s Chief Engineer from NASA’s Jet Propulsion Lab (JPL) in Pasadena, Calif.

“Dawn is NASA at its best: ambitious, exciting, innovative, and productive.”

4. Juno Jupiter Orbiter

The solar powered Juno spacecraft was launched on Aug. 5 at Cape Canaveral Air Force Station in Florida, to embark on a five year, 2.8 billion kilometer (1.7 Billion mi) trek to Jupiter, our solar system’s largest planet. It was the first of three NASA planetary science liftoffs scheduled in 2011.

Juno Jupiter Orbiter soars skyward to Jupiter on Aug. 5, 2011 from Cape Canaveral Air Force Station, Florida. Credit: Ken Kremer

Juno’s goal is to map to the depths of the planets interior and elucidate the ingredients of Jupiter’s genesis hidden deep inside. These measurements will help answer how Jupiter’s birth and evolution applies to the formation of the other eight planets.

The 4 ton spacecraft will arrive at the gas giant in July 2016 and fire its braking rockets to go into a polar orbit and circle the planet 33 times over about one year.

The suite of nine instruments will scan the gas giant to find out more about the planets origins, interior structure and atmosphere, measure the amount of water and ammonia, observe the aurora, map the intense magnetic field and search for the existence of a solid planetary core.

“Jupiter is the Rosetta Stone of our solar system,” said Scott Bolton, Juno’s principal investigator from the Southwest Research Institute in San Antonio. “It is by far the oldest planet, contains more material than all the other planets, asteroids and comets combined and carries deep inside it the story of not only the solar system but of us. Juno is going there as our emissary — to interpret what Jupiter has to say.”

5. Opportunity reaches Endeavour Crater on Mars

The long lived Opportunity rover finally arrived at the rim of the vast 14 mile (22 kilometer) wide Endeavour Crater in mid-August 2011 following an epic three year trek across treacherous dune fields – a feat once thought unimaginable. All told, Opportunity has driven more than 34 km ( 21 mi) since landing on the Red Planet way back in 2004 for a mere 90 sol mission.

Endeavour Crater Panorama from Opportunity Mars Rover in August 2011
Opportunity arrived at the rim of Endeavour on Sol 2681, August 9, 2011 after a three year trek. The robot photographed segments of the huge craters eroded rim in this panoramic vista. Endeavour Crater is 14 miles (22 kilometers) in diameter. Mosaic Credit: NASA/JPL/Cornell/Marco Di Lorenzo/Kenneth Kremer

In November, the rover discovered the most scientifically compelling evidence yet for the flow of liquid water on ancient Mars in the form of a water related mineral vein at a spot dubbed “Homestake” along an eroded ridge of Endeavour’s rim.

Read my story about the Homestake discovery here, along with our panoramic mosaic showing the location – created by Ken Kremer and Marco Di Lorenzo and published by Astronomy Picture of the Day (APOD) on 12 Dec. 2011.

Watch for my upcoming story detailing Opportunity’s accomplishments in 2011.

6. GRAIL Moon Mappers

The Gravity Recovery and Interior Laboratory, or GRAIL mission is comprised of twin spacecraft tasked to map the moon’s gravity and study the structure of the lunar interior from crust to core.

Twin GRAIL Probes GO for Lunar Orbit Insertion on New Year’s Eve and New Year’s Day
GRAIL spacecraft will map the moon's gravity field and interior composition. Credit: NASA/JPL-Caltech

The dynamic duo lifted off from Cape Canaveral on September 10, 2011 atop the last Delta II rocket that will likely soar to space from Florida. After a three month voyage of more than 2.5 million miles (4 million kilometers) since blastoff, the two mirror image GRAIL spacecraft dubbed Grail-A and GRAIL-B are sailing on a trajectory placing them on a course over the Moon’s south pole on New Year’s weekend.

Each spacecraft will fire the braking rockets for about 40 minutes for insertion into Lunar Orbit about 25 hours apart on New Year’s Eve and New Year’s Day.

Engineers will then gradually lower the satellites to a near-polar near-circular orbital altitude of about 34 miles (55 kilometers).

The spacecraft will fly in tandem and the 82 day science phase will begin in March 2012.

“GRAIL is a Journey to the Center of the Moon”, says Maria Zuber, GRAIL principal investigator from the Massachusetts Institute of Technology (MIT). “GRAIL will rewrite the book on the formation of the moon and the beginning of us.”

“By globally mapping the moon’s gravity field to high precision scientists can deduce information about the interior structure, density and composition of the lunar interior. We’ll evaluate whether there even is a solid or liquid core or a mixture and advance the understanding of the thermal evolution of the moon and the solar system,” explained co-investigator Sami Asmar to Universe Today. Asmar is from NASA’s Jet Propulsion Laboratory (JPL)

7. Curiosity Mars Rover

The Curiosity Mars Science Lab (MSL) rover soared skywards on Nov. 26, the last of 2011’s three planetary science missions. Curiosity is the newest, largest and most technologically sophisticated robotic surveyor that NASA has ever assembled.

“MSL packs the most bang for the buck yet sent to Mars.” John Grotzinger, the Mars Science Laboratory Project Scientist of the California Institute of Technology, told Universe Today.

The three meter long robot is the first astrobiology mission since the Viking landers in the 1970’s and specifically tasked to hunt for the ‘Ingredients of Life’ on Mars – the most Earth-like planet in our Solar System.


Video caption: Action packed animation depicts sequences of Curiosity departing Earth, the nail biting terror of the never before used entry, descent and landing on the Martian surface and then looking for signs of life at Gale Crater during her minimum two year expedition across hitherto unseen and unexplored Martian landscapes, mountains and craters. Credit: NASA

Curiosity will gather and analyze samples of Martian dirt in pursuit of the tell-tale signatures of life in the form of organic molecules – the carbon based building blocks of life as we know it.

NASA is targeting Curiosity to a pinpoint touch down inside the 154 km (96 mile) wide Gale Crater on Aug. 6, 2012. The crater exhibits exposures of phyllosilicates and other minerals that may have preserved evidence of ancient or extant Martian life and is dominated by a towering 3 mile (5 km) high mountain.

“10 science instruments are all aimed at a mountain whose stratigraphic layering records the major breakpoints in the history of Mars’ environments over likely hundreds of millions of years, including those that may have been habitable for life,” Grotzinger told me.

Titan Upfront
The colorful globe of Saturn's largest moon, Titan, passes in front of the planet and its rings in this true color snapshot from NASA's Cassini spacecraft. Credit: NASA/JPL-Caltech/Space Science Institute
Curiosity Mars Science Laboratory Rover and Ken Kremer - inside the Cleanroom at the Kennedy Space Center. Last View of Curiosity just prior to folding and encapsulation for launch. Credit: Ken Kremer

This past year Ken was incredibly fortunate to witness the ongoing efforts of many of these magnificent endeavors.

Posted on by Ken Kremer

Sounds of Comet Tempel 1 smashing into Stardust-NExT

News conference held Feb. 15 following the flyby of comet Tempel 1 by the Stardust-NExT spacecraft on Valentine's Day, Feb. 14. The spacecraft's closest approach was a distance of 112 miles. Participants are: Ed Weiler, NASA's associate administrator, Science Mission Directorate, Washington; Joe Veverka, Stardust-NExT principal investigator, Cornell University; Tim Larson, Stardust-NExT project manager, NASA's Jet Propulsion Laboratory, Pasadena, Calif.; Don Brownlee, Stardust-NExT co-investigator, University of Washington, Seattle; and Pete Schultz, Stardust-NExT co-investigator, Brown University.

As Stardust-Next was racing past Comet Tempel at 9.8 km/sec, or 24,000 MPH, it encountered a hail of bullet like particles akin to a warplane meeting the fury of armed resistance fighters which potentially could have utterly destroyed the probe.

NASA has released a cool sound track of the sounds of thousands of cometary dust particles pelting Stardust-NExT. The audio was recorded by an instrument aboard the spacecraft called the Dust Flux Monitor which measures sound waves and electrical pulses from dust impacts.

Telemetry downlinked after the Feb. 14 flyby indicates the spacecraft flew through waves of disintegrating cometary particles.

“The data indicate Stardust went through something similar to a B-17 bomber flying through flak in World War II,” says Don Brownlee, Stardust-NExT co-investigator from the University of Washington in Seattle.

I contacted co-investigator Don Brownlee for further insight into the sounds and sights of the Tempel 1 flyby.

“The 12 biggest particles penetrated the centimeter thick front honeycomb plate of the whipple meteoroid shield and were detected with the Dust Flux Monitor Instrument,“ Brownlee told me. “The instrument had two type of sensors made in a collaboration between the University of Chicago and the University of Kent in the UK.
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The shielding was installed to protect Stardust from the hail of cometary particles during its prior flyby at Comet Wild 2 in 2004. Brownlee was the Principal Investigator for Stardust during its original mission at Wild 2.

I asked Brownlee if the shields were essential to the spacecraft surviving the Tempel 1 flyby ?

“Yes,’ he replied.

“A total of approximately 5,000 particle impacts were detected,” Brownlee said. This was over a period of about 11 minutes during closest approach. The movie is in real time and is a visual representation of the sounds. It covers just a portion of the flyby.

“Like at Wild 2, the particles came out in bursts and clumps. The Tempel 1 flyby, the Wild 2 flyby and the recent imaging of Comet Hartley confirm that fragmenting. Dust and ice clods are commonly released into space by comets.”

“The biggest at Wild 2 was about 0.5 cm and this time at Tempel 1 they were probably a bit bigger. The penetrating impacts at Tempel 1 were about twice what they were at Wild 2 ….. Also about twice as fast!”

“The data indicate Stardust went through something similar to a B-17 bomber flying through flak in World War II,” said Don Brownlee, Stardust-NExT co-investigator from the University of Washington in Seattle. “Instead of having a little stream of uniform particles coming out, they apparently came out in chunks and crumbled.”

To my eye, I was surprised that the flyby images seemed to surpass those at Wild 2. Brownlee agreed.

“I was surprised,” said Brownlee. “The team did a terrific job and the images are better than before. Tempel is a little closer to the sun, the flyby was a little closer, the pictures were taken at a much higher rate and the imaging team put in a great effort to plan the exposures and to clean up the camera before the encounter. The mirror was scanning at it’s maximum rate!”

Listen to the Stardust-NExT post flyby briefing

News conference held Feb. 15 following the flyby of comet Tempel 1 by the Stardust-NExT spacecraft on Valentine’s Day, Feb. 14. The spacecraft’s closest approach was a distance of 112 miles. Participants are: Ed Weiler, NASA’s associate administrator, Science Mission Directorate, Washington; Joe Veverka, Stardust-NExT principal investigator, Cornell University; Tim Larson, Stardust-NExT project manager, NASA’s Jet Propulsion Laboratory, Pasadena, Calif.; Don Brownlee, Stardust-NExT co-investigator, University of Washington, Seattle; and Pete Schultz, Stardust-NExT co-investigator, Brown University.

Posted on by Ken Kremer

Movies of Comet Tempel 1 Encounter by Stardust-NExT

NASA's Stardust-NExT mission took this image of comet Tempel 1 at 8:39 p.m. PST (11:39 p.m. EST) on Feb 14, 2011. The comet was first visited by NASA's Deep Impact mission in 2005. Credit: NASA/JPL-Caltech/Cornell. Image brightened and enhanced by Ken Kremer to show additional detail.

Want to know what it feels like at close range to ride on a spaceship past a zooming comet that’s spewing dust and debris that could destroy you at any moment ?

Check out the movies (above & below) which gives you a front row seat at NASA’s newest ‘Comet Experience’. Hitch a ride on the rear of Stardust-NExT as it flew past Compet Tempel 1 at 9.8 km/sec, or 24,000 MPH.

The movie comprises the highest resolution images of the fleeting 8 minutes of the closest approach period that occurred between 8:35:26 p.m. to 8:43:08 p.m. PST on Feb. 14, 2011 (4:35:26 a.m. to 4:43:08 a.m. UTC, Feb. 15, 2011, according to the clock kept aboard the spacecraft).

Stardust started taking these the excellent quality photos at a distance of 2,462 kilometers (1,530 miles) away from the center of the comet and get to within 185 kilometers (115 miles). By the end of the movie, the spacecraft is 2,594 kilometers (1,611 miles) away from the center of the comet.

Think about it and the navigational precision required to pull off this feat. After a journey of near 6 billion kilometers (3.5 Billion miles) and 12 years, the highest quality science and images are captured in what amounts to an instant in time.

“And they did it with Math !”, exclaimed NASA Asspciate Admisistrator Ed Weiler at the post encounter briefing. Weiler exhorted school kids worldwide to study math and science if that want to accomplish great deeds.

Comet Tempel 1 was approximately 335 million kilometers (208 million miles) away from Earth and on the other side of the sun during the encounter. Tempel 1 is oblong in shape and has an average diameter of about 6 kilometers (4 miles).

The individual images are all online. Check out these alternate movie versions prepared by Dimitri Demeeter at Youtube and nasatech.net at the links below.

Here’s 1/10 sec with text

Here’s 1/4 sec with text

Here’s 1/2 sec with text

Here’s 1/10 sec w/o text

Here’s 1/2 sec w/o text

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Highlights from the Comet Tempel 1 Post Flyby briefing

more Stardust goodies coming up

Read more about the Stardust-NExT Flyby and mission in my earlier stories here, here, here, here and here

Posted on by Ken Kremer

NASA’s Stardust Discovers Human made Deep Impact Crater on Comet Tempel 1

Tempel 1, as Seen by Two Spacecraft. These two images show the different views of comet Tempel 1 seen by NASA's Deep Impact spacecraft (left) and NASA's Stardust spacecraft (right). Two craters, about 300 meters (1,000 feet) in diameter, help scientists locate the area hit by the impactor released by Deep Impact in July 2005. The dashed lines correlate the features. Stardust approached the comet from a different angle on Feb. 14, 2011. Credit: NASA/JPL-Caltech/University of Maryland/Cornell

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NASA’s aging and amazing Stardust space probe has at last discovered the human made crater created on Comet Tempel 1 in 2005 by the history making cosmic smash up with NASA’s Deep Impact penetrator. Stardust streaked past the comet on Feb. 14 at 10.9 km/sec, or 24,000 MPH, and succeeded in briefly photographing the crater as it approached within 178 km (111 mi) during the fleeting moments of the probes closest approach.

The intentional celestial collision in 2005 was designed to violently unleash the buried remnants of the early solar system into an enormous ejecta cloud of dusty debris that scientists could sift for clues to help unlock the secrets of how we all formed and evolved some 4.5 Billion Years ago.

Tempel 1 is the first comet to receive a second visit by probes from Earth.

Comets have continuously smashed into Earth over the eons and delivered vast quantities of key ingredients – such as water and organic molecules – that may have sparked the formation of life on the early Earth.

NASA approved the use of the already orbiting Stardust-NExT spacecraft to follow up on the science discoveries by Deep Impact as the best and most economical way to try and locate the crater blast site, image new terrain and look for changes on the comets surface since the 2005 mission as the comet also completed another orbit around our Sun and eroded due to solar heating.

The human made crater is about 150 meters wide and was formed by a 375 kilogram (800 pound) projectile propelled into the speeding path of Comet Tempel 1 by the Deep Impact mothership in 2005.

Tempel 1 Impact Site.
This pair of images shows the before-and-after comparison of the part of comet Tempel 1 that was hit by the impactor from NASA's Deep Impact spacecraft. The left-hand image is a composite made from images obtained by Deep Impact in July 2005. The right-hand image shows arrows identifying the rim of the crater caused by the impactor. The crater is estimated to be 150 meters (500 feet) in diameter. This image also shows a brighter mound in the center of the crater likely created when material from the impact fell back into the crater. Credit: NASA/JPL-Caltech/University of Maryland/Cornell

Stardust-NExT took 72 high resolution science images of the comet during the Valentine’s Day encounter flyby on Feb, 14 at 11:40 p.m. EST (8:40 p.m. PST). The probe absolutely had to be precisely navigated to exactly hit the aim point for sequencing the images to match the right moment in the erratic rotation of the volatile comet.

The results of the Stardust-NExT mission were announced at a post encounter new briefing after most of the images and science data had streamed back to Earth. The science team and NASA said that all the mission objectives were accomplished.

“If you ask me was this mission 100 percent successful in terms of the science, I’d have to say no. It was 1000 percent successful!” said Stardust-NExT principal investigator Joe Veverka of Cornell University, Ithaca, N.Y., at the news briefing.

“We found the Deep Impact crater. We see erosion in comparison to 2005. So we do see changes. Erosion on the scale of 20 to 30 meters of material has occurred in the five or six years since we took the first picture. We are seeing a change, but we have to spend time quantifying the changes and understanding what they mean.”

“We saw a lot of new territory. It’s amazing with lots of layers. There is lots of surface sublimation. We had to arrive at precisely the right time in order to see new and old territory.”

“We had monitored the comets rotation for several years. And we got the longitude almost perfect within 1 or 2 degrees,” Veverka said.

Tempel 1 Impact Site
Credit: NASA/JPL-Caltech/University of Maryland/Cornell

It took a few years of careful study to deduce the comets complex rotational patterns which change as the body orbits in a wide orbital path between Mars and Jupiter and is heated by the sun.

Peter Schultz, a science team co-investigator agreed and showed the comparison images.

“We saw the crater,” said Schultz, of University. “It’s subdued; it’s about 150 meters across and has a small central mound in the center. It looks as if from the impact, the stuff went up and came back down. So we did get it, there’s no doubt. I think one of the bottom-line messages is that this surface of the comet where we hit is very weak. It’s fragile. So the crater partly healed itself.”

“It was about the size we expected. But more subdued.”

The probes mission is almost complete since it has very little fuel left. The remaining science data from the flyby is being sent back and some outbound data is being collected.

“This spacecraft has logged over 3.5 billion miles since launch, and while its last close encounter is complete, its mission of discovery is not,” said Tim Larson, Stardust-NExT project manager at JPL. “We’ll continue imaging the comet as long as the science team can gain useful information, and then Stardust will get its well-deserved rest.”

Stardust-NExT is a repurposed spacecraft that has journeyed nearly 6 billion kilometers since it was launched in 1999.

Initially christened as Stardust, the spaceships original task was to fly by Comet Wild 2 in 2004. It also collected priceless cometary dust particles from the coma which was safely parachuted back to Earth inside a return canister in 2006. High powered science analysis of the precious comet dust will help researchers discern the origin and evolution of our solar system.

This was humanities first revisit to a comet and at a bargain basement price by using an old spacecraft already in space.

“The cost was just $29 Million dollars. A new Discovery class mission costs $300 to 500 Million. So that’s maybe 6% the cost of developing and launching a new mission,” said Ed Weiler, the associate administrator for NASA’s Science Mission Directorate at NASA HQ in Washington, DC.

Read more about the Stardust-NExT Flyby and mission in my earlier stories here, here, here and here

Changes to Smooth Terrain (Annotated)
This image layout depicts changes in the surface of comet Tempel 1, observed first by NASA's Deep Impact Mission in 2005 (top right) and again by NASA's Stardust-NExT mission on Feb. 14, 2011 (bottom right). Between the two visits, the comet made one trip around the sun. The image at top left is a wider shot from Deep Impact. The smooth terrain is at a higher elevation than the more textured surface around it. Scientists think that cliffs, illustrated with yellow lines to the right, are being eroded back to the left in this view. The cliffs appear to have eroded as much as 20 to 30 meters (66 to 100 feet) in some places, since Deep Impact took the initial image. The box shows depressions that have merged together over time, also from erosion. This erosion is caused by volatile substances evaporating away from the comet. Credit: NASA/JPL-Caltech/University of Maryland/Cornell
Posted on by Ken Kremer

Stardust-NExT zooms by Comet Tempel 1 for Cosmic Encounter

Comet Tempel 1 imaged by NASA's Stardust on Feb 14, Valentine’s Day. NASA's Stardust-NExT mission took this image of comet Tempel 1 at 8:38 p.m. PST (11:38 p.m. EST) on Feb 14, 2011. . The comet was first visited by NASA's Deep Impact mission in 2005. Credit: NASA/JPL-Caltech/Cornell Update Feb 15: Beautifully sharp Comet images now being downlinked. New story upcoming.

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NASA’s Stardust-NExT comet chaser successfully zoomed by Comet Temple 1 exactly as planned a short while ago at 11:37 p.m. EST on Feb. 14.

The cosmic Valentine’s Day encounter between the icy comet and the aging probe went off without a hitch. Stardust snapped 72 science images as it raced by at over 10 km/sec or 24,000 MPH and they are all centered in the cameras field of view. The probe came within 181 km (112 miles) of the nucleus of the volatile comet.

The images are being transmitted back now and it will take a several hours until the highest resolution images are available for the science team and the public to see. The first few images from a distance of over a thousand miles can be seen here

Tempel 1 is the first comet to be visited twice by spaceships from Earth. The primary goal was to find out how much the comet has changed in the five years since she was last visited by NASA’s Deep Impact mission in 2005, says Joe Ververka of Cornell University, who is the principal investigator of the Stardust-NExT mission. Deep Impact delivered a 375 kg projectile which blasted the comet and created an impact crater and an enormous cloud of dust so that scientists could study the composition and interior of the comet.

“We are going to be seeing the comet just after its closest passage to the sun. We know the comet is changing because the ice melts. We hope to see old and new territory and the crater and complete the Deep Impact experiment.”

Stardust-NExT is a repurposed spacecraft. Initially christened as Stardust, the spaceships original task was to fly by Comet Wild 2 in 2004. It also collected priceless cometary dust particles from the coma which were safely parachuted back to Earth inside a return canister in 2006. High powered science analysis of the precious comet dust will help researchers discern the origin and evolution of our solar system.

Stardust-NExt approaching Comet Tempel 1.
Artist concept of NASA's Stardust-NExT mission, which will fly by Comet Tempel 1 on Feb. 14, 2011. Credit: NASA/JPL-Caltech/LMSS

Stardust was hurriedly snapping high resolution pictures every 6 seconds and collecting data on the dust environment during the period of closest approach which lasted just about 8 minutes. The anticipation was building after 12 years of hard work and a journey of some 6 Billion kilometers (3.5 Billion miles)

“The Stardust spacecraft did a fantastic job,” says Tim Larson, the Stardust-NExT mission project manager from the Jet Propulsion Laboratory (JPL), Pasadena, Calif. “Stardust has already flown past a asteroid and a comet and returned comet particles to Earth”

“Because of the flyby geometry the antenna was pointed away from earth during the encounter. Therefore all the science images and data was stored in computer memory on board until the spacecraft was rotated to point towards Earth about an hour after the flyby.”

Each image takes about 15 minutes to be transmitted back to Earth by the High Gain Antenna at a data rate of 15,800 bits per second and across about 300 million miles of space.

NASA had bracketed five special images from the closest range as the first ones to be sent back. Instead, the more distant images were sent first. It will take about 10 hours to receive all the images.

So everyone had to wait a few hours longer to see the fruit of their long labor. Most of the team from NASA, JPL and Lockheed Martin has been working on the mission for a dozen years since its inception.

“We had a great spacecraft and a great team,” says Ververka. “Apparently, everything worked perfectly. The hardest thing now is we have to wait a couple of hours before we see all the goodies stored on board.”

The entire flyby was carried out autonomously using a preprogrammed sequence of commands. Due to the vast distance from Earth there was no possibility for mission controllers to intervene in real time.

Confirmation of a successful fly by and science imaging was not received until about 20 minutes after the actual event at about 11:58 p.m. EST. The dust flux monitor also registered increased activity just as occurred during the earlier Stardust flyby of Comet Wild 2 in 2004.

The Stardust-NExT science briefing on NASA TV will be delayed a few hours, until perhaps about 4 p.m. EST

Check back here later at Universe Today, on Tuesday, Feb. 15 for continuing coverage of the Valentine’s Day encounter of Stardust-NExT with the icy, unpredictable and fascinating Comet Tempel 1

Comet Tempel 1 imaged by NASA's Stardust on Feb 14, Valentine’s Day.
NASA's Stardust-NExT mission took this image of comet Tempel 1 at 8:36 p.m. PST (11:36 p.m. EST) on Feb 14, 2011, from a distance of approximately 2200 km (1360 miles). The comet was first visited by NASA's Deep Impact mission in 2005. Credit: NASA/JPL-Caltech/Cornell
Stardust-NExT Spacecraft & Comet Tempel 1.
Artist rendering of upcoming flyby on February, 14, 2011. Credit: NASA

Stardust-NExT: 2 Comet Flybys with 1 Spacecraft.
Stardust-NExT made history on Valentine’s Day - February, 14, 2011 – Tempel 1 is the first comet to be visited twice by spacrecraft from Earth. Stardust has now successfully visited 2 comets and gathered science data: Comet Wild 2 in 2004 (left) and Comet Tempel 1 in 2011 (right). Artist renderings Credit: NASA. Collage: Ken Kremer.
Posted on by Ken Kremer

Romantic Valentines Day Encounter Looms with Icy Comet

NASA's Romantic Rendezvous in space on Valentine’s Day - Feb. 14. The planned Valentine's Day (Feb. 14, 2011) rendezvous between NASA's Stardust-NExT mission and Comet Tempel 1 inspired this chocolate-themed artist's concept. Credit: NASA/JPL-Caltech. Video and graphics below illustrate the icy encounter and animate the flyby trajectory. NASA TV: Live Coverage listed below. Update: See below the latest navigation camera images taken on Feb. 11 – newly obtained from JPL. These images are crucial for precisely aiming Stardust-NExT

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At last, NASA embraces a romantic rendezvous in the dark void of deep space.

And soon the whole world can watch the up close meet up of the hot Stardust probe and the volatile, icy comet. The historic space tryst is less than a day away!

The Stardust-NExT spacecraft successfully hot fired its thrusters for the final course correction maneuver (TCM-33) on Feb. 12, setting up the fleeting celestial encounter with Comet Tempel 1 on Valentine’s Day, Feb. 14, Monday, at 11:37 p.m. EST. The space science probe will fly by the speeding comet at a distance of approximately 200 kilometers (124 miles) and at a speed of 10 km/sec.

Naturally, the fleeing comet is icy, unpredictable and exploding with jets of gas and dust particles. So there is some uncertainly at NASA and amongst the science team as to what we’ll actually see when the cameras unveil the hidden secrets of the nucleus of Temple 1.

The encounter phase has begun now (Feb. 13) at 24 hours prior to closest approach (Feb. 14) and concludes 24 hours after closest approach.

“The final TCM burn on Feb. 12 went well,” JPL spokesman DC Agle told me today (Feb.13)

It’s been a long wait and a far flung journey. Stardust has cruised some 6 Billion kilometers through our solar system – looping several times around the sun over a dozen years and is now nearly bereft of fuel.

For three and a half long years, the anticipation has been building since NASA approved the repurposing of the Stardust spacecraft in 2007 and fired the thrusters to alter the probes trajectory to Comet Temple 1 for this bonus extended mission.

But until the photos are transmitted across 300 million kilometers of space back to Earth, we won’t know which face of the comets surface was turned towards the camera as the curtain pulls back for the revealing glimpse.

Everything hinges on how accurately the mission team aims the reliable probe and the finicky rotation of the changeable comet.

The irregularly shaped nucleus of Tempel 1 measures barely 5 to 8 km in diameter.

Stardust-NExT: 2 Comet Flybys with 1 Spacecraft.
Stardust-NExT makes history on Valentine’s Day - February, 14, 2011
Tempel 1 is the first comet to be visited twice by spacecraft from Earth. Stardust will have visited 2 comets and gathered science data: Comet Wild 2 in 2004 (left) and Comet Tempel 1 in 2011 (right).
Artist renderings Credit: NASA. Collage: Ken Kremer.

The Feb. 14 encounter marks the first time in history that a comet has been visited twice by spaceships from Earth. The revisit provides the first opportunity for up-close observations of a comet both before and after a single orbital pass around the sun.

In July 2005, NASA’s Deep Impact probe delivered a 375 kg projectile that penetrated at high speed directly into the comets nucleus. The blast created an impact crater and ejected an enormous cloud of debris that was studied by the Deep Impact spacecraft as well as an armada of orbiting and ground based telescopes.

Somewhat unexpectedly, the new crater was totally obscured from the cameras view by light reflecting off the dust cloud.

“The primary goal is to find out how much the comet’s surface has changed between two close passages to the sun since it was last visited in 2005,” says Joe Ververka of Cornell University, who is the principal investigator of the Stardust-NExT mission.

This time around, researchers hope to determine the size of the crater. Numerous bets hinge on that determination.

It’s also quite possible that the crater itself has significantly changed in the intervening five and one half years as the Jupiter-class comet orbits between Mars and Jupiter.

“Comets rarely behave,” says Tim Larson, the Stardust-NExT mission project manager from the Jet Propulsion Laboratory (JPL), Pasadena, Calif.

“Temple 1 exhibits a complex rotation. The rotation period is about 41 hours. But the trajectory changes due to the comet jets and activity.”

“Ideally we would like to obtain photos of old and new territory and the crater from the Deep Impact encounter in 2005,” Larson explained.

“Tempel 1 is the most observed comet in history using telescopes worldwide as well as the Hubble and Spitzer Space Telescopes.”

Engineers are using all this data to fine tune the aim of the craft and get a handle on which sides of the comet will be imaged. But either way the team will be elated with the science results regardless of whether the images reveal previously seen or new terrain.

Stardust-NExT approaching Comet Tempel 1
Artist concept of NASA's Stardust-NExT mission, which will fly by Comet Tempel 1 on Feb. 14, 2011. Credit: NASA/JPL-Caltech/LMSS

Today, Feb. 13, mission controllers at JPL are uplinking the final flyby sequences and parameters for Monday’s (Feb. 14) historic encounter.

Stardust-NExT will take 72 high resolution images of Comet Tempel 1 during the close approach. The team expects the nucleus to be resolved in several of the closest images. These will be stored in an onboard computer and relayed back to Earth starting about three hours later.

“All data from the flyby (including the images and science data obtained by the spacecraft’s two onboard dust experiments) are expected to take about 10 hours to reach the ground,” according to a NASA statement.

3 D stereo view of Comet Wild 2 from Stardust flyby in 2004. Credit: NASA/
Stardust-NExT is a repurposed spacecraft and this will be the last hurrah for the aging probe. Stardust was originally launched way back in 1999 and accomplished its original goal of flying through a dust cloud surrounding the nucleus of Comet Wild 2 on Jan. 2, 2004. During the flyby, the probe also collected comet particles which were successfully returned to Earth aboard a sample return capsule which landed in the Utah desert in January 2006.

Stardust continued its solitary voyage through the void of the space. Until now !

Watch the Stardust-NExT Romantic Rendezvous: Live on NASA TV

NASA has scheduled live mission commentary of the flyby and a post encounter news briefing on Feb. 14 and Feb. 15. These will be televised on NASA TV as follows:

February 14, Monday
11:30 p.m. – 1 a.m. (Feb. 15) – Live Stardust-NExT Mission Commentary (including coverage of closest approach to Comet Tempel 1 and re-establishment of contact with the spacecraft following the encounter) – JPL

February 15, Tuesday
3 – 4:30 a.m. Live Stardust-NExT Mission Commentary (resumes with the arrival of the first close-approach images of Comet Tempel 1) – JPL

1 p.m. – Stardust-NExT Post-Encounter News Briefing – JPL

Five facts you should know about NASA’s Stardust-NExT spacecraft as it prepares for a Valentine’s “date” with comet Tempel 1. From a NASA Press Release

1. “The Way You Look Tonight” – The spacecraft is on a course to fly by comet Tempel 1 on Feb. 14 at about 8:37 p.m. PST (11:37 p.m. EST) — Valentine’s Day. Time of closest approach to Tempel 1 is significant because of the comet’s rotation. We won’t know until images are returned which face the comet has shown to the camera.

Stardust- Earth return capsule with cometary dust particles in 2006. Credit: NASA/JPL
2. “It’s All Coming Back To Me Now” – In 2004, Stardust became the first mission to collect particles directly from a comet, Wild 2, as well as samples of interstellar dust. The samples were returned in 2006 via a capsule that detached from the spacecraft and parachuted to the ground at a targeted area in Utah. Mission controllers then placed the still-viable Stardust spacecraft on a flight path that could reuse the flight system, if a target of opportunity presented itself. Tempel 1 became that target of opportunity.

3. “The First Time Ever I Saw Your Face” – The Stardust-NExT mission will allow scientists for the first time to look for changes on a comet’s surface that occurred after one orbit around the sun. Tempel 1 was observed in 2005 by NASA’s Deep Impact mission, which put an impactor on a collision course with the comet. Stardust-NExT might get a glimpse of the crater left behind, but if not, the comet would provide scientists with previously unseen areas for study. In addition, the Stardust-NExT encounter might reveal changes to Tempel 1 between Deep Impact and Stardust-Next, since the comet has completed an orbit around the sun.

4. “The Wind Beneath My Wings” – This Tempel 1 flyby will write the final chapter of the spacecraft’s success story. The aging spacecraft approached 12 years of space travel on Feb. 7, logging almost 6 billion kilometers (3.5 billion miles) since launch. The spacecraft is nearly out of fuel. The Tempel 1 flyby and return of images are expected to consume the remaining fuel.

5. “Love is Now the Stardust of Yesterday” – Although the spacecraft itself will no longer be active after the flyby, the data collected by the Stardust-NExT mission will provide comet scientists with years of data to study how comets formed and evolved.

Do you know the artists names who wrote and sing these celestially romantic tunes ?

NASA Stardust NExT Video: Date with a Comet – Tempel 1

Stardust-NExT Spacecraft & Comet Tempel 1.
Artist rendering of upcoming flyby on February, 14, 2011. Credit: NASA
13 Feb 2011 Position of STARDUST-NExT probe
Looking Down on the Sun. This image shows the current position of the STARDUST spacecraft and the spacecraft's trajectory (in blue) around the Sun. Credit: NASA

Latest navigation camera images of Comet Temple 1 coma and surrounding stars.
Taken by Stardust-NExT at about 10:30 a.m. on Feb. 11 – newly obtained from JPL. This region is about 1.2 degrees on a side - 351 x 351 pixels. Exposure duration 10 seconds. These images are crucial for precisely aiming Stardust-NExT. Credit: NASA/JPL
Enlargement of latest navigation camera image of Comet Temple 1 coma and surrounding stars showing a small section around the comet. Taken by Stardust-NExT at about 10:30 a.m. on Feb. 11 – newly obtained from JPL. Exposure duration 10 seconds. These images are crucial for precisely aiming Stardust-NExT. Credit: NASA/JPL
Posted on by Ken Kremer

Stardust NExT Targets Valentines Day Encounter with Comet Tempel 1

Stardust-NExT: 2 Comet Flybys with 1 Spacecraft. Stardust-NExT makes history on Valentine’s Day - February, 14, 2011 – by becoming the first spacecraft to visit 2 comets and gather science data: Comet Wild 2 in 2004 (left) and Comet Tempel 1 in 2011 (right). Artist renderings Credit: NASA. Collage: Ken Kremer. See video below of Jan 19, 2011 Media briefing from the Science Team about plans for the Temple 1 cometary encounter

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After a more than decade long journey of 6 billion kilometers, hopes are high for a celestial date in space between an icy comet and a thrusting probe on Valentine’s Day 2011. The rendezvous in space between NASA’s approaching Stardust-NExT spacecraft and Comet Tempel 1 takes place nearly on the exact opposite side of the Sun on Feb 14, 2011 at approximately 11:37 p.m. EST (8:37 p.m. PST).

The top science goal is to find out “how much the comet’s surface has changed between two close passages to the sun” since it was last visited in 2005, said principal investigator Joe Veverka of Cornell University, Ithaca, N,Y at a media briefing today, Jan 19, at NASA Headquarters. Indeed it’s the first time in history that a comet has been visited twice by space probes from Earth.

The lead scientists and engineers outlined the plans for the cometary flyby at the briefing. See a video of the entire briefing below.


Since the last visit in 2005, the comet has completed another orbit around the sun. “It will be the first time we’ll be able to see changes after a comet has passed through one perihelion,” explained Veverka. Tempel 1 belongs to the Jupiter family of comets and orbits between Mars and Jupiter.


Comet Tempel 1 suffered a cosmic collision during that first encounter with an emissary from Earth when NASA’s Deep Impact smashed a copper projectile directly into the comets nucleus. The blast created an impact crater and ejected an enormous cloud of gas and debris. Reflected light off the dust particles totally obscured the view of the crater and prevented any images from being taken. Researchers had hoped to determine the size of the crater. A lot of bets hinge on that determination.

“We have a chance to complete the Deep Impact experiment. We hope to see how big the impact crater is and what that tells us about the mechanical properties, ” said Veverka.

20 Jan. 2011 Position of STARDUST-NExT probe - Looking Down on the Sun.
This image shows the current position of the STARDUST-NExT spacecraft and the spacecraft's trajectory (in blue) around the Sun. Credit: NASA

With just over 3 weeks remaining, the craft is approximately 24.6 million kilometers (15.3 million miles) away from its encounter. Stardust-NExT will zoom past the nearly 6-kilometer-wide comet (3.7 miles) at a distance of approximately 200 kilometers (124 miles) and at a speed of 10 km/sec according to Tim Larson, the mission’s project manager from the Jet Propulsion Laboratory (JPL), Pasadena, Calif.

“The spacecraft is still working well 12 years after launch. This is a bonus mission with a scientifically desirable target which we can get close to,” said Larson.

“Everything will happen autonomously,” stated Larson. “The craft will be about 2 AU away from Earth at encounter. Since the round trip signals will take about 40 minutes there is no chance for any real time changes.”

Different features on Tempel 1 discovered by Deep Imapct in 2005. Credit: NASA

“Stardust-NExT will take 72 high resolution images during the close approach encounter. These will be stored in an onboard computer and relayed back to Earth starting about an hour later. It will take about 12 hours to get them all back.”

NASA says that after processing, the images are expected to be available at approximately 4:30 a.m. EST (1:30 a.m. PST) on Feb. 15.

“For the first time we’ll go back to see what happens to a comet since our last visit,” explained Pete Schultz, co-investigator of Brown University, Providence, R.I. “The comet has been out to the orbit of Jupiter and back to Mars and had several outbursts of gas and dust. In 2005 we saw old and new surfaces. So it has a complicated geologic history. We hope to resolve the crater and see ejecta. But there are many unknowns. What we see – whether its the crater or the other unseen side – all depends on the rotation of the comet nucleus.”

“The comet dynamics are complex and erratic, not inert,” said Steve Chesley, a co-investigator at JPL. “They are like a rocket with no one at the controls. The orbit can change. So it is a huge challenge to target a spacecraft for a flyby or rendezvous.”

Stardust successful original mission was to fly by Comet Wild 2 on Jan 2, 2004. It then returned cometary dust particle in a sample return canister to Earth on Jan. 19, 2006 which reentered the atmosphere at the highest speed ever and parachuted to a safe landing. Credit: NASA

Stardust-NeXT is a repurposed spacecraft. The Valentine’s Day encounter will be the last hurrah for the aging probe. Stardust was originally launched way back in 1999. It flew by Comet Wild 2 on Jan. 2, 2004 and collected cometary dust particles which were returned to Earth in a sample return capsule in Jan. 2006. Since then it has continued its solitary voyage through the void of the space.

The craft is nearly out of fuel and all movements consume fuel. It is totally dependent on the reaction control thrusters for navigating through space and pointing its camera and science instruments, said Larson.

“We are confident that we will have enough fuel to finish up this mission. It has been a big, big challenge to maintain a reserve supply. After the mission there won’t be much left that the spacecraft can do. The last trajectory correction maneuver is two days before arrival. That is also when we will take our last optical navigation images for targeting the spacecraft.”
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Only about a third of the surface of Tempel 1 was photographed by Deep Impact in 2005. “We’ll be looking at old territory and new and some overlap,” explained Veverka. “The science team is awfully excited and just can’t wait to see the pictures on Valentine’s day.”

“We have no idea how quickly the surface features change and whether its millions of years or days,” concluded Veverka.

“We expect new discoveries no matter what we see,” Larson summed up

Stardust-NExT Spacecraft & Comet Tempel 1. Artist rendering of Stardust-NExT spacecraft nearing Comet Tempel 1 for upcoming flyby on February, 14, 2011. Credit: NASA
See video and graphics below of Jan 19, 2011 Media briefing from the Science Team about plans for the cometary encounter
Planned imaging of Comet Tempel 1 by Stardust-NExT during flyby. Blue area is unseen and unmapped territory never imaged by Deep Impact during 2005 flyby. Bulls eye in yellow area is expected location of 2005 impact crater and expected new coverage. There is some overlap. Credit: NASA
Planned imaging of Comet Tempel 1 by Stardust-NExT during flyby. Blue area is unseen and unmapped territory never imaged by Deep Impact during 2005 flyby. Credit: NASA

Jan. 19, 2010: Science Team Media Briefing

The Stardust spacecraft has been repackaged for the Stardust-NexT mission. Stardust-NExT will rendezvous with Comet Tempel 1 on February 14, giving scientists an opportunity, for the first time, to search a comet’s surface for changes following its orbit around the sun. Mission scientists discussed the relevance of the mission at a briefing at NASA headquarters in Washington

Stardust successful original mission was to fly by Comet Wild 2 on Jan 2, 2004 and return cometary dust particle to earth in Jan. 2006. It is equipped with 3 science instruments. Credit: NASA

Posted on by Nancy Atkinson

New Results from Stardust Mission Paint Chaotic Picture of Early Solar System

Secondary electron image of the Coki section analyzed in this study showing mineral shards surrounded by compressed aerogel. Credit: Lawrence Livermore National Lab.

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One of the most surprising results from the Stardust mission – which returned comet dust samples to Earth in 2006 – is that comets don’t just consist of particles from the icy parts of the outer solar system, which was the common assumption, but also includes sooty dust from the hot, inner region close to the Sun. A new study confirms this finding, and also provides the first chronological information from the Wild 2 comet (pronounced like Vilt 2). The find paints a chaotic picture of the early solar system.

Even some of the first looks at the cometary particles returned by Stardust showed that contrary to the popular scientific notion, there was enough mixing in the early solar system to transport material from the sun’s sizzling neighborhood and deposit it in icy deep-space comets. Whether the mixing occurred as a gentle eddy in a stream or more like an artillery blast is still unknown.

“Many people imagined that comets formed in total isolation from the rest of the solar system. We have shown that’s not true,” said Donald Brownlee back in 2006, principal investigator for Stardust.

The new study, conducted by scientists from Lawrence Livermore (Calif.) National Laboratory, shows the dust from comet 81P/Wild 2 has been altered by heating and other processes, which could have only occurred if a transport of space dust took place after the solar system formed some 4.57 billion years ago.

“The mission was expected to provide a unique window into the early solar system,” the team, led by Jennifer Matzel wrote in their paper, “by returning a mix of solar system condensates, amorphous grains from the interstellar medium, and true stardust – crystalline grains originating in distant stars. Initial results, however, indicate that comet Wild 2 instead contains an abundance of high-temperature silicate and oxide minerals analogous to minerals in carbonaceous chondrites.”

Corresponding false color mineral map overlaid on a montage of brightfield Transmission Electron Microscope (TEM) images.

They analyzed a particle from the comet, about five micrometers across, known as Coki. The particle does not appear to contain any of the radiogenic isotope aluminum-26, which implies that this particle crystallized 1.7 million years after the formation of the oldest solar system solids. This means that material from the inner solar system must have traveled to the outer solar system, across a period of at least two million years.

“The inner solar system material in Wild 2 underscores the importance of radial transport of material over large distances in the early solar nebula,” said Matzel. “These findings also raise key questions regarding the timescale of the formation of comets and the relationship between Wild 2 and other primitive solar nebula objects.”

The presence of CAIs in comet Wild 2 indicates that the formation of the solar system included mixing over radial distances much greater than anyone expected.

Sources: LLNL, Astrobiology

Posted on by Nancy Atkinson

Comet, Cometary Dust Formed in Different Parts of Solar System

stardust_wild2.thumbnail.jpg

Scientists studying the particles of comet dust brought to Earth by the Stardust spacecraft have uncovered a bit of a mystery. Research on the particles seem to indicate that while the comet formed in the icy fringes of the solar system, the dust appears to have been formed close to the sun and was bombarded by intense radiation before being flung out beyond Neptune and trapped in the comet. The finding opens the question of what was going on in the early life of the solar system to subject the dust to such intense radiation and hurl them hundreds of millions of miles from their birthplace.

The Stardust spacecraft flew to Comet Wild-2 in 2004, coming approximately 150 miles from the comet’s nucleus, and captured particles of dust and gases from the comet’s coma and then returned those particles to Earth in 2006.

Researchers from the University of Minnesota and Nancy University in France analyzed gases locked in the tiny dust grains, which are about a quarter of a billionth of a gram in weight. They were looking for helium and neon, two noble gases that don’t combine chemically with other elements, and therefore would be in the same condition as when the comet dust formed.

The analysis of the helium and neon isotopes suggests that some of the Stardust grains match a special type of carbonaceous material found in meteorites. The gases most likely came from a hot environment exposed to magnetic flares that must have been close to the young sun.

About 10 percent of the mass of Wild 2 is estimated to be from particles transported out from hot inner zones to the cold zone where Wild 2 formed. Earlier research showed that the comet formed in the Kuiper Belt, outside the orbit of Neptune, and only recently entered the inner regions of the solar system.

“Somehow these little high-temperature particles were transported out very early in the life of the solar system,” said Bob Pepin from the University of Minnesota. “The particles probably came from the first million years or even less, of the solar system’s existence.” That would be close to 4.6 billion years ago. If our middle-aged sun were 50 years old, then the particles were born in the first four days of its life.

The studies of cometary dust are part of a larger effort to trace the history of our celestial neighborhood.
“We want to establish what the solar system looked like in the very early stages,” said Pepin. “If we establish the starting conditions, we can tell what happened in between then and now.”

Stardust launched in February 1999, began collecting interstellar dust in 2000 and met up with Wild-2 in January 2004. It’s tennis raquet-sized collector made of an ultra-light material called aerogel, trapped aggregates of fine particles that hit at 13,000 miles per hour and split on impact. It is the first spacecraft to bring cometary dust particles back to Earth.

This study also has relevance in learning about the history of our own planet. “Because some scientists have proposed that comets have contributed these gases to the atmospheres of Earth, Venus and Mars, learning about them in comets would be fascinating,” Pepin said.

The research appears in the Jan. 4 issue of the journal Science

Original News Sources: University of Minnesota Press Release, Lawrence Livermore National Laboratory Press Release