Water On The Moon Was Blown in by Solar Wind

When they first set foot on the Moon, the Apollo 11 astronauts painted a picture of the landscape as a bone-dry desert. So astronomers were naturally surprised when in 2009, three probes showed that a lot of water is locked up in minerals in the soil. There has been some debate as to where the water came from, but now two researchers with the National Museum of Natural History in Paris, France, have determined that most of the water in the soil on the surface of the Moon was formed due to protons in the solar wind colliding with oxygen in lunar dust, rather than from comet or meteorite impacts.

The first hints that there was water on the Moon came when India’s Chandrayaan-1 found hints of water across the lunar surface when it measured a dip in reflected sunlight at a wavelength absorbed only by water and hydroxyl, a molecule that contains one atom of hydrogen and one atom of oxygen.

To help clarify this picture, NASA scientists turned to data collected by two of their space probes – the Cassini probe, which buzzed the moon in 1999 on its way to Saturn, and NASA’s Deep Impact spacecraft, which flew past the moon in June 2009 en route to an encounter with the comet Hartley 2. Both spacecraft confirmed the evidence of water and hydroxyl, molecules that are likely both present on the moon.

Lunar Crater as imaged by NASA's  Moon Mineralogy Mapper. Image Credit: SRO/NASA/JPL-Caltech/USGS/Brown Univ.
Lunar Crater as imaged by NASA’s Moon Mineralogy Mapper. Image Credit: SRO/NASA/JPL-Caltech/USGS/Brown Univ.

There were three likely explanations as to how that water got there. Comets and meteorites were two possibilities, while others believed it may be caused by solar wind. In the latter case, the water would have been formed by streams of plasma emanating from the sun’s upper atmosphere and smashing high-energy protons into the moon’s surface. Cosmic rays from outside the solar system could inject ions into lunar rocks as well, causing chemical changes that create water.

To find out the likeliest source of the water, Alice Stephant and Francois Robert measured the ratio of hydrogen and deuterium in soil samples from the Apollo 16 and Apollo 17 missions. They ran the samples through a type of mass spectrometer that not only detects which isotopes are present but how deep down they are in a surface sample.

In studying tiny grains of lunar soil samples, they found that the reduction of oxygen from silicates in the soil by protons from the solar wind was almost certainly the means by which the water was generated. They came to that conclusion through determining the lithium isotope ratio in the samples which gave the isotope ratio for the hydrogen. From that, they were able to calculate the deuterium-hydrogen ratio which they compared to the amount of water actually in the granule sample.

Because there tends to be more deuterium further from the sun, each possible source of lunar water should give a different ratio. Comets and meteorites have distinctive proportions, while protons from the solar wind or cosmic rays would each have different ratios.

What they found was that on average, the granules contained just 15 percent water from somewhere else (presumably comets or meteorites) leaving the rest to have been formed due to the solar wind interaction. They note also that for some samples, all of the water was due to solar wind interaction.

“We confirm that result,” said Stephant. “Water-rich meteorite and comet impacts do not bring important amounts of water to the surface of the moon.”

Alberto Saal at Brown University in Providence, Rhode Island, is pleased with the result. “I think the idea that most of the water in the surface of the moon comes from solar wind implantations is most likely correct,” he says.

In their paper published in Proceedings of the National Academy of Sciences, Alice Stephant and François Robert describe their study and the results they found. However, they were also quick to point out that their conclusions only relate to water found on the surface of the moon – whereas the origin of the water below the surface is still open to interpretation.

Further reading: PNAS

No Images of Comet ISON from Deep Impact/EPOXI Spacecraft Due to Communication Loss

Disappointing news today from Dr. Mike A’Hearn, Principal Investigator of the EPOXI mission, which has been using the repurposed spacecraft from the Deep Impact mission to study comets. The spacecraft was going to take some much-anticipated images of Comet ISON, but apparently a communication problem has occurred and the images may have been lost or possibly never taken.

“We have not received any of our expected observations of comet ISON due to a spacecraft problem,” A’Hearn wrote in an update on the EXPOXI website. “Communication with the spacecraft was lost some time between August 11 and August 14 (we only talk to the spacecraft about once per week). The last communication was on August 8. After considerable effort, the team on August 30 determined the cause of the problem. The team is now trying to determine how best to try to recover communication.”

No additional information was provided about the cause of the problem, however.

The Deep Impact mission intentionally crashed an impactor into comet Tempel-1 on July 4, 2005. Since then, EPOXI — the name comes from two combined missions to re-use the observing spacecraft, the Extrasolar Planet Observations and Characterization (EPOCh) and the Deep Impact Extended Investigation (DIXI) — has gone on to study comet Hartley 2, performing a close fly-by in 2010, studied C/2009 P1 (Garradd) in 2012, and has continued to be used as a remote observatory for studying comets.

EPOXI took images of Comet ISON on January 17, 2013, showing that the comet’s brightness varied on a timescale of hours (see the video above). There was another observing window from mid-February to March 8, where the team took infrared images of the comet.

The additional observing window from early July to early September is the timeframe for which there was a communication problem, and A’Hearn didn’t specify if any early images were received from the spacecraft, although he said they had “not received any of our expected observations.”

We’ll provide more information when it becomes available.

European Asteroid Smasher Could Bolster Planetary Defense

Planetary Defense is a concept very few people heard of or took seriously – that is until last week’s humongous and totally unexpected meteor explosion over Russia sent millions of frightened residents ducking for cover, followed just hours later by Earth’s uncomfortably close shave with the 45 meter (150 ft) wide asteroid named 2012 DA14.

This ‘Cosmic Coincidence’ of potentially catastrophic space rocks zooming around Earth is a wakeup call that underscores the need to learn much more about the ever present threat from the vast array of unknown celestial debris in close proximity to Earth and get serious about Planetary Defense from asteroid impacts.

The European Space Agency’s (ESA) proposed Asteroid Impact and Deflection Assessment mission, or AIDA, could significantly bolster both our basic knowledge about asteroids in our neighborhood and perhaps even begin testing Planetary Defense concepts and deflection strategies.

After two years of work, research teams from the US and Europe have selected the mission’s target – a so called ‘binary asteroid’ named Didymos – that AIDA will intercept and smash into at about the time of its closest approach to Earth in 2022 when it is just 11 million kilometers away.

“AIDA is not just an asteroid mission, it is also meant as a research platform open to all different mission users,” says Andres Galvez, ESA studies manager.

Asteroid Didymos could provide a great platform for a wide variety of research endeavors because it’s actually a complex two body system with a moon – and they orbit each other. The larger body is roughly 800 meters across, while the smaller one is about 150 meters wide.

Didymos with its Moon
Didymos with its Moon. Credit: ESA

So the smaller body is some 15 times bigger than the Russian meteor and 3 times the size of Asteroid 2012 DA14 which flew just 27,700 km (17,200 mi) above Earth’s surface on Feb. 15, 2013.

The low cost AIDA mission would be comprised of two spacecraft – a mother ship and a collider. Two ships for two targets.

The US collider is named the Double Asteroid Redirection Test, or DART and would smash into the smaller body at about 6.25 km per second. The impact should change the pace at which the objects spin around each other.

ESA’s mothership is named Asteroid Impact Monitor, or AIM, and would carry out a detailed science survey of Didymos both before and after the violent collision.

“The project has value in many areas,” says Andy Cheng, AIDA lead at Johns Hopkins’ Applied Physics Laboratory, “from applied science and exploration to asteroid resource utilisation.” Cheng was a key member of NASA’s NEAR mission that first orbited and later landed on the near Earth Asteroid named Eros back in 2001.

Recall that back in 2005, NASA’s Deep Impact mission successfully lobbed a projectile into Comet Tempel 1 that unleashed a fiery explosion and spewing out vast quantities of material from the comet’s interior, including water and organics.

NASA’s Deep Impact images Comet Tempel 1 alive with light after colliding with the impactor spacecraft on July 4, 2005.  ESA and NASA are now proposing the AIDA mission to smash into Asteroid Didymos.  CREDIT: NASA/JPL-Caltech/UMD
NASA’s Deep Impact images Comet Tempel 1 alive with light after colliding with the impactor spacecraft on July 4, 2005. ESA and NASA are now proposing the AIDA mission to smash into Asteroid Didymos. CREDIT: NASA/JPL-Caltech/UMD

ESA has invited researchers to submit AIDA experiment proposals on a range of ideas including anything that deals with hypervelocity impacts, planetary science, planetary defense, human exploration or innovation in spacecraft operations. The deadline is 15 March.

“It is an exciting opportunity to do world-leading research of all kinds on a problem that is out of this world,” says Stephan Ulamec from the DLR German Aerospace Center. “And it helps us learn how to work together in international missions tackling the asteroid impact hazard.”

The Russian meteor exploded without warning in mid air with a force of nearly 500 kilotons of TNT, the equivalent of about 20–30 times the atomic bombs detonated at Hiroshima and Nagasaki.

Over 1200 people were injured in Russia’s Chelyabinsk region and some 4000 buildings were damaged at a cost exceeding tens of millions of dollars. A ground impact would have decimated cities like New York, Moscow or Beijing with millions likely killed.

ESA’s AIDA mission concept and NASA’s approved Osiris-REx asteroid sample return mission will begin the path to bolster our basic knowledge about asteroids and hopefully inform us on asteroid deflection and Planetary Defense strategies.

Ken Kremer

Near-Earth asteroid Eros imaged from NASA’s orbiting NEAR spacecraft. Credit: NASA
Near-Earth asteroid Eros imaged from NASA’s orbiting NEAR spacecraft. Credit: NASA

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

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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.

Sounds of Comet Tempel 1 smashing into Stardust-NExT

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.

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

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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

Stardust-NExT Unveils Astoundingly Detailed and Crater-rich Photos of Comet Tempel 1

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NASA’s Stardust-NExT raced past Comet Tempel 1 overnight Feb 14/15 at over 10 km/sec or 24,000 MPH and is now sending back the 72 astoundingly detailed and crisp science images of Comet Tempel 1 taken during closest approach at 11:37 p.m. EST on Feb. 14.

The high resolution images are amazingly sharp and clearly show a pockmarked and crater rich terrain of both new and previously unseen territory on the icy comets surface. The Stardust-NExT comet chaser zoomed within 181 km (112 miles) of the nucleus of the volatile comet.

See the photo gallery above and below, which is being updated as the images come back. I am enhancing and brightening certain images to show further details. The new images of Tempel 1 from Stardust-NExT surpass my expectations and look even sharper then those taken by NASA’s Deep Impact comet smasher in July 2005.

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

NASA news briefing on Stardust-NExT at 3:30 p.m Feb 15 live on NASA TV

Update: Read my follow up story on the discovery of the Deep Impact crater here

Photo gallery of Comet Tempel 1 images from NASA’s Stardust-NExT comet mission on Feb 14, 2011

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.
Image brightened and enhanced to show additional detail.
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.
Image brightened and enhanced to show additional detail.
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 to show additional detail.
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

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 to show additional detail.

Images brightened and enhanced to show additional detail by Ken Kremer

Stardust-NExT zooms by Comet Tempel 1 for Cosmic Encounter

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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.