Ancient comets may have created Titan's nitrogen-rich atmosphere
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Titan is a fascinating world to planetary scientists. Although it’s a moon of Saturn it boasts an opaque atmosphere ten times thicker than Earth’s and a hydrologic cycle similar to our own – except with frigid liquid methane as the key component instead of water. Titan has even been called a living model of early Earth, even insofar as containing large amounts of nitrogen in its atmosphere much like our own. Scientists have wondered at the source of Titan’s nitrogen-rich atmosphere, and now a team at the University of Tokyo has offered up an intriguing answer: it may have come from comets.
Traditional models have assumed that Titan’s atmosphere was created by volcanic activity or the effect of solar UV radiation. But these rely on Titan having been much warmer in the past than it is now…a scenario that Cassini mission scientists don’t think is the case.
New research suggests that comet impacts during a period called the Late Heavy Bombardment – a time nearly 4 billion years ago when collisions by large bodies such as comets and asteroids were occurring regularly among worlds in our solar system – may have generated Titan’s nitrogen atmosphere. By firing lasers into ammonia-and-water-ice material similar to what would have been found on primordial Titan, researchers saw that nitrogen was a typical result. Over the millennia these impacts could have created enough nitrogen to cover the moon in a dense haze, forming the thick atmosphere we see today.
“We propose that Titan’s nitrogen atmosphere formed after accretion, by the conversion from ammonia that was already present on Titan during the period of late heavy bombardment about four billion years ago.”
– Yasuhito Sekine et al., University of Tokyo, Japan
This model, if true, would also mean that the source of Titan’s nitrogen would be different than that of other outer worlds, like Pluto, and even inner planets like our own.
Top image is a combination of a color-composite of Titan made from raw Cassini data taken on October 12, 2010 and a recolored infrared image of the comet Siding Spring, taken by NASA’s WISE observatory on January 10, 2010. The background stars were also taken by the Cassini orbiter. NASA / JPL / SSI and Caltech/UCLA. Edited by J. Major.
Note: the image at top is not scientifically accurate…the comet’s tail would be, based on the lighting of Titan, pointing more to the ten o’clock position as well as forward toward the viewer’s left shoulder. This would make it ‘look’ as if it were going the opposite direction though, away from Titan, and so I went with the more immediately decipherable version seen here. To see a more “realistic” version, click here.
Stardust-NExT photographed jets of gas and particles streaming from Comet Tempel 1 during Feb 14, 2011 flyby. The raw image taken during closest approach has been extensively enhanced by outside analysts to visibly show the jets. Annotations show the location of the jets and the man-made crater created by a projectile hurled by NASA’s prior Deep Impact mission in 2005. Credit: NASA/JPL-Caltech/University of Maryland/Post process and annotations by Marco Di Lorenzo/Kenneth Kremer
[/caption]Farewell Stardust-NExT !
Today marks the end to the final chapter in the illustrious saga of NASA’s Stardust-NExT spacecraft, a groundbreaking mission of cometary exploration.
Mission controllers at NASA’s Jet Propulsion Laboratory commanded the probe to fire the main engines for the very last time today at about 7 p.m. EDT (March 24). The burn will continue until the spacecraft entirely depletes the tiny amount of residual fuel remaining in the propellant tanks. The Stardust probe is now being decommissioned and is about 312 million kilometers away from Earth.
This action will effectively end the life of the storied comet hunter, which has flown past an asteroid (Annefrank), two comets (Wild 2 and Tempel 1) and also returned the first ever pristine samples of a comet to Earth for high powered analysis by the most advanced science instruments available to researchers.
NASA’s Stardust space probe completed her amazing science journey on Feb. 14, 2011 by streaking past Comet Tempel 1 at 10.9 km/sec, or 24,000 MPH and successfully sending back 72 high resolution images of the comets nucleus and other valuable science data. Tempel 1 became the first comet to be visited twice by spacecraft from Earth.
During the Feb. 14, 2011 flyby of Comet Tempel 1, Stardust-NExT discovered the man-made crater created back in 2005 by NASA’s Deep Impact mission and also imaged gas jets eminating from the comet. My imaging partner Marco Di Lorenzo and myself prepared two posters illustrating the finding of the jets and the Deep Impact crater included in this article.
6 Views of Comet Tempel 1 and Deep Impact crater from Stardust-NExT spacecraft flyby on Feb. 14, 2011. Arrows show location of man-made crater created in 2005 by NASA’s prior Deep Impact comet smashing 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 rocket burn will be the last of some 2 million rocket firings all told since the Stardust spacecraft was launched back in 1999. Over a dozen years, Stardust has executed 40 major flight path maneuvers and traveled nearly 6 billion kilometers.
The rocket firing also serves another purpose as a quite valuable final contribution to science. Since there is no fuel gauge on board or precise method for exactly determining the quantity of remaining fuel, the firing will tell the engineers how much fuel actually remains on board.
To date the team has relied on several analytical methods to estimate the residual fuel. Comparing the results of the actual firing experiment to the calculations derived from estimates will aid future missions in determining a more accurate estimation of fuel consumption and reserves.
“We call it a ‘burn to depletion,’ and that is pretty much what we’re doing – firing our rockets until there is nothing left in the tank,” said Stardust-NExT project manager Tim Larson of NASA’s Jet Propulsion Laboratory in Pasadena, Calif in a statement. “It’s a unique way for an interplanetary spacecraft to go out. Essentially, Stardust will be providing us useful information to the very end.”
Just prior to the burn, Stardust will turn its medium gain antenna towards Earth and transmit the final telemetry in real time. Stardust is being commanded to fire the thrusters for 45 minutes but the team expects that there is only enough fuel to actually fire for up to perhaps around ten minutes.
On March 24, at about 4 p.m. PDT, four rocket motors on NASA's Stardust spacecraft, illustrated in this artist's concept, are scheduled to fire until the spacecraft's fuel is depleted. Image credit: NASA/JPL-Caltech
As its final act, the transmitters will be turned off (to prevent accidental transmissions to other spacecraft), all communications will cease and that will be the end of Stardust’s life.
With no more fuel available, the probe cannot maintain attitude control, power its solar array or point its antenna. And its far enough away from any targets that there are no issues related to planetary protection requirements.
“I think this is a fitting end for Stardust. It’s going down swinging,” Larson stated in the press release.
Read more about the Stardust-NExT Flyby and mission in my earlier stories here, here, here, here, here, here and here
Relive the Feb. 14 Flyby of Comet Tempel 1 in this movie of NASA/JPL images
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.Stardust-NExT location on March 11, 2011 just prior to farewell transmission. Credit: NASA/JPL
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.
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
Siding Spring Comet via WISE. credit: NASA/JPL-Caltech/UCLA
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An old story got new legs this week as word went viral of a possible new 9th planet in our solar system – a gas giant bigger than Jupiter – which could be hiding somewhere in the Oort Cloud, just waiting to be found.
An article this week in The Independent suggested the new planet, called Tyche, had already been found among data from the WISE mission. This prompted the WISE team to post a rebuttal on their Facebook page: “Not true. A pair of scientists published a paper stating that if such a big planet exists in the far reaches of the Solar System, then WISE should have seen it. That is true. But, analysis over the next couple of years will be needed to determine if WISE has actually detected such a world or not.”
To make sense of this all, Universe Today sought out a scientist who has looked at the outer solar system as much as anyone, if not more: Mike Brown, of Eris, Haumea and Makemake fame – to get his take on Tyche.
“Yes,” said Brown, “this is all getting pretty funny these days!”
The story starts at least a decade ago. For years John Matese of the University of Louisiana at Lafayette and colleague Daniel Whitmire have been trying to figure out why many of the comets that originate from way out in the distant-most part of our solar system — the Oort Cloud — have strange orbits that don’t jive with theories of how comets should behave. The two scientists first suggested that the gravitational influence from a dark companion to the Sun — a dim brown-dwarf or red-dwarf star — was sending comets careening towards the inner solar system. They called it Nemesis, (another thing that went viral), but the Nemesis idea has widely been refuted.
Last year, Matese and Whitmire suggested that possibly a large planet four times the mass of Jupiter in the Oort Cloud could explain why long-period comets appear to be clustered in a band inclined to the ecliptic instead of coming from random directions. (Here’s their paper.)
Then came a revival of their theory with several articles about it this week, reporting it as seemingly fact.
Could there possibly be a giant planet 500 times as distant as Neptune?
“Absolutely,” Brown said. “Many people have speculated about such possibilities for a long time. It’s an intriguing idea because, well, it would be fun, to say the least.”
But beyond fun and excitement, is there actually any evidence for it?
The layout of the solar system, including the Oort Cloud, on a logarithmic scale. Credit: NASA
“Well, the quality of the data that Matese and Whitmire have to work with is pretty crummy –no fault of their own — it’s just the historical record of where comets have come from,” Brown said in an email. “I don’t believe that anyone understands the ins and outs of the data set well enough to really draw a robust conclusion. But, Matese and Whitmire did the best they could and think the data point to something out there.”
Does Brown think there is really something out there?
“Well,” he said, “if I had to bet one way or another I’d bet no. The data don’t convince me, and there is no other hint anywhere that such a thing is real. So I’m pretty skeptical.”
That being said, however, Brown believes WISE really does have a good chance of detecting this type of object way out there – if it exists — even if the predictions have nothing to do with the real object.
“This is something that people will absolutely be looking for when the data are released,” Brown said, “and, indeed, the WISE team is undoubtedly already looking for — not because of the prediction, but simply because it’s the right way to search this unknown region of the solar system!”
So don’t worry about the International Astronomical Union having to confirm or name a new planet in our solar system, at least for now.
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
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
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.
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
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/CornellStardust-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.
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
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.
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
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/JPL2. “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: NASA13 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/JPLEnlargement 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
During its one-year mission, NASA's Wide-field Infrared Survey Explorer, or WISE, mapped the entire sky in infrared light. Among the multitudes of astronomical bodies that have been discovered by the NEOWISE portion of the WISE mission are 20 comets. Image credit: NASA/JPL-Caltech/UCLA
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The WISE spacecraft has completed a special mission called NEOWISE, looking for small bodies in the solar system, and has discovered a plethora of previously unknown objects. The NEOWISE mission found 20 comets, more than 33,000 asteroids in the main belt between Mars and Jupiter, and 134 near-Earth objects (NEOs). More data from NEOWISE also have the potential to reveal a brown dwarf even closer to us than our closest known star, Proxima Centauri, if such an object does exist. Likewise, if there is a hidden gas-giant planet in the outer reaches of our solar system, data from WISE and NEOWISE could detect it.
“WISE has unearthed a mother lode of amazing sources, and we’re having a great time figuring out their nature,” said Edward (Ned) Wright, the principal investigator of WISE at UCLA.
“Even just one year of observations from the NEOWISE project has significantly increased our catalog of data on NEOs and the other small bodies of the solar systems,” said Lindley Johnson, NASA’s program executive for the NEO Observation Program.
The NEOs are asteroids and comets with orbits that come within 45 million kilometers (28 million miles) of Earth’s path around the sun.
The NEOWISE mission made use of the the WISE spacecraft, the Wide-field Infrared Survey Explorer that launched in December 2009. WISE scanned the entire celestial sky in infrared light about 1.5 times. It captured more than 2.7 million images of objects in space, ranging from faraway galaxies to asteroids and comets close to Earth.
However, in early October 2010, after completing its prime science mission, the spacecraft ran out of the frozen coolant that keeps its instrumentation cold. But two of its four infrared cameras remained operational, which were still optimal for asteroid hunting, so NASA extended the NEOWISE portion of the WISE mission by four months, with the primary purpose of hunting for more asteroids and comets, and to finish one complete scan of the main asteroid belt.
Now that NEOWISE has successfully completed a full sweep of the main asteroid belt, the WISE spacecraft will go into hibernation mode and remain in polar orbit around Earth, where it could be called back into service in the future.
In addition to discovering new asteroids and comets, NEOWISE also confirmed the presence of objects in the main belt that had already been detected. In just one year, it observed about 153,000 rocky bodies out of approximately 500,000 known objects. Those include the 33,000 that NEOWISE discovered.
NEOWISE also observed known objects closer and farther to us than the main belt, including roughly 2,000 asteroids that orbit along with Jupiter, hundreds of NEOs and more than 100 comets.
These observations will be key to determining the objects’ sizes and compositions. Visible-light data alone reveal how much sunlight reflects off an asteroid, whereas infrared data is much more directly related to the object’s size. By combining visible and infrared measurements, astronomers also can learn about the compositions of the rocky bodies — for example, whether they are solid or crumbly. The findings will lead to a much-improved picture of the various asteroid populations.
NEOWISE took longer to survey the whole asteroid belt than WISE took to scan the entire sky because most of the asteroids are moving in the same direction around the sun as the spacecraft moves while it orbits Earth. The spacecraft field of view had to catch up to, and lap, the movement of the asteroids in order to see them all.
“You can think of Earth and the asteroids as racehorses moving along in a track,” said Amy Mainzer, the principal investigator of NEOWISE at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “We’re moving along together around the sun, but the main belt asteroids are like horses on the outer part of the track. They take longer to orbit than us, so we eventually lap them.”
NEOWISE data on the asteroid and comet orbits are catalogued at the NASA-funded International Astronomical Union’s Minor Planet Center, a clearinghouse for information about all solar system bodies at the Smithsonian Astrophysical Observatory in Cambridge, Mass. The science team is analyzing the infrared observations now and will publish new findings in the coming months.
The first batch of observations from the WISE mission will be available to the public and astronomical community in April.
