The surviving co-pilot of the Virgin Galactic crash was unaware that SpaceShipTwo’s re-entry system was unlocked prematurely during the flight test, according to an update from the National Transportation Safety Board.
In an interview with investigators, the board said Peter Siebold provided testimony that was consistent with other information gathered so far since the crash. The incident, which killed fellow co-pilot Mike Alsbury when the craft plunged into the Mojave desert, took place Oct. 31.
“The NTSB operations and human performance investigators interviewed the surviving pilot on Friday. According to the pilot, he was unaware that the feather system had been unlocked early by the copilot,” read an update on the board’s website.
“His description of the vehicle motion was consistent with other data sources in the investigation. He stated that he was extracted from the vehicle as a result of the break-up sequence and unbuckled from his seat at some point before the parachute deployed automatically.”
Accidents are due to a complex set of circumstances, which means the NTSB finding that the re-entry system was deployed prematurely is only a preliminary finding. The investigation into the full circumstances surrounding the crash could take anywhere from months to a year, according to multiple media reports.
Virgin was performing another in a series of high-altitude test flights in preparation for running tourists up to suborbital space early next year. A handful of ticket-holders, who made deposits of up to $250,000 each, have reportedly asked for their money back. The Richard Branson-founded company has not revealed when the first commercial flight is expected to take place.
Meanwhile, Virgin does have another version of SpaceShipTwo already under assembly right now, which is considered 95% structurally complete and 60% assembled, according to NBC News. The prototype could take to the skies before the NTSB investigation is complete, the report added.
If it weren’t for the Sun, Jupiter’s Great Red Spot would be a much blander feature on the gas giant, a new study reveals. This stands apart from what most scientists think about why for why the spot looks so colorful: that there are features in the clouds that give it its distinctive shade.
The new data comes from observations with the Cassini spacecraft, combined with experiments in the lab. They conclude that the Red Spot’s immense height, combined with sunlight breaking apart the atmosphere there into certain chemicals, make the feature that red that is visible even in small telescopes.
“Our models suggest most of the Great Red Spot is actually pretty bland in color, beneath the upper cloud layer of reddish material,” said Kevin Baines, a Cassini team scientist based at NASA’s Jet Propulsion Laboratory in California, in a statement. “Under the reddish ‘sunburn’ the clouds are probably whitish or grayish.”
The lab experiments combined ammonia and acetylene gases (atmospheric components from Jupiter) with ultraviolet light (simulating what the Sun produces), which created a ruddy substance that matched observations made with the Cassini spacecraft back in 2000. They also tried breaking apart ammonium hydrosulfide, a common element in Jupiter’s high clouds, but the color produced was actually a bright green.
The Great Red Spot is a storm that has been raging on Jupiter since at least when telescopes were first used in the 1600s. Over the past few decades, its size has shrunk considerably –it’s now half of what historical measurements showed — but it is still much larger than Earth. Scientists are hoping the forthcoming Juno mission, which will arrive at Jupiter at 2016, will help learn more about what is going on.
Results were presented at the Division for Planetary Science of the American Astronomical Society’s annual meeting this week in Tucson, Arizona. A press release did not disclose publication plans or if the research is peer-reviewed.
We are now in the final hours before Rosetta’s Philae lander is released to attempt a first-ever landing on a comet. At 9:03 GMT (1:03 AM PST) on Wednesday, November 12, 2014, Philae will be released and directed towards the surface of comet 67P/Churyumov–Gerasimenko. 7 hours later, the lander will touch down.
Below you’ll find a timeline of events, info on how to watch the landing, and an overview of how the landing will (hopefully) work.
In human affairs, we build contingencies for missteps, failures. With spacecraft, engineers try to eliminate all single point failures and likewise have contingency plans. The landing of a spacecraft, be it on Mars, Earth, or the Moon, always involves unavoidable single point failures and points of no return, and with comet 67P/Churyumov–Gerasimenko, Rosetta’s Philae lander is no exception.
Rosetta’s and Philae’s software and hardware must work near flawlessly to give Philae the best chance possible of landing safely. And even with flawless execution, it all depends on Philae’s intercepting a good landing spot on the surface. Philae’s trajectory is ballistic on this one way trip to a comet’s surface. It’s like a 1 mile per hour bullet. Once fired, it’s on its own, and for Philae, its trajectory could lead to a pristine flat step or it could be crevasse, ledge, or sharp rock.
The accuracy of the landing is critical but it has left a 1 square kilometer of uncertainty. For this reason, engineers and scientists had to survey the whole surface for the most mild features. Comet 67P has few areas that are not extreme in one way or another. Site J, now called Agilkia, is one such site.
When first announced in late September, the time of release was 08:35 GMT (12:35 AM PST). Now the time is 9:03 GMT. The engineers and computer scientists have had six weeks to further refine their trajectory. It’s a complicated calculation that has required running the computer simulation of the descent backwards. Backwards because they can set a landing time then run Philae backwards to the moment of release. The solution is not just one but many, thousands or millions if you want to look in such detail. With each release point, the engineers had to determine how, or if, Rosetta could be navigated to that coordinate point in space and time.
Arrival time of the radio signal with landing status: 16:30 GMT
Rosetta/Philae at 500 million km [320 million miles], 28.5 minutes light time
Arrival of First Images: 06:00 GMT, November 13, 2014
The gravity field of the comet is so weak, it is primarily the initial velocity from Rosetta that delivers Philae to the surface. But the gravity is there and because of the chaotic shape and unknown (as yet) mass distribution inside, the gravity will make Philae move like a major league knuckleball wobbling to the plate and a batter. Furthermore, the comet during the seven hour trip will make half a rotation. The landing site will not be in site when Philae is released.
And as Philae is on final approach, it will use a small rocket not to slow down but rather thrust it at the comet, landing harpoons will be fired, foot screws will try to burrow into the comet, and everyone on Earth will wait several minutes for a message to be relayed from Philae to Rosetta to the Deep Space Network (DSN) antennas on Earth. Philae will be on its own as soon as it leaves Rosetta and its fate is a few hours away.
Why travel to a comet? Comets represent primordial material leftover from the formation of the solar system. Because cometary bodies were formed and remained at a distance from the heat of the sun, the materials have remained nearly unchanged since formation, ~4.5 billion years ago. By looking at Rosetta’s comet, 67P/Churyumov–Gerasimenko, scientists will gain the best yet measurements of a comet’s chemical makeup, its internal structure created during formation, and the dynamics of the comet as it approaches the warmth of the Sun. Theories propose that comets impacting on Earth delivered most of the water of our oceans. If correct, then we are not just made of star-stuff, as Carl Sagan proclaimed, we are made of comet stuff, too. Comets may also have delivered the raw organic materials needed to start the formation of life on Earth.
Besides the ESA live feeds, one can take a peek at NASA’s Deep Space Network (DSN) at work to see which telescopes are communicating with Rosetta. JPL’s webcast can watched below:
No one knows exactly why a NASA solar probe stopped talking to Earth six weeks ago, but it’s possible the spacecraft is out of power and is drifting without a way of calling for help, the agency said in an update.
On Oct. 1, NASA suddenly lost contact with one of the two Solar TErrestrial RElations Observatory (STEREO) spacecraft, which are currently examining the far side of the Sun. The probes are considered crucial for solar forecasting, so the loss is a blow. While the STEREO-Behind probe has been mute since then, the agency says “not all hope is lost” for a recovery.
STEREO-Behind went silent after NASA deliberately reset the spacecraft. Along with its twin, STEREO-Ahead, in the coming years the spacecraft will need to reposition its antenna to avoid getting fried by the Sun. Also, there is a period where each spacecraft will need to work autonomously, because the Sun’s radio interference will make it difficult or impossible for communications to get through.
To prepare the spacecraft, NASA has been testing them out ahead of these events, which are called “solar conjunction operations.” STEREO-Ahead passed the tests and entered these operations in August, where it will remain until 2016. STEREO-Behind was supposed to go into this phase on Dec. 1. Preparations started Sept. 27, when STEREO-Behind was put into the same safe mode test that was used on STEREO-Ahead.
“One part of this test was to observe the firing of the spacecraft hard command loss timer, which resets the spacecraft if no commands are received after three days,” NASA wrote in an update. “The purpose of this is to correct any problems that might be preventing the spacecraft from receiving commands from the ground. While the spacecraft is out of contact on the far side of the Sun, this reset will occur every three days.”
The timer did fire as planned on Oct. 1, and the spacecraft reset as expected. However, the radio signal coming from STEREO-Behind wasn’t as strong as expected. Then, it disappeared altogether.
While there’s not much information to work with, NASA says it does know a few things. Before the reset, information or telemetry from the spacecraft showed it was working fine. After the reset, though, they could tell the inertial measurement unit (IMU) was turned on. This is unusual, and shows that the guidance system’s star tracker hadn’t picked up its guide stars as expected.
“This is not unexpected—there have been other occasions when it took the star tracker several minutes, or even a few days, to start determining the spacecraft orientation based on star images,” NASA said.
“In fact, on Sept. 28, as part of the same test sequence, the spacecraft was reset, and it took 12 minutes for the star tracker to start providing an attitude solution. When the star tracker is ofline, the spacecraft will automatically turn on the IMU to provide rotational rate information.”
NASA thinks the star tracker’s struggles would explain why the radio signal wasn’t as strong as expected, because the spacecraft’s high-gain antenna wasn’t aimed at Earth properly. But there’s more — it appears one of the IMU’s laser gyroscopes isn’t working and is giving “bad data to the attitude control system”, NASA said. So now the spacecraft was facing two failures, which is tough for it to deal with, the agency added.
Did the spacecraft recognize the problem? If it did, it would have used the last backup system — five solar aspect sensors — which should have made sure the solar panels were pointed in the right direction to provide power. If not, the spacecraft might have thought it was in a roll, turned on its thrusters, and then spun itself in such a way that it could have lost sunlight power.
NASA is trying to send out commands to address all of these failure possibilities, and it emphasizes that a recovery is still possible. The Solar and Heliospheric Observatory (SOHO), for example, also lost power in 1998 when a spin put its solar panels out of reach of the Sun. However, as its orbit changed, the Sun’s light eventually fell across the panels and power was restored. The spacecraft was recovered and still works today.
And Orion is so big and heavy that she’s not launching on just any old standard rocket.
To blast the uncrewed Orion to orbit on its maiden mission requires the most powerful booster on Planet Earth – namely the United Launch Alliance Delta IV Heavy rocket.
Liftoff of the state-of-the-art Orion spacecraft on the unmanned Exploration Flight Test-1 (EFT-1) mission is slated for December 4, 2014, from Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida.
Just days ago, the launch team successfully completed a countdown and wet dress rehearsal fueling test on the rocket itself – minus Orion – at launch complex 37.
The high fidelity rehearsal included fully powering up the booster and loading the tanks with cryogenic fuel and oxidizer, liquid oxygen, and liquid hydrogen.
ULA technicians and engineers practiced the countdown on Nov. 5 which included fueling the core stages of the Delta IV Heavy rocket.
“Working in control rooms at Cape Canaveral Air Force Station in Florida, countdown operators followed the same steps they will take on launch day. The simulation also allowed controllers to evaluate the fuel loading and draining systems on the complex rocket before the Orion spacecraft is placed atop the launcher,” said NASA.
The next key mission milestone is attachment of the completed Orion vehicle stack on top of the rocket. Read more about the fully assembled Orion – here.
Today’s scheduled rollout of Orion to the launch pad for hoisting atop the rocket was scrubbed due to poor weather.
The triple barreled Delta IV Heavy booster became the world’s most powerful rocket upon the retirement of NASA’s Space Shuttle program in 2011 and is the only rocket sufficiently powerful to launch the Orion EFT-1 spacecraft.
The first stage of the mammoth Delta IV Heavy generates some 2 million pounds of liftoff thrust.
“The team has worked extremely hard to ensure this vehicle is processed with the utmost attention to detail and focus on mission success,” according to Tony Taliancich, ULA’s director of East Coast Launch Operations.
“The Delta IV Heavy is the world’s most powerful launch vehicle flying today, and we are excited to be supporting our customer for this critical flight test to collect data and reduce overall mission risks and costs for the program.”
From now until launch technicians will continue to conduct the final processing, testing, and checkout of the Delta IV Heavy booster.
The Delta IV Heavy first stage is comprised of a trio of three Common Booster Cores (CBCs).
Each CBC measures 134 feet in length and 17 feet in diameter. They are equipped with an RS-68 engine powered by liquid hydrogen and liquid oxygen propellants producing 656,000 pounds of thrust. Together they generate 1.96 million pounds of thrust.
The first CBC booster was attached to the center booster in June. The second one was attached in early August.
This fall I visited the ULA’s Horizontal Integration Facility (HIF) during a media tour after the three CBCs had been joined together as well as earlier this year after the first two CBCs arrived by barge from their ULA assembly plant in Decatur, Alabama, located about 20 miles west of Huntsville. See my photos herein.
Orion is NASA’s next generation human rated vehicle that will eventually carry America’s astronauts beyond Earth on voyages venturing farther into deep space than ever before – beyond the Moon to Asteroids, Mars, and other destinations in our Solar System.
The two-orbit, four and a half hour EFT-1 flight will lift the Orion spacecraft and its attached second stage to an orbital altitude of 3,600 miles, about 15 times higher than the International Space Station (ISS) – and farther than any human spacecraft has journeyed in 40 years.
“This mission is a stepping stone on NASA’s journey to Mars,” said NASA Associate Administrator Robert Lightfoot.
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“The EFT-1 mission is so important to NASA. We will test the capsule with a reentry velocity of about 85% of what’s expected by [astronauts] returning from Mars.”
“We will test the heat shield, the separation of the fairing, and exercise over 50% of the eventual software and electronic systems inside the Orion spacecraft. We will also test the recovery systems coming back into the Pacific Ocean.”
Stay tuned here for Ken’s continuing Orion and Earth and planetary science and human spaceflight news.
Doesn’t this make you want to book a trip on the next spaceship? Stunning footage from space here shows what auroras look like from the International Space Station. So many ripples of green. Such awesomeness.
Check out that landing mark! A Soyuz spacecraft carrying three people touched down safely in remote Kazakhstan late Sunday (EDT) and went for a brief sleigh ride in the snow, as you can see from the drag marks on the landscape.
The flawless landing included the Expedition 40/41 crew members of Reid Wiseman (NASA), Alexander Gerst (European Space Agency) and Maxim Suraev (Roscosmos), who spent 165 days in space, mainly living on the International Space Station. Check out some more landing pictures and video below.
NASA’s ongoing hunt for exoplanets has entered a new phase as NASA officially confirmed that the Transiting Exoplanet Survey Satellite (TESS) is moving into the development phase. This marks a significant step for the TESS mission, which will search the entire sky for planets outside our solar system (a.k.a. exoplanets). Designed as the first all-sky survey, TESS will spend two years of an overall three-year mission searching both hemispheres of the sky for nearby exoplanets.
Previous sky surveys with ground-based telescopes have mainly picked out giant exoplanets. In contrast, TESS will examine a large number of small planets around the very brightest stars in the sky. TESS will then record the nearest and brightest main sequence stars hosting transiting exoplanets, which will forever be the most favorable targets for detailed investigations. During the third year of the TESS mission, ground-based astronomical observatories will continue monitoring exoplanets identified by the TESS spacecraft.
“This is an incredibly exciting time for the search of planets outside our solar system,” said Mark Sistilli, the TESS program executive from NASA Headquarters, Washington. “We got the green light to start building what is going to be a spacecraft that could change what we think we know about exoplanets.”
“During its first two years in orbit, the TESS spacecraft will concentrate its gaze on several hundred thousand specially chosen stars, looking for small dips in their light caused by orbiting planets passing between their host star and us,” said TESS Principal Investigator George Ricker of the Massachusetts Institute of Technology..
All in all, TESS is expected to find more than 5,000 exoplanet candidates, including 50 Earth-sized planets. It will also find a wide array of exoplanet types, ranging from small, rocky planets to gas giants. Some of these planets could be the right sizes, and orbit at the correct distances from their stars, to potentially support life.
“The most exciting part of the search for planets outside our solar system is the identification of ‘earthlike’ planets with rocky surfaces and liquid water as well as temperatures and atmospheric constituents that appear hospitable to life,” said TESS Project Manager Jeff Volosin at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Although these planets are small and harder to detect from so far away, this is exactly the type of world that the TESS mission will focus on identifying.”
Now that NASA has confirmed the development of TESS, the next step is the Critical Design Review, which is scheduled to take place in 2015. This would clear the mission to build the necessary flight hardware for its proposed launch in 2017.
“After spending the past year building the team and honing the design, it is incredibly exciting to be approved to move forward toward implementing NASA’s newest exoplanet hunting mission,” Volosin said.
TESS is designed to complement several other critical missions in the search for life on other planets. Once TESS finds nearby exoplanets to study and determines their sizes, ground-based observatories and other NASA missions, like the James Webb Space Telescope, would make follow-up observations on the most promising candidates to determine their density and other key properties.
By figuring out a planet’s characteristics, like its atmospheric conditions, scientists could determine whether the targeted planet has a habitable environment.
“TESS should discover thousands of new exoplanets within two hundred light years of Earth,” Ricker said. “Most of these will be orbiting bright stars, making them ideal targets for characterization observations with NASA’s James Webb Space Telescope.”
“The Webb telescope and other teams will focus on understanding the atmospheres and surfaces of these distant worlds, and someday, hopefully identify the first signs of life outside of our solar system,” Volosin said.
TESS will use four cameras to study sections of the sky’s north and south hemispheres, looking for exoplanets. The cameras would cover about 90 percent of the sky by the end of the mission.
This makes TESS an ideal follow-up to the Kepler mission, which searches for exoplanets in a fixed area of the sky. Because the TESS mission surveys the entire sky, TESS is expected to find exoplanets much closer to Earth, making them easier for further study.
In addition, Ricker said TESS would provide precision, full-frame images for more than 20 million bright stars and galaxies.
“This unique new data will comprise a treasure trove for astronomers throughout the world for many decades to come,” Ricker said.
Now that TESS is cleared to move into the next development stage, it can continue towards its goal of being a key part of NASA’s search for life beyond Earth.
“I’m still hopeful that in my lifetime, we will discover the existence of life outside of our solar system and I’m excited to be part of a NASA mission that serves as a key stepping stone in that search,” Volosin said.
Science fiction aficionados, take heed. The highly-anticipated movie Interstellar is sharp and gripping. Nolan and cast show in the end that they have the right stuff. Nearly a three hour saga, it holds your attention and keeps you guessing. Only a couple of scenes seemed to drift and lose focus. Interstellar borrows style and substance from some of the finest in the genre and also adds new twists while paying attention to real science. If a science-fiction movie shies away from imagining the unknown, taking its best shot of what we do not know, then it fails a key aspect of making sci-fi. Interstellar delivers in this respect very well.
The movie begins quite unassuming in an oddly green but dusty farmland. It does not rely on showing off futuristic views of Earth and humanity to dazzle us. However, when you see a farming family with a dinner table full of nothing but variations of their cash crop which is known mostly as feedstock for swine and cattle, you know humanity is in some hard times. McConaughey! Save us now! I do not want to live in such a future!
One is left wondering about what got us to the conditions facing humanity from the onset of the movie. One can easily imagine a couple of hot topic issues that splits the American public in two. But Nolan doesn’t try to add a political or religious bent to Interstellar. NASA is in the movie but apparently after decades of further neglect, it is literally a shadow of even its present self.
Somehow, recent science fiction movies — Gravity being one exception — would make us believe that the majority of American astronauts are from the Midwest. Driving a John Deere when you are 12, being raised under big sky or in proximity to the home of the Wright Brothers would make you hell-bent to get out of Dodge and not just see the world but leave the planet. Matthew McConaughey adds to that persona.
We are seemingly in the golden age of astronomy. At present, a science fiction movie with special effects can hardly match the imagery that European and American astronomy is delivering day after day. There is one of our planets that gets a very modest delivery in Interstellar. An undergraduate graphic artist could take hold of NASA imagery and outshine those scenes quite easily. However, it appears that Nolan did not see it necessary to out-do every scene of past sci-fi or every astronomy picture of the day (APOD) to make a great movie.
Nolan drew upon American astro-physicist Dr. Kip Thorne, an expert on Einstein’s General Relativity, to deliver a world-class presentation of possibly the most extraordinary objects in our Universe – black holes. It is fair to place Thorne alongside the likes of Sagan, Feynman, Clarke and Bradbury to advise and deliver wonders of the cosmos in compelling cinematic form. In Instellar, using a black hole in place of a star to hold a planetary system is fascinating and also a bit unbelievable. Whether life could persist in such a system is a open question. There is one scene that will distress most everyone in and around NASA that involves the Apollo Moon landings and one has to wonder if Thorne was pulling a good one on old NASA friends.
Great science fiction combines a vision of the future with a human story. McConaughey and family are pretty unassuming. John Lithgow, who plays grandpa, the retired farmer, doesn’t add much and some craggy old character actor would have been just fine. Michael Cane as the lead professor works well and Cane’s mastery is used to thicken and twist the plot. His role is not unlike the one in Children of Men. He creates bends in the plot that the rest of the cast must conform to.
There was one piece of advice I read in previews of Interstellar. See it in Imax format. So I ventured over to the Imax screening at the Technology Museum in Silicon Valley. I think this advice was half correct. The Earthly scenes gained little or nothing from Imax but once they were in outer space, Imax was the right stuff. Portraying a black hole and other celestial wonders is not easy for anyone including the greatest physicists of our era and Thorne and Nolan were right to use Imax format.
According to industry insiders, Nolan is one of a small group of directors with the clout to demand film recording rather than digital. Director Nolan used film and effects to give Interstellar a very earthy organic feel. That worked and scenes transitioned pretty well to the sublime of outer space. Interstellar now shares the theaters with another interesting movie with science fiction leanings. The Stephen Hawking biography, “The Theory of Everything” is getting very good reviews. They hold different ties to science and I suspect sci-fi lovers will be attracted to seeing both. With Interstellar, out just one full day and I ran into moviegoers that had already seen it more than once.
Where does Interstellar stand compared to Stanley Kubricks works? It doesn’t make that grade of science fiction that stands up as a century-class movie. However, Thorne’s and Nolan’s accounting of black holes and worm holes and the use of gravity is excellent. Instellar makes a 21st Century use of gravity in contrast to Gravity that was stuck in the 20th Century warning us to be careful where you park your space vehicle. In the end, Matthew McConaughey serves humanity well. Anne Hathaway plays a role not unlike Jody Foster in Contact – an intellectual but sympathetic female scientist.
Jessica Chastain playing the grown up daughter of McConaughey brings real angst and an edge to the movie; even Mackenzie Foy playing her part as a child. Call it the view ports for each character – they are short and narrow and Chastain uses hers very well. Matt Damon shows up in a modest but key role and does not disappoint. Nolan’s directing and filmography is impressive, not splashy but one is gripped by scenes. Filming in the small confines of spaceships and spacesuits is challenging and Nolan pulls it off very well. Don’t miss Interstellar in the theaters. It matches and exceeds the quality of several recent science fiction movies. Stepping back onto the street after the movie, the world seemed surprisingly comforting and I was glad to be back from the uncertain future Nolan created.
“Thousands of meteors per hour would have been visible — truly astounding to the human eye.” That’s Nick Schneider’s description of what you and I would have seen standing on Mars during Comet Siding Spring’s close flyby last month. “It would have been really mind-blowing,” he added. Schneider is instrument lead for MAVEN’s Imaging Ultraviolet Spectrograph (IUVS).
He and a group of scientists who work as lead investigators for instruments on the MAVEN and Mars Reconnaissance Orbiter (MRO) spacecraft shared the latest results from the comet flyby during a media teleconference earlier today. There were many surprises. Would we expect anything less from a comet?
Here’s a summary of the results:
A very dusty ice ball – The comet’s dust tail and the amount of dust in its coma were much larger than expected, prompting Jim Green, director of NASA’s Planetary Science Division in Washington, to remark: “It makes me very happy we hid them (the spacecraft) on the backside of Mars. That really saved them.” Siding Spring dumped several tons of fine dust into the Martian atmosphere prompting a spectacular meteor shower and possibly causing a yellow, twilight afterglow above the Curiosity landing site from vaporizing sodium atoms contained in the minerals. That, and dust in the mid-levels of the atmosphere at the time contributed to the rover’s difficulty in getting good photos of the comet itself. Scientists are still examining the images.
Chemistry of Mars’ atmosphere changed – Dust vaporized in the intense meteor shower produced a striking increase in the amount of magnesium, iron and others metals in Mars’ upper atmosphere. “We were pressed back in our chairs,” said Mike Schneider. The bombardment created a temporary new layer of comet-tainted air and may have acted as condensation nuclei for the formation of high-altitude clouds. MAVEN’s Neutral Gas and Ion Mass Spectrometer (NGIMS) recorded huge spikes in the levels of eight different metals during the comet’s passage and then trailed off a day or so later. “They came to MAVEN as a free sample from no less than an Oort Cloud comet,” said Mehdi Benna, instrument scientist for MAVEN’s Neutral Gas and Ion Mass Spectrometer.
Flaming comet dust creates new ionospheric layer – Comet dust slamming into the atmosphere at 125,000 mph (56 km/sec) knocked electrons loose from atoms in the thin Martian air 50-60 miles (80-100 km) high, ionizing them and creating a very dense ionization layer in the planet’s lower ionosphere seven hours after the comet’s closest approach. Normally, Mars ionosphere is only seen on the dayside of the planet, but even when the MARSIS instrumenton Mars Express beamed radio waves through the atmosphere on the nightside of the planet, it picked up a very strong signal.
Nucleus spins once during your work day – Comet Siding Spring’s icy core spins once every 8 hours and its irregular shape causes strong variations in the comet’s brightness. The comet’s size appears less certain – at least for the moment – with estimates anywhere between a few hundred meters to 2 km (1.2 miles). More analysis on images taken by MRO’s HiRISE camera should narrow that number soon.
Dust motes of many sizes – Color variations across Siding Spring’s coma seen by Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) indicate it’s releasing dust particles of different sizes – big and little.
The scientists involved in the encounter couldn’t be happier with how the instruments functioned and the amount of hard data returned. Said Jim Green: “We are so lucky to observe this once-in-a-lifetime event.” How true when you consider that it takes about 8 million years for a comet from the Oort Cloud, that vast reservoir of frozen comets extending nearly a light year from the Sun, to get here in the first place. Nick Schneider put it another way:
“Not only is this a free sample of the Oort Cloud in Mars’ atmosphere, but it gives us a chance to learn more about Mars itself.”
If you’d like to listen in to the hour-long teleconference at any time, it’ll be up for the next week or so HERE.