Clouds swirl near Titan's north pole in this annotated still image from the Cassini mission. Credit: NASA/JPL-Caltech/Space Science Institute
Swoosh! At long last, and later than models predicted, clouds are starting to appear on Titan’s nothern hemisphere. The region is just starting to enter a seven-year-long summer, and scientists say this could be an indication of coming summer storms there.
This moon of Saturn is of particular interest to astrobiologists because it has hydrocarbons (like ethane and methane), which are organic molecules that are possible precursors to the chemistry that made life possible. But what is also neat about Titan is it has its own weather system and liquid cycle — which makes it closer to Earth than to our own, nearly atmosphere-less Moon.
“The lack of northern cloud activity up til now has surprised those studying Titan’s atmospheric circulation,” wrote Carolyn Porco, the imaging lead for Cassini, in a message distributed to journalists.
“Today’s reports of clouds, seen a few weeks ago, and other recent indicators of seasonal change, are exciting for what they imply about Titan’s meteorology and the cycling of organic compounds between northern and southern hemispheres on this unusual moon, the only one in our solar system covered in liquid organics.”
Clouds swirl near Titan’s north pole in this annotated still image from the Cassini mission. Credit: NASA/JPL-Caltech/Space Science Institute
The pictures were taken by the Cassini spacecraft, which has been orbiting Saturn and its moons since 2004. The satellite arrived at the system in time to see clouds forming in the southern hemisphere, but the moon has been nearly bereft of clouds since a large storm occurred in 2010.
This particular cloud system occurred over Ligeia Mare, which is near Titan’s north pole, and included gentle wind speeds of about seven to 10 miles per hour (11 to 16 kilometers per hour.)
The sequence takes place between July 20 and 22, with most of the pictures separated by about 1-2 hours (although there is a 17.5-hour jump between frames 2 and 3.)
Comet ISON was one of the two comets studied by scientists using the Atacama Large Millimeter/submillimeter Array (ALMA). The diagram shows where it was located in the solar system at the time of observations. 3-D images of its coma (atmosphere) revealed organic compounds. Credit: B. Saxton (NRAO/AUI/NSF); NASA/ESA Hubble; M. Cordiner, NASA, et al.
While Comet ISON’s breakup around Thanksgiving last year disappointed many amateur observers, its flight through the inner solar system beforehand showed scientists something neat: it was carrying organic materials with it.
A group examined the molecules surrounding the comet in its coma (atmosphere) and, along with observations of Comet Lemmon, created a 3-D model that you can see above. Among other results, this revealed the presence of formaldehyde and HNC (hydrogen, nitrogen and carbon). The formaldehyde was expected, but the spot where HNC was found came as a surprise.
Scientists used to think that HNC is produced from the nucleus, but the research revealed that it actually happens when larger molecules or organic dust breaks down in the coma.
“Understanding organic dust is important, because such materials are more resistant to destruction during atmospheric entry, and some could have been delivered intact to early Earth, thereby fueling the emergence of life,” stated Michael Mumma, a co-author on the study who is director of the Goddard Center for Astrobiology. “These observations open a new window on this poorly known component of cometary organics.”
Observation were made possible using the powerful Atacama Large Millimeter/submillimeter Array (ALMA). The array of 66 radio telescopes in Chile allows astronomers to map molecules and peer past dust clouds in star systems under formation, among other things. ALMA was completed last year and is the largest telescope of its type in the world.
The array’s resolution allowed scientists to probe for these molecules in moderately bright comets, which is also new. Previously, these types of studies were limited to “blockbuster” visitors such as Comet Hale-Bopp in the 1990s, NASA sated.
The study, which was led by the Goddard Center for Astrobiology’s Martin Cordiner at NASA’s Goddard Space Flight Center, was published in Astrophysical Journal Letters. The research is also available in preprint version on Arxiv.
Rosetta NAVCAM image taken on 10 August 2014 from a distance of about 110 km from comet 67P/Churyumov-Gerasimenko. The comet nucleus is about 4 km across. Credit: ESA/Rosetta/NAVCAM
With the historic arrival of the European Space Agency’s (ESA) Rosetta spacecraft at destination Comet 67P/Churyumov-Gerasimenko flawlessly accomplished on August 6, 2014 after a decade long journey, ground breaking up close science at this bizarre world has begun while the team diligently and simultaneously searches for a landing site for the attached Philae comet lander.
Rosetta started collecting cometary dust from the coma encircling the comet’s nucleus with the onboard COSIMA instrument on Sunday, August 10, 2014 as the spacecraft orbits around and ahead of the icy wanderer from a distance of approximately 100 kilometers (62 miles). See coma image below.
Hopes are high that unprecedented science discoveries await at this alien world described as a “Scientific Disneyland,” by Mark McCaughrean, senior scientific adviser to ESA’s Science Directorate, during ESA’s live arrival day webcast. “It’s just astonishing.”
COSIMA stands for Cometary Secondary Ion Mass Analyser and is one of Rosetta’s suite of 11 state-of-the-art science instruments with a combined mass of 165 kg.
Its purpose is to conduct the first “in situ” analysis of the grains of dust particles emitted from the comets nucleus and determine their physical and chemical characteristics, including whether they are organic or inorganic – in essence what is cometary dust material made of and how it differs from the surface composition.
COSIMA will collect the coma dust using 24 specially designed ‘target holders’ – the first of which was opened to study the comets environment on Aug. 10. Since the comet is not especially active right now, the team plans to keep the target holder open for at least a month and check the progress of any particle collections on a weekly basis.
COSISCOPE image of the first target taken on 19 July 2014 (before the exposure, on 10 August, for cometary dust collection). The 1×1 cm target consists of a gold plate covered with a thin layer (30 µm) of gold nanoparticles (“gold black”). Illumination is by two LEDs, from the right side in this case. The bright dots on the vertical strip on the right side are used for target identification and for defining the coordinate system. Credits: ESA/Rosetta/MPS for COSIMA Team MPS/CSNSM/UNIBW/TUORLA/IWF/IAS/ESA/BUW/MPE/LPC2E/LCM/FMI/UTU/LISA/UOFC/vH&S
In fact the team says the coma environment “is still comparable to a high-quality cleanroom”at this time.
But everyone expects that to change radically as Rosetta continues escorting Comet 67P as it loops around the sun, getting closer and warming the surface every day and until reaching perihelion in August 2015.
COSIMA is managed by the Max Planck Institute for Solar System Research (Max-Planck-Institut für Sonnensystemforschung ) in Katlenburg-Lindau, Germany, with Principal Investigator Martin Hilchenbach.
There are also substantial contributions from the Institut d’Astrophysique Spatiale in France, Finnish Meteorological Institute, Osterreichisches Forschungszentrum Seibersdorf and more.
The target holders measure about one square centimeter and were developed by the Universität der Bundeswehr in Germany.
Each of these targets measures one square centimeter and is comprised of a gold plate covered with a thin 30 µm layer of gold nanoparticles (“gold black”) which the team says should “decelerate and capture cometary dust particles impacting with velocities of ~100 m/s.”
The target will be illuminated by a pair of LED’s to find the dust particles. The particles will be analyzed by COSIMA’s built in mass spectrometer after being located on the target holder by the French supplied COSISCOPE microscopic camera and ionized by a beam of indium ions.
Photo of the COSIMA (Cometary Secondary Ion Mass Analyser) instrument on Rosetta. Credit: Max Planck Institute for Solar System Research/ESA
The team expects any grains found on the first target to be analyzed by mid-September 2014.
“COSIMA uses the method of Secondary Ion Mass Spectrometry. They will be fired at with a beam of Indium ions. This will spark individual ions (we say secondary ions) from their surfaces, which will then be analysed with COSIMA’s mass spectrometer,” according to a description from the COSIMA team.
The mass spec has the capability to analyze the elemental composition in an atomic mass range of 1 to 4000 atomic mass units, determine isotopic abundances of some key elements, characterize organic components and functional groups, and conduct mineralic and petrographic characterization of the inorganic phases, all of which will inform as as never before about solar system chemistry.
Comets are leftover remnants from the formation of the solar system. Scientists believe they delivered a vast quantity of water to Earth. They may have also seeded Earth with organic molecules – the building blocks of life as we know it.
Any finding of organic molecules and their identification by COSIMA will be a major discovery for Rosetta and ESA and inform us about the origin of life on Earth.
Data obtained so far from Rosetta’s VIRTIS instrument indicates the comets surface is too hot to be covered in ice and must instead have a dark, dusty crust.
Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.
ESA’s Rosetta Spacecraft nears final approach to Comet 67P/Churyumov-Gerasimenko in late July 2014. This collage of imagery from Rosetta combines Navcam camera images at right taken nearing final approach from July 25 (3000 km distant) to July 31, 2014 (1327 km distant), with OSIRIS wide angle camera image at left of comet’s expanding coma cloud on July 25. Images to scale and contrast enhanced to show further detail. Credit: ESA/Rosetta/NAVCAM/OSIRIS/MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA Collage/Processing: Marco Di Lorenzo/Ken Kremer
A picture of Comet 67P/Churyumov-Gerasimenko. Credit: ESA/Rosetta/NAVCAM
What’s one of the first things you do when arriving at a new destination? Likely it would be scoping out the local neighborhood. Getting a sense of its terrain and the good things to do around there.
That’s part of what Rosetta’s team is working on since arriving at its comet early in the morning of Aug. 6 (Eastern time). While only a few pictures have been beamed back to the public so far of Comet 67P/Churyumov-Gerasimenko, the glimpses of its surface are tantalizing. Which is important, because a little spacecraft is on its way there.
As the team busily calibrates its instruments and snaps pictures of the surface, one of their first tasks will be to pick a landing site for Philae, the machine that is scheduled to leave Rosetta and actually touch softly down on the surface in November. This is the first time such a soft-landing has been attempted, and it’s been a long decade of waiting for the scientists who sent the two spacecraft on their way.
Picking a spot will be difficult for the team, they explained last week. The gravity is light and the terrain is not only difficult to navigate, but also hard to choose from. Would you prefer a crater or a cliff? That will be what science investigators will examine in the coming months.
As they do that, check out the latest pictures of the comet in the gallery below.
A view of Comet 67P/Churyumov-Gerasimenko taken by the Rosetta spacecraft on Aug. 9, 2014. Credit: ESA/Rosetta/NAVCAMA dark hollow beckons in this picture of Comet 67P/Churyumov-Gerasimenko taken by the Rosetta spacecraft Aug. 5, 2014. Credit: ESA/Rosetta/NAVCAMThe Rosetta spacecraft captured the “rubbe duckie” shape of Comet 67P/Churyumov-Gerasimenko on Aug. 6, 2014. Credit: ESA/Rosetta/NAVCAMThe mottled surface of Comet 67P/Churyumov-Gerasimenko beckons in this picure taken by the Rosetta spacecraft on Aug. 7, 2014. Credit: ESA/Rosetta/NAVCAM
NASA's Curiosity rover looks across a rock field in this raw picture from Mars taken Aug. 8, 2014. Credit: NASA/JPL-Caltech
This picture alone illustrates the challenge NASA has as it slowly moves the Curiosity rover across Mars to its mountainous destination. You can see rocks surrounding the rover on Sol 713 (on Aug. 8), which is a challenge because of the ongoing wear and tear on Curiosity’s aluminum wheels.
In mid-July, Curiosity crossed one of the most difficult stretches of terrain yet since NASA spotted the damage and took measures to mitigate further problems, which includes picking out the smoothest terrain possible for its rover — which just celebrated two years on the Red Planet.
“For about half of July, the rover team at NASA’s Jet Propulsion Laboratory in Pasadena, California, drove Curiosity across an area of hazardous sharp rocks on Mars called ‘Zabriskie Plateau’,” NASA wrote in a recent press release.
A closeup of Curiosity’s wheels on Mars on Aug. 9, 2014. Credit: NASA/JPL-Caltech
“Damage to Curiosity‘s aluminum wheels from driving across similar terrain last year prompted a change in route, with the plan of skirting such rock-studded terrain wherever feasible. The one-eighth mile (200 meters) across Zabriskie Plateau was one of the longest stretches without a suitable detour on the redesigned route toward the long-term science destination.”
The rover is planning to make its way up the slope of science destinations on Mount Sharp, which is about two miles (3 kilometers) away. NASA pointed out that an interim stop for the rover will take place less than a third of a mile away (500 meters).
“The wheels took some damage getting across Zabriskie Plateau, but it’s less than I expected from the amount of hard, sharp rocks embedded there,” added Jim Erickson, project manager for Curiosity at NASA’s Jet Propulsion Laboratory, in a statement.
A low view of the terrain taken by the Mars Curiosity rover in August 2014. Credit: NASA/JPL-Caltech
“The rover drivers showed that they’re up to the task of getting around the really bad rocks. There will still be rough patches ahead. We didn’t imagine prior to landing that we would see this kind of challenge to the vehicle, but we’re handling it.”
Curiosity has driven out of its landing ellipse and will continue the trek to the mountain, stopping to perform science along the way.
NASA plans to heavily borrow from Curiosity’s design for its next rover, called Mars 2020. The science instruments for that rover were selected last week. While Curiosity was made to seek potentially habitable environments in the past or present, Mars 2020 will have the capability to search for organic materials that could indicate precursors to life.
The Mars Curiosity rover leaves tracks in the sand in this picture taken Aug. 9, 2014. Credit: NASA/JPL-CaltechA shadow of Mars Curiosity lies across the surface in this picture taken Aug. 9, 2014. Credit: NASA/JPL-Caltech
The "super moon" of August 2014 captured by Expedition 40's Oleg Artemyev on the International Space Station. Credit: OlegMKS / Twitter
With the full Moon approaching just a little bit closer than Earth to usual, a cosmonaut on the International Space Station took a few moments of his time to capture a few shots of it setting behind the Earth. Oleg Artemyev was just a shade closer to that Moon than the rest of us, and the sequence of pictures (below the jump) is stunning.
As Universe Today’s David Dickinson explained last week, the so-called “supermoon” refers to a phenomenon where the full Moon falls within 24 hours of perigee (closest approach to the Earth.) We’re in a cycle of supermoons right now, with this weekend’s the second in a three-part cycle this year.
The Moon appears about 14% bigger between its furthest and closest approaches to Earth. While the difference is subtle in the sky, it does produce higher tides on Earth (with an example being Hurricane Sandy in 2012.)
Technically the perigee happened August 10 at 6:10 p.m. UTC (2:10 p.m. EDT), but people (including Artemyev) took several pictures of the moon a bit before and after that time. One example from our Universe Today Flickr pool is at the bottom of this post. You can see more examples on Flickr.
1 Martian Year on Mars! Curiosity treks to Mount Sharp in this photo mosaic view captured on Sol 669, June 24, 2014. Navcam camera raw images stitched and colorized. Credit: NASA/JPL-Caltech/Marco Di Lorenzo/Ken Kremer – kenkremer.com
2 Years on Mars!
Curiosity treks to Mount Sharp, her primary science destination, in this photo mosaic view captured on Sol 669, June 24, 2014. Navcam camera raw images stitched and colorized. Credit: NASA/JPL-Caltech/Marco Di Lorenzo/Ken Kremer – kenkremer.com
Story and mosaics updated[/caption]
NASA’s most scientifically powerful rover ever dispatched to the Red Planet, Curiosity, is celebrating her 2nd anniversary on Mars since the dramatic touchdown inside Gale Crater on Aug. 6, 2012, EDT (Aug. 5, 2012, PDT) while simultaneously approaching a bedrock unit that for the first time is actually part of the humongous mountain she will soon scale and is the primary science destination of the mission.
Mount Sharp is a layered mountain that dominates most of Gale Crater and towers 3.4 miles (5.5 kilometers) into the Martian sky and is taller than Mount Rainier.
Aug. 6, 2014 marks ‘2 Years on Mars’ and Sol 711 for Curiosity in an area called “Hidden Valley.”
“Getting to Mount Sharp is the next big step for Curiosity and we expect that in the Fall of this year,” Dr. Jim Green, NASA’s Director of Planetary Sciences at NASA Headquarters, Washington, DC, told me in an interview making the 2nd anniversary.
The 1 ton rover is equipped with 10 state-of-the-art science instruments and searching for signs of life.
The mysterious mountain is so huge that outcrops of bedrock extend several miles out from its base and Curiosity is now within striking distance of reaching the area the rover team calls “Pahrump Hills.”
2 Earth Years on Mars!
NASA’s Curiosity rover celebrated the 2nd anniversary on Mars at ‘Hidden Valley’ as shown in this photo mosaic view captured on Aug. 6, 2014, Sol 711. Note the valley walls, rover tracks and distant crater rim. Navcam camera raw images stitched and colorized. Credit: NASA/JPL-Caltech/Ken Kremer-kenkremer.com/Marco Di Lorenzo
Scientists anticipate that the outcrops at “Pahrump Hills” offer a preview of a geological unit that is part of the base of Mount Sharp for the first time since landing rather than still belonging to the floor of Gale Crater.
“We’re coming to our first taste of a geological unit that’s part of the base of the mountain rather than the floor of the crater,” said Curiosity Project Scientist John Grotzinger of the California Institute of Technology, Pasadena, in a statement.
“We will cross a major terrain boundary.”
Since “Pahrump Hills” is less than one-third of a mile (500 meters) from Curiosity she should arrive soon.
In late July 2014, the rover arrived in an area of sandy terrain called “Hidden Valley” which is on the planned route ahead leading to “Pahrump Hills” and easily traversable with few of the sharp edged rocks that have caused significant damage to the rovers six aluminum wheels.
This full-circle panorama of the landscape surrounding NASA’s Curiosity Mars rover on July 31, 2014, Sol 705, offers a view into sandy lower terrain called “Hidden Valley,” which is on the planned route ahead. It combines several images from Curiosity’s Navigation Camera. South is at the center. Credit: NASA/JPL-Caltech
The sedimentary layers in the lower slopes of Mount Sharp have been Curiosity’s long-term science destination.
They are the principal reason why the science team specifically chose Gale Crater as the primary landing site based on high resolution spectral observations collected by NASA’s powerful Mars Reconnaissance Orbiter (MRO) indicating the presence of deposits of clay-bearing sedimentary rocks.
Curiosity’s goal all along has been to determine whether Mars ever offered environmental conditions favorable for microbial life. Finding clay bearing minerals. or phyllosilicates, in Martian rocks is the key to fulfilling its major objective.
The team expected to find the clay bearing minerals only in the sedimentary layers at the lower reaches of Mount Sharp.
Curiosity rover panorama of Mount Sharp captured on June 6, 2014 (Sol 651) during traverse inside Gale Crater. Note rover wheel tracks at left. She will eventually ascend the mountain at the ‘Murray Buttes’ at right later this year. Assembled from Mastcam color camera raw images and stitched by Marco Di Lorenzo and Ken Kremer. Credit: NASA/JPL/MSSS/Marco Di Lorenzo/Ken Kremer-kenkremer.com
Soon after landing, the team spotted some rather interesting looking outcrops barely a half mile away from the touchdown zone at a spot dubbed ‘Yellowknife Bay” and decided to take a detour towards it to investigate.
Well the scientists won the bet and struck scientific gold barely six months after landing when they drilled into a rock outcrop named “John Klein” at “Yellowknife Bay” and unexpectedly discovered the clay bearing minerals on the crater floor.
Yellowknife Bay was found to be an ancient lakebed where liquid water flowed on Mars surface billions of years ago.
The discovery of phyllosilicates in the 1st drill sample during the spring of 2013 meant that Curiosity had rather remarkably already fulfilled its primary goal of finding a habitable zone during its first year of operations!
The rock analysis “yielded evidence of a lakebed environment billions of years ago that offered fresh water, all of the key elemental ingredients for life, and a chemical source of energy for microbes, if any existed there,” according to NASA.
Curiosity accomplished Historic 1st drilling into Martian rock at John Klein outcrop on Feb 8, 2013 (Sol 182) and discovered a habitable zone, shown in this context mosaic view of the Yellowknife Bay basin taken on Jan. 26 (Sol 169). The robotic arm is pressing down on the surface at John Klein outcrop of veined hydrated minerals – dramatically back dropped with her ultimate destination; Mount Sharp. Credit: NASA/JPL-Caltech/Ken Kremer-kenkremer.com/Marco Di Lorenzo
“Before landing, we expected that we would need to drive much farther before answering that habitability question,” said Curiosity Project Scientist John Grotzinger of the California Institute of Technology, Pasadena. “We were able to take advantage of landing very close to an ancient streambed and lake. Now we want to learn more about how environmental conditions on Mars evolved, and we know where to go to do that.”
During the rovers second Earth year on the Red Planet, Curiosity has been driving as fast as possible towards a safe entry point to the slopes of Mount Sharp. The desired destination for the car sized rover is now about 2 miles (3 kilometers) southwest of its current location.
‘Driving, Driving, Driving’ is indeed the rover teams mantra.
The main map here shows the assortment of landforms near the location of NASA’s Curiosity Mars rover as the rover’s second anniversary of landing on Mars nears. The gold traverse line entering from upper right ends at Curiosity’s position as of Sol 705 on Mars (July 31, 2014). The inset map shows the mission’s entire traverse from the landing on Aug. 5, 2012, PDT (Aug. 6, EDT) to Sol 705, and the remaining distance to long-term science destinations near Murray Buttes, at the base of Mount Sharp. The label “Aug. 5, 2013” indicates where Curiosity was one year after landing. Credit: NASA/JPL-Caltech/Univ. of Arizona
To date, Curiosity’s odometer totals over 5.5 miles (9.0 kilometers) since landing inside Gale Crater on Mars in August 2012. She has taken over 174,000 images.
Curiosity still has about another 2 miles (3 kilometers) to go to reach the entry way at a gap in the treacherous sand dunes at the foothills of Mount Sharp sometime later this year.
And NASA is moving forward with future Red Planet missions when it recently announced the selection of 7 instruments chosen to fly aboard the Mars 2020 rover, the agency’s next rover going to Mars that will search for signs of ancient life as well as carry a technology demonstration that will help pave the way for ‘Humans to Mars’ in the 2030s. Read my story – here.
Coincidentally, ESA’s Rosetta comet hunting spacecraft arrived in orbit at its destination Comet 67P after a 10 year voyage on the same day as Curiosity’s 2 Earth year anniversary.
Stay tuned here for Ken’s continuing Rosetta, Curiosity, Opportunity, Orion, SpaceX, Boeing, Orbital Sciences, commercial space, MAVEN, MOM, Mars and more planetary and human spaceflight news.
Up close view of hole in one of rover Curiosity’s six wheels caused by recent driving over rough Martian rocks. Mosaic assembled from Mastcam raw images taken on Dec. 22, 2013 (Sol 490). Credit: NASA/JPL/MSSS/Ken Kremer – kenkremer.com/Marco Di Lorenzo
Artist's conception of the internal environment of the moon. Credit: NAOJ
Rather than being dead inside, the Moon still has a warm interior that is due to the effect of the Earth’s gravity on our closest major celestial neighbor, a new study says. The results came after looking at results from the SELENE (SELenological and ENgineering Explorer) spacecraft as well as other missions exploring the Moon.
“I believe that our research results have brought about new questions. For example, how can the bottom of the lunar mantle maintain its softer state for a long time? To answer this question, we would like to further investigate the internal structure and heat-generating mechanism inside the Moon in detail,” stated Yuji Harada, the principal investigator of the research team.
“Another question has come up: How has the conversion from the tidal energy to the heat energy in the soft layer affected the motion of the Moon relative to the Earth, and also the cooling of the Moon?” he added. “We would like to resolve those problems as well so that we can thoroughly understand how the Moon was born and has evolved.”
A diagram of the moon’s interior showing its viscosity (the thickness of its interior liquid) as well as parameters of its internal density. Credit: NAOJ
Clues to the Moon’s interior come from examining how the Earth’s gravity deforms its inside through tidal forces. Models show that tidal changes within the moon are likely due to a “soft layer” deep within the lunar mantle. Scientists learned that the Moon has a core (inner portion, made up of metal) and a mantle (made up of rock) through the Apollo missions, which saw astronauts deploy seismic devices that revealed the interior structure.
“The previous studies indicated that there is the possibility that a part of the rock at the deepest part inside the lunar mantle may be molten. This research result supports the above possibility since partially molten rock becomes softer,” the National Astronomical Observatory of Japan stated. “This research has proven for the first time that the deepest part of the lunar mantle is soft, based upon the agreement between observation results and the theoretical calculations.”
Researchers believe the heat occurs in a soft layer that is deep within the mantle, and not throughout the entire Moon. They said that possible future research directions could include why it is only this layer that remains soft, and how tidal energy changes the Moon’s cooling and its relative motion to Earth.
NAVCAM image taken by Rosetta on 5 August 2014 from a distance of about 145 km from comet 67P/Churyumov-Gerasimenko. Image has been rotated 180 degrees. Credit: ESA/Rosetta/NAVCAM
Where would you land here?
Newly released NAVCAM image taken by Rosetta on 5 August 2014 from a distance of about 145 km from comet 67P/Churyumov-Gerasimenko. Image has been rotated 180 degrees. Credit: ESA/Rosetta/NAVCAM[/caption]
Following the flawless and history making arrival of the European Space Agency’s (ESA) Rosetta spacecraft at its long sought destination of Comet 67P/Churyumov-Gerasimenko on Wednesday, Aug. 6, the goal of conducting ground breaking science at this utterly alien and bizarre icy wanderer that looks like a ‘Scientific Disneyland’ can actually begin.
Rosetta is the first spacecraft in history to rendezvous with a comet and enter orbit – after a more than 10 year chase of 6.4 billion kilometers (4 Billion miles) along a highly complex trajectory from Earth. The arrival event was broadcast live from mission control at ESA’s spacecraft operations centre (ESOC) in Darmstadt, Germany. Read my complete arrival story – here.
So what’s ahead for Rosetta? Another audacious and history making event – Landing on the comet!
A top priority task is also another highly complex task – ‘Finding a landing strip’ on the bizarre world of Comet 67P for the piggybacked Philae comet lander equipped with 10 science instruments.
“The challenge ahead is to map the surface and find a landing strip,” said Andrea Accomazzo, ESA Rosetta Spacecraft Operations Manager, at the Aug. 6 ESA webcast.
That will be no easy task based on the spectacular imagery captured by the OSIRIS high resolution science camera and the Navcam camera that has revealed an utterly wacky and incredibly differentiated world like none other we have ever visited or expected when the mission was conceived.
Magnificently detailed new navcam images were released by ESA today, Aug, 7, streaming back to Earth across some 405 million kilometers (250 million miles) of interplanetary space – see above and below.
The team will have its hand full trying to find a safe spot for touchdown.
“We now see lots of structure and details. Lots of topography is visible on the surface,” said Holger Sierks, principal investigator for Rosetta’s OSIRIS camera from the Max Planck Institute for Solar System Research in Gottingen, Germany, during the webcast.
“There is a big depression and 150 meter high cliffs, rubble piles, and also we see smooth areas and plains. It’s really fantastic”
“We see a village of house size boulders. Some about 10 meters in size and bigger and they vary in brightness. And some with sharp edges. We don’t know their composition yet,” explained Sierks.
Newly released NAVCAM image taken on 6 August 2014 from a distance of about 96 km from comet 67P/Churyumov-Gerasimenko. Credit: ESA/Rosetta/NAVCAM
The key to finding a safe landing site for Philae will be quickly conducting a global comet mapping campaign with OSIRIS, Navcam and the remaining suite of 11 science instruments to provide a detailed scientific study of the physical characteristics and chemical composition of the surface.
They also need to determine which areas are hard or soft.
Holger Sierks, OSIRIS principal investigator, discusses spectacular hi res comet images returned so far by Rosetta during the Aug. 6 ESA webcast from mission control at ESOC, Darmstadt, Germany. Credit: Roland Keller
“Our first clear views of the comet have given us plenty to think about,” says Matt Taylor, ESA’s Rosetta project scientist.
“Is this double-lobed structure built from two separate comets that came together in the Solar System’s history, or is it one comet that has eroded dramatically and asymmetrically over time? Rosetta, by design, is in the best place to study one of these unique objects.”
The image of Comet 67P/Churyumov-Gerasimenko was taken by Rosetta’s OSIRIS narrow-angle camera on 3 August 2014 from a distance of 285 km. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
Yesterday’s (Aug. 6) critical final thruster firing placed the 1.3 Billion euro robotic emissary from Earth into a triangular shaped orbit about 100 kilometers (62 miles) above and in front of the comet’s incredibly varied surface.
Therefore the initial mapping will be conducted from the 100 km (62 mi.) standoff distance.
Since the landing is currently targeted for November 11, 2014, in barely three months time there is not a moment to waste.
“Over the next few months, in addition to characterizing the comet nucleus and setting the bar for the rest of the mission, we will begin final preparations for another space history first: landing on a comet,” says Taylor.
The team will identify up to five possible landing sites by late August and expect to choose the primary site by mid-September.
Then the team has to plan and build the programming and maneuvers for the final timeline to implement the sequence of events leading to the nailbiting landing.
With Rosetta now travelling in a series of 100 kilometer-long (62 mile-long) triangular arcs in front of the comet lasting about 3 days each, it will also be firing thrusters at each apex.
After catching up with the comet Rosetta will slightly overtake and enter orbit from the ‘front’ of the comet as both the spacecraft and 67P/CG move along their orbits around the Sun. Rosetta will carry out a complex series of manoeuvres to reduce the separation between the spacecraft and comet from around 100 km to 25-30 km. From this close orbit, detailed mapping will allow scientists to determine the landing site for the mission’s Philae lander. Immediately prior to the deployment of Philae in November, Rosetta will come to within just 2.5 km of the comet’s nucleus. This animation is not to scale; Rosetta’s solar arrays span 32 m, and the comet is approximately 4 km wide. Credit: ESA–C. Carreau
But it will also gradually edge closer over the next six weeks to about 50 km distance and then even closer to lower Rosetta’s altitude about Comet 67P until the spacecraft is captured by the comet’s gravity.
In November 2014, Rosetta will attempt another historic first when it deploys the Philae science lander from an altitude of just about 2.5 kilometers above the comet for the first ever attempt to land on a comet’s nucleus.
The three-legged lander will fire harpoons and use ice screws to anchor itself to the 4 kilometer (2.5 mile) wide comet’s surface. Philae will collect stereo and panoramic images and also drill into and sample its incredibly varied surface.
How will Philae land?
Stefan Ulamec, Philae Lander Manager from the German Aerospace Center (DLR) talked about the challenges of landing in a low gravity environment during the ESA webcast.
“The touchdown will be at a speed of just 1 m/s,” Ulamec explained. “This is like walking and bouncing against a wall.”
Details in an upcoming story!
Why study comets?
Comets are leftover remnants from the formation of the solar system. Scientists believe they delivered a vast quantity of water to Earth. They may have also seeded Earth with organic molecules.
ESA’s Rosetta spacecraft on final approach to Comet 67P/Churyumov-Gerasimenko in early August 2014. This collage of navcam imagery from Rosetta was taken on Aug. 1, 2, 3 and 4 from distances of 1026 km, 500 km, 300 km and 234 km. Not to scale. Credit: ESA/Rosetta/NAVCAM – Collage/Processing: Marco Di Lorenzo/Ken Kremer- kenkremer.com
Stay tuned here for Ken’s continuing Rosetta, Curiosity, Opportunity, Orion, SpaceX, Boeing, Orbital Sciences, commercial space, MAVEN, MOM, Mars and more Earth and Planetary science and human spaceflight news.
ESA’s Rosetta Spacecraft nears final approach to Comet 67P/Churyumov-Gerasimenko in late July 2014. This collage of imagery from Rosetta combines Navcam camera images at right taken nearing final approach from July 25 (3000 km distant) to July 31, 2014 (1327 km distant), with OSIRIS wide angle camera image at left of comet’s expanding coma cloud on July 25. Images to scale and contrast enhanced to show further detail. Credit: ESA/Rosetta/NAVCAM/OSIRIS/MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA Collage/Processing: Marco Di Lorenzo/Ken Kremer
Artist's conception of "spacecraft/rover hybrids for the exploration of small solar system bodies", a concept funded under Phase II of NASA' Innovative Advanced Concepts program in 2014. Credit: NASA
How do crazy but neat ideas such as the Mars crane make it to space? It’s through years, sometimes decades, of development to try to solve a problem in space exploration. NASA has an entire program devoted to far-out concepts that are at least a decade from making it into space, and has just selected five projects for a second round of funding.
One of them is a robotic swarm of spacecraft that we’ve written about before on Universe Today. Flying out from a mothership, these tiny spacecraft would be able to tumble across the surface of a low-gravity moon or asteroid.
“The systematic exploration of small bodies would help unravel the origin of the solar system and its early evolution, as well as assess their astrobiological relevance,” stated its principal investigator, Stanford University’s Marco Pavone, in a 2012 story. “In addition, we can evaluate the resource potential of small bodies in view of future human missions beyond Earth.”
The concept, called “Spacecraft/Rover Hybrids for the Exploration of Small Solar System Bodies“, is among the selectees in the second phase of the NASA Innovative Advanced Concepts program. Each will receive up to $500,000 to further develop their concept during the next two years. While Phase I studies are considered to show if a project is feasible, Phase II begins to narrow down the design.
Artist’s conception of a 10-meter sub-orbital large balloon reflector funded under NASA’s Innovative Advanced Concepts program. Credit: NASA
“This was an extremely competitive year for NIAC Phase II candidates,” stated Jay Falker, the program’s executive at NASA Headquarters. “But the independent peer review process helped identify those that could be the most transformative, with outstanding potential for future science and exploration.”
This is the rest of the selected concepts:
10 meter Sub-Orbital Large Balloon Reflector (Christopher Walker, University of Arizona): A telescope that uses part of a balloon as a reflector. The telescope would fly high in the atmosphere, perhaps doing examinations of Earth’s atmosphere or performing telecommunications or surveillance.
Low-Mass Planar Photonic Imaging Sensor(Ben S.J. Yoo, University of California, Davis): A new way of thinking about telescopes that would use a low-mass planar photonic imaging sensor. This could be useful for missions to the outer solar system.
Orbiting Rainbows (Marco Quadrelli, NASA Jet Propulsion Laboratory): Using “an orbiting cloud of dust-like matter” for astronomical imaging by taking advantage of the spots where light passes through.
