ISS astronauts Barry “Butch” Wilmore, NASA, Samantha Cristoforetti, ESA and Terry Virts, NASA send Christmas 2014 greetings from the space station to the people of Earth. Credit: NASA/ESA
ISS astronauts Barry “Butch” Wilmore, NASA, Samantha Cristoforetti, ESA and Terry Virts, NASA send Christmas 2014 greetings from the space station to the people of Earth. Credit: NASA/ESA
Story/pics expanded. Send holiday tweet to crew below![/caption]
There is a long tradition of Christmas greetings from spacefarers soaring around the High Frontier and this year is no exception!
The Expedition 42 crew currently serving aboard the International Space Station has decorated the station for the Christmas 2014 holiday season and send their greetings to all the people of Earth from about 240 miles (400 km) above!
“Merry Christmas from the International Space Station!” said astronauts Barry Wilmore and Terry Virts of NASA and Samantha Cristoforetti of ESA, who posed for the group shot above.
Italian astronaut Samantha Cristoforetti is in the holiday spirit as the station is decorated with stockings for each crew member and a tree. Credit: NASA/ESA
“It’s beginning to look like Christmas on the International Space Station,” said NASA in holiday blog update.
“The stockings are out, the tree is up and the station residents continue advanced space research to benefit life on Earth and in space.”
And the six person crew including a trio of Russian cosmonauts, Aleksandr Samokutyayev, Yelena Serova, and Anton Shkaplerov who celebrate Russian Orthodox Christmas, are certainly hoping for and encouraging a visit from Santa. Terry Virts even tweeted a picture of the special space style milk and cookies awaiting Santa and his Reindeer for the imminent arrival!
“No chimney up here- so I left powdered milk and freeze dried cookies in the airlock. Fingers crossed,” tweeted Virts.
No chimney up here- so I left powdered milk and freeze dried cookies in the airlock. Fingers crossed. Credit: NASA/Terry Virts
And here’s a special Christmas video greeting from Wilmore and Virts:
Video Caption: Aboard the International Space Station, Expedition 42 Commander Barry Wilmore and Flight Engineer Terry Virts of NASA offered their thoughts and best wishes to the world for the Christmas holiday during downlink messages from the orbital complex on Dec. 17. Wilmore has been aboard the research lab since late September and will remain in orbit until mid-March 2015. Virts arrived at the station in late November and will stay until mid-May 2015. Credit: NASA
“We wish you all a Merry Christmas and Happy New Year. Christmas for us is a time of worship. It’s a time that we think back to the birth of what we consider our Lord. And we do that in our homes and we plan to do the same thing up here and take just a little bit of time just to reflect on those topics and, also, just as the Wise Men gave gifts, we have a couple of gifts,” Wilmore says in the video.
“It’s such an honor and so much fun to be able to celebrate Christmas up here. This is definitely a Christmas that we’ll remember, getting a chance to see the beautiful Earth,” added Virts. “Have fun with your family. Merry Christmas!”
And you can send a holiday tweet to the crew – here:
Meanwhile the crew is still hard at work doing science and preparing for the next space station resupply mission launch by SpaceX from Cape Canaveral, Florida.
A SpaceX Falcon 9 rocket is now set to blastoff on Jan. 6, 2015 carrying the Dragon cargo freighter on the CRS-5 mission bound for the ISS.
The launch was postponed from Dec. 19 when a static fire test of the first stage engines on Dec. 17 shut down prematurely.
SpaceX Falcon 9 rocket is set to soar to ISS after completing successful static fire test on Dec. 19 ahead of planned CRS-5 mission for NASA in early January 2015. Credit: Ken Kremer – kenkremer.com
A second static fire test of the SpaceX Falcon 9 went the full duration and cleared the path for the Jan. 6 liftoff attempt.
Among the science studies ongoing according to NASA are:
“Behavioral testing for the Neuromapping study to assess changes in a crew member’s perception, motor control, memory and attention during a six-month space mission. Results will help physicians understand brain structure and function changes in space, how a crew member adapts to returning to Earth and develop effective countermeasures.”
“Another study is observing why human skin ages at a quicker rate in space than on Earth. The Skin B experiment will provide scientists a model to study the aging of other human organs and help future crew members prepare for long-term missions beyond low-Earth orbit.”
Merry Christmas to All!
Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.
An artist concept of the view from an airship orbiting Venus. Credit: NASA Langley HAVOC team.
Venus presents a special challenge to space explorers. Yes, there is a surface, but hellish temperatures and atmospheric pressure on the surface of Venus has a tendency to crush spacecraft fairly quickly. Short of building a submarine-rated surface explorer, maybe there’s a better way to look at the hothouse planet? A newly proposed NASA concept suggests using airships. Yes, airships with people in them.
But as you will see below, balloons and airships have been discussed extensively in the past decade by NASA and the Europeans as the best way of exploring Venus without needing to touch its hellish surface.
Venus may seem nothing but a distraction to an agency that is talking about exploring Mars in the 2030s (with Orion’s recent uncrewed test being the first advertised step of that, although critics say it won’t get us to the Red Planet). Leaving that aside, however, exploring Venus by balloon is not a new idea at all, even within NASA. The backers of the High Altitude Venus Operational Concept (HAVOC) even argue we should head to Venus before Mars, as one of the co-leads recently told Universe Today.
“A human mission to Venus is not on a lot of people’s radar, but we’ve really enjoyed working on the concepts for this mission,” said Langley’s Chris Jones, project co-lead, in an interview with Universe Today’s Nancy Atkinson. “This was an internal study: what does the future of humankind in space look like? Frankly, we see Venus as potentially no later than the second planetary destination that humans might go to, after Mars or even before Mars.”
Artist’s conception of the High Altitude Venus Operational Concept (HAVOC) mission, a far-out concept being developed by NASA, approaching the planet. Credit: NASA Langley Research Center/YouTube (screenshot)
Why? Jones explained that because it takes a shorter time to get to Venus, that makes it a “stepping stone or practice run” to get humans to Mars. “The best would be a long lived surface lander, but technology issues for surface robotic missions are pretty significant, and a human mission to surface is nearly insurmountable. What’s left is a good platform for a science mission at mid-level altitudes, and it paints a good picture for a human mission in the atmosphere at 50 kilometers.”
The proposed flight profile of the HAVOC airship at Venus. Credit: Space Mission Analysis Branch, NASA Langley Research Center.
The clouds of Venus, Jones said, present an ideal spot for humans to roam from a spacecraft. The conditions at 50 kilometers (31 miles) above the surface are about the same pressure and atmosphere as Earth.
“Air itself is a lifting gas at those altitudes,” he added, “so you don’t have to bring some ridiculous supply of helium for this to work. And the rest of the environmental parameters at 50 kilometers are actually quite nice: the gravity is about the same as on Earth’s surface, the atmospheric pressure is about the same as Earth, and we can potentially manufacture a significant amount of that air by processing carbon dioxide. These are some of the facts we saw early on that inspired us to do this.”
There also would be more solar power and protection from radiation than Mars, and the temperature — although fairly hot — would be possible to account for fairly easily in spacecraft designs.
Jones provided some details on how the crew would spend about 30 days exploring the planet after a journey there and back (440 days total). Bear in mind that the mission is just in the early stages of even thinking about development. Cost, timeline, approvals and many other hurdles would need to be overcome before it could even become a reality.
Details of the proposed HAVOC airship mission to Venus. Credit: Space Mission Analysis Branch, NASA Langley Research Center.
“The big parameters of Venus’ atmosphere is the big longitudinal winds,” Jones said. “If you just rode them, it would take you about 110 hours to circle the planet. The other component of winds would push you towards the poles. In order to stay near the equator where there is less turbulence, the airship would ride the longitudinal winds while using a propulsion system to counter those winds pushing you towards the poles.”
The concept arose from science objectives for the planet out of NASA’s Venus Exploration Analysis Group, Jones said, whose aims include understanding the atmosphere and its interaction with the surface. NASA’s Langley Research Center also has human objectives they considered, such as showing how people can work in deep space and develop advanced technologies to accomplish that.
The proposed Venus exploration plan for HAVOC. Credit: Space Mission Analysis Branch, NASA Langley Research Center.
The HAVOC mission would start with a series of phased exploration sorties. The first phase would be examining the Venusian atmosphere with a robotic mission, and the second would be crewed ride to orbit that would include deploying an uncrewed robotic airship in the atmosphere.
The third phase is the 30-day mission described above, while the fourth phase could potentially be as long as a year. If it gets to a Phase 5, that would be a “permanent presence in Venus’ atmosphere”, Jones said.
A size comparison of ships for the proposed HAVOC mission to Venus. Credit: Space Mission Analysis Branch, NASA Langley Research Center.
Of note: balloons have been discussed before within NASA, particularly by Venus exploration advocate Geoffrey Landis of NASA Glenn, and Jones told Universe Today that this new team found much inspiration from Landis’ previous work.
Universe Today interviewed Landis in 2008 about missions he proposed about human-colony airships and uncrewed solar-powered airplanes. And in this 2010 study, he suggested three ideas for exploring the surface using uncrewed low-altitude balloons. One would skim the clouds around 25 kilometers (15.6 miles) and two other concepts (more rigid, naturally), would fly about 5 kilometers (3 miles) high. This was presented at an American Institute of Aeronautics and Astronautics meeting that year.
The remaining core of the High Altitude Venus Operational Concept (HAVOC), a far-out mission being developed by NASA, in this artist’s concept. Credit: NASA Langley Research Center/YouTube (screenshot)
“A notable advantage of the carbon dioxide atmosphere of Venus is that this allows a much wider range of lifting gasses for a balloon; not merely the hydrogen or helium usually used for terrestrial balloons,” Landis wrote in the paper. “Oxygen and nitrogen, in fact, are lifting gasses in the Venus atmosphere (although not good ones). At the altitudes considered, two other lifting gasses are water (which is a gas at the temperatures considered) and ammonia.”
Landis was also not deterred by harsh surface conditions. While Venus’ surface is difficult — its 480 Celsius (900 Fahrenheit) thick atmosphere destroyed the Soviet Venera probes in minutes — he’s secured early-stage NASA funding for a robotic landsailing rover concept nicknamed “Zephyr”. “Sailing on Venus! How cool is that? The project will have an exceptional public engagement factor,” the description page for the Venus Landsailing Rover reads.
In a nutshell, Glenn has created electronics that can continue to function in temperatures similar to what are found on the surface. Simulations also show that solar cells would work, albeit at reduced efficiency. Hence the idea to use a heavily-reinforced landsail to take advantage of Venus’ 100-times-more-pressure-than-Earth atmosphere at the surface. Wind speeds are less than a meter of second, but have terrific force behind them. And at least some of Venus appears to be flat, with rocks only a centimeter thick in pictures from Venera.
Artist’s concept for a landsail rover on Mars, based on an idea by NASA’s Geoffrey Landis. Credit: NASA
Balloons have also been considered by the European Space Agency, particularly in the form of an uncrewed Venus Entry Probe discussed in detail in this presentation by Surrey Satellite Technology Ltd. It would include a Low Venus Orbiter that would map the planet to complement closer-to-ground measurements, a Venus Relay Satellite that would send information from the balloon, and the “aerobot” itself.
“The aerobot consists of a long-duration balloon and gondola … that will analyze the Venusian middle cloud layer at an altitude of ~55 km, where the environment is relatively benign. The balloon will deploy a swarm of active ‘ballast’ micro-sondes, which, once deployed, will determine vertical profiles of the lower atmosphere,” the presentation reads. More detailed information is available from this 2004 ESA workshop presentation by Surrey and this ESA webpage, which says the study was completed in 2005.
Students have even explored Venusian balloon ideas, such as in the 2014 Summer School Alpbach cosponsored by the European Space Agency. An uncrewed idea called EvolVe suggests a joint orbiter and balloon mission to see how tectonic activity and volcanoes affected the surface of Venus, among other scientific goals. The balloon would hover in the same general region, about 50 to 60 km (31 miles to 37 miles), and probe the surface using radar and other tools. It’s one of two concepts selected for further investigation that could lead to a science conference presentation and/or science journal publication.
A mosaic of images of Comet 67P/Churyumov–Gerasimenko taken from the Rosetta spacecraft Dec. 14. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
Remember how breathless we felt when the Philae lander actually made it to the surface of its target comet a few weeks ago? Sure, the maneuvers didn’t go as planned, but the images the spacecraft obtained in its brief spurts of activity on the surface are still being shared and discussed eagerly by scientists (amid a controversial image release policy, to be sure.)
Well, the truck delivery for Philae — the Rosetta spacecraft, still doing maneuvers above — is going to do something special in February. The machine is going to scoot down real close to the comet, just before heating from the Sun could make it dangerous to do so due to gas and dust emissions.
The plan is to bring Rosetta to an astounding four miles (six kilometers) above Comet 67P/Churyumov–Gerasimenko, so close that the images sent back to Earth will have a resolution of just a few inches per pixel. Scientists hope to learn more about how reflective the comet is and also to better understand how gas is emitted as 67P draws close to the Sun.
A mosaic of images of Comet 67P/Churyumov–Gerasimenko taken from the Rosetta spacecraft Dec. 14. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
“As the comet becomes more and more active, it will not be possible to get so close to the comet. So this opportunity is very unique,” stated Matt Taylor, the Rosetta project scientist from the European Space Research and Technology Center, in a NASA press release.
Rosetta’s closest view of the comet previous to this was a six-mile (10 kilometer) mapping orbit that it did for a short time before moving to release the Philae lander. After that, its orbit was expected to range between 20 km and 50 km (12.4 miles and 18.6 miles) through the end of this month.
Philae, meanwhile, made it down to the surface and did manage to send pictures back during its approximately 60 hours of activity, before shutting down due to a lack of sunlight hitting its solar panels. Philae is now wedged in a shady spot on the comet, but it’s possible more sunlight could fall in that area when the comet nears its closest approach to the Sun in 2015, between the orbits of Earth and Mars.
The European Space Agency is saying that about 20% of the mission’s science is expected to flow from Philae (at most), and 80% from Rosetta. Early results from both spacecraft present some intriguing properties about the comet. Based on the ratio of isotopes (types) of hydrogen on the comet, it’s more likely that it was asteroids that delivered water to Earth. Also, Philae was unable to dig very far into the surface, implying that underneath the dust must be something like a thick layer of ice.
A recent Rosetta blog post on the European Space Agency says that the team expects to take a break for the holidays from posting — unless, of course, they manage to track down the Philae lander in pictures. The location of the spacecraft is still unknown, but it’s believed that Rosetta’s high-resolution camera may be able to catch the lander or its glint — coupled with clues Philae’s experiments gave to its location.
This (in blue) is where the Philae lander came to rest on Comet 67P/Churyumov-Gerasimenko. The graphic is based on topographic modelling of the comet's nucleus and Philae's picture of a nearby cliff (in white). Credit: ESA/Rosetta/Philae/CNES/FD/CIVA
In scientific style, researchers are slowly narrowing down where the Philae lander arrived on Comet 67P/Churyumov-Gerasimenko. Earlier today (Dec. 17) at the American Geophysical Union meeting, more pictures from the European spacecraft were released showing its landing site and also what the terrain looked like underneath Philae as it bounced to its destination. The pictures were also placed on NASA’s website.
The lander is sleeping in a shady spot on the comet’s surface after the dramatic touchdown — actually, three touchdowns — on Nov. 12, when it flew for more than two hours across the surface and bounced as high as two miles (3.2 kilometers). This was partly because harpoons expected to secure it to the surface failed to deploy, and also because the comet crust was icier than expected, according to Gizmodo.
You can see in the diagram above Philae’s predicament; it’s wedged in a spot that doesn’t get a lot of sunlight, at least for now. That could change as 67P draws closer to the Sun in the late winter or early spring, but nobody yet knows for sure. And yes, the search for the landing site still continues in earnest, but the challenge now is the orbiting Rosetta spacecraft only has so much bandwidth to send back images, according to Wired. As more high-resolution OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System) pictures arrive, scientists hope to figure out where it went.
Two pictures from Philae highlighted in today’s release are below. Will the lander take more? Scientists certainly hope so, but even if that doesn’t happen, the lander was only expected to return 20% of the science results in any case. Rosetta is still active and will stick with the comet through mid-2015, when 67P gets closest to the Sun.
The Philae lander captured a picture of a nearby cliff, nicknamed “Perihelion Cliff”, on the nucleus of Comet 67P/Churyumov-Gerasimenko. Reports say this picture had been released before, but was processed to show more detail (such as the glare, believed to be reflection from the lander). Credit: ESA/Rosetta/Philae/CIVAPhilae’s blurred view of the surface during its first bounce from Comet 67P/Churyumov-Gerasimenko on Nov. 12, 2014. The lander sailed for about two hours in the first bounce, made contact briefly, then bounced again before coming to rest. The black squares represent areas where data was not collected. Credit: ESA/Rosetta/Philae/CIVA
Artist's impression of Venus Express entering orbit in 2006. Credit: ESA - AOES Medialab
Venus Express is mostly dead. The spacecraft spent more than eight years faithfully relaying information from the Morning Star/Evening Star planet, but it’s now out of fuel, out of control and within weeks of burning up in the atmosphere.
While we mourn the end of the productive mission, the European Space Agency spacecraft showed us a lot about the planet that we once considered a twin to Earth. Some of the surprises, as you can see below, including a possibly slowing-down rotation, and the realization that volcanoes may still be active on the hellish planet.
False color composite of a rainbow-like feature known as a ‘glory’, seen on Venus on 24 July 2011. The image is composed of three images at ultraviolet, visible, and near-infrared wavelengths from the Venus Monitoring Camera. The images were taken 10 seconds apart and, due to the motion of the spacecraft, do not overlap perfectly. The glory is 1200 km across, as seen from the spacecraft, 6000 km away. It’s the only glory ever seen on another planet. Credit: ESA/MPS/DLR/IDA.
Quick video summary: Venus Express found that the spacecraft’s rotation may have slowed down by 6.5 minutes between 1996 (when the Magellan spacecraft was in orbit) and 2012. The surprising information emerged when scientists discovered surface features weren’t in the expected areas, and couldn’t find any calculation errors between the data.
Animation of Venus’ southern polar vortex made from VIRTIS thermal infrared images; white is cooler clouds at higher altitudes. Credit: ESA/VIRTIS-VenusX/INAF-IASF/LESIA-Obs. de Paris (G. Piccioni, INAF-IASF)
Quick video summary: Volcanic flows may still be active on Venus’ surface, according to 2010 data from the mission. Scientists looked at surface areas that had not been “weathered” very much (indicating that they are relatively young) and detected at least nine spots where the heat in those zones is much higher than the areas around it.
A picture of Venus’ clouds. Despite the planet being extremely hot, Venus Express found a cold layer in the atmosphere at temperatures of about -175 degrees Celsius (-283 Fahrenheit) that is colder than anything on Earth. It’s so chilling that carbon dioxide may freeze and fall as snow or ice. Credit: ESA/MPS/DLR/IDAArtist’s impression of Venus with the solar wind flowing around the planet, which has little magnetic protection. Venus Express found that a lot of water has bled into space over the years from the planet, which happens when the sun’s ultraviolet radiation breaks oxygen and hydrogen molecules apart and pushes them into space. Credit: ESA – C. Carreau
“The available information provides evidence of the spacecraft losing attitude control,” stated Patrick Martin, ESA’s Venus Express mission manager, who added it was because the machine exhausted its fuel as controllers tried to raise it to a more stable altitude above Venus.
The demise of the mission, in a sense, began when controllers chose to bring Venus Express into the atmosphere this summer. The goal was not only to learn more about Venus, but also to get information on how future spacecraft could “surf” the atmosphere when, say, landing on the planet.
Artist’s conception of Venus Express doing an aerobraking maneuver in the atmosphere in 2014. Credit: ESA–C. Carreau
The orbit was reduced to about 130 km to 135 km (80.7 miles to 83.9 miles) above the planet at its lowest approach, which took place in earnest between June 18 and July 11. Controllers then did 15 small thruster burns, which raised the spacecraft’s minimum altitude to 460 km (286 miles).
But it wasn’t a stable orbit, with the spacecraft continuing to spiral into the planet as gravity pulled it down. ESA decided to again try raising the spacecraft’s altitude between Nov. 23 and Nov. 30, but lost consistent contact with the spacecraft Nov. 28. It appears Venus Express is out of gas, the agency said.
It’s hard to know exactly when the spacecraft will die, but it serves as a good example of how space recycling can end up making an interesting mission. The design and some of the instruments on Venus Express were based upon those used for other missions, particularly Mars Express and Rosetta. And the lessons of the spacecraft will certainly be used in future missions.
Tomorrow, we’ll run down some of the highlights of the mission.
The Cliffs of Churyumov-Gerasimenko: an enhanced and procosessed crop of an image from Rosetta's navcam. Credits: ESA/Rosetta/NAVCAM, processing by Stuart Atkinson.
Images from space don’t get more dramatic than this. Image processing wizard Stuart Atkinson zoomed in on one of the most intriguing views yet of Comet 67P/Churyumov-Gerasimenko, highlighting the contrasts of dark and light, smooth and rugged, soft contours and frighteningly vertical cliffs.
The orginal image, below, is a four-image mosaic made from images snapped by Rosetta’s navigation camera, taken from a distance of 20.1 km from the center of Comet 67P/Churyumov-Gerasimenko on 10 December. The image resolution is 1.71 m/pixel and the individual 1024 x 1024 frames measure 1.75 km across. The mosaic is slightly cropped and measures 2.9 x 2.6 km.
This four-image mosaic comprises images taken from a distance of 20.1 km from the center of Comet 67P/Churyumov-Gerasimenko on December 10, 2014. Credit: ESA/Rosetta/NAVCAM.
Illustration of a rocky planet being bombarded by comets. (Image credit: NASA/JPL-Caltech)
Where did all of our water come from? What might seem like a simple question has challenged and intrigued planetary scientists for decades. So results just released by Rosetta mission scientists have been much anticipated and the observations of the Rosetta spacecraft instruments are telling us to look elsewhere. The water of comet 67P/Churyumov-Gerasimenko does not resemble Earth’s water.
Because the Earth was extremely hot early in its formation, scientists believe that Earth’s original water should have boiled away like that from a boiling kettle. Prevailing theories have considered two sources for a later delivery of water to the surface of the Earth once conditions had cooled. One is comets and the other is asteroids. Surely some water arrived from both sources, but the question has been which one is the predominant source.
There are two areas of our Solar System in which comets formed about 4.6 billion years ago. One is the Oort cloud far beyond Pluto. Everything points to Comet 67P’s origins being the other birthplace of comets – the Kuiper Belt in the region of Neptune and Pluto. The Rosetta results are ruling out Kuiper Belt comets as a source of Earth’s water. Previous observations of Oort cloud comets, such as Hyakutake and Hale-Bopp, have shown that they also do not have Earth-like water. So planetary scientists must reconsider their models with weight being given to the other possible source – asteroids.
The question of the source of Earth’s water has been tackled by Earth-based instruments and several probes which rendezvous with comets. In 1986, the first flyby of a comet – Comet 1P/Halley, an Oort cloud comet – revealed that its water was not like the water on Earth. How the water from these comets –Halley’s and now 67P – differs from Earth’s is in the ratio of the two types of hydrogen atoms that make up the water molecule.
Illustration of the Rosetta spacecraft showing the location of the ROSINA mass spectrometer instrument, DFMS. The difference between a Deuterium and Hydrogen atom is also illustrated. A water molecule with Deuterium is known as heavy water due to the additional mass of Dueterium vs. Hydrogen (i.e., an extra neutron). (Credit: ESA/Rosetta)
Measurements by spectrometers revealed how much Deuterium – a heavier form of the Hydrogen atom – existed in relation to the most common type of Hydrogen in these comets. This ratio, designated as D/H, is about 1 in 6000 in Earth’s ocean water. For the vast majority of comets, remote or in-situ measurements have found a ratio that is higher which does not support the assertion that comets delivered water to the early Earth surface, at least not much of it.
Most recently, Hershel space telescope observations of comet Hartley 2 (103P/Hartley) caused a stir in the debate of the source of Earth’s water. The spectral measurements of the comet’s light revealed a D/H ratio just like Earth’s water. But now the Hershel observation has become more of an exception because of Rosetta’s latest measurements.
A plot displaying the Deuterium/Hydrogen (D/H) ratio of Solar System objects. Asteroids have a D/H ratio that matches that of the Earth, while comets – except for two measured to date – have higher ratios. Objects are grouped by color: planets & moons (blue), chrondritic meteorites from the asteroid belt (grey), Oort cloud comets (purple), and Jupiter family comets (pink). Diamond markers = In Situ measurements; circles = remote astronomical measurements. (Credit: Altwegg, et al. 2014)
The new measurements of 67P were made by the ROSINA Double Focusing Mass Spectrometer (DFMS) on board Rosetta. Unlike remote observations using light which are less accurate, Rosetta was able to accurately measure the quantities of Deuterium and common Hydrogen surrounding the comet. Scientists could then simply determine a ratio. The results are reported in the paper “67P/Churyumov-Gerasimenko, a Jupiter Family Comet with a high D/H ratio” by K. Altwegg, et al., published in the 10 December 2014 issue of Science.
New Rosetta mission findings do not exclude comets as a source of water in and on the Earth’s crust but does indicate comets were a minor contribution. A four-image mosaic comprises images taken by Rosetta’s navigation camera on 7 December from a distance of 19.7 km from the centre of Comet 67P/Churyumov-Gerasimenko. (Credit: ESA/Rosetta/Navcam Imager)
The ROSINA instrument observations determined a ratio of 5.3 ± 0.7 × 10-4, which is approximately 3 times the ratio of D/H for Earth’s water. These results do not exclude comets as a source of terrestrial water but they do redirect scientists to consider asteroids as the predominant source. While asteroids have much lower water content compared with comets, asteroids, and their smaller versions, meteoroids, are more numerous than comets. Every meteor/falling star that we see burning up in our atmosphere delivers a myriad of compounds, including water, to Earth. Early on, the onslaught of meteoroids and asteroids impacting Earth was far greater. Consequently, the small quantities of water added delivered by each could add up to what now lies in the oceans, lakes, streams, and even our bodies.
A view the Cassini spacecraft took during its flyby of Jupiter's southern pole in 2000. Credit: NASA/JPL/Space Science Institute
Gimme a rocketship – we want to see what those bands are made of! This is a strange view of Jupiter, a familiar gas giant that humanity has sent several spacecraft to. This particular view, taken in 2000 and highlighted on the European Space Agency website recently, shows the southern hemisphere of the mighty planet.
The underneath glimpse came from the Cassini spacecraft while it was en route to Saturn. Lucky for researchers, at the time the Galileo Jupiter spacecraft was still in operation. But now that machine is long gone, leaving us to pine for a mission to Jupiter until another spacecraft gets there in 2016.
That spacecraft is called Juno and is a NASA spacecraft the agency sent aloft in August 2011. And here’s the cool thing; once it gets there, Juno is supposed to give us some insights into how the Solar System formed by looking at this particular planet.
Juno will repeatedly dive between the planet and its intense belts of charged particle radiation, coming only 5,000 kilometers (about 3,000 miles) from the cloud tops at closest approach. (NASA/JPL-Caltech)
“Underneath its dense cloud cover, Jupiter safeguards secrets to the fundamental processes and conditions that governed our Solar System during its formation. As our primary example of a giant planet, Jupiter can also provide critical knowledge for understanding the planetary systems being discovered around other stars,” NASA wrote on the spacecraft’s web page.
The spacecraft is supposed to look at the amount of water in Jupiter’s atmosphere (an ingredient of planet formation), its magnetic and gravitational fields and also its magnetic environment — including auroras.
Much further in the future (if the spacecraft development is approved all the way) will be a European mission called JUICE, for Jupiter Icy Moon Explorer.
Artist’s impression of the Jupiter Icy Moons Explorer (JUICE) near Jupiter and one of its moons, Europa. Credit: ESA/AOES
The mission will check out the planet and three huge moons, Ganymede, Callisto and Europa, to get a better look at those surfaces. It is strongly believed that these moons could have global oceans that may be suitable for life.
Earlier this month, the European Space Agency approved the implementation phase for JUICE, which means that designers now have approval to come up with plans for the spacecraft. But it’s not going to launch until 2022 and get to Jupiter until 2030, if the schedule holds.
A mosaic of Comet 67P/Churyumov-Gerasimenko taken Dec. 2 with the Rosetta spacecraft. The shadowed area is a crater in which Philae is expected to be. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
Don’t forget about Philae! The comet lander made a touchdown a month ago this week on its target, marking the first time we’ve ever made a soft landing on such a body. Celebrations were quickly mixed with confusion, however, as controllers realized the spacecraft drifted quite a ways off target. In fact, we still don’t know exactly where it is.
The parent Rosetta spacecraft is working well in orbit and still transmitting images of the comet while Philae hibernates in a shady spot below. This latest image here shows a clear view of where the European Space Agency thinks the lander arrived — somewhere in the rim of that shadowy crater you see up front.
“The internal walls are seen in quite some detail. It is thought that Philae’s final touchdown site might be located close to the rim of this depression, but further high-resolution imaging is still being obtained and analyzed to confirm this,” the agency wrote in a statement concerning the image of Comet 67P/Churyumov-Gerasimenko.
This is based on data collected from Philae in a brief science surge on the surface. Recently, information based on measured magnetic fields showed the spacecraft likely hit an object — perhaps a crater rim — as it drifted for two hours on the surface, unsecured by the harpoons that were supposed to fire to hold it in place.
The distortion at bottom of this Dec. 1, 2014 mosaic of Comet 67P/Churyumov-Gerasimenko occured as imagers made image joining adjustments for the comet’s rotation and the movements of the Rosetta spacecraft. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
Searches for the lander are ongoing, but it’s hard to pick it out on such a boulder-strewn landscape. Yet the agency is doing its mightiest, and has made some progress on the problem since the landing took place. Rosetta caught several glimpses of the lander during its journey across the surface. And they have data from an experiment that communicated between Rosetta and Philae which could help pinpoint the location.
Rosetta science results have been quiet in the past week, although ESA has released several images of the comet. This comes as the agency has been criticized for its data release policy regarding the mission. It’s a vigorous debate, with there being examples of more open missions (such as Curiosity) and more closed missions (such as the Hubble Space Telescope) to compare Rosetta’s releases with.
As these activities continue, however, Rosetta will remain transmitting information from 67P through at least part of 2015, watching the comet increase in activity as both draw closer to the Sun. Jets and gas are visible already in some of the recent images of the comet, which you can see below.
Comet 67P/Churyumov-Gerasimenko viewed by the Rosetta spacecraft on Nov. 30, 2014 showing off layered material in the “neck” of the comet. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0Erupting gas and dust is just visible in the “neck” region of Comet 67P/Churyumov-Gerasimenko in this montage taken Nov. 26, 2014 by the Rosetta spacecraft. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0Gas and dust stream from Comet 67P/Churyumov–Gerasimenko in this mosaic from the Rosetta spacecraft taken Nov. 20, 2014. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
