The Rosetta spacecraft takes a selfie Oct. 7 with its target, 67P/Churyumov–Gerasimenko, from an altitude of about 9.9 miles (16 kilometers). Credit: ESA/Rosetta/Philae/CIVA
With the Philae mission down on the comet and preliminary science results coming from its brief science surge on the surface, little has been said about the delivery vehicle. But while Philae is in hibernation, the Rosetta spacecraft remains quietly in orbit around Comet 67P/Churyumov–Gerasimenko for what will prove to be a dramatic 2015.
Should the orbiter remain healthy, it will be the first to be a “comet escort” — to watch a comet changing from up close as the celestial body draws closer to the Sun. And to stay out of the debris field, Rosetta will have some fancy footwork to perform in the next few months, says the European Space Agency (ESA).
“Burns” with the comet are planned on Saturday (Nov. 22) and Wednesday (Nov. 26) to bring it up about 30 kilometers (19 miles) above, and then it will scoot down closer to about 20 kilometers (12.5 miles) on Dec. 3. Rosetta will remain in this orbit for a while to look at the comet’s nucleus, as well as to measure plasma, dust and gas that is expected to increase as the comet gets closer to the Sun.
Rosetta will stay as close to 67P as possible, but if activity heats up to an unacceptable risk, it will jump to a “high-activity” trajectory that will keep it away from the worst of the debris. And it’s also going to keep an ear out for Philae, just in case more sunlight on the comet ends up recharging the hibernating lander’s battery. “Early next year, Rosetta will be switched into a mode that allows it to listen periodically for beacon signals from the surface.,” ESA wrote.
There has been some discussion about the magnitude of Philae’s success given that it did land on the comet as planned, but the harpoons (which had travelled a decade in space at that point) did not fire on to the surface as planned. This meant that the lander drifted for about two hours before settling far from its prime landing spot, mostly outside of the sunlight it needs to recharge its batteries.
The Mars Society prototype habitat in Utah conducts studies on what it would be like to live on Mars.
Credit: Mars Society MRDS
If you wanna get humans to Mars, there are so many technical hurdles in the way that it will take a lot of hard work. How to help people survive for months on a hostile surface, especially one that is bathed on radiation? And how will we keep those people safe on the long journey there and back?
NASA is greatly concerned about the radiation risk, and is asking the public for help in a new challenge as the agency measures radiation with the forthcoming uncrewed Orion test flight in December. There’s $12,000 up for grabs across at least a few awards, providing you get your ideas into the agency by Dec. 12.
“One of the major human health issues facing future space travelers venturing beyond low-Earth orbit is the hazardous effects of galactic cosmic rays (GCRs),” NASA wrote in a press release.
“Exposure to GCRs, immensely high-energy radiation that mainly originates outside the solar system, now limits mission duration to about 150 days while a mission to Mars would take approximately 500 days. These charged particles permeate the universe, and exposure to them is inevitable during space exploration.”
Orion in orbit in this artists concept. Credit: NASA
Here’s an interesting twist, too — more data will come through the Orion test flight as the next-generation spacecraft aims for a flight 3,600 miles (5,800 kilometers) above Earth’s surface. That’s so high that the vehicle will go inside a high-radiation environment called the Van Allen Belts, which only the Apollo astronauts passed through in the 1960s and 1970s en route to the Moon.
While a flight to Mars will also just graze this area briefly, scientists say the high-radiation environment will give them a sense of how Orion (and future spacecraft) perform in this kind of a zone. So the spacecraft will carry sensors on board to measure overall radiation levels as well as “hot spots” within the vehicle.
You can find out more information about the challenge, and participation details, at this link.
Our last panorama from Philae? This image was taken with the CIVA camera; at center Philae has been added to show its orientation on the surface. Credit: ESA
And we have touchdown! This is what the feet of the Philae lander experienced as the spacecraft touched down on its cometary destination last week. You can hear the brief sound from the Cometary Acoustic Surface Sounding Experiment (CASSE) above. What’s even cooler is the scientific data that short noise reveals.
CASSE is embedded in the three legs of Philae and recorded the first of three landings for the spacecraft, which bounced for about two hours before coming to rest somewhere on Comet 67P/Churyumov–Gerasimenko (where is still being determined).
About that first touchdown: “The Philae lander came into contact with a soft layer several centimetres thick. Then, just milliseconds later, the feet encountered a hard, perhaps icy layer on 67P/Churyumov-Gerasimenko,” stated German Space Agency (DLR) researcher Klaus Seidensticker. He is the lead for the Surface Electric Sounding and Acoustic Monitoring Experiment (SESAME), which includes CASSE.
CASSE also recorded information from the lander’s feet from Philae’s final resting spot, and transmitted information about the MUlti PUrpose Sensor (MUPUS) as the latter instrument drilled into the surface. Other instruments on SESAME found no dust particles nearby the lander (which scientists say means the landing site is quiescent) and also sensed water ice beneath the lander.
Philae is now in hibernation as its final resting spot does not include a lot of sunlight to recharge the solar panels, but the researchers are hoping that more energy might be available as 67P draws closer to the Sun in 2015. The orbiting Rosetta spacecraft is continuing to collect data on the comet.
MAVEN's Ultraviolet Imaging Spectrograph (IUVS) uses limb scans to map the chemical makeup and vertical structure across Mars' upper atmosphere. It detected strong enhancements of magnesium and iron from ablating incandescing dust from Comet Siding Spring. Credit: NASA
NASA’s newest Mars spacecraft is “go” for at least a year — and potentially longer. After taking a time-out from commissioning to observe Comet Siding Spring whizz by the Red Planet in October, the Mars Atmosphere and Volatile Evolution (MAVEN) officially began its science mission Monday (Nov. 17). And so far things are going well.
“From the observations made both during the cruise to Mars and during the transition phase, we know that our instruments are working well,” stated principal investigator Bruce Jakosky, who is with NASA’s Goddard Space Flight Center in Maryland. “The spacecraft also is operating smoothly, with very few ‘hiccups’ so far. The science team is ready to go.”
MAVEN arrived in orbit Sept. 16 after facing down and overcoming a potential long delay for its mission. NASA and other federal government departments were in shutdown while MAVEN was in final launch preparations, but the mission received a special waiver because it is capable of communicating with the rovers on Mars. Given the current relay spacecraft are aging, MAVEN could serve as the next-generation spacecraft if those ones fail.
Three views of an escaping atmosphere, obtained by MAVEN’s Imaging Ultraviolet Spectrograph. By observing all of the products of water and carbon dioxide breakdown, MAVEN’s remote sensing team can characterize the processes that drive atmospheric loss on Mars. Image Credit: University of Colorado/NASA
But that’s providing that MAVEN can last past the next year in terms of hardware and funding. Meanwhile, its primary science mission is better understanding how the atmosphere of Mars behaves today and how it has changed since the Red Planet was formed.
“The nine science instruments will observe the energy from the Sun that hits Mars, the response of the upper atmosphere and ionosphere, and the way that the interactions lead to loss of gas from the top of the atmosphere to space,” Jakosky added.
“Our goal is to understand the processes by which escape to space occurs, and to learn enough to be able to extrapolate backwards in time and determine the total amount of gas lost to space over time. This will help us understand why the Martian climate changed over time, from an early warmer and wetter environment to the cold, dry planet we see today.”
A 3-D reconstruction of the Rosetta comet (67P/Churyumov-Gerasimenko) in a 2003 model from the Hubble Space Telescope. Credit: NASA, ESA and Philippe Lamy (Laboratoire d'Astronomie Spatiale)
Okay, let’s take a deep breath about Rosetta and remember just how far we’ve come since the mission arrived at its target comet in August. Lately we’ve been focused on reporting on the Philae landing, but remember how we barely knew how the comet looked until this summer? How much of a surprise the rubber duckie shape was to us?
This Hubble Space Telescope model from 2003 shows us why. From afar, Comet 67P/Churyumov-Gerasimenko is a tiny object to image, even for the NASA probe’s powerful lens. Back then, the telescope was tasked with examining the comet to look at its size and shape to better design the Philae lander spacecraft. And the model reveals no duckie; it looks more like a sombrero from some angles.
The main concern of scientists back then was redirecting Rosetta to a new target when its original comet (46P/Wirtanen) fell out of reach due to a launch delay. 67P was bigger and had a higher gravity, requiring scientists to make adjustments to Philae before landing, according to the release. So Hubble sprung into action to look at 67P. Below are the release images from that time.
A 2003 illustration of Comet 67P/Churyumov-Gerasimenko based on Hubble Space Telescope observations. Credit: NASA, ESA and Philippe Lamy (Laboratoire d’Astronomie Spatiale)
And here’s a fun quote from 2003 that finally came last Wednesday, when Philae touched down for its (sadly brief, so far) mission on the comet: “Although 67P/C-G is roughly three times larger than the original Rosetta target, its elongated shape should make landing on its nucleus feasible, now that measures are in place to adapt the lander package to the new configuration before next year’s launch,” stated Philippe Lamy of the Space Astronomy Laboratory (Laboratoire d’Astronomie Spatiale) in France.
We’ve sure come a long way since then. Below are some of the pictures Rosetta caught of 67P as it made its approach to its target this year, after a decade flying through space. While Philae is in what could be permanent hibernation, Rosetta is orbiting, working well and expected to keep up observations when the comet draws closer to the sun in 2015.
Animation of Comet 67P/Churyumov-Gerasimenko as seen by Rosetta on June 27-28, 2014Comet 67P/C-G photographed on July 14, 2014 from a distance of approximately 12 000 km. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDARaw pixelated image of the comet (left) and after smoothing. Credit: ESAComet 67P/Churyumov-Gerasimenko at 621 miles (1,000 km) on August 1. Wow! Look at that richly-textured surface. This photo has higher resolution than previous images because it was taken with Rosetta’s narrow angle camera. The black spot is an artifact. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDAPhoto of Comet 67P/C-G taken by Rosetta on August 6, 2014. Credit: ESA
Artist's conception of asteroid Bennu from the NASA film "Bennu's Journey." Credit: NASA/YouTube (screenshot)
We’ve been super-excited about the Philae landing recently, the first soft landing on a comet. But imagine if the spacecraft was equipped to bring a sample of Comet 67P/Churyumov–Gerasimenko back to Earth. What sort of secrets could we learn from examining the materials of the comet up close?
That dream will remain a dream for 67P, but guess what — if all goes to plan, that idea will execute for asteroid Bennu. Check out the new video above for more details on the audacious mission; below the jump is a brief mission description.
There is a mission expected to launch in 2016 called OSIRIS-REx that will spend two years flying to the asteroid to nab a sample, then will come back to Earth in 2023 to deliver it to scientists. This is exciting because asteroids are a sort of time capsule showing how the Solar System used to be in the early days, before gravity pulled rocks and ice together to gradually form the planets and moons that we have today.
“Scientists tell us that asteroid Bennu has been a silent witness to titanic events in the solar system’s 4.6 billion year history,” NASA wrote on a website commemorating the new video. “When it returns in 2023 with its precious cargo, OSIRIS-REx will help to break that silence and retrace Bennu’s journey.”
For more information on OSIRIS-REx, check out the mission’s website.
Artist’s impression of a baby star still surrounded by a protoplanetary disc in which planets are forming. Credit: ESO
It may seem all but impossible to determine how the Solar System formed, given that it happened roughly 4.5 billion years ago. Luckily, much of the debris that was left over from the formation process is still available today for study, circling our Solar System in the form of rocks and debris that sometimes make their way to Earth.
Among the most useful pieces of debris are the oldest and least altered type of meteorites, which are known as chondrites. They are built mostly of small stony grains, called chondrules, that are barely a millimeter in diameter.
And now, scientists are being provided with important clues as to how the early Solar System evolved, thanks to new research based on the the most accurate laboratory measurements ever made of the magnetic fields trapped within these tiny grains.
To break it down, chondrite meteorites are pieces of asteroids — broken off by collisions — that have remained relatively unmodified since they formed during the birth of the Solar System. The chondrules they contain were formed when patches of solar nebula – dust clouds that surround young suns – was heated above the melting point of rock for hours or even days.
The dust caught in these “melting events” was melted down into droplets of molten rock, which then cooled and crystallized into chondrules. As chondrules cooled, iron-bearing minerals within them became magnetized by the local magnetic field in the gas cloud. These magnetic fields are preserved in the chondrules right on up to the present day.
A slice of the NWA 5205 meteorite from the Sahara Desert displays wall-to-wall chondrules. Credit: Bob King
The chondrule grains whose magnetic fields were mapped in the new study came from a meteorite named Semarkona – named after the town in India where it fell in 1940.
Roger Fu of MIT – working under Benjamin Weiss – was the chief author of the study; with Steve Desch of Arizona State University’s School of Earth and Space Exploration attached as co-author.
According to the study, which was published this week in Science, the measurements they collected point to shock waves traveling through the cloud of dusty gas around the newborn sun as a major factor in solar system formation.
“The measurements made by Fu and Weiss are astounding and unprecedented,” says Steve Desch. “Not only have they measured tiny magnetic fields thousands of times weaker than a compass feels, they have mapped the magnetic fields’ variation recorded by the meteorite, millimeter by millimeter.”
The scientists focused specifically on the embedded magnetic fields captured by “dusty” olivine grains that contain abundant iron-bearing minerals. These had a magnetic field of about 54 microtesla, similar to the magnetic field at Earth’s surface (which ranges from 25 to 65 microtesla).
Coincidentally, many previous measurements of meteorites also implied similar field strengths. But it is now understood that those measurements detected magnetic minerals that were contaminated by the Earth’s own magnetic field, or even from the hand magnets used by the meteorite collectors.
Artist depiction of a protoplanetary disk permeated by magnetic fields. Objects in the foregrounds are millimeter-sized rock pellets known as chondrules. Credit: Hernán Cañellas
“The new experiments,” Desch says, “probe magnetic minerals in chondrules never measured before. They also show that each chondrule is magnetized like a little bar magnet, but with ‘north’ pointing in random directions.”
This shows, he says, that they became magnetized before they were built into the meteorite, and not while sitting on Earth’s surface. This observation, combined with the presence of shock waves during early solar formation, paints an interesting picture of the early history of our Solar System.
“My modeling for the heating events shows that shock waves passing through the solar nebula is what melted most chondrules,” Desch explains. Depending on the strength and size of the shock wave, the background magnetic field could be amplified by up to 30 times. “Given the measured magnetic field strength of about 54 microtesla,” he added, “this shows the background field in the nebula was probably in the range of 5 to 50 microtesla.”
There are other ideas for how chondrules might have formed, some involving magnetic flares above the solar nebula, or passage through the sun’s magnetic field. But those mechanisms require stronger magnetic fields than what has been measured in the Semarkona samples.
This reinforces the idea that shocks melted the chondrules in the solar nebula at about the location of today’s asteroid belt, which lies some two to four times farther from the sun than the Earth’s orbits.
Desch says, “This is the first really accurate and reliable measurement of the magnetic field in the gas from which our planets formed.”
Artist's conception of a future lunar rover gathering regolith to construct a moon base using 3-D printing. Credit: Foster+Partners/European Space Agency/YouTube (screenshot)
The Moon is so close to us, and yet so far. Just last year the Chang’e-3 spacecraft and Yutu rover made the first soft landing on the surface in more than a generation. Humans haven’t walked in the regolith since 1972. But that hasn’t decreased the desire of some to bring people back there — with an armful of new technologies to make life easier.
Take the European Space Agency’s desire to do 3-D printing on the lunar surface. Rovers with big scoopers would pick up the moon dust and use that as raw materials to make a habitat that humans would then enjoy. Far out? Perhaps, but it is something the agency is seriously examining in consultation with Foster+Partners. See the video above.
Universe Today recently explored the value of being on the Moon or a nearby asteroid. In a nutshell, the lower gravity would make it easier to loft things from the base, making it potentially cheaper to explore the Solar System. That said, there are considerable startup costs. One thing that could be considered is the value of investing in smart robots that could build simple structures on the moon or even (gasp) build other prototypes to replace or supplement them.
As ESA explained in a 2013 blog post, the agency envisions using robots to use more “local” resources on the moon and to reduce the need to ship stuff in from planet Earth. “As a practice, we are used to designing for extreme climates on Earth and exploiting the environmental benefits of using local, sustainable materials,” stated Xavier De Kestelier of Foster + Partners specialist modelling group. “Our lunar habitation follows a similar logic.”
The new video takes that concept a bit further and specifies a location: Shackleton Crater, which receives near-constant sunlight in certain areas, next to spots that are in permanent shadow. As ESA explains, being in this crater allows the best of two scenarios: constant energy available for solar panels, but areas to build structures that would be more sensitive to extreme heat.
ESA plans to push forward its research from 2013 to look at “harnessing concentrated sunlight to melt regolith rather than using a binding liquid,” as the agency explains on its YouTube page. Moon dust structures glued together with more moon dust? Sounds like the ultimate snow fort.
Artist's impression (not to scale) of the Rosetta orbiter deploying the Philae lander to comet 67P/Churyumov–Gerasimenko. Credit: ESA–C. Carreau/ATG medialab.
What price do you put on scientific discovery? From the way Twitter lit up last week when the Philae spacecraft touched down on Comet 67P/Churyumov–Gerasimenko — it was a top-trending topic for a while — it appears there’s a lot of discussion going on about the Rosetta mission and its value to humanity.
A recent infographic (which you can see below) points out that the Rosetta mission, which included the now-hibernating Philae lander, cost as much as about four Airbus 380 jetliners. Is US$1.75 billion (€1.4 billion) a bargain for letting us explore further into the universe, or could the money have been better-served elsewhere?
This is a question often brought up about the value of space exploration, or what is called “blue-sky” research in general. The first developers of lasers, for example, could not have predicted how consumers would use them millions of times over to watch DVDs and Blu-Rays. Or in a more practical use, how medical lasers are used today for surgeries.
An infographic of Rosetta spacecraft spending. Credit: Scienceogram.org (infographic), ESA/Rosetta/NAVCAM (comet image), ESA (Rosetta graphic), ESA/Airbus (data), Scienceogram.org (other data).
“Like a lot of blue-skies science, it’s very hard to put a value on the mission,” wrote Scienceogram.org, the organization that produced the infographic. “First, there are the immediate spin-offs like engineering know-how; then, the knowledge accrued, which could inform our understanding of our cosmic origins, amongst other things; and finally, the inspirational value of this audacious feat in which we can all share, including the next generation of scientists.”
To put the value of the Rosetta mission in more everyday terms, Scienceogram points out that the comet landing cost (per European citizen and per year between 1996 and 2015) was less than half the ticket price for Interstellar. That said, it appears that figure does not take into account inflation, so the actual cost per year may be higher.
The Rosetta spacecraft is still working well and is expected to observe its target comet through 2015. The Philae lander did perform the incredible feat of landing on 67P on Wednesday, but it ended up in a shadowy spot that prevented it from gathering sunlight to stay awake. The lander is now in hibernation, perhaps permanently, but scientists have reams of data from the lander mission to pore over.
It’s been said that Rosetta, in following 67P as it gets closer to the Sun, will teach us more about cometary behavior and the origins of our Solar System. Is the mission and its social-media-sensation pictures worth the price? Let us know in the comments. More information on the infographic (and the spreadsheet of data) are available here.
A still of the Philae spacecraft bouncing off Comet 67P/Churyumov–Gerasimenko in an animation of Rosetta spacecraft images. The image was taken Nov. 12, 2014 at 10:35 a.m. EDT (3:35 p.m. UTC). Credit: ESA/Rosetta/NAVCAM; pre-processed by Mikel Canania
When the Philae lander arrived at its target comet last week, the little spacecraft landed three times in two hours before coming to a rest. While controllers could see this information from data coming in, they didn’t have any photographic proof — until now.
Here’s another cool thing about these images — some of the credit to Philae’s discovery comes through crowdsourcing! This is what the European Space Agency’s Rosetta blog said about who found this:
Credit for the first discovery goes to Gabriele Bellei, from the interplanetary division of Flight Dynamics, who spent hours searching the NAVCAM images for evidence of the landing.
Once the images were published, blog reader John Broughton posted a comment to report that he had spotted the lander in them (thank you, John). There was also quite some speculation by Rosetta blog readers in the comments section, wondering which features might be attributable to the lander. Martin Esser, Henning, and Kasuha in particular were among the first to make insightful observations on the topic, although many others have since joined in.
Last but not least, a careful independent review of the images was made by Mikel Catania from the earth observation division of Flight Dynamics, with the same conclusion. He also made the annotated animation shown here.
This goes to show you that while there is disappointment that Philae is in a long (perhaps permanent) sleep sooner than scientists hoped, data from the spacecraft will continue to be analyzed in the coming months and years. And don’t forget that the orbiting Rosetta spacecraft is in good health and will continue to return data on 67P as it draws closer to the Sun through 2015.
A still of the Philae spacecraft bouncing off Comet 67P/Churyumov–Gerasimenko in an animation of Rosetta spacecraft images. The image was taken Nov. 12, 2014 at 10:35 a.m. EDT (3:35 p.m. UTC). Credit: SA/Rosetta/NAVCAM; pre-processed by Mikel Catania
