After more than eight years orbiting a hellish planet, Venus Express is showing its age. The spacecraft made some risky maneuvers this summer, dipping down into the atmosphere as it nears the end of its mission. Now, the European Space Agency reports it has mostly lost contact with the probe. The reason could be lack of fuel.
The “anomaly” started Nov. 28 when the agency’s operations center lost touch with the spacecraft. Since then, ground stations at ESA and NASA have been trying to hail the probe. All they’ve received since then is a little bit of telemetry showing that the spacecraft has it solar panels pointing towards the Sun, and it’s slowly rotating.
Artist’s conception of Venus Express doing an aerobraking maneuver in the atmosphere in 2014. Credit: ESA–C. Carreau
“It is possible that the remaining fuel on board VEX was exhausted,” ESA wrote in a blog post, pointing out that in recent weeks it has been trying to raise the spacecraft’s altitude for more science observations. But with the spacecraft spinning, its high-gain antenna is likely out of contact with Earth and it’s hard to reach it.
“The operations team is currently attempting to downlink the table of critical events that is stored in protected memory on board, which may give details of the sequence of events which occurred over the past few days,” ESA added. “The root cause of the anomaly (fuel situation or otherwise) remains to be established.”
Artist depiction of Huygens landing on Titan. Credit: ESA
It’s almost exactly 10 years ago that humanity parachuted a spacecraft into Titan, that moon of Saturn that could hold chemistry similar to what sat on Earth before life arose. Called Huygens, the probe survived for just about an hour on the surface on Jan. 14, 2005, transmitting information back about conditions there and on the way down.
Huygens is long dead, but its carrier craft is doing just fine. On Dec. 10, Cassini will make the 107th close pass by Titan to learn more about the moon’s atmosphere. Although Huygens made it to the surface fine, showing at least a basic understanding of how a parachute behaves on Titan, there’s still so much more we need to learn.
Specifically, Cassini’s different instruments have been coming up with different answers for Titan’s atmospheric density, so this flyby is hoping to resolve some of that. In part, they hope to get more accurate measurements by measuring how much drag the spacecraft experiences when it flies past the moon.
Titan’s landscape as seen by the Huygens probe descent through Saturn’s largest moons atmosphere (credit: ESA, NASA, JPL, UA, Rene Pascal)
When Huygens probed the atmosphere on its way down, scientists figured that its measurements agreed in many ways with those taken by the flying-by Voyager 2 spacecraft previously. That said, the probe also discovered “a significant correspondence of wind shear and buoyant stability structures” in the stratosphere and lower tropopause of Titan, according to a 2006 presentation on Huygens results.
Carbon dioxide ice begins to feel the heat in the south pole region every spring. In this image of 'Inca City' taken in August 2014, you can see a few fans coming out from channels (araneiforms) that are created when pressurized gas escapes from the melting ice. Picture taken by the Mars Reconnaissance Orbiter's HiRISE camera. Credit: NASA/JPL/University of Arizona
We’ve been watching Mars with spacecraft for about 50 years, but there’s still so little we know about the Red Planet. Take this sequence of images in this post recently taken by a powerful camera on NASA’s Mars Reconnaissance Orbiter. Spring arrives in the southern hemisphere and produces a bunch of mysteries, such as gray-blue streaks you can see in a picture below.
That’s where citizen scientists can come in, according to a recent post for the University of Arizona’s High Resolution Imaging Science Experiment (HiRISE) camera that took these pictures. They’re asking people with a little spare time to sign up for Planet Four (a Zooniverse project) to look at mysterious Mars features. With amateurs and professionals working together, maybe we’ll learn more about these strange changes you see below.
On Aug. 20, 2014, Martian dust mounds are on top of the araneiforms in ‘Inca City’, as well as dark areas on the terrain showing where the ice cap in the southern hemisphere burst and sent gas and dust into the surroundings. Fans in the area are pointing in multiple directions, showing how the wind has changed. Image taken by the Mars Reconnaissance Orbiter’s HiRISE camera. Credit: NASA/JPL/University of ArizonaOn Aug. 25, 2014, more fans and blotches appear on the Martian landscape around “Inca City”, a location in the southern polar region, as the ice bursts in the springtime sun. Image obtained by the Mars Reconnaissance Orbiter’s HiRISE camera. Credit: NASA/JPL/University of ArizonaAs of Sept. 6, 2014, fans in “Inca City” in the Martian southern hemisphere are now blue-gray. Why this color appears in the spring is unknown. It could be because of particles falling into ice underneath, or gas bursting from the ice condensing and falling as frost. It could even be a combination of the two. Image taken by the Mars Reconnaissance Orbiter’s HiRISE orbiter. Credit: NASA/JPL/University of ArizonaAs spring takes hold in the southern polar region of Mars on Sept. 27, 2014, cracks are now developing in the ice at “Inca City” with multiple new dust fans appearing. Cracks develop when the ice does not have a path to easily rupture and release gas. Picture taken by the Mars Reconnaissance Orbiter’s HiRISE camera. Credit: NASA/JPL/University of Arizona
This is a type of shrimp that lives in hydrothermal vents (areas of hot water) in the Caribbean. NASA is studying Rimicaris hybisae and other "extreme shrimp" to learn more about lifeforms that could survive on other worlds. Credit: Chris German, WHOI/NSF, NASA/ROV Jason C: 2012 Woods
For all of the talk about aliens that we see in science fiction, the reality is in our Solar System, any extraterrestrial life is likely to be microbial. The lucky thing for us is there are an abundance of places that we can search for them — not least Europa, an icy moon of Jupiter believed to harbor a global ocean and that NASA wants to visit fairly soon. What lurks in those waters?
To gain a better understanding of the extremes of life, scientists regularly look at bacteria and other lifeforms here on Earth that can make their living in hazardous spots. One recent line of research involves shrimp that live in almost the same area as bacteria that survive in vents of up to 750 degrees Fahrenheit (400 degrees Celsius) — way beyond the boiling point, but still hospitable to life.
Far from sunlight, the bacteria receive their energy from chemical combinations (specifically, hydrogen sulfide). While the shrimp certainly don’t live in these hostile areas, they perch just at the edge — about an inch away. The shrimp feed on the bacteria, which in turn feed on the hydrogen sulfide (which is toxic to larger organisms if there is enough of it.) Oh, and by the way, some of the shrimps are likely cannibals!
One species called Rimicaris hybisae, according to the evidence, likely feeds on each other. This happens in areas where the bacteria are not as abundant and the organisms need to find some food to survive. To be sure, nobody saw the shrimps munching on each other, but scientists did find small crustaceans inside them — and there are few other types of crustaceans in the area.
But how likely, really, are these organisms on Europa? Bacteria might be plausible, but something larger and more complicated? The researchers say this all depends on how much energy the ecosystems have to offer. And in order to see up close, we’d have to get underwater somehow and do some exploring.
In a recent Universe Today interview with Mike Brown, a professor of planetary science at the California Institute of Technology, the renowned dwarf-planet hunter talked about how a submarine could do some neat work.
“In the proposed missions that I’ve heard, and in the only one that seems semi-viable, you land on the surface with basically a big nuclear pile, and you melt your way down through the ice and eventually you get down into the water,” he said. “Then you set your robotic submarine free and it goes around and swims with the big Europa whales.” You can see the rest of that interview here.
The puzzling, fascinating surface of Jupiter’s icy moon Europa looms large in this newly-reprocessed color view, made from images taken by NASA’s Galileo spacecraft in the late 1990s. Image credit: NASA/JPL-Caltech/SETI Institute
Philae landed nearly vertically on its side with one leg up in outer space. Here we see it in relation to the panoramic photos taken with the CIVA cameras. Credit: ESA
No, scientists haven’t found Philae yet. But as they churn through the scientific data on the comet lander, more information is emerging about the crazy landing last month that included three touchdowns and an incredible two hours of drifting before Philae came to rest in a relatively shady spot on the surface.
Among the latest: the tumbling spacecraft “collided with a surface feature” shortly after its first landing, perhaps grazing a crater rim with one of its legs. This information comes from an instrument called ROMAP (Rosetta Lander Magnetometer and Plasma Monitor) that monitors magnetic fields. The instrument is now being used to track down the spacecraft.
ROMAP’s usual role is to look at the comet’s magnetic field as it interacts with the solar wind, but the challenge is the orbiter (Rosetta) and lander both create tiny ones of their own due to the magnetic circuitry. Usually this data is removed to see what the comet’s environment is like. But during the landing, ROMAP was used to track Philae’s descent.
Four images of Comet 67P/Churyumov–Gerasimenko taken on Nov. 30, 2014 by the orbiting Rosetta spacecraft. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
Philae was supposed to fire harpoons to secure itself to the surface when it touched down at 3:34 p.m. UTC (10:34 a.m. EST) Nov. 12, but the mechanism failed. ROMAP’s data then shows the spin rate increasing, with the lander turning at one rotation every 13 seconds.
The grazing collision happened at 4:20 pm. UTC (11:20 a.m. EST), making the rotation decrease to once every 24 seconds. Then the final two touchdowns happened around 5:25 p.m. UTC (12:25 p.m. EST) and 5:31 p.m. UTC (12:31 p.m. EST). Controllers hope they can figure out exactly where Philae arrived once they look at data from ROMAP, CONSERT and other instruments on the lander.
Philae is now hibernating because there isn’t enough sunlight in its landing spot to recharge its battery through the solar panels. Rosetta, meanwhile, continues orbiting 67P and sending back pictures of the comet as it draws closer to the Sun, including the image you see further up in this blog post, released today (Dec. 2) a few days after it was taken in space.
A 3-D model of 6 Hebe based on its light curve. The asteroid is about 120 miles in diameter and orbits in the main asteroid belt between Mars and Jupiter. Credit: Charles University_Josef Durech_Vojtech Sidorin
In the reeds that line the banks of the celestial river Eridanus, you’ll find Hebe on the prowl this month. Discovered in 1847 by German amateur astronomer Karl Ludwig Hencke , the asteroid may hold the key to the origin of the H-chondrites, a large class of metal-rich stony meteorites found in numerous amateur and professional collections around the world. You can now see this interesting minor planet with nothing more than a pair of binoculars or small telescope.
Judging by his demeanor, it might have been unwise to tell Karl Hencke he was wasting his time looking for asteroids.
The first four asteroids – Ceres, Pallas, Juno and Vesta – were discovered in quick succession from 1801 to 1807. Then nothing turned up for years. Most astronomers wrongly assumed all the asteroids had been found and moved on to other projects like measuring the orbits of double stars and determining stellar parallaxes. Nothing could have been further from the truth. Hencke, who worked as a postmaster during the day, doggedly persisted in sieving the stars for new asteroids in his free time at night. His systematic search began in 1830. Fifteen years and hundreds of cold nights at the eyepiece later he turned up 5 Astrae (asteroid no. 5) on Dec. 8, 1845, and 6 Hebe on July 1, 1847.
Hebe orbits in the main asteroid belt between Mars and Jupiter with an average distance from the Sun of 225 million miles. It spins on its axis once every 7.3 hours. Credit: Wikipedia
Energized by the finds, astronomers returned to their telescopes with renewed gusto to join in the hunt once again. The rest is history. As of November 2014 there are 415,688 numbered asteroids and a nearly equal number of unnumbered discoveries. Fittingly, asteroid 2005 Hencke honors the man who kept the fire burning.
You’ll find Hebe trucking along in Eridanus this month just north of Delta (left) and Epsilon Eridani, a pair of +3.5 magnitude stars. This map shows stars to magnitude +9.5 with Hebe’s position marked every 5 nights. Click to enlarge. Source: Chris Marriott’s SkyMap software
At 120 miles (190 km) across, Hebe is one of the bigger asteroids (officially 33rd in size in the main belt) and orbits the Sun once every 3.8 years. It will be our guest this final month of the year shining at magnitude +8.2 in early December, +8.5 by mid-month and +8.9 when you don your party hat on New Year’s Eve. All the while, Hebe will loop across the barrens of Eridanus west of Orion. Use the maps here to help track it down. I’ve included a detailed color map above, but also created a “black stars on white” version for those that find reverse charts easier to use.
Use this wide view of the sky to get oriented before zeroing in with the more detailed map above. Hebe lies just a few degrees north of Delta and Epsilon Eridani for much of December. Best viewing time is from 10 p.m. to 2 a.m. local time early in the month. Source: Stellarium
In more recent times, Hebe’s story takes an interesting turn. Through a study of its gravitational nudges on other asteroids, astronomers discovered that Hebe is a very compact, rocky object, not a loosey-goosey pile of rubble like some asteroids. Its high density provides strong evidence for a composition of both rock and iron. Scientists can determine the approximate composition of an asteroid’s surface by studying its reflectance spectrum, or what colors or wavelengths are reflected back from the object after a portion is absorbed by its surface. They use infrared light because different minerals absorb different wavelengths of infrared light. That data is compared to infrared absorptions from rocks and meteorites found on Earth. Turns out, our friend Hebe’s spectrum is a good match to two classes of meteorites – the H-chondrites, which comprise 40% of known meteorites – and the rarer IIE silicated iron meteorites.
Did this slice of meteorite come from Hebe? A 12.9-gram specimen of NWA 2710, an H5 stony chondrite, sparkles in the light. The shiny flecks are iron-nickel metal set in a stony matrix. Credit: Bob King
Because Hebe orbits close to an unstable zone in the asteroid belt, any impacts it suffers are soon perturbed by Jupiter’s gravity and launched into trajectories than can include the Earth. When you spot Hebe in your binoculars the next clear night, you might just be seeing where many of the more common space rocks in our collections originated.
A montage of images taken of Jupiter and its moon Io (foreground) by the New Horizons mission in 2007. Jupiter is shown in infrared wavelengths while Io is close to true-color. On top of Io is an eruption from the volcano Tvashtar. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
New Horizons, you gotta wake up this weekend. There’s so much work ahead of you when you reach Pluto next year! The spacecraft has been sleeping quietly for weeks in its last great hibernation before the dwarf planet close encounter in July. On Saturday (Dec. 6), the NASA craft will open its eyes and begin preparations for that flyby.
How cool will those closeups of Pluto and its moons look? A hint comes from a swing New Horizons took by Jupiter in 2007 en route. It caught a huge volcanic plume erupting off of the moon Io, picked up new details in Jupiter’s atmosphere and gave scientists a close-up of a mysterious “Little Red Spot.” Get a taste of the fun seven years ago in the gallery below.
An eruption from the Tvashtar volcano on Io, Jupiter’s moon, in several different wavelength images taken by the New Horizons spacecraft in 2007. The left image from the Long Range Reconnaissance Imager (LORRI) shows lava glowing in the night. At top right, the Multispectral Visible Imaging Camera (MVIC) spotted sulfur and sulfor dioxide deposits on the sunny side of Io. The remaining image from the Linear Etalon Imaging Spectral Array (LEISA) shows volcanic hotspots on Io’s surface. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research InstituteJupiter’s “Little Red Spot” seen by the New Horizons spacecraft in 2007. The spot turned red in 2005 for reasons scientists were then unsure of, but speculated it could be due to stuff from inside the atmosphere being stirred up by a storm surge. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research InstituteA “family portrait” of the four Galilean satellites around Jupiter taken by the New Horizons spacecraft and released in 2007. From left, the montage includes Io, Europa, Ganymede and Callisto. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research InstituteA composite of Jupiter’s bands (and atmospheric structures) taken in several images by the New Horizons Multispectral Visual Imaging Camera, showing differences due to sunlight and wind. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research InstituteIn February and March 2007, a huge plume erupted from the Tvashtar volcano on Jupiter’s moon Io. The image sequence taken by New Horizons showed the largest such explosion then viewed by a spacecraft — even accounting for the Galileo spacecraft that examined Io between 1996 and 2001. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research InstituteThe New Horizons flyby of Io in 2007 (right) revealed a changing feature on the surface of the Jupiter moon since Galileo’s image of 1999 (left.) Inside the circle, a new volcanic eruption spewed material; other pictures showed this region was still active. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Screenshot of ground testing of the Orion spacecrafts "glass cockpit." Credit: NASA/YouTube (screenshot)
If it’s good enough for a Boeing 787, it’s gotta be good enough for space, right? NASA’s Orion spacecraft — poised for its first uncrewed flight on Thursday (Dec. 4) — will eventually include a “glass cockpit” that will make it easier for astronauts to step across the Solar System, based on the passenger jet avionics.
Why go for glass over switches? The huge benefit is weight (which means less fuel expended to heft the spacecraft), according to the NASA video above.
“One big benefit is the weight savings because you don’t need to have a physical switch,” said astronaut Lee Morin, who was involved in the design, in the video. “With a physical switch, not only is there the weight of the switch, but you also have the weight of the wire to the switch, and you have to have the weight of the circuity that takes that wire and feeds it into the vehicle computers.”
This means that the new spacecraft will sport only 60 physical switches for the astronauts to control (the video did not specify what they would do), which could also be simpler in terms of usability.
The cockpit, however, is not quite ready for prime-time. Although Exploration Test Flight-1 (ETF-1) will have most of the Orion systems included in the crew portion, the glass cockpit will not be among them, according to the flight’s press kit. “The only crew module systems that will not fly on this vehicle are the environmental control and life support system; and the crew support systems such as displays, seats and crew-operable hatches,” it reads.
But there will be more testing ahead. Orion is slated to run its next flight in about 2017 or 2018, which could include a more complete spacecraft at that time. Meanwhile, people are already starting to gather for the test flight, which will see the deepest space exploration by a crew capsule since the Apollo era. Orion will roar into space and return for a high-speed re-entry to make sure that heat shield works when NASA sticks people inside.
One day – and it really is only matter of time – humans will set foot on the surfaces of other far-flung worlds in our Solar System, leaving the Earth and Moon far behind to wander the valleys of Mars, trek across the ice of Europa, and perhaps even soar through the skies of Titan like winged creatures from ancient legends. But until then we must rely on the exploration of our robotic emissaries and our own boundless imagination and curiosity to picture what such voyages would be like. Here in “Wanderers,” video artist Erik Wernquist has used both resources in abundance to visualize fascinating off-world adventures yet to be undertaken by generations to come. Continue reading “This Short Film is a Stunning Preview of Human Space Exploration”
Artist's conception of the Dawn spacecraft approaching the asteroid Ceres. Credit: NASA/JPL-Caltech
The year 2015 is going to be a big one for far-off spacecraft. Among them is the long-running Dawn mission, which is on its way to the dwarf planet Ceres (by way of Vesta) and should settle into orbit in April after a radiation blast delayed the original flight plan.
And today (Dec. 1) comes a special day for Dawn — when it turns its cameras to Ceres to capture the world, which will appear about nine pixels across. The reason? Besides scientific curiosity, it turns out to be a perfect calibration target, according to NASA.
“One final calibration of the science camera is needed before arrival at Ceres,” wrote Marc Rayman, the mission director at the Jet Propulsion Laboratory, in a recent blog post.
“To accomplish it, the camera needs to take pictures of a target that appears just a few pixels across. The endless sky that surrounds our interplanetary traveler is full of stars, but those beautiful pinpoints of light, while easily detectable, are too small for this specialized measurement. But there is an object that just happens to be the right size. On Dec. 1, Ceres will be about nine pixels in diameter, nearly perfect for this calibration.”
The Dawn spacecraft’s first image of Ceres, taken July 20, 2010. Credit: NASA/JPL-Caltech/MPS/DLR/IDA
This isn’t the first picture of Ceres by Dawn — not by a long-shot — but it sure will loom bigger than you see in the image at left, which was taken in 2010. Dawn hadn’t even arrived at Vesta at the time, the blog post points out, and the spacecraft was about 1,300 times further from Ceres then as it is now. Translating that into visual magnitude, the new pictures of Ceres will show an appearance about as bright as Venus, from Earth’s perspective.
In October, the Dawn blog said that more pictures of Ceres are planned on Jan. 13, when Ceres will appear 25 pixels across. This won’t be quite the best view ever — that was taken by the Hubble Space Telescope, which you can see below, — but just wait a couple of weeks. The mission planners say that by Jan. 26, the images will be slightly better. On Feb. 4, they will be twice as good and by Feb. 20, seven times as good.
As with the calibration photo taken today, these photos in 2015 will have a double purpose: optical navigation. It’s to help the spacecraft figure out where to go, because our pictures of Ceres are so fuzzy that mission planners will need more exact information as the mission proceeds.
You can read more information about the picture-taking, and Dawn’s planned approach to Ceres, in the Nov. 28 entry of the Dawn blog.
Pictures of the asteroid Ceres taken by the Hubble Space Telescope and released in 2005. It shows the asteroid rotating over two hours and 20 minutes, which is about a quarter of a day on Ceres (nine hours). At the time, scientists said the bright spot is a mystery. Credit: NASA, ESA, J. Parker (Southwest Research Institute), P. Thomas (Cornell University), and L. McFadden (University of Maryland, College Park)
