An image from ESA's Mars Express taken in May of 2010 shows the north pole of Mars during the red planet's summer solstice. All the carbon dioxide ice has gone, leaving just a bright cap of water ice. Credit: ESA.
Get a satellite’s-eye view of the Martian north pole in this new animation from the Mars Express spacecraft, using data from the Mars Advanced Radar for Subsurface and Ionospheric Sounding instrument, MARSIS. This instrument allows for studying the surface heights, providing a 3-D view of the Mars’ north pole.
You can see the prominent gap in the ice cap, which is a 318 km-long, 2 km-deep chasm called Chasma Boreale.
In all, the ice cap has a diameter of about 1000 km and consists of many thin layers of ice mixed with dust that extend to a depth of around 2 km below the cap.
ESA says the layers result from variations in the orbit and rotation of Mars that affect the amount of sunlight received at the poles, and thus the amount of melting and deposition of materials over time. Meanwhile, strong prevailing winds are thought to be responsible for shaping the spiral troughs.
The MARSIS instrument works by sending low-frequency radio waves towards the surface of Mars, and they are reflected back to the spacecraft from the planet’s surface. The strength and timing of the radar echoes are a gauge of the depths of different types of interfaces, such as between rock, water or ice.
Video credit: ESA/ASI/NASA/JPL/La Sapienza University/INAF (A. Frigeri)
The Elektro-L satellite's view of how the Nov. 3, 2013 solar eclipse effected Earth. Blackness from the eclipse covers Africa. Credit: Elektro-L/Vitaliy EgorovVitaliy Egorov.
The final eclipse for 2013 was a grand event, witnessed across the Atlantic and the heart of Africa this past Sunday. Like so many other photographers along the North American east coast, we were at the ready to greet the partially eclipsed Sun at dawn. And as the shadow of the Moon touched down, teams on land, air and sea were ready to meet with the fleeting umbra as it raced eastward towards sunset over the Horn of Africa region.
But a fleet of spacecraft were also on hand to witness the rare spectacle as well. Turned earthward and sunward, these spacecraft documented not only the passage of the Moon’s shadow over the Earth, but recorded multiple partial solar eclipses from orbit as well.
The first view comes from the Roscosmos Electro-L satellite based in a geostationary orbit over the Indian Ocean:
Electro-L had captured such a view before, during the annular eclipse over Australia earlier this year in May. Roscosmos increased the frame capture rate of Electro-L to twice its usual speed for the sequence. As you watch the Earth pass from a waning gibbous to crescent phase, you can just see the umbra, or central shadow of the Moon, slide into view and come into contact with the sunset terminator over eastern Africa. You can also see the cloud cover that marks the dust storms that plagued eclipse-chasers based around the Lake Turkana region in Kenya.
One of the first public pictures of the umbra of the Moon as seen from space was taken from the Mir space station during a total solar eclipse in 1999. To our knowledge, such a feat has yet to be duplicated aboard the International Space Station. The phase angle of the ISS’s orbit during the eclipse was nearly perpendicular to the Sun-Moon-Earth syzygy, and unfavorable for this particular eclipse.
Thanks to the Russian journalist Vitaliy Egorov for bringing the Electro-L eclipse sequence to the attention of Universe Today!
Next up is a sequence of images from NASA’s Aqua satellite:
Sunday’s eclipse and the Moon’s umbra off of the west coast of Africa as seen from the Aqua satellite. (Credit: NASA/GSFC/Jeff Schmaltz/MODIS Land Rapid Response Team).
Launched in 2002, Aqua is part of the “A-train” (as in “Afternoon”) constellation of Earth-observing satellites. Perched in a low-Earth Sun-synchronous orbit, Aqua caught sight of the umbra of the Moon at around 14:45 UT on Sunday, November 3rd as it raced to make first landfall over the nation of Gabon and awaiting eclipse chasers.
Some Sun observing spacecraft caught sight of the eclipse as well. The European Space Agency’s Proba-2 nabbed three partial solar eclipses from its vantage point in low Earth orbit:
PROBA-2 used its SWAP imager to grab the sequences. Orbiting the Earth once every 99 minutes or 14.5 time a day, these “orbital eclipses” are quick, lasting about 10 minutes each in duration.
Finally, EUMETSAT’s MeteoSat-10 meteorological satellite based in a geostationary orbit over Africa captured an outstanding sequence, showing nearly the entire trek of the umbra across the entire path of the eclipse:
The sequence runs from 7:30 to 18:30 UT on November 3rd. Note how the video shows the shadow fade in and sharpen as the eclipse touches down off of the US East Coast and intensifies from an annular to total along the first 15 seconds of its track, only to speed up and flatten towards sunset over Africa. And all in six seconds!
And back here on Earth, we couldn’t resist stitching together the bounty from our own minor eclipse expedition for a stop-motion view of the partially eclipsed Sun rising over the Vehicle Assembly Building at the Kennedy Space Center in Florida:
We’d like to also mention a photo that isn’t a “solar eclipse seen from space…” Y’know the one, which shows the Earth, the Moon’s shadow, and a totally-eclipsed Sun, against a star dappled Milky Way. We won’t dignify it with a link. This has already been debunked by Bad Astronomer himself Phil Plait, but the bogus pic now seems to make its rounds across ye’ ole Web now during every eclipse. Seriously? Do we all crave “link juice” that bad? There are lots of real awesome eclipse photos out there, from Earth & beyond! Please, do your part to tell that well meaning friend/coworker/relative/stranger on Twitter that this “ultimate eclipse photo…” isn’t.
How rare are hybrid solar eclipses? Well, the next solar eclipse that is both annular and total along its track occurs over southeast Asia on April 20th, 2023. It’s interesting to note that this past weekend’s eclipse may have been the first sunrise solar eclipse over the VAB since it was built in 1966. Eclipses in the same 18 years and 11 days- long saros cycle repeat, but move about 120 degrees westward. Thus, follow an eclipse cycle through a “triple saros”— known as an “Exeligmos,” an ultimate scrabble word if you can land it on a triple word score! —and an eclipse’s geometry will roughly line back up over a 54 year 33 day long span. Saros 143 produced a an eclipse crossing a similar path on October 2nd, 1959 (before the VAB was built!) and will repeat its Atlantic sunrise performance on December 6th, 2067! Let’s see, by then I’ll be…
Mars Express over water-ice crater. ESA Celebrates 10 Years since the launch of Mars Express. This artists concept shows Mars Express set against a 35 km-wide crater in the Vastitas Borealis region of Mars at approximately 70.5°N / 103°E. The crater contains a permanent patch of water-ice that likely sits upon a dune field – some of the dunes are exposed towards the top left in this image. Copyright ESA/DLR/FU-Berlin-G.Neukum
Go from the highest volcano to the deepest canyon on Mars in this great new complication video from images taken by ESA’s Mars Express. The data shown here was gathered from the nearly 12,500 orbits by the Mars Express spacecraft since its arrival at the Red Planet in late 2003, and used to create digital topographic models of almost the entire surface of the planet. Not only does this provide unique and stunning visualization to create these “flyovers” of various locals on Mars, it also enables researchers to acquire new and surprising information about the evolution of the Red Planet.
The images in this movie were taken by the High Resolution Stereo Camera and the video was released by the DLR German Aerospace Center as part of the ten years of Mars Express celebrations in June 2013, and was just released online today.
Enjoy another recent Mars Express video, a flythrough of Hebes Chasma:
Researchers work in the Antarctic polar night during a storm (Credit: Stefan Hendricks, Alfred Wegner Institute)
Some day, human explorers will land a spacecraft on the surface of Europa, Enceladus, Titan, or some other icy world and investigate first-hand the secrets hidden beneath its frozen surface. When that day comes — and it can’t come too soon for me! — it may look a lot like this.
One of a series of amazing photos by Stefan Hendricks taken during the Antarctic Winter Ecosystem & Climate Study (AWECS), a study of Antarctica’s sea ice conducted by the Alfred Wegener Institute in Germany, the image above shows researchers working on the Antarctic ice during a winter snowstorm. It’s easy to imagine them on the night-side surface of Europa, with the research vessel Polarstern standing in for a distant illuminated lander (albeit rather oversized).
Hey, one can dream!
One of the goals of the campaign, called CryoVex, was to look at how ESA’s CryoSat mission can be used to understand the thickness of sea ice in Antarctica. The extent of the Antarctic sea ice in winter is currently more than normal, which could be linked to changing atmospheric patterns.
Antarctica’s massive shelves of sea ice in winter are quite dramatic landscapes, and remind us that there are very alien places right here on our own planet.
See this and more photos from the mission on the ESA website (really, go check them out!)
Photo taken by ESA astronaut Luca Parmitano on Sept. 5, 2013 (ESA/NASA)
Italian astronaut Luca Parmitano shares a lot of fantastic photos taken from his privileged position 260 miles up aboard the Space Station, orbiting the planet 16 times a day. This is his latest, a stunning view of nighttime city lights spread out beneath a glowing dome of ghostly airglow and shimmering aurorae, with a backdrop of brightly shining stars. The dark silhouette of a solar array is in the foreground at right.
And in case you were wondering, yes, astronauts certainly can see stars while in space. A lot of them, in fact. (Except up there, they don’t twinkle… but they’re no less beautiful!)
“Every time we look into the sky and we admire the same stars, we share the same experience with all those who still know how to dream.”
– Luca Parmitano
Luca Parmitano is the first of ESA’s new generation of astronauts to fly into space. The current mission, Volare, is ESA’s fifth long-duration Space Station mission. During his six-month-long stay aboard the ISS, Luca has been conducting research for ESA and international partners as well as taken many photographs of our planet, sharing them on Twitter, Flickr, and the Volare mission blog.
A quasar resides in the hub of the nearby galaxy NGC 4438. Credit: NASA/ESA, Jeffrey Kenney (Yale University), Elizabeth Yale (Yale University)
50 million light-years away a quasar resides in the hub of galaxy NGC 4438, an incredibly bright source of light and radiation that’s the result of a supermassive black hole actively feeding on nearby gas and dust (and pretty much anything else that ventures too closely.) Shining with the energy of 1,000 Milky Ways, this quasar — and others like it — are the brightest objects in the visible Universe… so bright, in fact, that they are used as beacons for interplanetary navigation by various exploration spacecraft.
“I must go down to the seas again, to the lonely sea and the sky,
And all I ask is a tall ship and a star to steer her by.”
Deep-space missions require precise navigation, especially when approaching bodies such as Mars, Venus, or comets. It’s often necessary to pinpoint a spacecraft traveling 100 million km from Earth to within just 1 km. To achieve this level of accuracy, experts use quasars – the most luminous objects known in the Universe – as beacons in a technique known as Delta-Differential One-Way Ranging, or delta-DOR.
How delta-DOR works (ESA)
Delta-DOR uses two antennas in distant locations on Earth (such as Goldstone in California and Canberra in Australia) to simultaneously track a transmitting spacecraft in order to measure the time difference (delay) between signals arriving at the two stations.
Unfortunately the delay can be affected by several sources of error, such as the radio waves traveling through the troposphere, ionosphere, and solar plasma, as well as clock instabilities at the ground stations.
Delta-DOR corrects these errors by tracking a quasar that is located near the spacecraft for calibration — usually within ten degrees. The chosen quasar’s direction is already known extremely well through astronomical measurements, typically to closer than 50 billionths of a degree (one nanoradian, or 0.208533 milliarcsecond). The delay time of the quasar is subtracted from that of the spacecraft’s, providing the delta-DOR measurement and allowing for amazingly high-precision navigation across long distances.
“Quasar locations define a reference system. They enable engineers to improve the precision of the measurements taken by ground stations and improve the accuracy of the direction to the spacecraft to an order of a millionth of a degree.”
– Frank Budnik, ESA flight dynamics expert
So even though the quasar in NGC 4438 is located 50 million light-years from Earth, it can help engineers position a spacecraft located 100 million kilometers away to an accuracy of several hundred meters. Now that’s a star to steer her by!
On July 16, Expedition 36 astronauts Chris Cassidy and Luca Parmitano had to cut a planned 7-hour spacewalk short after only an hour and a half due to a malfunction in Parmitano’s space suit, leaking water into his helmet and eventually cutting off his vision, hearing, and communications. Fortunately the Italian test pilot was able to safely return inside the ISS, but for several minutes he was faced with a pretty frightening situation: stuck outside Space Station with his head in a fishbowl that was rapidly filling with water.
On August 20, he shared his personal account of the event on his ESA blog.
“The only idea I can think of is to open the safety valve by my left ear: if I create controlled depressurisation, I should manage to let out some of the water, at least until it freezes through sublimation, which would stop the flow. But making a ‘hole’ in my spacesuit really would be a last resort…”
Parmitano’s description of his suit mishap begins as I’m sure all spacewalks do: with a sense of energy and enthusiasm for a job about to be performed in a challenging yet exotic and undeniably privileged location.
“My eyes are closed as I listen to Chris counting down the atmospheric pressure inside the airlock – it’s close to zero now. But I’m not tired – quite the reverse! I feel fully charged, as if electricity and not blood were running through my veins. I just want to make sure I experience and remember everything. I’m mentally preparing myself to open the door because I will be the first to exit the Station this time round. Maybe it’s just as well that it’s night time: at least there won’t be anything to distract me.”
But even though the EVA initially progressed as planned — ahead of schedule, in fact — it soon became obvious to Parmitano that something was amiss with his suit.
“The unexpected sensation of water at the back of my neck surprises me – and I’m in a place where I’d rather not be surprised. I move my head from side to side, confirming my first impression, and with superhuman effort I force myself to inform Houston of what I can feel, knowing that it could signal the end of this EVA.”
Luca Parmitano on EVA on July 16, 2013. (ESA)
It didn’t take long before an uncomfortable situation escalated into something potentially very dangerous.
“As I move back along my route towards the airlock, I become more and more certain that the water is increasing. I feel it covering the sponge on my earphones and I wonder whether I’ll lose audio contact. The water has also almost completely covered the front of my visor, sticking to it and obscuring my vision. I realise that to get over one of the antennae on my route I will have to move my body into a vertical position, also in order for my safety cable to rewind normally. At that moment, as I turn ‘upside-down’, two things happen: the Sun sets, and my ability to see – already compromised by the water – completely vanishes, making my eyes useless; but worse than that, the water covers my nose – a really awful sensation that I make worse by my vain attempts to move the water by shaking my head. By now, the upper part of the helmet is full of water and I can’t even be sure that the next time I breathe I will fill my lungs with air and not liquid. To make matters worse, I realise that I can’t even understand which direction I should head in to get back to the airlock. I can’t see more than a few centimetres in front of me, not even enough to make out the handles we use to move around the Station.”
After contemplating opening a hole in his helmet to let out some of the water — a “last resort,” indeed — Parmitano managed to get back inside the airlock with help from Cassidy. But he still had to deal with the process of repressurization, which itself takes a few minutes.
“I try to move as little as possible to avoid moving the water inside my helmet. I keep giving information on my health, saying that I’m ok and that repressurization can continue. Now that we are repressurizing, I know that if the water does overwhelm me I can always open the helmet. I’ll probably lose consciousness, but in any case that would be better than drowning inside the helmet.”
Now, a month after the mishap, Parmitano reflects on the nature of the event and of space travel in general.
“Space is a harsh, inhospitable frontier and we are explorers, not colonisers. The skills of our engineers and the technology surrounding us make things appear simple when they are not, and perhaps we forget this sometimes.”
ESA astronaut Luca Parmitano is the first of ESA’s new generation of astronauts to fly into space. Luca will serve as flight engineer on the Station for Expeditions 36 and 37. He qualified as a European astronaut and was proposed by Italy’s ASI space agency for this mission.
ALMA/Spitzer image of a monster star in the process of forming
Even though it comprises over 99% of the mass of the Solar System (with Jupiter taking up most of the rest) our Sun is, in terms of the entire Milky Way, a fairly average star. There are lots of less massive stars than the Sun out there in the galaxy, as well as some real stellar monsters… and based on new observations from the Atacama Large Millimeter/submillimeter Array, there’s about to be one more.
Early science observations with ALMA have provided astronomers with the best view yet of a monster star in the process of forming within a dark cloud of dust and gas. Located 11,000 light-years away, Spitzer Dark Cloud 335.579-0.292 is a stellar womb containing over 500 times the mass of the Sun — and it’s still growing. Inside this cloud is an embryonic star hungrily feeding on inwardly-flowing material, and when it’s born it’s expected to be at least 100 times the mass of our Sun… a true stellar monster.
The location of SDC 335.579-0.292 in the southern constellation of Norma (ESO, IAU and Sky & Telescope)
The star-forming region is the largest ever found in our galaxy.
“The remarkable observations from ALMA allowed us to get the first really in-depth look at what was going on within this cloud,” said Nicolas Peretto of CEA/AIM Paris-Saclay, France, and Cardiff University, UK. “We wanted to see how monster stars form and grow, and we certainly achieved our aim! One of the sources we have found is an absolute giant — the largest protostellar core ever spotted in the Milky Way.”
SDC 335.579-0.292 had already been identified with NASA’s Spitzer and ESA’s Herschel space telescopes, but it took the unique sensitivity of ALMA to observe in detail both the amount of dust present and the motion of the gas within the dark cloud, revealing the massive embryonic star inside.
“Not only are these stars rare, but their birth is extremely rapid and their childhood is short, so finding such a massive object so early in its evolution is a spectacular result.”
– Team member Gary Fuller, University of Manchester, UK
The image above, a combination of data acquired by both Spitzer and ALMA (see below for separate images) shows tendrils of infalling material flowing toward a bright center where the huge protostar is located. These observations show how such massive stars form — through a steady collapse of the entire cloud, rather than through fragmented clustering.
SDC 335.579-0.292 seen in different wavelengths of light.
“Even though we already believed that the region was a good candidate for being a massive star-forming cloud, we were not expecting to find such a massive embryonic star at its center,” said Peretto. “This object is expected to form a star that is up to 100 times more massive than the Sun. Only about one in ten thousand of all the stars in the Milky Way reach that kind of mass!”
(Although, with at least 200 billion stars in the galaxy, that means there are still 20 million such giants roaming around out there!)
Over the past six years wind speeds in Venus' atmosphere have been steadily rising (ESA)
High-altitude winds on neighboring Venus have long been known to be quite speedy, whipping sulfuric-acid-laden clouds around the superheated planet at speeds well over 300 km/h (180 mph). And after over six years collecting data from orbit, ESA’s Venus Express has found that the winds there are steadily getting faster… and scientists really don’t know why.
Cloud structures in Venus’ atmosphere, seen by Venus Express’ Ultraviolet, Visible and Near-Infrared Mapping Spectrometer (VIRTIS) in 2007 (ESA)
By tracking the movements of distinct features in Venus’ cloud tops at an altitude of 70 km (43 miles) over a period of six years — which is 10 of Venus’ years — scientists have been able to monitor patterns in long-term global wind speeds.
What two separate studies have found is a rising trend in high-altitude wind speeds in a broad swath south of Venus’ equator, from around 300 km/h when Venus Express first entered orbit in 2006 to 400 km/h (250 mph) in 2012. That’s nearly double the wind speeds found in a category 4 hurricane here on Earth!
“This is an enormous increase in the already high wind speeds known in the atmosphere. Such a large variation has never before been observed on Venus, and we do not yet understand why this occurred,” said Igor Khatuntsev from the Space Research Institute in Moscow and lead author of a paper to be published in the journal Icarus.
Long-term studies based on tracking the motions of several hundred thousand cloud features, indicated here with arrows and ovals, reveal that the average wind speeds on Venus have increased from roughly 300 km/h to 400 km/h over the first six years of the mission. (Khatuntsev et al.)
A complementary Japanese-led study used a different tracking method to determine cloud motions, which arrived at similar results… as well as found other wind variations at lower altitudes in Venus’ southern hemisphere.
“Our analysis of cloud motions at low latitudes in the southern hemisphere showed that over the six years of study the velocity of the winds changed by up 70 km/h over a time scale of 255 Earth days – slightly longer than a year on Venus,” said Toru Kouyama from Japan’s Information Technology Research Institute. (Their results are to be published in the Journal of Geophysical Research.)
Both teams also identified daily wind speed variations on Venus, along with shifting wave patterns that suggest “upwelling motions in the morning at low latitudes and downwelling flow in the afternoon.” (via Cloud level winds from the Venus Express Monitoring Camera imaging, Khatuntsev et al.)
A day on Venus is longer than its year, as the planet takes 243 Earth days to complete a single rotation on its axis. Its atmosphere spins around it much more quickly than its surface rotates — a curious feature known as super-rotation.
“The atmospheric super-rotation of Venus is one of the great unexplained mysteries of the Solar System,” said ESA’s Venus Express Project Scientist Håkan Svedhem. “These results add more mystery to it, as Venus Express continues to surprise us with its ongoing observations of this dynamic, changing planet.”
The European/Russian ExoMars Trace Gas Orbiter (TGO) will launch in 2016 and sniff the Martian atmosphere for signs of methane which could originate for either biological or geological mechanisms. Credit: ESA
Has life ever existed on Mars? Or anywhere beyond Earth?
Answering that question is one of the most profound scientific inquiries of our time.
Europe and Russia have teamed up for a bold venture named ExoMars that’s set to blast off in search of Martian life in about two and a half years.
Determining if life ever originated on the Red Planet is the primary goal of the audacious two pronged ExoMars missions set to launch in 2016 & 2018 in a partnership between the European and Russian space agencies, ESA and Roscosmos.
In a major milestone announced today (June 17) at the Paris Air Show, ESA signed the implementing contract with Thales Alenia Space, the industrial prime contractor, to start the final construction phase for the 2016 Mars mission.
“The award of this contract provides continuity to the work of the industrial team members of Thales Alenia Space on this complex mission, and will ensure that it remains on track for launch in January 2016,” noted Alvaro Giménez, ESA’s Director of Science and Robotic Exploration.
ExoMars 2016 Mission to the Red Planet. It consists of two spacecraft – the Trace Gas Orbiter (TGO) and the Entry, Descent and Landing Demonstrator Module (EDM) which will land. Credit: ESA
The ambitious 2016 ExoMars mission comprises of both an orbiter and a lander- namely the methane sniffing Trace Gas Orbiter (TGO) and the piggybacked Entry, Descent and Landing Demonstrator Module (EDM).
ExoMars 2016 will be Europe’s first spacecraft dispatched to the Red Planet since the 2003 blast off of the phenomenally successful Mars Express mission – which just celebrated its 10th anniversary since launch.
Methane (CH4) gas is the simplest organic molecule and very low levels have reportedly been detected in the thin Martian atmosphere. But the data are not certain and its origin is not clear cut.
Methane could be a marker either for active living organisms today or it could originate from non life geologic processes. On Earth more than 90% of the methane originates from biological sources.
The ExoMars 2016 orbiter will investigate the source and precisely measure the quantity of the methane.
The 2016 lander will carry an international suite of science instruments and test European landing technologies for the 2nd ExoMars mission slated for 2018.
The 2016 ExoMars Trace Gas Orbiter will carry and deploy the Entry, Descent and Landing Demonstrator Module to the surface of Mars. Credit: ESA-AOES Medialab
The 2018 ExoMars mission will deliver an advanced rover to the Red Planet’s surface. It is equipped with the first ever deep driller that can collect samples to depths of 2 meters where the environment is shielded from the harsh conditions on the surface – namely the constant bombardment of cosmic radiation and the presence of strong oxidants like perchlorates that can destroy organic molecules.
Elements of the ExoMars program 2016-2018. Credit: ESAThereafter Russia agreed to take NASA’s place and provide the much needed funding and rockets for the pair of planetary launches scheduled for January 2016 and May 2018.
NASA does not have the funds to launch another Mars rover until 2020 at the earliest – and continuing budget cuts threaten even the 2020 launch date.
NASA will still have a small role in the ExoMars project by funding several science instruments.
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Learn more about Mars, Curiosity, Opportunity, MAVEN, LADEE and NASA missions at Ken’s upcoming lecture presentations
June 23: “Send your Name to Mars on MAVEN” and “CIBER Astro Sat, LADEE Lunar & Antares Rocket Launches from Virginia”; Rodeway Inn, Chincoteague, VA, 8 PM
