Tag: science

SpaceX wins NASA satellite launch contract

6:28 pm

The competition heats up: NASA has awarded SpaceX the contract to launch its Earth science satellite, Surface Water and Ocean Topography (SWOT).

This sentence from the press release is puzzling:

The total cost for NASA to launch SWOT is approximately $112 million, which includes the launch service; spacecraft processing; payload integration; and tracking, data and telemetry support.

Since SpaceX touts a launch price for its Falcon 9 rocket as $62 million, I wonder why this launch will cost NASA almost twice as much. Was there so little competition in the bidding that SpaceX could bid higher and thus get more money? Or is NASA so disinterested in saving money that it left itself open to overpaying for something that everyone else gets for far else?

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Ceres’ cratered surface

10:27 am

Ceres' crated surface

Cool image time! The picture on the right, reduced to show here, was taken on October 17 and was the tenth image taken by Dawn in its new extended mission in orbit around Ceres.

This image of the limb of dwarf planet Ceres shows a section of the northern hemisphere. A shadowy portion of Occator Crater can be seen at the lower right — its bright “spot” areas are outside of the frame of view. Part of Kaikara Crater (45 miles, 72 kilometers in diameter) is visible at top left.

The image was taken from 920 miles away and has a resolution of about 460 feet per pixel.

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Drilling at the Chicxulub impact site has unveiled the crater’s shape

10:19 am

The new rock core drilled at the crater impact site that is thought to have help cause the extinction of the dinosaurs 65 million years ago has helped reveal the crater’s formation and shape, including the existence of an inner ring of mountains which scientists call a peak-ring.

After a decade of planning, the project penetrated 1,335 metres into the sea floor off the coast of Progreso, Mexico, in April and May. Drillers hit the first peak-ring rocks at a depth of 618 metres, and a pinkish granite at 748 metres. Geologists know that the granite must have come from relatively deep in the crust — perhaps 8–10 kilometres down — because it contains big crystals. The size of these crystals suggests that they formed by the slow cooling of deep, molten rock; in contrast, rapid cooling at shallow depth tends to form small crystals. Finding the granite relatively high in the drill core means that something must have lifted it up and then thrown down it on top of other rocks.

That rules out one idea of how craters form, in which the pulverized rock stays mostly in place like hot soup in a bowl. Instead, the core confirms the ‘dynamic collapse’ model of cosmic impacts, in which the asteroid punches a deep hole in the crust, causing the rock to flow like a liquid and spurt skyward. That rock then falls back to Earth, splattering around in a peak ring.

To put it another way, the impact moved the earth like a pebble dropped into a pond of water, causing at least two big circular ripples that flowed just like water but then quickly froze in place to form the two concentric peak-ring mountain ranges.

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Scientists puzzle over possible connection between a fast radio burst and a gamma ray burst

9:31 am

The uncertainty of science: In trying to explain the relatively new mystery of fast radio bursts (FRB), of which only about 20 have been detected and of which very little is known, scientists are intrigued by a gamma ray burst (GRB) that apparently occurred at the same time and place of one FRB.

Seeing the FRB event in a different wavelength would normally help astronomers better understand the FRB The problem is that this particular GRB only makes the mystery of FRBs more baffling.

One puzzle is that the two signals portray different pictures of the underlying source, which seems to be as much as 10 billion light years (3.2 gigaparsecs) away. Whereas the radio burst lasted just a few milliseconds, the γ-ray signal lasted between two and six minutes, and it released much more energy in total than the radio burst. “We’ve pumped up the energy budget more than a billion times,” says study co-author Derek Fox, an astrophysicist at Penn State.

This has big implications for the FRB’s origin. One leading theory suggests that FRBs are flares from distant magnetars — neutron stars with enormous magnetic fields that could generate short, energetic blasts of energy, and do so repeatedly, as at least one FRB is known to do. Although magnetars are thought to produce γ-rays, they would not emit such high energy and over such a long time, says Fox. “This is a severe challenge for magnetar models,” he says.

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New conclusions about Pluto from New Horizons data

1:00 am

Based on New Horizons data scientists have proposed that Pluto’s equatorial tilt has been shifted because of a seasonal pile-up of nitrogen that literally causes the planet to tip over.

Over the course of a Pluto year, nitrogen and other exotic gases condense on the permanently shadowed regions, and eventually, as Pluto goes around the sun, those frozen gases heat up, become gaseous again and re-condense on the other side of the planet, resulting in seasonal “snowfall” on Sputnik Planitia. “Each time Pluto goes around the sun, a bit of nitrogen accumulates in the heart,” Keane said. “And once enough ice has piled up, maybe a hundred meters thick, it starts to overwhelm the planet’s shape, which dictates the planet’s orientation. And if you have an excess of mass in one spot on the planet, it wants to go to the equator. Eventually, over millions of years, it will drag the whole planet over.”

The theory also requires there to be a subsurface ocean as well.

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TMT legal case in Hawaii gets messier

7:02 pm

The permit process in Hawaii for the Thirty Meter Telescope has gotten far messier, with the telescope’s opponents appealing to the state’s Supreme Court, complaining about witness procedures and the lawyers who are working for the state, while the land board running the procedures has asked the court to dismiss this appeal.

Essentially, the opponents are using every trick in the book to delay the permit process, and it appears that the law in Hawaii, including one just passed in August, is designed to aid them in this tactic.

TMT will not be built in Hawaii.The consortium that is building it needs a decision by early next year at the latest. They ain’t gonna get it. The luddites going to win, and Hawaii will be far poorer because of it.

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The Fact and Fiction of the NASA EmDrive Paper Leak

9:00 am

A NASA paper outlining work that appears to substantiate the EmDrive concept that involves the production of a thrust in a way that violates the laws of physics was leaked last week, and this story tries to figure out what has been learned.

To me, the key is this paragraph:

In essence, the NASA EmDrive in the paper consists of a closed copper cone, the inside of which is being bombarded with microwaves. To test the EmDrive, the researchers powered it with 40, 60, and 80 watts and found that it generated up to 58, 128, and 119 micronewtons of thrust, respectively. Given that this “anomaly” was still observed by White and his colleagues after accounting for error, this suggests that the results of the experiment show an EmDrive is indeed possible.

Based on these results, the researchers estimated that their contraption would be capable of generating approximately 1.2 millinewtons of thrust per kilowatt were they to scale up the power input. To put this in perspective, the Hall thruster—one of the most powerful in development and powered by ejecting plasma—generates about 60 millinewtons of thrust per kilowatt. [emphasis mine]

Interestingly , the article did not comment on how little thrust this EmDrive test produced. This tiny amount, however, to me suggests strongly that what they are measuring is some outside force acting on the drive that they have missed that would invalidate all the theories listed in the article. And even if the thrust drive does prove a new component of fundamental physics, as suggested in the article, the system simply doesn’t appear to produce enough thrust to make it practical.

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Mars rover update: November 14, 2016

12:10 pm

Curiosity

Curiosity looking south, Sol 1516

For the overall context of Curiosity’s travels, see Pinpointing Curiosity’s location in Gale Crater.

Since my last update on November 3rd, Curiosity has reached the region of sand dunes and has started to pick its way through it. The panorama above was created using images from the rover’s left navigation camera, taken on Sol 1516. It looks south, with Mount Sharp rising on the left.

That same day Curiosity also used its mast camera to zoom in on the canyon gap in the center of the panorama. The first image below is the wider mast camera shot, with the an outline showing the even closer zoom-in below that.
» Read more

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Oxo Crater on Ceres

10:13 am

Oxo Crater on Ceres

Cool image time! The Dawn image at the right, cropped to show here, was taken on April 19, 2016. It shows the crater Oxo on Ceres and is especially intriguing because it not provides high resolution imagery of the crater’s bright rim, the second brightest feature on Ceres, it also shows how the southeastern part of the crater’s rim has literally slide down into the crater, leaving behind a gaping rombus-shaped pit.

The slumping, combined with the bright material on the rim, is more evidence that at some point in the past Ceres was geologically active.

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The pushback against Trump begins

9:59 am

Articles today in the science journals Science and Nature give us a taste of the upcoming resistance by the science community to any policy changes put forth by the new Trump administration.

Both articles assume that the Paris climate agreement is already the law of the land, despite the basic fact that the Senate has not approved it. In fact, if Trump and Congress decide to cut all American ties with it, they can. Right now it is merely something that Obama has agreed to, and under our Constitution, the legalities binding us to that agreement are weak, at best.

This quote from the Science article outlines how the science community plans to structure its resistance:

With oilmen like Harold Hamm, CEO of Continental Resources, and Forrest Lucas, the founder of Lucas Oil, named as potential candidates to lead the Departments of Energy and the Interior, respectively, in a Trump administration, the mostly likely historical analogue for the next few years could be the start of Ronald Reagan’s presidency, when he appointed senior officials who were often hostile to the policies of their own agencies. For example, Reagan’s Secretary of the Interior, James Watt, wanted to sell off public lands and reduce forest protections, and his EPA head, Anne Gorsuch, moved to soften clear air and water rules. Some agency staff fought back, and there were frequent leaks, resignations, and lawsuits. Both Watt and Gorsuch ultimately resigned amidst political chaos, and were replaced by less polarizing appointments. If Trump follows a similar path, “there could be a whole lot of churn,” Victor predicts.

Indeed, Trump may quickly learn the limits of the presidency, Victor adds. “The Oval Office will be a lonely place,” he says, if the White House attempts to make radical changes that agency professional staff fiercely opposes. [emphasis mine]

And then there is this quote from the Nature article:

“Trump will be the first anti-science president we have ever had,” says Michael Lubell, director of public affairs for the American Physical Society in Washington DC. “The consequences are going to be very, very severe.”

Calling Trump “the first anti-science president” is the kind of name-calling that is typical of the left and the Democratic Party. Not only is it a silly statement, based merely on the partisan hatred of Republicans by scientists, almost all of whom are Democratic Party loyalists, it has nothing to do with reality. Scientists have no more right to a blank check from the government than anyone else. They need to justify their research, and show that it is worthwhile. Since the 1990s they have not had to do this, which has resulted in blooming budgets and a lot of questionable results. And I say this as a science guy. Unlike these partisans, however, I also recognize that there is a gigantic amount of needless spending in the science budgets of numerous government agencies. Their budgets have grown significantly since 2000, with little to show for it. It is time to bring that spending under some control.

This is only the first shot across the bow. I have no doubt that the science community plans to link up with the partisan mainstream press to create a full-court press against any policy changes or budget cuts that either Trump or Congress may propose. These people do not respect the concept of democracy, and will resist the will of the public in every way they can.

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Decline in sunspots continues

10:26 pm

Late Sunday NOAA posted its monthly update of the solar cycle, covering sunspot activity for October. As I do every month, I am posting it here with annotations to give it context.

October 2016 Solar Cycle graph

The graph above has been modified to show the predictions of the solar science community. The green curves show the community’s two original predictions from April 2007, with half the scientists predicting a very strong maximum and half predicting a weak one. The red curve is their revised May 2009 prediction.

The sunspot decline continued in October, dropping the sunspot number for the month to below the 2007 low prediction. Though the decline continues to track that low prediction, the sunspot count for November has been even lower, suggesting that the ramp down to solar minimum will continue to under perform that prediction and will arrive at minimum sooner than expected. As I noted last month, this fast decline will also mean that the ending solar cycle will be a both a weak and a short cycle, two phenomenon that in the past never went together. In the past, a short cycle meant the maximum was strong, while a long cycle would correspond with a weak maximum.

The Sun continues to behave in a manner that is unprecedented, and suggests the possibility that a Grand Minimum might be coming.

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Largest Texas meteorite ever found by accident on dude ranch

10:13 am

The largest Texas meteorite ever, weighing 760 pounds, has been found on a Texas dude ranch.

The owner found it entirely by accident. It apparently had been there for a long time, but no one had noticed it, mostly because of its weathered appearance that made it appear much like any other boulder. Tests proved beyond doubt, however, that it was a meteorite, an L4 chrondite. It has now been sold to a meteorite collection at Texas Christian University in Ft. Worth.

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Curiosity finds a meteorite

6:37 pm

The Curiosity science team have identified and now analyzed a nickel-iron meteorite that Curiosity spotted on October 27.

Scientists of the Mars Science Laboratory (MSL) project, which operates the rover, first noticed the odd-looking rock in images taken by Curiosity’s Mast Camera (Mastcam) at at a site the rover reached by an Oct. 27 drive. “The dark, smooth and lustrous aspect of this target, and its sort of spherical shape attracted the attention of some MSL scientists when we received the Mastcam images at the new location,” said ChemCam team member Pierre-Yves Meslin, at the Research Institute in Astrophysics and Planetology (IRAP), of France’s National Center for Scientific Research (CNRS) and the University of Toulouse, France.

ChemCam found iron, nickel and phosphorus, plus lesser ingredients, in concentrations still being determined through analysis of the spectrum of light produced from dozens of laser pulses at nine spots on the object. The enrichment in both nickel and phosphorus at some of the same points suggests the presence of an iron-nickel-phosphide mineral that is rare except in iron-nickel meteorites, Meslin said.

The find is not unprecedented but it is interesting nonetheless.

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TMT consortium picks Canary Islands as alternative site to Hawaii

6:52 pm

Faced with delays from protesters and an Hawaiian government slow-walking its permit process, the consortium building the Thirty Meter Telescope has announced that it will build the telescope on the Canary Islands if it continues to be blocked in Hawaii.

The article does not say when they will make this decision, but based on previous reports, they have to make their decision soon in order to begin construction no later than April 2018.

I fully expect them to abandon Hawaii, since I see no desire by the Hawaiian government to play fair during the new permit hearings. Instead, it seems to me that they are rigging this process so that it will never end.

Posted from the south rim of the Grand Canyon, where Diane and I plan a nice day hike tomorrow down the Hermit Trail.

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Saturn from above

9:53 am

Saturn from above.

Cool image time! The image on the right, reduced in resolution to show here, shows Saturn from above as Cassini began re-positioning itself into a higher inclination orbit for its last year of orbit dives near and inside the planet’s rings.

The view looks toward the sunlit side of the rings from about 41 degrees above the ring plane. The image was taken with the Cassini spacecraft wide-angle camera on July 16, 2016 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 752 nanometers. The view was acquired at a distance of approximately 1 million miles (2 million kilometers) from Saturn. Image scale is 68 miles (110 kilometers) per pixel.

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Resonance experiment

6:01 pm

An evening pause: While I am sure there are engineers out there who can explain how the interaction of the vibrator with the plate causes the patterns, I look at this from my more philosophical side, and note how this experiment reveals very simply how the universe is filled with hidden wonders and patterns that challenge us as humans to uncover.

Hat tip Tom Wilson.

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More climate fear-mongering

12:27 pm

This article from the journal Nature yesterday, Climate change could flip Mediterranean lands to desert, about a new Science journal paper, is very typical of too much of the climate research and reporting these days.

First, they outline the coming and certain disaster:

Maintaining the historic ranges of the region’s ecosystems would require limiting warming to just 1.5 ºC, by making substantial cuts to the world’s greenhouse-gas emissions, the analysis concludes. Otherwise, the vegetation and ecosystems of the Mediterranean basin will shift as temperatures rise. Increasing desertification in southern Europe is just one of the changes that would result. “Everything is moving in parallel. Shrubby vegetation will move into the deciduous forests, while the forests move to higher elevation in the mountains,” says Joel Guiot, a palaeoclimatologist at the European Centre for Geoscience Research and Education in Aix-en-Provence, France, and lead author of the study.

Then they point out the necessary political solution, which of course requires us to agree to an odious international agreement that will limit our individual freedoms and give more power to international governments:

“I like that they’re doing this comparison across different warming scenarios in line with the Paris agreement, to start to gauge the sensitivity to them,” says Benjamin Cook, a climate scientist at the NASA Goddard Institute for Space Studies in New York City. The study confirms the vulnerability of many ecosystems, and could guide policymakers’ efforts to help natural systems adapt to climate change, says Patrick Gonzalez, principal climate-change scientist at the US National Park Service based at the University of California, Berkeley. “This study shows how essential it is for nations to meet their Paris commitments.”

Only at the very end of the article, almost as an aside, do they note these inconvenient facts about the limitations of the paper (which also happens to be based entirely on computer models):
» Read more

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New Horizons returns the last data from Pluto fly-by

2:47 pm

The New Horizons science team announced today that they have finally received the last bit of data obtained by the spacecraft during its July 14, 2015 fly-by of Pluto.

Having traveled from the New Horizons spacecraft over 3.1 billion miles (five hours, eight minutes at light speed), the final item – a segment of a Pluto-Charon observation sequence taken by the Ralph/LEISA imager – arrived at mission operations at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, at 5:48 a.m. EDT on Oct. 25. The downlink came via NASA’s Deep Space Network station in Canberra, Australia. It was the last of the 50-plus total gigabits of Pluto system data transmitted to Earth by New Horizons over the past 15 months.

Once they have checked this data, they will wipe the spacecraft’s onboard hard drives to prepare for the January 1, 2019 fly-by of Kuiper Belt object 2014 MU69.

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New details emerge of Schiaparelli crash site

10:36 am

Schiaparelli crash site

A new high resolution image from Mars Reconnaissance Orbiter’s HIRISE camera, reduced in resolution on the right, confirms that Schiaparelli crashed into the ground on October 19.

The scene shown by HiRISE includes three locations where hardware reached the ground. A dark, roughly circular feature is interpreted as where the lander itself struck. A pattern of rays extending from the circle suggests that a shallow crater was excavated by the impact, as expected given the premature engine shutdown. About 0.8 mile (1.4 kilometers) eastward, an object with several bright spots surrounded by darkened ground is likely the heat shield. About 0.8 mile (1.4 kilometers) south of the lander impact site, two features side-by-side are interpreted as the spacecraft’s parachute and the back shell to which the parachute was attached.

The center insert is a close-up of the impact site on the left, which clearly shows that the lander hit the ground hard, producing impact ejecta. That the rays are somewhat asymmetric also suggests that Schiaparellit hit the ground at an oblique angle.

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Birds that can fly practically forever

10:01 am

New research using data loggers tagged to thirteen common swifts has revealed that these birds were capable of remaining airborne for months at a time.

The researchers found that some of the birds made a few brief night landings in winter but remained airborne for 99% of the time. Three birds didn’t touch down once in the entire ten months….“Common swifts have evolved to be very efficient flyers, with streamlined body shapes and long and narrow wings, generating lift force at low cost,” says Anders Hedenström, a study co-author and a biologist at Lund University in Sweden. The birds even eat while airborne, snatching flying termites, ballooning spiders and other aerial insects for in-flight meals.

Hedenström says that common swifts have adapted to a low-energy lifestyle, but his team does not yet know whether the birds sleep while aloft. “Most animals suffer dramatically from far less sleep loss,” says Niels Rattenborg, a neurobiologist at Max Planck Institute for Ornithology in Seewiesen, Germany. “But these birds seem to have found a trick through evolution that allows them to get by on far less sleep.”

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The effect of weightlessness on the spine

9:04 am

New observations of astronauts before and after four to seven month long missions to ISS has found the back pain many astronauts experience appears to be caused by significant muscle atrophy.

The MRI scans indicated significant atrophy of the paraspinal lean muscle mass —which plays a critical role in spinal support and movement—during the astronauts’ time in space. The lean muscle, or “functional,” cross-sectional area of the lumbar paraspinal muscles decreased by an average of 19 percent from preflight to immediate postflight scans. A month or two later, only about two-thirds of the reduction had recovered. There was an even more dramatic reduction in the functional cross-sectional area of the paraspinal muscles relative to total paraspinal cross-sectional area. The ratio of lean muscle decreased from 86 percent preflight to 72 percent immediately postflight. At follow-up, the ratio recovered to 81 percent, but was still less than the preflight value.

In contrast, there was no consistent change in the height of the spinal intervertebral discs. Dr. Chang and coauthors write, “These measurements run counter to previous hypotheses about the effects of microgravity on disc swelling.” Further studies will be needed to clarify the effects on disc height, and whether they contribute to the increase in body height during space missions, and to the increased risk of herniated disc disease.

These results are very encouraging, because they indicate that the back problems seen are mostly attributable to weakened muscles, not actual spinal damage, and can therefore be more easily mitigated by new exercises while in orbit.

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Aggressive SETI observations of Tabby’s star upcoming

8:29 am

Breakthrough Listen, an effort to listen for radio signals from alien civilizations that, plans to devote significant time this year observing Tabby’s star to see if an alien mega-structures are causing that star’s unexplained dimming.

While Siemion and his colleagues are skeptical that the star’s unique behavior is a sign of an advanced civilization, they can’t not take a look. They’ve teamed up with UC Berkeley visiting astronomer Jason Wright and Tabetha Boyajian, the assistant professor of physics and astronomy at Louisiana State University for whom the star is named, to observe the star with state-of-the-art instruments the Breakthrough Listen team recently mounted on the 100-meter telescope. Wright is at the Center for Exoplanets and Habitable Worlds at Pennsylvania State University.

The observations are scheduled for eight hours per night for three nights over the next two months, starting Wednesday evening, Oct. 26. Siemion, Wright and Boyajian are traveling to the Green Bank Observatory in rural West Virginia to start the observations, and expect to gather around 1 petabyte of data over hundreds of millions of individual radio channels.

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Juno successfully completes engine burn with smaller thrusters

7:01 pm

Having successfully left safe mode, engineers had Juno do a 31 minute engine burn on Tuesday to adjust its orbit using its smaller thrusters.

The burn, which lasted just over 31 minutes, changed Juno’s orbital velocity by about 5.8 mph (2.6 meters per second) and consumed about 8 pounds (3.6 kilograms) of propellant. Juno will perform its next science flyby of Jupiter on Dec. 11, with time of closest approach to the gas giant occurring at 9:03 a.m. PDT (12:03 p.m. EDT). The complete suite of Juno’s science instruments, as well as the JunoCam imager, will be collecting data during the upcoming flyby.

That they will definitely collect data during the December 11 flyby means that they are going to delay again the main engine burn that will reduce the spacecraft’s orbit to 14 days, its official science orbit. This also means that they are still uncomfortable firing that main engine. It is also not clear from the press release whether this burn was planned, or was added to compensate for the main engine issues.

The vagueness makes me think that Juno has some serious issues that they haven’t yet told us about.

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The storms of Jupiter’s south pole

10:12 am

storms on Jupiter

Cool image time! Even though Juno has been unable to gather any additional data since its first close approach of Jupiter in August because of technical problems, the science team has set up its website to allow the public to download the images produced so far, process those images, and then upload them to the site for the world to see.

The image to the right, reduced in resolution to show here, is one example of the many different processed images produced by interested members of the general public. It highlights the seemingly incoherent storms that are raging at Jupiter’s south pole.

close-up of storms

To the left is a cropped section of the full resolution image. It shows the complex transition zone between the darker polar regions and the brighter band that surrounds it. This chaotic atmospheric behavior is something that no climate scientist has ever seen before. It will take decades of research to untangle and even begin to understand what is happening.

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Schiaparelli failure focuses in on altimeter data

9:50 am

The investigation into the landing failure last week of the ExoMars 2016 lander, Schiaparelli, is now focusing on a failure in the spacecraft’s altitude software.

The most likely culprit is a flaw in the craft’s software or a problem in merging the data coming from different sensors, which may have led the craft to believe it was lower in altitude than it really was, says Andrea Accomazzo, ESA’s head of solar and planetary missions. Accomazzo says that this is a hunch; he is reluctant to diagnose the fault before a full post-mortem has been carried out. But if he is right, that is both bad and good news.

European-designed computing, software and sensors are among the elements of the lander that are to be reused on the ExoMars 2020 landing system, which, unlike Schiaparelli, will involve a mixture of European and Russian technology. But software glitches should be easier to fix than a fundamental problem with the landing hardware, which ESA scientists say seems to have passed its test with flying colours. “If we have a serious technological issue, then it’s different, then we have to re-evaluate carefully. But I don’t expect it to be the case,” says Accomazzo.

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ISRO begins ground tests of its first lunar lander

9:36 am

The competition heats up: ISRO, India’s space agency, has begun testing the sensors its first lunar lander, Chandrayaan-2, will use to descend safely to the surface.

ISRO Satellite Centre or ISAC, which is the lead centre for the country’s second moon mission, has artificially created eight to ten craters to make the terrain resemble the lunar surface. This terrain is now the test bed for the lunar Lander’s sensors. Between Friday and Monday, a small ISRO-owned aircraft carrying equipment with the sensors flew a few times over these craters to see how well they performed.

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Changing seasons on Titan

9:15 am

Since entering Saturn orbit in 2004, Cassini has seen the seasons on Titan shift through half a Saturn year.

As Titan approaches its northern summer solstice, NASA’s Cassini spacecraft has revealed dramatic seasonal changes in the atmospheric temperature and composition of Saturn’s largest moon. Winter is taking a grip on the southern hemisphere and a strong vortex, enriched in trace gases, has developed in the upper atmosphere over the south pole. These observations show a polar reversal in Titan’s atmosphere since Cassini arrived at Saturn in 2004, when similar features were seen in the northern hemisphere.

Sadly, there will not be any spacecraft at Saturn during the second half of this Saturn year. After Cassini ends its mission in 2017 it will likely be many decades before another spacecraft arrives, since at this moment none has even been proposed.

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