December 6, 2016December 18, 2016 by Evan Gough

Cassini’s First Ring-Grazing Orbit A Success

This graphic shows the closest approaches of Cassini's final two orbital phases. Ring-grazing orbits are shown in gray (at left); Grand Finale orbits are shown in blue. The orange line shows the spacecraft's Sept. 2017 final plunge into Saturn. Credit: NASA/JPL-Caltech

The Cassini-Huygens mission is coming to an end.

Cassini was launched in 1997 and reached Saturn in 2004. It will end its mission by plunging into the gas giant. But before then, it will dive through Saturn’s rings a total of 20 times.

An artist's illustration of Cassini entering orbit around Saturn. Public Domain, https://commons.wikimedia.org/w/index.php?curid=626636 — An artist’s illustration of Cassini entering orbit around Saturn. Public Domain, https://commons.wikimedia.org/w/index.php?curid=626636

The first dive through the rings was just completed, and represents the beginning of Cassini’s final mission phase. On December 4th at 5:09 PST the 2,150 kg, plutonium-powered probe, crossed through a faint and dusty ring created by the moons Janus and Epimetheus. This brought it to within 11,000 km of Saturn’s F-ring.

Though the end of a mission might seem sad, people behind the mission are excited about this final phase, a series of close encounters with the most iconic structures in our Solar System: Saturn’s glorious rings.

“This is a remarkable time in what’s already been a thrilling journey.” – Linda Spilker, NASA/JPL

“It’s taken years of planning, but now that we’re finally here, the whole Cassini team is excited to begin studying the data that come from these ring-grazing orbits,” said Linda Spilker, Cassini project scientist at JPL. “This is a remarkable time in what’s already been a thrilling journey.”

Even casual followers of space news have enjoyed the steady stream of eye candy from Cassini. But this first orbit through Saturn’s rings is more about science than pictures. The probe’s cameras captured images 2 days before crossing through the plane of the rings, but not during the closest approach. In future ring-grazing orbits, Cassini will give us some of the best views yet of Saturn’s outer rings and some of the small moons that reside there.

Cassini is about more than just beautiful images though. It’s a vital link in a series of missions that have opened up our understanding of the Solar System we inhabit. Here are some of Cassini’s important discoveries:

New Moons

The Cassini mission discovered 7 new moons orbiting Saturn. Methone, Pallene and Polydeuces were all discovered in 2004. Daphnis, Anthe, and Aegaeon were discovered between 2005 and 2009. The final moon is currently named S/2009 S 1.

This image shows the moon Daphnis in the Keeler gap in Saturn's A ring. The moon's gravity causes the wave shapes in the rings. By NASA/JPL/Space Science Institute - http://www.esa.int/SPECIALS/Cassini-Huygens/SEM1XQ5TI8E_1.html, Public Domain, https://commons.wikimedia.org/w/index.php?curid=17953334 — This image shows the moon Daphnis in the Keeler gap in Saturn’s A ring. The moon’s gravity causes the wave shapes in the rings. By NASA/JPL/Space Science Institute – http://www.esa.int/SPECIALS/Cassini-Huygens/SEM1XQ5TI8E_1.html, Public Domain, https://commons.wikimedia.org/w/index.php?curid=17953334

In 2014, NASA reported that yet another new moon may be forming in Saturn’s A ring.

This Cassini image shows what might be a new moon forming in Saturn's rings. The new moon, if it is one, is only about 1 km in diameter. By NASA/JPL-Caltech/Space Science Institute - http://photojournal.jpl.nasa.gov/jpeg/PIA18078.jpg, Public Domain, https://commons.wikimedia.org/w/index.php?curid=32184174 — This Cassini image shows what might be a new moon forming in Saturn’s rings. The new moon, if it is one, is only about 1 km in diameter. By NASA/JPL-Caltech/Space Science Institute – http://photojournal.jpl.nasa.gov/jpeg/PIA18078.jpg, Public Domain, https://commons.wikimedia.org/w/index.php?curid=32184174

Huygens lands on Titan

The Huygens lander detached from the Cassini orbiter on Christmas Day 2004. It landed on the frigid surface of Saturn’s moon Titan after a 2 1/2 hour descent. The lander transmitted 350 pictures of Titan’s descent to the surface. An unfortunate software error caused the loss of another 350 pictures.

The first-ever images of the surface of a new moon or planet are always exciting. This image was taken by the Huygens probe at its landing site on Titan. Image Credit: ESA/NASA/JPL/University of Arizona

Enceladus Flyby

Cassini performed several flybys of the moon Enceladus. The first was in 2005, and the last one was in 2015. The discovery of ice-plumes and a salty liquid ocean were huge for the mission. The presence of liquid water on Enceladus makes it one of the most likely places for microbial life to exist in our Solar System.

In 2005 Cassini discovered jets of water vapor and ice erupting form the surface of Enceladus. The water could be from an subsurface sea. Image Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA

Each of Cassini’s final ring-grazing orbits will last one week. Cassini’s final orbit will bring it close to Saturn’s moon Titan. That encounter will change Cassini’s path. Cassini will leap over the rings and make the first of 22 plunges through the gap between Saturn and its rings.

In September 2017, the Cassini probe will finally reach the end of its epic mission. In order to prevent any possible contamination of Saturn’s moons, the probe will make one last glorious plunge into Saturn’s atmosphere, transmitting data until it is destroyed.

The Cassini mission is a joint mission between the European Space Agency, NASA, and the Italian Space Agency.

November 22, 2016November 26, 2016 by Nancy Atkinson

Cassini Is About To Graze Saturn’s Rings In Mission Endgame

A lovely view of Saturn and its rings as seen by the Cassini spacecraft on Aug. 12, 2009. Credit: NASA/JPL-Caltech/Space Science Institute.

There is a Twitter-bot that randomly tweets out “NOOOOOOOO Cassini can’t be ending!” (with varying amounts of “O’s”). @CassiniNooo represents the collective sigh of sadness and consternation felt by those of us who can’t believe the the historic and extensive Cassini mission will be over in just a matter of months.

And next week is the beginning of the end for Cassini.

On November 30, Cassini will begin a phase of the mission that the science team calls “Cassini’s Ring-Grazing Orbits,” as the spacecraft will start skimming past the outer edge of the rings, coming within – at times — 4,850 miles (7,800 kilometers) of the rings.

“The scientific return will be incredible,” Linda Spilker, Cassini project scientist, told me earlier this year. “We’ll be studying things we just couldn’t do any other place.”

Between November 30, 2016 and April 22, 2017 Cassini will circle high over and under the poles of Saturn, diving every seven days for a total of 20 times through the unexplored region at the outer edge of the main rings.

During the close passes, Cassini’s instruments will attempt to directly sample the icy ring particles and molecules of faint gases that are found close to the rings. Cassini will also capture some of the best high-resolution images of the rings, and garner the best views ever of the small moons Atlas, Pan, Daphnis and Pandora, which orbit near the rings’ outer edges.

During the first two ring-grazing orbits, the spacecraft will pass directly through an extremely faint ring produced by tiny meteors striking the two small moons Janus and Epimetheus. Later ring crossings in March and April will send the spacecraft through the dusty outer reaches of the F ring.

“Even though we’re flying closer to the F ring than we ever have, … there’s very little concern over dust hazard at that range,” said Earl Maize, Cassini project manager at JPL.

Of course, the ultimate ‘endgame’ is that Cassini will plunge into Saturn with its “Grand Finale,” ending the mission on September 15, 2017. Since Cassini is running out of fuel, destroying the spacecraft is necessary to ensure “planetary protection,” making sure any potential microbes from Earth that may still be attached to the spacecraft don’t contaminate any of Saturn’s potentially habitable moons.

This graphic illustrates the Cassini spacecraft's trajectory, or flight path, during the final two phases of its mission. The view is toward Saturn as seen from Earth. The 20 ring-grazing orbits are shown in gray; the 22 grand finale orbits are shown in blue. The final partial orbit is colored orange. Image credit: NASA/JPL-Caltech/Space Science Institute — This graphic illustrates the Cassini spacecraft’s trajectory, or flight path, during the final two phases of its mission. The view is toward Saturn as seen from Earth. The 20 ring-grazing orbits are shown in gray; the 22 grand finale orbits are shown in blue. The final partial orbit is colored orange. Image credit: NASA/JPL-Caltech/Space Science Institute

To prepare for the Grand Finale, Cassini engineers have been slowly adjusting the spacecraft’s orbit since January of this year, doing maneuvers and burns of the engine to bring Cassini into the right orbit so that it can ultimately dive repeatedly through the narrow gap between Saturn and its rings, before making its mission-ending plunge. During some of those final orbits, Cassini will pass as close as 1,012 miles (1,628 kilometers) above the cloudtops of Saturn.

One question for Cassini’s engineering team is how much fuel is actually left in the tank for Cassini’s main engines, which do the majority of the work for orbit adjustments. Each time they’ve used the main engines this past year, the team has held their breath, hoping there is enough fuel.

One final burn of the main engine remains, on December 4. This maneuver is important for fine-tuning the orbit and setting the correct course to enable the remainder of the mission, said Maize.

“This will be the 183rd and last currently planned firing of our main engine,” he said. “Although we could still decide to use the engine again, the plan is to complete the remaining maneuvers using thrusters,” said Maize.

A montage of images from Cassini of various moons and the rings around Saturn. Credit: NASA/JPL-Caltech/Space Science Institute

When I visited with Maize and Spilker earlier this year, Spilker wistfully said that they had begun to experience some of the “lasts” of the mission — the final flyby of Enceladus and other moons. And there’s one big “last” coming up: on Nov. 29, 2016, Cassini will come within 6,800 miles (11,000 km) of Titan, the final flyby of this eerily Earthlike but yet totally alien moon.

This final flyby, named Flyby T-125 has two primary goals: Mapmaking of Titan’s surface, and enabling the change in Cassini’s orbit to begin the end of the mission. But it also might be the most daring and thrilling part of Cassini’s nearly 20-year mission.

But still ….. NOOOOOO!

Keep track of Cassini’s latest endeavours at the Cassini website

November 18, 2016October 26, 2019 by Fraser Cain

Weekly Space Hangout – November 18, 2016: Dr. Jason Wright and Tabby’s Star

Host: Fraser Cain (@fcain)

Special Guest:
Dr. Jason Wright is Professor in Penn State University’s Department of Astronomy and Astrophysics. Jason studies nearby stars, their ages and activity levels, and their planetary systems (exoplanets.) Jason also does a lot of outreach and research about Tabby’s Star (the “”alien magastructure”” star.) Continue reading “Weekly Space Hangout – November 18, 2016: Dr. Jason Wright and Tabby’s Star”

September 13, 2016March 27, 2017 by Fraser Cain

Weekly Space Hangout Live with Sondy Springmann and Morgan Rehnberg

Host: Fraser Cain (@fcain)

Guests:
Alessondra Springmann (@sondy)
Morgan Rehnberg (MorganRehnberg.com / @MorganRehnberg)

Fraser, Morgan and Sondy were all at the Kennedy Space Center in Florida to watch the launch of the OSIRIS-REx Mission. Sondy and Morgan talked about the mission, answered questions about space and astronomy, Cassini.

Just a sneak preview before the Weekly Space Hangout starts up later this week!

We’ve had an abundance of news stories for the past few months, and not enough time to get to them all. So we are now using a tool called Trello to submit and vote on stories we would like to see covered each week, and then Fraser will be selecting the stories from there. Here is the link to the Trello WSH page (http://bit.ly/WSHVote), which you can see without logging in. If you’d like to vote, just create a login and help us decide what to cover!

We record the Weekly Space Hangout every Friday at 12:00 pm Pacific / 3:00 pm Eastern. You can watch us live on Google+, Universe Today, or the Universe Today YouTube page.

You can also join in the discussion between episodes over at our

May 11, 2016May 15, 2016 by Evan Gough

New Composite Image Of Saturn’s Polar Vortex Mesmerizes

This image of Saturn's southern polar vortex reveals previously unseen detail of the giant storm. Image: NASA/JPL/Space Science Institute

Atmospheric features on our Solar System’s gas giants dwarf anything similar on Earth. Earth’s atmosphere spawns hurricanes as larger as 1500 km in diameter. But on Saturn, a feature called the southern polar vortex has an eye that is 8,000 km across, or two thirds the diameter of the entire Earth.

A new high-resolution of Saturn’s southern polar vortex captured by the Cassini probe is ten times more detailed than any previous picture, and reveals details that were previously unseen. The image, which is a composite of two images taken by Cassini in July 2008, was captured when the spacecraft was 392,000 km from Saturn, and 56º below the plane of Saturn’s rings. Despite the distance and position, the image still has a resolution of 2 km per pixel.

Previous images of the vortex revealed clouds of immense proportions ringing the edge of the vortex, but showed the vortex itself to be clear. This is similar to a hurricane on Earth, where the eye itself is clear, but is ringed by wall-clouds of towering heights. This new image shows cloud formations within the vortex itself. The vortex is punctuated with wispy white cloud formations, and a smaller vortex at 10:00 within the larger formation.

The clouds inside the vortex are more than just pretty curiosities, of course. They are deep convective structures welling up from deep within Saturn’s atmosphere, and they form their own distinctive ring. This is all the more interesting because the eye of the vortex itself is generally clear, and is considered by scientists to be an area of downwelling.

The convection on display in Saturn’s southern polar vortex is an important clue to understanding how Saturn transfers energy through its atmosphere. On Earth, hurricanes are caused by warm water, and they move across the surface of the ocean as the warm water does.

Saturn, of course, has no liquid ocean, and the vortex is powered by warm atmospheric gases from deeper in Saturn. As they rise and cool they condense into clouds. The vortex also remains stationary, rather than following a warm mass of water. It’s locked into position over Saturn’s south pole.

Cassini’s narrow angle camera captured this new image, using a combination of two spectral filters. One was sensitive to wavelengths of polarized visible light centered at 617 nanometers, and the other to infrared light centered at 750 nanometers.

These two previously released infrared images of Saturn show the entire south polar region with the hurricane-like vortex in the center. The top image shows the polar region in false color, with red, green, and blue depicting the appearance of the pole in three different near-infrared colors (NASA/JPL/University of Arizona)

Cassini is a joint mission of NASA, the ESA, and the Italian Space Agency. It was launched in 1997, and has had its mission extended to September 2017. Cassini will end its mission in what the team operating Cassini is calling a Grand Finale. This will be a series of deep dives between Saturn and its rings, and will end with the spacecraft plunging into Saturn’s atmosphere.

To see a gallery of Cassini images, go here.

At Universe Today, we’ve written about Saturn’s polar vortices before. Have a look:

Violent Polar Cyclones on Saturn Imaged in Unprecedented Detail by Cassini

Hexagonal Structure at Saturn’s North Pole

May 7, 2016 by Jason Major

Enceladus’ Jets Selectively Power-Up Farther From Saturn

Icy water vapor geysers erupting from fissures on Enceladus. Credit: NASA/JPL

A crowning achievement of the Cassini mission to Saturn is the discovery of water vapor jets spraying out from Enceladus‘ southern pole. First witnessed by the spacecraft in 2005, these icy geysers propelled the little 515-kilometer-wide moon into the scientific spotlight and literally rewrote the mission’s objectives. After 22 flybys of Enceladus during its nearly twelve years in orbit around Saturn, Cassini has gathered enough data to determine that there is a global subsurface ocean of salty liquid water beneath Enceladus’ frozen crust—an ocean that gets sprayed into space from long “tiger stripe” fissures running across the moon’s southern pole. Now, new research has shown that at least some of the vapor jets get a boost in activity when Enceladus is farther from Saturn.

The gravitational pull of Saturn changes the amount of particles spraying from Enceladus at different points in its orbit. When it's farther from Saturn (left) the plume contains more icy particles and thus appears brighter. Credit: NASA/JPL-Caltech/University of Arizona/Cornell/SSI. — The gravitational pull of Saturn changes the amount of particles spraying from Enceladus at different points in its orbit. When it’s farther from Saturn (left) the plume contains more icy particles and thus appears brighter. Credit: NASA/JPL-Caltech/University of Arizona/Cornell/SSI.

By measuring the changes in brightness of a distant background star as Enceladus’ plumes passed in front of it in March 2016, Cassini observed a significant increase in the amount of icy particles being ejected by one particular jet source.

"Baghdad Sulcus," one of Enceladus' plume sources, imaged by Cassini during a close pass in Nov. 2011. (NASA/JPL/SSI) — *“Baghdad Sulcus,” one of Enceladus’ plume sources, imaged by Cassini during a close pass in Nov. 2011. (NASA/JPL/SSI)*

Named “Baghdad 1,” the jet went from contributing 2% of the total vapor content of the entire plume area to 8% when Enceladus was at the farthest point in its slightly-eccentric orbit around Saturn. This small yet significant discovery indicates that, although Enceladus’ plumes are reacting to morphological changes to the moon’s crust due to tidal flexing, it’s select small-scale jets that are exhibiting the most variation in output (rather than a simple, general increase in outgassing across the full plumes.)

“How do the tiger stripe fissures respond to the push and pull of tidal forces as Enceladus goes around its orbit to explain this difference? We now have new clues!” said Candice Hansen, senior scientist at the Planetary Science Institute and lead planner of the study. “It may be that the individual jet sources along the tiger stripes have a particular shape or width that responds most strongly to the tidal forcing each orbit to boost more ice grains at this orbital longitude.”

The confirmation that Enceladus shows an increase in overall plume output at farther points from Saturn was first made in 2013.

Whether this new finding means that the internal structure of the fissures is different than what scientists have suspected or some other process is at work either within Enceladus or in its orbit around Saturn still remains to be determined.

“Since we can only see what’s going on above the surface, at the end of the day, it’s up to the modelers to take this data and figure out what’s going on underground,” said Hansen.

Sources: Planetary Science Institute and NASA/JPL

Enceladus' water ice plumes were first observed by Cassini in 2005. (NASA/JPL/SSI) — *Enceladus’ now-famous water ice plumes were first observed by Cassini in 2005. (NASA/JPL/SSI)*

April 6, 2016April 15, 2016 by Evan Gough

Mysterious Pull On Cassini Probe May Help Find Planet Nine

Artist's impression of Planet Nine, blocking out the Milky Way. The Sun is in the distance, with the orbit of Neptune shown as a ring. Credit: ESO/Tomruen/nagualdesign

Finding a ninth planet in our Solar System this late in the game would be fascinating. It would also be somewhat of a surprise, considering our observational capabilities. But new evidence, in the form of small perturbations in the orbit of the Cassini probe, points to the existence of an as-yet undetected planet in our solar system.

Back in January, Konstantin Batygin and Mike Brown, two planetary scientists from the California Institute of Technology, presented evidence supporting the existence of a ninth planet. Their paper showed that some Kuiper Belt Objects (KBOs) display unexpected behaviour. It appears that 6 KBOs are affected by their relationship to a large object, but the KBOs in question are too distant from the known gas giants for them to be responsible. They think that a large, distant planet, in the distant reaches of our Solar System, could be responsible for the unexpected orbital clustering of these KBOs.

The calculated orbit of Planet Nine. Credit: Nature/K. Batygin and M. E. Brown Astronom. J. 151, 22 (2016)

Now, the Ninth Planet idea is gaining steam, and another team of researchers have presented evidence that small perturbations in the orbit of the Cassini spacecraft are caused by the new planet. Agnès Fienga at the Côte d’Azur Observatory in France, and her colleagues, have been working on a detailed model of the Solar System for over a decade. They plugged the hypothetical orbit and size of Planet Nine into their model, to see if it fit.

Planet Nine is calculated to be about 4 times as large as Earth, and 10 times as massive. It’s orbit takes between 10,000 and 20,000 years. A planet that large can only be hiding in so many places, and those places are a long way from Earth. Fienga found a potential home for Planet Nine, some 600 astronomical units (AU) from here. That much mass at that location could account for the perturbations in Cassini’s orbit.

There’s more good news when it comes to Planet Nine. By happy accident, it’s predicted location in the sky is towards the constellation Cetus, in the southern hemisphere. This means that it is in the view of the Dark Energy Survey, a southern hemisphere project that is studying the acceleration of the universe. The Dark Energy Survey is not designed to search for planetary objects, but it has successfully found at least one icy object.

There are other ways that the existence of Planet Nine could be confirmed. If it’s as large as thought, then it will radiate enough internal heat to be detected by instruments designed to study the Cosmic Microwave Background (CMB). There is also an enormous amount of data from multiple experiments and observations done over the years that might contain an inadvertent clue. But looking through it is an enormous task.

As for Brown and Batygin, who initially proposed the existence of Planet Nine based on the behaviour of KBOs, they are already proposing a more specific hunt for the elusive planet. They have asked for a substantial amount of observing time at the Subaru Telescope on Mauna Kea in Hawaii, in order to examine closely the location that Fienga’s solar system model predicts Planet Nine to be at.

For a more detailed look at Batygin’s and Brown’s work analyzing KBOs, read Matt Williams’ article here.

March 11, 2016March 18, 2016 by Evan Gough

Cassini Watches Star Through Enceladus’ Plume

When the Cassini probe first saw the plumes coming from Saturn’s moon Enceladus, it was a surprise. When it dipped through the plumes, some questions about the basic nature of the phenomenon were answered. But there are still many more questions, and today Cassini has an opportunity to find some answers.

Cassini will be in a perfect position today to observe the light from Epsilon Orionis, the central star in Orion’s belt, as it passes through Enceladus’ plume. This type of observation is known as a stellar occultation, and it promises to provide new information about the composition and density of the plume. Cassini’s Ultraviolet Imaging Spectrograph (UVIS) will do the capturing, and once the information is relayed back to Earth, it will be analyzed for clues.

An artist's impression of the plumes coming from Enceladus. Image: NASA/JPL. — An artist’s impression of the plumes coming from Enceladus. Image: NASA/JPL.

We already know a few things about Enceladus’ plumes. First of all, Enceladus itself is any icy world, with subsurface oceans. The moon is locked in an orbital resonance, which creates its eccentric orbit. This eccentric orbit is responsible for heating the south polar oceans, which drives material through the ice sheets and creates its stunning plumes, in a process known as cryovolcanism. (Radioactive decay might also have something to do with heating.)

Cassini has been at Saturn’s system for 12 years, and has gradually painted a more detailed picture of Enceladus. Over time, we’ve learned that the plumes themselves are similar to what comets are made of. Cassini initially detected mostly water vapor, with traces of molecular nitrogen, methane, and carbon dioxide. Later, the presence of the hydrocarbons propane, formaldehyde, and acetylene was confirmed.

This is all very interesting, but why would anyone other than chemistry geeks care? Because the universe, including our Solar System, is largely a cold, sterile place. And the plumes coming from Enceladus indicate the presence of water, potentially warm, salty, water at that. And warm water might mean life, or the potential for life.

Cassini has previously observed two other stellar occultations. But with today’s observation, we stand to learn even more about the plumes of Enceladus. We’ll not only learn more about their density and composition, but since is the third such occultation to be observed, we’ll learn something about the plume’s behaviour over time. We probably won’t learn anything definitive about Enceladus’ life-supporting potential, but we will almost certainly find another piece of the puzzle, and fill in a blank spot in our knowledge.

And that’s what science is all about.

March 3, 2016March 18, 2016 by Evan Gough

Surfing On Titan Would Be Best In Summer

The view from the beach on Titan? Image: NASA — The view from the beach on Titan? A recent study has shown that Titan's seas experience very low waves, making it a perfect place for a probe to set down.Credit: NASA

Space is mostly vast and empty. So whenever we notice something like ripples on a lake, on the frozen moon of a gas giant, we take notice.

At a meeting of the American Geophysical Union in San Francisco this week, it was reported that Cassini images of Saturn’s moon Titan showed light being reflected from the Ligeia Mare, a frigid sea of hydrocarbons on that moon. Subsequent images showed the same phenomenon on two other seas of Titan, as well. These are thought to be waves, the first waves detected anywhere other than Earth, and suggest that Titan has more geophysical activity than previously thought.

Surfers on Earth, known for seeking out remote and secretive locations, shouldn’t get too excited. According to mathematical modelling and radar imagery, these waves are only 1.5 cm (0.6 inches) tall, and they’re moving only 0.7 metres (2.3 feet) per second. Plus, they’re on a sea of liquid hydrocarbons—mostly methane—that is a frigid -180 degrees Celsius (-292 F.)

The left image shows a mosaic of images of Titan taken by the Cassini spacecraft in near infrared light. Titan’s polar seas are visible as sunlight glints off of them. The right image is a radar image of Kraken Mare. Credit: NASA Jet Propulsion Laboratory.

Planetary scientists are taking note, though, because these waves show that Titan has an active environment, rather than just being a moon frozen in time. It’s thought that the change in seasons on Titan is responsible for these waves, as Titan begins its 7 year summer. Processes related to the changing seasons on Titan have created winds, which have cause these ripples.

There’s other evidence of active weather on Titan, including dunes, river channels, and shorelines. But this is the first observation of active weather phenomena, rather than just the results. All together, it shows that Titan is a more active, dynamic environment than previously thought.

Titan’s hydrocarbon lakes are thought to be up to 200 metres (656 ft.) deep, and are clustered around the north polar region. Just one of its lakes is thought to contain approximately 9,000 cubic km of methane, which is about 40 times more than the Earth’s reserves of oil and gas.

Titan is the second largest moon in the Solar System, second only to Ganymede, and both moons are larger than the planet Mercury. Titan was discovered in 1655 by Christiaan Huygens.

February 5, 2016March 27, 2017 by Fraser Cain

Weekly Space Hangout – Feb. 5, 2016: Dr. Or Graur

Host: Fraser Cain (@fcain)

Special Guest: Dr. Or Graur, Research Associate at the Center for Cosmology and Particle Physics at New York University; Researches what type of star leads to a thermonuclear, or “Type Ia,” supernova.

Guests:
Carolyn Collins Petersen (thespacewriter.com / space.about.com / @spacewriter )
Morgan Rehnberg (cosmicchatter.org / @MorganRehnberg )
Jolene Creighton (fromquarkstoquasars.com / @futurism)
Alessondra Springmann (@sondy)

Continue reading “Weekly Space Hangout – Feb. 5, 2016: Dr. Or Graur”