Grand Finale – Painting inspired by the Cassini Mission to Saturn
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Also in Exploring the Solar System Exploring the Solar System: The Mass of the Sun Marvellous Mars Drawing Workshop at Dunsink Observatory Dublin Astronomical Sketching – Education in action Stars Wonderful Stars at Wexford Town Library Ireland Get ready the Perseids are coming Space the final Frontier – World Space Week 2016 On the richness of the lunar surface Dark Sky Magic at Ballycroy National Park Mayo Ireland Grand Finale – Painting inspired by the Cassini Mission to Saturn View the entire series … Continue reading

Titan: Frozen Moon of Saturn
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It’s hard to believe that it’s been 12 years since the Huygens probe touched down on the surface of Saturn’s moon Titan – the only moon in the solar system with a dense atmosphere and clouds. The probe returned images of rugged terrain as it descended, and revealed what appears to be drainage channels flowing down to a possible shoreline. The lander returned data for about 90 minutes after touchdown. Huygens is the most distant landing of any human-made craft. The Huygens lander was part of the Cassini mission to Saturn; the mission was so successful, it was extended in 2008, and again in 2010. The spacecraft has flown by numerous moons, and returned a treasure trove of scientific data; it has also returned some of the most spectacular imagery ever produced by a robotic probe. Cassini is now in its final months at Saturn, with the probe slated to burn up on Saturn’s atmosphere this September. From JPL Press Release 2017-006: 2005 Historic Descent … Continue reading

Spacecraft 3D: NASA’s Augmented Reality Smartphone App
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NASA has an app for smartphones that lets you learn about and interact with several different spacecraft that explore our solar system, study the Earth, and observe the cosmos. You can hold a virtual Mars rover in the palm of your hand, or watch as a rocket’s boosters fall away, and its fairing separate! Seeing the Curiosity rover popup in my hand, and being able to rotate it, zoom, and deploy its mast – using my Android – just blew me away! I think students would LOVE this! If you have an iOS/Android phone,download Spacecraft 3D now and experience #AugmentedReality! https://t.co/gPQPe62z6k pic.twitter.com/8RuPfOZktS — : NASA_Eyes (@nasa_eyes) December 8, 2016 A photo target must be used for the app to generate the spacecraft model; the photo can be small enough to fit in your hand, or printed larger for use on a tabletop. The app can email you a link to the AR target (http://www.jpl.nasa.gov/apps/images/3dtarget.pdf) which includes some cool Mars pics … Continue reading

Cassini’s Final Months at Saturn
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NASA’s Cassini mission to Saturn is in its final months. The spacecraft has been put into a polar orbit which brings it over Saturn’s poles, and very close to the main rings. Cassini has sent back spectacular views of  Saturn’s north polar region shortly before it made its first close pass by the outer edge of Saturn’s main rings. In late April, Cassini will again change its orbit, bringing the spacecraft between Saturn’s innermost ring, and its cloudtops. These orbits send tingles through my spine when I think about them; there is a chance that a ring particle might impact the spacecraft, rendering it nonfunctional. According to NASA Eyes on the Solar System, when Cassini passes through the ring plane from now through April, it will be travelling at 21 km/sec. When it changes orbit in late April, and gets closer to Saturn, it will be passing over the cloudtops at about 34 km/sec. If Cassini survives all its passes … Continue reading

Across the Universe: Friends in high places
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This column first appeared in The Tablet in June, 2008 The Mars Phoenix mission landed successfully near the north pole of Mars [in 2008]. Even though I don’t study Mars myself, I feel a special connection because the mission is being run out of my old department at the University of Arizona. I know those guys on the TV, explaining how they’ll be digging for ice in the Martian soil. Mars wasn’t the only tourist attraction that summer. The scientists of the Cassini/Huygens Saturn probes held a team meeting in Rome in June, 2008, and two dozen of them came out to visit me at Castel Gandolfo. I showed them our telescopes and libraries and meteorite collection. Friends of mine on the team arranged the visit. Why do I have so many friends in high places? It’s just the nature of my field. There are only a few thousand professional planetary astronomers in the world. We go to the same annual meetings, we … Continue reading

Across the Universe: Reflections on a Mirror
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This column first ran in The Tablet in March 2010 The International Astronomical Union’s committee on planetary surfaces nomenclature (on which I serve as their resident “Latin expert” which no doubt would shock my high school Latin teachers) has voted [in 2010] to give a smooth surface feature on Saturn’s moon Titan the name “Jingpo Lacus”, after Jingpo Lake in China. From the way they reflect radar waves, regions like these on Titan’s surface appear to be very, very smooth. Our best guess is that they’re pools of liquid hydrocarbons, something like lakes of liquid natural gas. Titan’s atmosphere, about twice that of Earth’s, has methane clouds and apparently conditions that allow for this methane to rain out and pool on the surface, much like water does on Earth. The surface temperature of Titan itself is hundreds of degrees below zero, so ordinary water there is frozen harder than rock. The rule is that we use the names of lakes … Continue reading

Enceladus, Ocean World
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NASA’s Cassini mission scientists have determined that the slight wobble observed in Saturn’s moon Enceladus, as it orbits the ringed giant planet, is too large for the moon to be entirely frozen to its core. This wobble, referred to as a libration, reveals that the icy crust of Enceladus is disconnected from its rocky interior. In other words: Enceladus’ icy crust is sliding around on top of a global ocean of liquid water, and where there’s water, life may follow. This graphic (above) is an update to Enceladus: Possible Hydrothermal Activity (left), which showed only a regional sea beneath the south polar region of Enceladus. As Enceladus orbits Saturn, it is subject to tidal forces due to gravitation. These forces stretch the moon, causing friction, which heat up the moon’s interior. This is a process is called tidal heating. Jupiter’s moon Io is the most volcanically active body in the solar system, as a result of tidal heating. It was … Continue reading

Dione and Cassini
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“This view from NASA’s Cassini spacecraft looks toward Saturn’s icy moon Dione, with giant Saturn and its rings in the background, just prior to the mission’s final close approach to the moon on August 17, 2015. At lower right is the large, multi-ringed impact basin named Evander, which is about 220 miles (350 kilometers) wide. The canyons of Padua Chasma, features that form part of Dione’s bright, wispy terrain, reach into the darkness at left. Imaging scientists combined nine visible light (clear spectral filter) images to create this mosaic view: eight from the narrow-angle camera and one from the wide-angle camera, which fills in an area at lower left. The scene is an orthographic projection centered on terrain at 0.2 degrees north latitude, 179 degrees west longitude on Dione. An orthographic view is most like the view seen by a distant observer looking through a telescope. North on Dione is up. The view was acquired at distances ranging from approximately … Continue reading

Cassini Returns to a Near Equatorial Orbit Around Saturn
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A dual view of Saturn’s icy moon Rhea marks the return of NASA’s Cassini spacecraft to the realm of the planet’s icy satellites. This follows nearly two years during which the spacecraft’s orbits carried it high above the planet’s poles. Those paths limited the mission’s ability to encounter the moons, apart from regular flybys of Titan. Cassini’s orbit will remain nearly equatorial for the remainder of 2015, during which the spacecraft will have four close encounters with Titan, two with Dione and three with the geyser-moon, Enceladus. The two views of Rhea were taken about an hour-and-a-half apart on Feb. 9, 2015, when Cassini was about 30,000 to 50,000 miles (50,000 to 80,000 kilometers) away from the moon. Cassini officially began its new set of equatorial orbits on March 16. The views show an expanded range of colors from those visible to human eyes in order to highlight subtle color variations across Rhea’s surface. In natural color, the moon’s surface … Continue reading

Titan’s Surface Imaged Using New Technique
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Radar images of Titan have always had a grainy appearance due to electronic noise. A new tool suppresses the noise, resulting in clearer views than ever before. During 10 years of discovery, NASA’s Cassini spacecraft has pulled back the smoggy veil that obscures the surface of Titan, Saturn’s largest moon. Cassini’s radar instrument has mapped almost half of the giant moon’s surface; revealed vast, desert-like expanses of sand dunes; and plumbed the depths of expansive hydrocarbon seas. What could make that scientific bounty even more amazing? Well, what if the radar images could look even better? Thanks to a recently developed technique for handling noise in Cassini’s radar images, these views now have a whole new look. The technique, referred to by its developers as “despeckling,” produces images of Titan’s surface that are much clearer and easier to look at than the views to which scientists and the public have grown accustomed. Typically, Cassini’s radar images have a characteristic grainy … Continue reading

Across the Universe: Desert or a dessert?
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First published in The Tablet in January, 2005, just after the Huygens probe landed on Saturn’s moon Titan. This text is based on what I submitted, which was edited for length when it was printed.   The most remarkable thing about the images from Saturn’s moon, Titan, which ESA’s Huygens probe has just sent us, is how “familiar” they look. They remind me of Nadar’s 19th century Collodion “wet plate” photographs taken from a balloon above Paris. Black and white, a bit fuzzy, these patterns of light and darkness can be grasped and processed by imagination and memory until we impose meaning on them. I picture myself floating through the clouds, gazing across at an intricate pattern of riverbeds cutting through rough light-colored mountains, flowing down to a flat, wine-dark sea. If these are riverbeds – and they certainly look like textbook examples of the many-branched “dendritic channels” made by rainfall flowing down hills on Earth – the fluid in them can’t have … Continue reading

Saturn: Beauty in Sight and Sound
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Created by stitching together over 30,000 photographs taken by the robotic Cassini spacecraft – No 3D models, CGI or texture maps used! Set to “Adagio for Strings” performed by the Greensboro Symphony Orchestra and conducted by Dmitry Sitkovetsky. This excerpt from the IMAX movie “In Saturn’s Rings” never fails to bring tears to my eyes due to its sheer beauty. Watch closely as the razor-thin rings momentarily vanishes as orbiter crosses the plane of their orbit. The Cassini orbiter was launched in October 1997, and entered orbit around Saturn on June 30, 2004. Its mission has been extended twice, and is currently scheduled to continue through September of 2017. Cassini has discovered plumes of water vapor pouring from its icy moon Enceladus, and discovered a new type of “Dusty Plasma” near Enceladus. Cassini landed a probe on Saturn’s largest moon, Titan, and has imaged hydrocarbon oceans and river-like structures there. Cassini has witnessed tiny shepherd moons within Saturn’s rings, and … Continue reading