In this illustration, the Dragonfly helicopter drone is descending to the surface of Titan. Image: NASA
The highly-anticipated Dragonfly robotic rotocraft mission to Saturn’s moon Titan is scheduled to launch in 2027. When it arrives in the mid-2030s, it will hover and zoom around in the thick atmosphere of Titan, sampling the air and imaging the landscape. What could be more exciting than that!?
Well, actually … there’s more: Dragonfly will also be equipped with a mass spectrometer that will help it search for the chemistry of life in this alien world. Astrobiologists want to know if Titan has the same type of chemistry on its surface that Earth did in its early history, which could have helped give rise to life on our planet.
The moons of Saturn, from left to right: Mimas, Enceladus, Tethys, Dione, Rhea; Titan in the background; Iapetus (top) and irregularly shaped Hyperion (bottom). Some small moons are also shown. All to scale. Credit: NASA/JPL/Space Science Institute
Continuing with our “Definitive Guide to Terraforming“, Universe Today is happy to present our guide to terraforming Saturn’s Moons. Beyond the inner Solar System and the Jovian Moons, Saturn has numerous satellites that could be transformed. But should they be?
Around the distant gas giant Saturn lies a system of rings and moons that is unrivaled in terms of beauty. Within this system, there is also enough resources that if humanity were to harness them – i.e. if the issues of transport and infrastructure could be addressed – we would be living in an age a post-scarcity. But on top of that, many of these moons might even be suited to terraforming, where they would be transformed to accommodate human settlers.
As with the case for terraforming Jupiter’s moons, or the terrestrial planets of Mars and Venus, doing so presents many advantages and challenges. At the same time, it presents many moral and ethical dilemmas. And between all of that, terraforming Saturn’s moons would require a massive commitment in time, energy and resources, not to mention reliance on some advanced technologies (some of which haven’t been invented yet).
During previous flybys, 'Magic Island' was not visible near Ligeia Mare's coastline (left). Then, during Cassini's July 20, 2013, flyby the feature appeared (right)/ Credit: NASA/JPL-CALTECH/ASI/CORNELL, image editing via Ian O'Neill/Discovery News.
Astronomers with the Cassini mission have detected a bright, mysterious geologic object on Saturn’s moon Titan that suddenly showed up in images from the mission’s radar instrument. The object appeared in Ligeia Mare, the second-largest sea Titan. The feature looks like an island and so the team named it “Magic Island.” However, it most likely is not an island that suddenly surfaced. But scientists say this may be the first observation of dynamic, geological processes in Titan’s northern hemisphere.
The object suddenly showed up in images beamed back from Cassini on July 10, 2013, showing regions of Ligeia Mare, a sea located near Titan’s north pole. But then just as suddenly, in a follow-up flyby only days later on July 26, the island was gone. Subsequent flybys confirmed that Magic Island had vanished and is what is known as a “transient feature.”
“This discovery tells us that the liquids in Titan’s northern hemisphere are not simply stagnant and unchanging, but rather that changes do occur,” said Jason Hofgartner, a Cornell graduate student in the and the lead author of a paper appearing in Nature Geoscience. “We don’t know precisely what caused this ‘magic island’ to appear, but we’d like to study it further.”
Map of Titan’s northern region of hydrocarbon ‘seas’ created from Cassini radar imaging. Credit: NASA/JPL/USGS.
Titan is currently the only other world besides Earth known to have stable bodies of liquid on its surface. But unlike Earth, Titan’s lakes aren’t filled with water — instead they’re full of liquid methane and ethane, organic compounds which are gases on Earth but liquids in Titan’s incredibly chilly -290º F (-180º C) environment.
So what was this object? Among the explanations from the team are:
Northern hemisphere winds may be kicking up and forming waves on Ligeia Mare. The radar imaging system might see the waves as a kind of “ghost” island. Scientists previously have seen what they think are waves in another nearby Titan sea, Punga Mare.
Gases may push out from the sea floor of Ligeia Mare, rising to the surface as bubbles.
Sunken solids formed by a wintry freeze could become buoyant with the onset of the late Titan spring warmer temperatures.
Suspended solids in Ligeia Mare, which are neither sunken nor floating, but act like silt in a terrestrial delta.
“Likely, several different processes – such as wind, rain and tides – might affect the methane and ethane lakes on Titan. We want to see the similarities and differences from geological processes that occur here on Earth,” Hofgartner said. “Ultimately, it will help us to understand better our own liquid environments here on the Earth.”
Enceladus and Dione, as seen by Cassini. Credit: NASA/JPL/Space Science Institute
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We’ve all experienced the Moon Illusion, where our own full Moon looks bigger when seen on the Earth’s horizon. But how about this illusion where you can’t really tell which of these two moons of Saturn is actually bigger, or which is closer, as seen by the Cassini spacecraft? Here, Dione, top right, appears closer to the spacecraft because it is larger than the moon Enceladus, lower left. However, Enceladus was actually closer to Cassini when its visible light, narrow-angle camera took this image.
Dione (1,123 kilometers, or 698 miles, across) is more than twice the size of Enceladus (504 kilometers, or 313 miles, across). The two moons are contrasted with Enceladus’ bright, reflective trailing hemisphere, and Dione’s darker, micrometeor-dusted side, decorated with wispy lighter materials.
Cassini took this image on Dec. 1, 2010 from about 510,000 kilometers (317,000 miles) from Enceladus and approximately 830,000 kilometers (516,000 miles) from Dione. Image scale is 3 kilometers (2 miles) per pixel on Enceladus and 5 kilometers (3 miles) per pixel on Dione.
