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Cassini Captures Narrow-Angle, Wide-Spectrum Views of Rhea

Composite image of Saturn's moon Rhea from Feb. 9, 2015. Credit: NASA/JPL-Caltech/SSI.

Composite image of Saturn’s moon Rhea from Feb. 9, 2015. Credit: NASA/JPL-Caltech/SSI.

After spending a couple of years in an orbit riding high over the northern pole of Saturn Cassini has swung back down alongside the planet’s ringplane, in perfect alignment to once again capture views of the icy moons that reside there. The image above is a composite made from several narrow-angle camera images acquired by Cassini on Feb. 9, 2015, showing an extended color view of Rhea as the spacecraft was heading to perform a targeted flyby of the larger haze-covered moon Titan.

Saturn’s second-largest moon, the heavily-cratered Rhea wouldn’t appear this golden to our eyes; its natural colors are much more monochromatic (i.e., grey.) But Cassini can “see” in light stretching from ultraviolet to infrared, and that added range lets us see Rhea in a new light.

Read the rest of this article on Discovery News here.

Voyager’s Valentine Turns 25 Today

If you’re in love with space exploration then you’ll fall for this: it’s the picture of Earth taken from the Voyager 1 spacecraft after it passed the orbit of Pluto in 1990. That image of our planet from almost 4 billion miles away inspired Carl Sagan to write his famous “Pale Blue Dot” passage, and reminds us that we are all just floating on “a mote of dust suspended in a sunbeam.”

This is from a post I originally published in 2010. I’ll keep trotting it out until it’s not cool anymore. (Which I don’t think will ever happen.)

Venus, Earth, Jupiter, Saturn, Uranus and Neptune as seen by Voyager 1 in 1990 (Credit: NASA)

On February 14, 1990, after nearly 13 years of traveling the solar system, the Voyager 1 spacecraft passed the orbit of Pluto and turned its camera around to take a series of photos of the planets. The image above shows those photos, isolated from the original series and are left to right, top to bottom: Venus, Earth, Jupiter, Saturn, Uranus, and Neptune.

From that distance, over 4 billion miles from the Sun, the planets each appear as little more than a bright dot against the vastness of interplanetary space.

“That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. … There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world.”

– Carl Sagan

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Saturn and Titan Show Off Their Crescents

Cassini image of Saturn and Titan from Aug. 11, 2013 (NASA/JPL-Caltech/SSI)

Cassini image of Saturn and Titan from Aug. 11, 2013 (NASA/JPL-Caltech/SSI)

It may not be in color but that doesn’t make it any less beautiful: this stunning image from Cassini shows Saturn and its largest moon Titan – the second-largest moon in our solar system, after Jupiter’s Ganymede – from their night sides, both showing their crescents against the blackness of space.

Titan’s crescent nearly wraps all the way around its globe, because of the way its thick atmosphere scatters sunlight.

The view was obtained at a distance of approximately 1.1 million miles (1.7 million kilometers) from about 3 degrees above the ringplane. The image was taken in violet wavelengths with Cassini’s wide-angle camera (WAC) on Aug. 11, 2013.

Source: NASA/JPL

Cassini Watches Clouds Form Over Titan’s Methane Sea

Animation of clouds forming over Ligeia Mare, one of Titan's many large methane lakes (NASA/JPL-Caltech/SSI)

Animation of clouds forming over Ligeia Mare, one of Titan’s many large methane lakes (NASA/JPL-Caltech/SSI)

What’s the weather forecast on Titan? Well if you’re planning a vacation down by the shores of Ligeia Mare you may get some cloudy skies, if what happened at the end of July repeats itself!

The animation above was made from images acquired by Cassini during a flyby of Titan in July 2014, showing the formation and dissipation of bright methane clouds over one of the moon’s polar lakes. Spanning a period of two days, the images reveal what may be the start of summer weather in Titan’s northern hemisphere… or just a bit of isolated “lake effect” cloudiness.

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What’s Ahead for Cassini?

If you’ve been a faithful reader of Lights in the Dark over the past five years you know that I just love Cassini (and you probably do too!) In orbit around Saturn since 2004, Cassini has taken us on an intimate tour of the Saturnian system for a decade now, revealing the incredible beauty of the ringed planet and its family of moons like no spacecraft ever has before. Thanks to Cassini and the Huygens probe, we have seen the surface of Titan for the first time, witnessed the jets of Enceladus, discovered many previously-unknown moons (and moonlets) and basically learned more about Saturn over the past ten years than since Galileo first pointed his telescope at it.

Cassini's final maneuver will be to dive through a gap in Saturn's rings in 2017 (NASA/JPL-Caltech)

Cassini’s will dive through a gap in Saturn’s rings in 2017 and sample the planet’s upper atmosphere (NASA/JPL-Caltech)

Although nearing the end of its life span, Cassini still has a few good years left and scientists are taking full advantage of its remaining time around Saturn to learn as much as they can before the spacecraft makes its final dive into the planet’s atmosphere in 2017.* The video above shows what awaits Cassini in the years ahead — some of its best discoveries may be yet to come. Check it out!

Learn more about the Cassini mission and read about its latest discoveries here and here.

*The exact plan for the end of Cassini’s mission has not yet been finalized.

Hubble Spots Saturn’s Northern Lights

Hubble image of aurora on Saturn (NASA/ESA)

Hubble image of aurora on Saturn (NASA/ESA)

Earth isn’t the only planet with auroras — any world with a magnetic field and an atmosphere can get a light show around its poles when its star’s wind is blowing hard enough!* The image above shows Saturn’s northern lights, as seen in ultraviolet light by the Hubble Space Telescope’s Advanced Camera for Surveys in April 2013.

See the full lineup of images below:

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