Today, Cassini Will Say Goodbye to Saturn’s Moon Dione

It’s curtains for the NASA mission’s close relationship with the satellite

The leading hemisphere of Dione shows tectonic faults running across its surface, along with craters, in false color, which was produced by an image in the ultraviolet, green, and infrared wavelengths taken by the Cassini Orbiter. The subtle variations in color may be caused by fine ice particles. NASA - digital version copyright/Science Faction/Corbis

Sometimes, even the best relationships must come to an end — even NASA’s Cassini Solstice Mission’s love affair with Dione, Saturn’s icy moon. Today, the Cassini spacecraft will make its last close flyby of Dione before heading off for more distant skies.

In a release, the agency reports that it expects the final close encounter between Cassini and Dione to take place at 2:33 p.m. EDT. Scientists will get one last look at the satellite via high-res photos, infrared spectrometry and dust analysis.

Officials expect the craft to fly within 295 miles of Dione, performing observations aimed at understanding the moon’s structure and geology. They’re looking for evidence of active geological processes like volcanoes — and this flyby represents their last chance to collect data on Dione.

Saturn has 62 known moons, all of which bear names from Greek and Roman mythology. But NASA hasn’t been able to investigate all of them as closely as Dione. Though Cassini has already had four “targeted encounters” with the moon, it still holds some mysteries.

For example, scientists are still scratching their heads over the fact that the moon seems to have recently spun 180 degrees after some impact — and they hope that a closer look at the moon’s geology will answer lingering questions.

But just because it’s curtains for Cassini and Dione doesn’t mean NASA will fall out of love with Saturn any time soon. In fact, the mission will continue until August 2017. In the meantime, Cassini will start to dart between Saturn’s rings in the hopes of getting a better look at the elusive F ring and other highlights before it leaves the planet forever.

In other words, Dione: It’s not you. It’s NASA. And NASA’s notorious for moving on.

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