Taxonomy term


Cassini's legacy after two decades

Scientists on Earth have received the last submission from the Cassini spacecraft. It descended into Saturn’s atmosphere at 122,500 kilometers per hour, which caused it to melt, thereby ensuring that Saturn’s moons Titan and Enceladus would remain protected from possible contamination by any errant Earth microbes. Cassini scientists had considered other options for the spacecraft’s end, including leaving it to float endlessly in space or parking it in orbit around Saturn. But ultimately, they chose to have it descend into Saturn’s atmosphere after deciding the data that could be returned from the descent were more valuable than any further data it might obtain by remaining in space. Scientists will make discoveries from these data for decades to come.

15 Sep 2017

Titan's oddly oriented dunes may be electrostatically sculpted

Saturn’s largest moon, Titan, which has a dense, nitrogen-rich atmosphere with evidence of large amounts of frozen water at the surface, is a world apart from Earth’s moon. Among other strange phenomena, Titan has vast fields of frozen hydrocarbon particles that form 100-meter-tall dunes whose crests point east, opposite the prevailing west-blowing winds predicted by atmospheric models of Titan. In a new study in Nature Geoscience, researchers have found that these mysterious dunes may be sculpted in part by electrostatic charging of the frozen hydrocarbon grains.

01 Aug 2017

Enceladus' extremely alkaline underground ocean

Saturn’s moon Enceladus is home to a vast underground ocean that erupts to the surface at the moon’s south pole in a giant plume of gas, ice and dust. Scientists studying observational data of this plume collected by the Cassini spacecraft, which has been orbiting Saturn since 2004, have recently learned more about the chemistry of Enceladus’ hidden ocean. 
24 Nov 2015

Sun shapes Titan's atmospheric makeup

Saturn’s largest moon, Titan, has a thick atmosphere composed of 98 percent nitrogen and about 1.4 percent methane, as well as small amounts of other gases. In a new study published in the Journal of Geophysical Research: Space Physics, astronomers have identified fluctuations in methane levels in Titan’s thermosphere that appear to be in tune with the 11-year solar cycle.
07 Sep 2015

Two new looks at Titan's dunes

Saturn’s largest moon, Titan, is covered with extensive fields of sand dunes around its equator. From a distance, the wind-swept landscape looks similar to those seen on Earth, Mars and Venus, but new research suggests that dune formation on Titan may require different conditions than previously thought.

31 Mar 2015

Cassini spots new moon in Saturn's rings

Saturn is famous for its rings, but the sixth planet from the sun also has dozens of moons — 62 at last count, 53 of which have names — and now, according to new observations, it may have a 63rd. In April of last year, NASA’s Cassini spacecraft spotted a newly formed object at the edge of Saturn’s outermost A ring.

08 Oct 2014

Saturn's polar hexagon stable over time

Saturn’s peculiar polar “hexagon” has proven perplexing for scientists studying the atmospheric phenomenon since Voyager 1 and 2 first observed it in the early 1980s. Now, an international team has completed the most thorough study of the six-sided jet stream yet, using images and data collected between 2008 and 2014 by the Cassini spacecraft.

07 Oct 2014

Benchmarks: April 9, 1895: James Edward Keeler confirms Saturn's rings not solid

On April 9 and 10, 1895, astronomer James Edward Keeler snapped the most important photographs of his life. With a 13-inch (33-centimeter) refracting telescope, Keeler captured proof that Saturn’s rings were not solid disks, but instead a collection of particles revolving around the planet. The discovery put to rest a question that astronomers had been pondering for more than two centuries.
01 Apr 2011

Keeler's legacy

James Edward Keeler led a brief life, but his legacy lives on. Scientists have named several natural phenomena after him.
01 Apr 2011

Saturn's rings: The remains of an icy moon

James Edward Keeler’s work didn’t end all speculation about Saturn’s rings. For example, scientists still don’t know when they formed, but researchers are getting closer to understanding how they came to be.
01 Apr 2011