Spacecraft

Cassini’s ring dive offers first close-up of Saturn’s cloud tops

Saturn's atmosphere
FIRST LOOK NASA’s Cassini spacecraft snapped these closest-ever views of Saturn’s atmosphere on April 26. The images show filamentary and cumulus clouds, along with a good view of the planet’s giant hurricane (middle).

Cassini has beamed back stunning images from the spacecraft’s daring dive between Saturn and its rings.

The first closeup pictures of the planet’s atmosphere reveal peculiar threadlike clouds and puffy cumulus ones, plus the giant hurricane first spotted on Saturn in 2008 (SN: 11/8/08, p. 9). Released April 27, the images of Saturn’s cloud tops are a “big step forward” for understanding the planet’s atmosphere, says Cassini imaging team member Andy Ingersoll, an atmospheric scientist at Caltech.

“I was pretty struck by…

In ‘grand finale,’ Cassini spacecraft sets off on collision course with Saturn

Cassini and Saturn
The Cassini spacecraft will explore the uncharted territory between Saturn and its rings (shown in this artist’s illustration) before plunging into the planet’s atmosphere in September.

DEEP DIVE

Cassini is bravely going where no spacecraft has gone before — between Saturn and its rings.

The probe, which launched in 1997 and has orbited Saturn since 2004, starts this daring expedition April 22. It will fly through the 2,400-kilometer-wide gap between Saturn and its rings 22 times before plunging into the planet’s atmosphere and burning up on Sept. 15.

Mission scientists designed this dramatic…

Food for microbes found on Enceladus

Enceladus’ plume
FINDING FOOD A deep dive into Enceladus’ plume, shown here in an artist’s illustration, reveals that the moon harbors molecular hydrogen. On Earth, the gas serves as a food source for some microbes, suggesting life could exist on Enceladus, too.

Saturn’s icy moon Enceladus packs snacks suitable for microbial life.

Data from the Cassini spacecraft show that the vaporous plume shooting out of the moon’s southern pole contains molecular hydrogen. It is probably generated when water in the moon’s subterranean ocean reacts with rock in its core, researchers report in the April 14 Science. Such reactions at hydrothermal vents and in other extreme environments on Earth produce high abundances of hydrogen, which some microbes use for food. There’s enough hydrogen on Enceladus to sustain microbial life, the team suggests.

“We are not saying Enceladus has life, but the discovery does move the moon higher on the list of potentially habitable places in the solar system,” says study coauthor J. Hunter Waite of the Southwest Research Institute in San Antonio.

Enceladus became a good target for finding life beyond Earth when researchers found a global ocean under the moon’s icy exterior and hints of hydrothermal activity (SN: 10/17/15, p. 8; SN: 4/18/15, p. 10)….