On its last orbits in 2017, the long-running Cassini spacecraft dove between Saturn’s rings and its upper atmosphere and bathed in a downpour of dust that astronomers call “ring rain.”
In research published today in Science, LASP research associate Hsiang-Wen (Sean) Hsu and his colleagues report that they successfully collected microscopic material streaming from the planet’s rings.
The findings, which were made with Cassini’s Cosmic Dust Analyzer and Radio and Plasma Wave Science instruments, come a little more than a year after the spacecraft burned up in Saturn’s atmosphere. They stem from the mission’s “grand finale,” in which Cassini completed a series of risky maneuvers to zip under the planet’s rings at speeds of 75,000 miles per hour.
New data collected from the Cassini spacecraft have revealed complex organic molecules originating from Saturn’s icy moon Enceladus, strengthening the idea that this ocean world hosts conditions suitable for life.
LASP research scientists Sascha Kempf and Sean Hsu co-authored a new study, published in Nature, based on the data.
Very little was known about Enceladus prior to 2005—the year when Cassini first flew by. Since then, it has become a continuous source of surprises, with secrets still being revealed even now, after the end of the mission.
NASA’s Cassini spacecraft has detected the faint but distinct signature of dust coming from beyond our solar system. The research, led by a team that includes scientists at the University of Colorado and LASP, will be published in the journal Science on Friday, April 15, 2016.
Cassini has been in orbit around Saturn since 2004, studying the giant planet, its rings, and its moons. The spacecraft has also sampled millions of ice-rich dust grains with its Cosmic Dust Analyzer (CDA) instrument. LASP research scientists Sascha Kempf, Sean Hsu, and Eberhard Grün are all co-investigators for the Cassini CDA instrument and co-authors of the paper.
The moon is engulfed in a permanent but lopsided dust cloud that increases in density when annual events like the Geminids spew shooting stars, according to a new study led by LASP scientists at the University of Colorado Boulder.
The cloud is made up primarily of tiny dust grains kicked up from the moon’s surface by the impact of high-speed, interplanetary dust particles, said CU-Boulder physics Professor and LASP research associate Mihály Horányi. A single dust particle from a comet striking the moon’s surface lofts thousands of smaller dust specks into the airless environment, and the lunar cloud is maintained by regular impacts from such particles, said Horányi.
An instrument to be designed and built at LASP has been selected to fly on a NASA mission to Jupiter’s icy moon, Europa, which is believed to harbor a subsurface ocean that may provide conditions suitable for life.
The LASP instrument, known as the SUrface Dust Mass Analyzer (SUDA), will be used to measure the composition of solid particles released from Europa’s surface due to meteoroid bombardment. The instrument also will be able to measure the properties of small, solid particles believed to be spewing from a hidden ocean within the moon, said University of Colorado Boulder Assistant Professor of Physics, Sascha Kempf, who will serve as principal investigator on the project.
Using data from the NASA Cassini mission, a team of scientists led by LASP researcher Sean Hsu, has successfully modeled dust streams being expelled from Saturn at speeds of more than 62 miles (100 km) per second. The data, taken from the Cosmic Dust Analyzer (CDA) and the magnetometer on board Cassini, provide new information about the sources of the dust, as well as interactions within the mix of subatomic particles in which the charged dust is immersed, called dusty plasma.
A study published in the journal Nature and co-authored by LASP scientist Sascha Kempf indicates that samples of water vapor and ice particles coming from Saturn’s icy moon Enceladus demonstrate evidence for a large, subterranean salt-water reservoir. The Cosmic Dust Analyzer (CDA) on board the NASA Cassini spacecraft measured the composition of plumes—emanating from fractures called tiger stripes—and found that ice grains close to the moon are salt rich, unlike those that make up the planet’s E Ring.