NASA & # 39; s Cassini Saturn probe may have disappeared, but it has not been forgotten.
Cassini deliberately plunged into the dense atmosphere of the ringed planet a year ago today (September 15) and ended a legendary 13-year run through the Saturn system.
Cassini's observations have already revolutionized the insights of scientists in the gas giant, the iconic rings and the many moons. And there will be more revelations. [Cassini’s Greatest Hits: The Best Images of Saturn]
"In so many ways, with this huge 13-year fire hose of data, we've really taken the cream off the top," said Cassini Project Scientist Linda Spilker, who is based at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California. , Space.com told. "But there is more in the data."
Some of the newly analyzed items will be released next month. A series of documents based on observations that Cassini made during his daring last laps of Saturn will be published on 5 October in the prestigious journal Science, according to Spilker.
NASA is funding another year of data analysis for the mission, she added. But the study of Cassini observations and the discoveries that result from such work will not dry up when the financing of the agency does.
"For many decades – probably until we go back to the Saturn system with a Cassini-like mission – I think scientists will go through that data," Spilker said.
A long and legendary mission
The $ 3,9 billion Cassini-Huygens mission – a joint operation by NASA, the European Space Agency and the Italian Space Agency – was launched in October 1997 and arrived in orbit around Saturn on the night of June 30, 2004.
On Christmas Day 2004, a lander named Huygens separated from the mother ship Cassini. Three weeks later, Huygens touched the giant moon Titan of Saturn and drew the very first (and so far the only) gentle landing in the outer solar system.
Huygens stopped blasting home about 90 minutes after landing, but the Cassini orbiter continued to zoom through the Saturn system for years and years. The spacecraft collected a wealth of data about the planet and its rings and moons, some of which were simply amazing.
In 2005, for example, Cassini saw geysers from the Antarctic of the icy satellite Enceladus. Further observations by the probe revealed that the geyser material contains water and organic chemicals – the carbonaceous building blocks of life as we know it – and that this stuff comes from a huge ocean of salt liquid water that locks under the icy shell of the 313 – mile-wide (504 kilometers) moon. [Photos: Enceladus, Saturn’s Cold, Bright Moon]
The ocean of Enceladus probably also has potential life-supporting chemical energy sources, according to mission scientists. (Another nice fact about the geysers: the material plume they emit generates the E-ring of Saturn.)
And the Cassini mission lifted the veil on a Titan of 3,200 miles wide (5,150 km), which is obscured by a thick and hazy atmosphere. Cassini's radar observations looked through the darkness for river systems, lakes and seas – not of water, but of liquid hydrocarbons.
The sky of the great moon is flooded with potential chemical energy, so it is possible that those lakes and seas support life – organisms that have to be very different from those found here on earth that require liquid water. (That does not mean that water-based life could not exist anywhere on Titan, the moon also seems to have an ocean under the ocean of liquid water.)
The potential of Enceladus and Titan to receive lives did indeed help determine the fate of Cassini. Mission team members wanted to make sure that the spacecraft, which ran out of fuel in the summer of 2017, was never polluted with earth's microbes. So the decision was taken to broadcast the mission in a glow of glory, high in the clouds of clouds of Saturn.
Cassini will most likely be remembered for identifying Enceladus as a possible life-sustaining ocean world and for capturing fascinating Titan, Spilker said. But audience reach is another big part of the legacy of the mission. [In Photos: Cassini’s Last Views of Saturn]
The beautiful photos of Cassini – from the clouds of Saturn, the rings of the planet, the rays of Enceladus, Titan, the strange ravioli-moon Pan and countless other objects and features – brought the wonders of the solar system to the Earth for millions of people. These images still offer inspiration, in fact; NASA continues to release and mark Cassini photo & # 39; s, even though the spacecraft itself is just a whirlwind of cinders in Saturn's air.
The mission team has always given priority to the audience. For example, NASA officials and Cassini scientists organized a "Wave at Saturn" campaign in July 2013 that instructed Earth residents to say hi to Cassini because it took a long distance view of the Earth during a solar eclipse the Saturn system, when the body of the gas giant cleared the sun from the perspective of the spacecraft.
And last week JPL won an Emmy prize for his efforts to hand out Cassini's dramatic "Grand Finale" campaign to the crowd.
However, a large part of Cassini's legacy still has to be written. More discoveries are waiting to be made, hidden in the datasets of the mission, as Spilker said. And then there are the possible Saturn missions to come – missions inspired and motivated by 13 years of Cassini observations, showing how complex, diverse and intriguing the Saturn system is.
"Oh, we absolutely have to go back," said Spilker.
There are currently no Saturn missions in NASA & # 39; s books, but that could change quickly. An effort called Dragonfly, which would send a robotic quadcopter to explore Titan's air, is one of the two finalists that NASA is considering for the next launch opportunity in its New Frontiers program. (New Frontiers missions are projects with an average cost of $ 1 billion, examples are the New Horizons Pluto probe and Juno Jupiter orbiter.)
The other finalist is a comet sample-return mission called CAESAR (Comet Astrobiology Exploration Sample Return Mission). NASA is expected to announce the selection next summer; the mission is likely to be launched in the middle of the 2020s.