Using new data from NASA's Cassini spacecraft, researchers believe they have solved a longstanding mystery of solar system science: the length of a day on Saturn. It's 10 hours, 33 minutes and 38 seconds. The figure has eluded planetary scientists for decades, because the gas giant has no solid surface with landmarks to track as it rotates, and it has an unusual magnetic field that hides the planet's rotation rate. The answer, it turned out, was hidden in the rings.
Astronomers using the NASA/ESA Hubble Space telescope have taken a series of spectacular images featuring the fluttering auroras at the north pole of Saturn. The observations were taken in ultraviolet light and the resulting images provide astronomers with the most comprehensive picture so far of Saturn’s northern aurora.
Saturn’s moon Titan may be nearly a billion miles away from Earth, but a recently published paper based on data from NASA’s Cassini spacecraft reveals a new way this distant world and our own are eerily similar. Just as the surface of oceans on Earth lies at an average elevation that we call “sea level,” Titan’s seas also lie at an average elevation.
When the Cassini mission arrived in the Saturn system in 2004, it discovered something rather unexpected in Enceladus’ southern hemisphere. From hundreds of fissures located in the polar region, plumes of water and organic molecules were spotted periodically spewing forth. This was the first indication that Saturn’s moon may have an interior ocean caused by hydrothermal activity near the core-mantle boundary.
When the Cassini spacecraft arrived around Saturn on July 1st, 2004, it became the fourth space probe to visit the system. But unlike the Pioneer 11 and Voyager 1 and 2 probes, the Cassini mission was the first to establish orbit around the planet for the sake of conducting long-term research. Since that time, the spacecraft and its accompanying probe – the Huygens lander – have revealed a startling amount about this system.
As the Cassini spacecraft nears the end of a long journey rich with scientific and technical accomplishments, it is already having a powerful influence on future exploration. In revealing that Saturn's moon Enceladus has many of the ingredients needed for life, the mission has inspired a pivot to the exploration of "ocean worlds" that has been sweeping planetary science over the past decade.
How chemical reactions on a lifeless planet floating around in the cold darkness of space can suddenly give rise to living organisms is one of the biggest questions in science. We don’t even know whether the molecular building blocks of life on Earth were created here or whether they were brought here by comets and meteorites.
As NASA's Cassini spacecraft makes its unprecedented series of weekly dives between Saturn and its rings, scientists are finding -- so far -- that the planet's magnetic field has no discernible tilt. This surprising observation, which means the true length of Saturn's day is still unknown, is just one of several early insights from the final phase of Cassini's mission, known as the Grand Finale.
Beyond the Solar System’s Main Asteroid Belt lies the realm of the giants. It is here, staring with Jupiter and extending to Neptune, that the largest planets in the Solar System are located. Appropriately named “gas giants” because of their composition, these planets dwarf the rocky (terrestrial) planets of the inner Solar System many times over.
This view from NASA's Cassini spacecraft is the sharpest ever taken of belts of the features called propellers in the middle part of Saturn's A ring.The propellers are the small, bright features that look like double dashes, visible on both sides of the wave pattern that crosses the image diagonally from top to bottom.
With its dense and hydrocarbon-rich atmosphere, Titan has been a subject of interest for many decades. And with the success of the Cassini-Huygens mission, which began exploring Saturn and its system of moons back in 2004, there are many proposals on the table for follow-up missions that would explore the surface of Titan and its methane seas in greater depth.
Cassini is the most sophisticated space probe ever built. Launched in 1997 as a joint NASA/European Space Agency mission, it took seven years to journey to Saturn. It’s been orbiting the sixth planet from the sun ever since, sending back data of immense scientific value and images of magnificent beauty.