On Jan. 14, 2005, ESA’s Huygens probe made its descent to the surface of Saturn’s hazy moon, Titan. Carried to Saturn by NASA’s Cassini spacecraft, Huygens made the most distant landing ever on another world, and the only landing on a body in the outer solar system. This video uses actual images taken by the probe during its two-and-a-half hour fall under its parachutes.
Huygens was a signature achievement of the international Cassini-Huygens mission, which will conclude on Sept. 15, 2017, when Cassini plunges into Saturn’s atmosphere.
This collage of images from NASA’s Cassini spacecraft shows Saturn’s northern hemisphere and rings as viewed with four different spectral filters. Each filter is sensitive to different wavelengths of light and reveals clouds and hazes at different altitudes. Credits: NASA/JPL-Caltech/Space Science Institute. Full image and caption
NASA’s Cassini spacecraft has sent to Earth its first views of Saturn’s atmosphere since beginning the latest phase of its mission. The new images show scenes from high above Saturn’s northern hemisphere, including the planet’s intriguing hexagon-shaped jet stream.
Cassini began its new mission phase, called its Ring-Grazing Orbits, on Nov. 30 [see earlier posting here]. Each of these weeklong orbits — 20 in all — carries the spacecraft high above Saturn’s northern hemisphere before sending it skimming past the outer edges of the planet’s main rings.
Cassini’s imaging cameras acquired these latest views on Dec. 2 and 3, about two days before the first ring-grazing approach to the planet. Future passes will include images from near closest approach, including some of the closest-ever views of the outer rings and small moons that orbit there.
“This is it, the beginning of the end of our historic exploration of Saturn. Let these images — and those to come — remind you that we’ve lived a bold and daring adventure around the solar system’s most magnificent planet,”
said Carolyn Porco, Cassini imaging team lead at Space Science Institute, Boulder, Colorado.
The next pass by the rings’ outer edges is planned for Dec. 11. The ring-grazing orbits will continue until April 22, when the last close flyby of Saturn’s moon Titan will once again reshape Cassini’s flight path. With that encounter, Cassini will begin its Grand Finale, leaping over the rings and making the first of 22 plunges through the 1,500-mile-wide (2,400-kilometer) gap between Saturn and its innermost ring on April 26.
This view from NASA’s Cassini spacecraft was obtained about two days before its first close pass by the outer edges of Saturn’s main rings during its penultimate mission phase. Credits: NASA/JPL-Caltech/Space Science Institute Full image and caption
On Sept. 15, the mission’s planned conclusion will be a final dive into Saturn’s atmosphere. During its plunge, Cassini will transmit data about the atmosphere’s composition until its signal is lost.
Launched in 1997, Cassini has been touring the Saturn system since arriving in 2004 for an up-close study of the planet, its rings and moons. Cassini has made numerous dramatic discoveries, including a global ocean with indications of hydrothermal activity within the moon Enceladus, and liquid methane seas on another moon, Titan.
The Cassini-Huygens mission is a cooperative project of NASA, ESA (European Space Agency) and the Italian Space Agency. NASA’s Jet Propulsion Laboratory, a division of Caltech in Pasadena, manages the mission for NASA’s Science Mission Directorate, Washington. JPL designed, developed and assembled the Cassini orbiter.
Saturn’s icy moon Mimas is dwarfed by the planet’s enormous rings.
The moon Mimas is dwarfed by Saturn and its beautiful rings, which cast stripped shadows on the gas giant. (Larger image.)
Because Mimas (near lower left) appears tiny by comparison, it might seem that the rings would be far more massive, but this is not the case. Scientists think the rings are no more than a few times as massive as Mimas, or perhaps just a fraction of Mimas’ mass. Cassini is expected to determine the mass of Saturn’s rings to within just a few hundredths of Mimas’ mass as the mission winds down by tracking radio signals from the spacecraft as it flies close to the rings.
The rings, which are made of small, icy particles spread over a vast area, are extremely thin – generally no thicker than the height of a house. Thus, despite their giant proportions, the rings contain a surprisingly small amount of material.
Mimas is 246 miles (396 kilometers) wide.
This view looks toward the sunlit side of the rings from about 6 degrees above the ring plane. The image was taken in red light with the Cassini spacecraft wide-angle camera on July 21, 2016.
The view was obtained at a distance of approximately 564,000 miles (907,000 kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 31 degrees. Image scale is 34 miles (54 kilometers) per pixel.
The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA’s Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.
Cassini spacecraft during its final year at Saturn will make some death defying dives bear the edges of the rings:
Now in its final year of operations, on Nov. 30, 2016, NASA’s Cassini mission will begin a daring set of ring-grazing orbits, skimming past the outside edge of Saturn’s main rings. Cassini will fly closer to Saturn’s rings than it has since its 2004 arrival. It will begin the closest study of the rings and offer unprecedented views of moons that orbit near them. Even more dramatic orbits ahead will bring Cassini closer to Saturn than any spacecraft has dared to go before.
Saturn’s north polar region displays its beautiful bands and swirls, which somewhat resemble the brushwork in a watercolor painting.
Each latitudinal band represents air flowing at different speeds, and clouds at different heights, compared to neighboring bands. Where they meet and flow past each other, the bands’ interactions produce many eddies and swirls.
The northern polar region of Saturn is dominated by the famous hexagon shape (see PIA11682) which itself circumscribes the northern polar vortex – seen as a dark spot at the planet’s pole in the above image – which is understood to the be eye of a hurricane-like storm (PIA14946).
This view looks toward the sunlit side of the rings from about 20 degrees above the ring plane. The image was taken with the Cassini spacecraft wide-angle camera on Sept. 5, 2016 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 728 nanometers.
The view was obtained at a distance of approximately 890,000 miles (1.4 million kilometers) from Saturn. Image scale is 53 miles (86 kilometers) per pixel.
The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA’s Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.
NASA’s Cassini spacecraft watched clouds of methane moving across the far northern regions of Saturn’s largest moon, Titan, on Oct. 29 and 30, 2016.
Several sets of clouds develop, move over the surface and fade during the course of this movie sequence, which spans 11 hours, with one frame taken every 20 minutes. Most prominent are long cloud streaks that lie between 49 and 55 degrees north latitude. While the general region of cloud activity is persistent over the course of the observation, individual streaks appear to develop then fade. These clouds are measured to move at a speed of about 14 to 22 miles per hour (7 to 10 meters per second).
There are also some small clouds over the region of small lakes farther north, including a bright cloud between Neagh Lacus and Punga Mare, which fade over the course of the movie. This small grouping of clouds is moving at a speed of about 0.7 to 1.4 miles per hour (1 to 2 meters per second).
Time-lapse movies like this allow scientists to observe the dynamics of clouds as they develop, move over the surface and fade. A time-lapse movie can also help to distinguish between noise in images (for example from cosmic rays hitting the detector) and faint clouds or fog.
In 2016, Cassini has intermittently observed clouds across the northern mid-latitudes of Titan, as well as within the north polar region — an area known to contain numerous methane/ethane lakes and seas see PIA19657 and PIA17655. However, most of this year’s observations designed for cloud monitoring have been short snapshots taken days, or weeks, apart. This observation provides Cassini’s best opportunity in 2016 to study short-term cloud dynamics.
Models of Titan’s climate have predicted more cloud activity during early northern summer than what Cassini has observed so far, suggesting that the current understanding of the giant moon’s changing seasons is incomplete.
The mission will continue monitoring Titan’s weather around the 2017 summer solstice in Titan’s northern hemisphere.
The movie was acquired using the Cassini narrow-angle camera using infrared filters to make the surface and tropospheric methane clouds visible.
The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA’s Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.
