4 min read

Cassini Significant Events 4/25/18 – 5/29/18

Saturn in all its splendor
Two kinds of dramatic shadows play across the face of Saturn in this view from NASA’s Cassini spacecraft from Dec. 6, 2007. › Full image and caption

Members of the Cassini flight team are honored to be receiving so many formal accolades for the 20-year mission's accomplishments, while even more were awarded this month. Meanwhile, the team continued archiving Cassini's repositories of telemetry (science and engineering data), radio science (active microwave probing data), and several other types of data. And the team is busily working on the task of writing, editing and finalizing the six-volume Cassini Mission Final Report. Most of the report will be for JPL-internal consumption, but its informative Volume-I content will eventually become available to the public readership.

Wednesday April 25

The International Academy of Digital Arts and Sciences honored NASA’s digital communications in the 2018 Webby Awards recently. An award went to NASA's accomplished digital media teams throughout the agency, while three other NASA sites won People's Voice Awards, which are given by popular vote in their categories. Honored for “Best Use of Online Media” was the Cassini project's extraordinary, multi-faceted, multi-platform real-time Grand Finale campaign: https://saturn.jpl.nasa.gov/for-your-consideration.

Monday May 14

Today's weekly image catches shadows of Saturn's rings, of obviously different densities, and an interesting moon-shadow:/resources/17838/a-stage-for-shadows.

NASA's Astronomy Picture of the Day published this image today of Cassini's view of the low-density object Hyperion: https://apod.nasa.gov/apod/ap180514.html.

Tuesday May 15

The planets that Cassini put to good use for gravity assists are all clearly visible in the early evenings now, and will continue to be for a few months. Cassini flew so close to Venus (the most brilliant object in the western sky) that their mutual gravitational connection removed a bit of that planet's solar-orbital momentum. It wasn't enough to cause any measurable change to the length of Venus's year, but plenty to fling Cassini much higher from the Sun than it had yet been. The following year Cassini exchanged momentum with Venus again, then it whipped by Earth. Cassini caused a change in the length of Earth's year by a vanishingly small amount, while that "elastic collision" again bent Cassini's trajectory and provided an enormous boost, enough to reach the outer solar system. Jupiter, high and bright in the east at sunset (offering a marvelous view in any telescope), donated some of its own Sun-relative angular momentum, to speed Cassini on its final leg to Saturn. The whole, richly illustrated timeline of Cassini's flight is viewable here: https://saturn.jpl.nasa.gov/the-journey/timeline.

Monday May 21

Several Cassini scientists participated in the five-day Ocean Worlds 2018 Conference at LPI, the Lunar and Planetary Institute in Houston, Texas, which began today. (Recall there are two "worlds," satellites of Saturn, that Cassini determined to have global subsurface oceans.)

An image featured today offers a close-up view of Saturn's largest moon Titan from six years ago. It is remarkable for its setting against the planet Saturn and edge-on to its ring system. Some of Titan's surface detail is visible and Titan's dense, hazy atmosphere and its high-altitude detached haze layer can easily be seen: /resources/17839/a-world-all-its-own.

The same image was selected as the NASA Astronomy Picture of the Day five days later.

Thursday May 24

Today, Saturn is one Earth-year into the northern summer season of its 29.5-year orbit of the Sun.

Friday May 25

The Cassini team's program manager and deputy project scientist, as well as the Huygens project manager, were present to receive the National Space Society's 2018 Space Pioneer Award at the International Space Development Conference in Los Angeles today. The NSS commented, "Cassini may be gone, [but] its enormous collection of data about Saturn -- the giant planet itself, its magnetosphere, rings and moons -- will continue to yield new discoveries for decades."

Sunday May 27

Saturn is visible in the eastern sky these evenings; it will reach opposition one month from today, when it will be rising at sunset. The rings are tilted widely toward us, making for a memorable sight in a small telescope. And its largest moon, Titan, is also visible. In addition to being a target of Cassini's investigations, that planet-like moon provided the changes in momentum and velocity (relative to Saturn) needed for Cassini to carefully shape its 293 orbits of Saturn.

Monday May 28

At the AIAA Space Ops meeting in Marseilles, France this week, the Cassini Flight Operations Team received the 2018 International SpaceOps Award for outstanding achievement. The citation reads, "For outstanding performance in the planning and execution of the Cassini mission, leading to unprecedented scientific data return from the Saturn system." A trophy and certificate were presented to the program manager during SpaceOps to recognize the team.