Mimas and Atlas (If You Look Carefully)


converted PNM fileThe great eye of Saturn’s moon Mimas is a 130-km-wide impact crater called Herschel. It seems to be looking back at you in this picture taken by the Cassini spacecraft. The small moon Atlas is also visible (sort of) just outside the main rings. You’re probably mistaking it for a bit of dust on you monitor. Mimas is 397 km across; Atlas is 32 km across.

Image Credit: NASA

Not All Rings Are Equal


ringsSaturn has multiple rings around the planet. While there isn’t one ring to rule them all, not all of them are equal. The D ring appears fainter than the C ring because it is comprised of less material. However, even rings as thin as the D ring can pose hazards to spacecraft. Given the high speeds at which the Cassini spacecraft travels,collisions with particles just fractions of a millimeter in size have the potential to damage key components. Nonetheless, near the end of Cassini’s mission, missionnavigators plan to thread the spacecraft’s orbit through the narrow region between the D ring and the top of the planet’s atmosphere.

Image Credit: NASA

 

Finding Saturn


pia08387_croppedAstronomers have paired the Cassini spacecraft with the National Science Foundation’s Very Long Baseline Array (VLBA) radio-telescope system to pinpoint the position of Saturn and its family of moons to within about 4 km. That’s about 50 times more precise than those provided by ground-based optical telescopes, improving out knowledge of Saturn’s orbit and benefiting spacecraft navigation and basic physics research.

Image Credit: NASA