Round and round they go… the animation above, made from 14 raw images taken by NASA’s Cassini spacecraft on August 23, 2016, shows the moons Prometheus and Atlas orbiting Saturn within the Roche Division gap between its A (top right) and F (center) rings. The gravitational tug of Prometheus (92 miles / 148 km long) is strong enough to pull on the fine, smoke-like icy particles of the F ring, creating streamer and “clump” features that follow it along.
The much smaller Atlas (23 miles / 37 km wide) follows a path around Saturn just past the outer edge of the A ring. It was once thought to be a “shepherd moon” of the A ring, but it’s now known that the pull of the more distant Janus and Epimetheus are responsible for that.
Atlas does have its very own ring, though—a very faint (i.e., not visible above) band of material that runs along its orbit named R/2004 S 1, discovered by the Cassini mission in July 2004.
Image credit: NASA/JPL-Caltech/SSI. Animation by Jason Major.
We are the stewards of over 400 years of scientific exploration of our Solar System, which it could be said began in earnest when Galileo Galilei first observed the motions of Jupiter’s moons in his homemade telescope in 1610. Over the centuries our knowledge—and our curiosity—about the seemingly endless variety of worlds in the Solar System has grown in leaps and bounds since Galileo’s first peeks at Jupiter, with increasingly more powerful telescopes both on Earth and in space and eventually even machines sent to join the planets in orbit around the Sun.
Last night NASA’s Juno spacecraft became humanity’s most recent emissary to the Solar System’s biggest planet, successfully performing the rocket burns needed to enter orbit around Jupiter—the first spacecraft to do so in 13 years. Amongst much excitement and deserved congratulations of the mission team, the video above was released showing Juno’s view as it approached the enormous planet the week before arrival after five years and 1.7 billion miles of travel. It’s dramatic and impressive and beautiful…just as it should be, considering the scope and achievement of the mission and the information that will soon be returned. Congratulations Juno!
“With Juno, we will investigate the unknowns of Jupiter’s massive radiation belts to delve deep into not only the planet’s interior, but into how Jupiter was born and how our entire solar system evolved.”
— NASA Administrator Charles Bolden
(HT to Rachelle Williams @AstroAnarchy for the video tip.)
After nearly 5 years of traveling through space NASA’s Juno spacecraft is just a few dozen hours away from entering orbit around Jupiter, the Solar System’s largest, most massive, and most extreme planet.
“We are ready,” said Scott Bolton, principal investigator of Juno from the Southwest Research Institute (SwRI). “The science team is incredibly excited to be arriving at Jupiter. The engineers and mission controllers are performing at an Olympic level getting Juno successfully into orbit. As Juno barrels down on Jupiter, the scientists are busy looking at the amazing approach science the spacecraft has already returned to Earth. Jupiter is spectacular from afar and will be absolutely breathtaking from close up.”
Learn more about the mission and find out how to watch the long-awaited event live below:
Recent findings from the New Horizons team reveal that Pluto’s third-largest satellite Nix is covered in the purest water ice yet observed in the dwarf planet system, even purer in spectra than what was seen on its slightly larger sibling Hydra. This analysis further supports the hypothesis that Pluto’s moons were created in an impact event that formed the Pluto-Charon system, over 4 billion years ago.