This unprocessed image shows features in Saturns atmosphere from closer than ever before. The view of Saturns polar vortex was captured by NASAs Cassini spacecraft during its first Grand Finale dive past the planet on April 26, 2017. Credit: NASA/JPL-Caltech/Space Science Institute
NASAs Cassini spacecraft sped through a gap between Saturn and its rings for the second time Tuesday after data from the probes first perilous passage through the unexplored region last week found it to contain fewer potentially hazardous dust particles than expected.
The finding is one of several results from Cassinis first trip through the ring gap that has puzzled scientists.Engineers in charge of keeping Cassini safe, on the other hand, are pleased that the space between Saturn and its rings harbours fewer dangers.
The region between the rings and Saturn is the big empty, apparently, said Earl Maize, Cassini project manager at NASAs Jet Propulsion Laboratory in Pasadena, California. Cassini will stay the course, while the scientists work on the mystery of why the dust level is much lower than expected.
Cassini radioed ground controllers April 27 that it safely made the first-ever flight through the 1,500-mile (2,400-kilometre) ring gap, coming closer to Saturn than any spacecraft in history.
The orbiter used its last flyby of Saturns largest moon Titan on April 22 to reshape its path around the planet, plunging Cassini on an orbit that will take it inside the rings once every week until Sept. 15, when it will dive into the ringed worlds hydrogen-helium atmosphere to end the mission.
Cassini made its second journey inside the rings Tuesday, and mission control at JPL received confirmation from the spacecraft around 1530 GMT (11:30 a.m. EDT) that it survived the encounter.
During last weeks flyby, Cassini turned to use its its 13-foot (4-metre) high-gain dish antenna as a shield to protect the spacecrafts sensitive components, like computers and scientific instruments, from the bombardment of any microscopic dust grains in its path.
Scientists crunching data captured last week said the passage produced far fewer dust impacts than predicted.
Models of the dust environment suggested Cassini would sail through the ring gap unscathed, so officials were not too concerned going into the first flyby. Nevertheless, recordings of the dust strikes were quieter than scientists expected.
The crafts radio and plasma wave science instrument detected hundreds of dust hits per second when Cassini was passing just outside Saturns rings over the last few months, but only registered a few impacts inside the ring gap.
Scientists converted the raw radio and plasma wave data into an audio format, NASA said, to listen for debris striking Cassinis antenna.
Dust particles hitting the instruments antennas sound like pops and cracks, covering up the usual whistles and squeaks of waves in the charged particle environment that the instrument is designed to detect, NASA said in a press release. The RPWS team expected to hear a lot of pops and cracks on crossing the ring plane inside the gap, but instead, the whistles and squeaks came through surprisingly clearly on April 26.
It was a bit disorienting we werent hearing what we expected to hear, said William Kurth, radio and plasma wave science team lead at the University of Iowa. Ive listened to our data from the first dive several times and I can probably count on my hands the number of dust particle impacts I hear.
Cassini made the trip through the ring gap at a relative velocity of about 77,000 mph (124,000 kilometres per hour), fast enough to travel from New York to Los Angeles in less than two minutes.
The video posted below includes the audio recording from Cassinis radio and plasma wave science instrument during the April 26 flyby.
The grains that hit Cassini were likely no bigger than a particle of smoke, or about 1 micron in size, according to NASA.
Cassinis swing inside Saturns rings Tuesday occurred without using the crafts antenna as a shield. Mission managers decided such a precaution was no longer necessary after sampling the dust during the first flyby.
But four of the 20 remaining ring gap passages will place Cassini closer to the inner edge of Saturns D ring, where scientists expect more dust particles. During those orbits, which begin in late May, the spacecraft will again turn its high-gain antenna into a shield.
Imagery from Cassinis approach to Saturn on April 26 revealed the closest-ever views of the planets clouds and a bizarre six-sided polar vortex scientists had only studied from afar before.
These images are shocking, said Kevin Baines, an atmospheric scientist on the Cassini team at JPL. We didnt expect to get anything nearly as beautiful as these images. All the different structures we see on them are phenomenal. We predicted wed see fogs and something pretty boring, but were seeing lots of great features a lot of activity going on on Saturn.
Baines called the hexagonal storm swirling at Saturns north pole the planets belly button.
This is a hole in the pole that is very deep, and we can tell that from looking at different colors of light, Baines said Friday in a Facebook Live event, comparing its structure to the behaviour of water in a flushing toilet. This is about 2,000 kilometres (1,200 miles) across.
Winds whip around the storm at up to 180 mph, or 300 kilometres per hour, Baines said. Like a hurricane on Earth, the wind speeds die down farther from the center of circulation, where individual storm clouds appear to move around Saturn in the planets jet stream.
Now we see structure, Baines said. You see the curly cues on here, all sorts of strange features that were trying to understand Now were seeing little tiny circular clouds that really have their own individual characters.
They might (have) convective upwelling from below, so were looking for lightning and other things to see if we can really confirm that, Baines said.
(For) this first dive, were focusing on looking at Saturn, said Linda Spilker, Cassinis project scientist at JPL. We got a series of images from the pole to the equator. We have other data as well, spectra in the infrared, the far-infrared and ultraviolet that will help us put together the puzzle of what were seeing.
During the missions second orbit through the ring gap, Cassinis cameras were programmed to take pictures of Saturns rings backlit by the sun, a viewing geometry that allows the instruments to see faint ringlets and other fine structures.
Future encounters will focus on studying Saturns interior, magnetic field and taking the first measurement of the mass of the planets rings, which will tell scientists about their age and origin.
The video posted below condenses one hour of observations into an animated movie showing a series of Cassini images taken April 26.
The movie shows Cassinis view of Saturn starting from an altitude of 45,000 miles to just 4,200 miles (72,400 kilometers to 6,700 kilometers) above the planets cloud tops.
I was surprised to see so many sharp edges along the hexagons outer boundary and the eye-wall of the polar vortex, said Kunio Sayanagi, an associate of the Cassini imaging team based at Hampton University in Virginia, who helped produce the new movie. Something must be keeping different latitudes from mixing to maintain those edges.
The images from the first pass were great, but we were conservative with the camera settings. We plan to make updates to our observations for a similar opportunity on June 28 that we think will result in even better views, said Andrew Ingersoll, a member of the Cassini imaging team based at Caltech.
Email the author.
Follow Stephen Clark on Twitter: @StephenClark1.
More:
[ 3 May 2017 ] NASA probe finds Saturn ring gap emptier than predicted News - Astronomy Now Online
- Astronomy clubs want to help you enjoy the eclipse safely - NPR - March 16th, 2024 [March 16th, 2024]
- You Can See a Rare, Bright Comet This Month. Will It Be Visible During the Solar Eclipse? - Smithsonian Magazine - March 16th, 2024 [March 16th, 2024]
- Solar Eclipse Path Map Shows States Where Sun Will Be Blocked Out - Newsweek - March 16th, 2024 [March 16th, 2024]
- Deep-space astronomy sensor peers into the heart of an atom - Space.com - March 16th, 2024 [March 16th, 2024]
- Physics and Astronomy Colloquium - Professor Paul Cassak; Department of Physics and Astronomy, West Virginia ... - The University of Iowa - March 16th, 2024 [March 16th, 2024]
- United Nations prioritizes discussion of Dark and Quiet Skies - Astrobites - March 16th, 2024 [March 16th, 2024]
- The burning acid behind ant stings was spotted around two stars - WAPT Jackson - March 16th, 2024 [March 16th, 2024]
- The oddities known as Centaurs may sprout their tales after jumping to new orbits - Astronomy Magazine - March 16th, 2024 [March 16th, 2024]
- Pair of astronomy brothers to host eclipse viewing event - KAIT - March 16th, 2024 [March 16th, 2024]
- How to watch the solar eclipse online - Astronomy Magazine - March 16th, 2024 [March 16th, 2024]
- How does a black hole get to the center of a galaxy, and does the galaxy revolve around it? - Astronomy Magazine - March 16th, 2024 [March 16th, 2024]
- The eclipse gives astronomy clubs an opportunity to shine - Voice Of Alexandria - March 16th, 2024 [March 16th, 2024]
- AI 'for all': How access to new models is advancing academic research, from astronomy to education - Source - Microsoft - March 16th, 2024 [March 16th, 2024]
- KU Department of Physics & Astronomy professor receives prestigious NSF award for black hole research - Salina Post - March 16th, 2024 [March 16th, 2024]
- Inspect impressive Mare Imbrium Astronomy Now - Astronomy Now Online - March 16th, 2024 [March 16th, 2024]
- The Sky This Week from March 15 to 22: A conjunction of Venus and Saturn - Astronomy Magazine - March 16th, 2024 [March 16th, 2024]
- Pons-Brooks and M31 - Astronomy Magazine - March 16th, 2024 [March 16th, 2024]
- The slightly weird mathematical coincidence behind an eclipse - Astronomy Magazine - March 16th, 2024 [March 16th, 2024]
- APOD: 2024 March 17 NGC 7714: Starburst after Galaxy Collision - Astronomy Picture of the Day - March 16th, 2024 [March 16th, 2024]
- How to Safely View the Eclipse National Radio Astronomy Observatory - National Radio Astronomy Observatory - March 16th, 2024 [March 16th, 2024]
- NOIRLab releases jaw-dropping images, video of remnants from massive star explosion | Astronomy.com - Astronomy Magazine - March 16th, 2024 [March 16th, 2024]
- JWST spots oceans' worth of water evaporating from a distant disk - Astronomy Magazine - March 16th, 2024 [March 16th, 2024]
- Radiation is vaporizing a young star's disk in the Orion Nebula - Astronomy Magazine - March 16th, 2024 [March 16th, 2024]
- APOD: 2024 March 12 A Galaxy Shaped Rocket Exhaust Spiral - Astronomy Picture of the Day - March 16th, 2024 [March 16th, 2024]
- Best laptops for astronomers and astrophotographers in 2024 - Space.com - March 16th, 2024 [March 16th, 2024]
- Why astronomers are worried about 2 major telescopes right now - Space.com - March 16th, 2024 [March 16th, 2024]
- The People Behind Webb | Webb - WebbTelescope.org - March 16th, 2024 [March 16th, 2024]
- X-ray image of universe reveals almost 1 million high-energy objects: 'These are mind-blowing numbers' - Space.com - February 1st, 2024 [February 1st, 2024]
- Galaxy named 'Nube' is almost invisible, baffling astronomers Earth.com - Earth.com - February 1st, 2024 [February 1st, 2024]
- Giant Star Seen 150 Days Before it Exploded as a Supernova - Universe Today - February 1st, 2024 [February 1st, 2024]
- UH astronomer named to prominent national astronomical society | University of Hawaii System News - University of Hawaii - February 1st, 2024 [February 1st, 2024]
- The Art of SeeingStates of Astronomy - Announcements - E-Flux - February 1st, 2024 [February 1st, 2024]
- Pluto isn't really a planet, but it might be Arizona's official state planet - Arizona Mirror - February 1st, 2024 [February 1st, 2024]
- Did You Know? Stars Near and Far Reveal Their Secrets to CSUN Scientists - California State University, Northridge - February 1st, 2024 [February 1st, 2024]
- Top 10 space stories of 2023 - Astronomy Magazine - February 1st, 2024 [February 1st, 2024]
- How we found the Milky Way's bar: This Week in Astronomy with Dave Eicher - Astronomy Magazine - February 1st, 2024 [February 1st, 2024]
- The best telescope to use with a smartphone - Astronomy Magazine - February 1st, 2024 [February 1st, 2024]
- JWST releases 19 awe-inspiring images of spiral galaxies - Astronomy Magazine - February 1st, 2024 [February 1st, 2024]
- Learning Shines Brightly at SuperKnova National Radio Astronomy Observatory - National Radio Astronomy Observatory - February 1st, 2024 [February 1st, 2024]
- The Crafoord Prize 2024 goes to three ERC grantees for their pioneering contributions to astronomy and mathematics ... - European Research Council - February 1st, 2024 [February 1st, 2024]
- The Moon's south pole is likely not the safest place for manned missions - Astronomy Magazine - February 1st, 2024 [February 1st, 2024]
- The moon could be perfect for cutting-edge telescopes but not if we don't protect it - Space.com - February 1st, 2024 [February 1st, 2024]
- February Astronomy: Spot the Milky Way and the Zodiacal Light While the Skies Are Darkest - Coachella Valley Independent - February 1st, 2024 [February 1st, 2024]
- You can stream an asteroid whizzing past Earth this weekend - Astronomy Magazine - February 1st, 2024 [February 1st, 2024]
- Chinese Astronomy at the Royal Observatory | Royal Observatory | Things to do in London - Time Out London - February 1st, 2024 [February 1st, 2024]
- Astronomers in Chile to scour universe with car-sized mega camera - - February 1st, 2024 [February 1st, 2024]
- Dark Matter Might Help Explain How Supermassive Black Holes Can Merge - Universe Today - February 1st, 2024 [February 1st, 2024]
- How far away is the sun? They went on a perilous journey to find out. - National Geographic - February 1st, 2024 [February 1st, 2024]
- Scientists spotted an asteroid hours before it burned up over Germany - Astronomy Magazine - February 1st, 2024 [February 1st, 2024]
- XRISM Unveils the Invisible: A New Era in X-Ray Astronomy - SciTechDaily - January 10th, 2024 [January 10th, 2024]
- New Astronomy Finding Uncovers the Mystery of Star Formation at the Edge of Galaxies - SBU News - Stony Brook News - January 10th, 2024 [January 10th, 2024]
- The Future Of Astronomy Lies In Artificial Intelligence - Forbes - January 10th, 2024 [January 10th, 2024]
- The 'Super Bowl of Astronomy' begins next week in New Orleans - Space.com - January 10th, 2024 [January 10th, 2024]
- Scientific American proposes policing the language of astronomy to make it beautiful and elegant, as well as ... - Why Evolution Is True - January 10th, 2024 [January 10th, 2024]
- 'Blob-like' home of farthest-known fast radio burst is collection of seven galaxies - Northwestern Now - January 10th, 2024 [January 10th, 2024]
- Astronomers revealed mysterious star formation by hearts of molecular clouds - Tech Explorist - January 10th, 2024 [January 10th, 2024]
- Spectroscopic sizing of interstellar icy grains with JWST - Nature.com - January 10th, 2024 [January 10th, 2024]
- Kip Thorne and the mind-bending science of Interstellar | Astronomy.com - Astronomy Magazine - January 10th, 2024 [January 10th, 2024]
- Here There Be DRAGNs National Radio Astronomy Observatory - National Radio Astronomy Observatory - January 10th, 2024 [January 10th, 2024]
- Unistellar's latest smart telescopes take the hassle out of backyard astronomy - Engadget - January 10th, 2024 [January 10th, 2024]
- 20 of the best places to view the 2024 total solar eclipse - Astronomy Magazine - January 10th, 2024 [January 10th, 2024]
- Northern Arizona astronomy: How old is our third generation sun? - Grand Canyon News - January 10th, 2024 [January 10th, 2024]
- Evidence builds that Kamo'oalewa is a chunk of the Moon accompanying Earth - Astronomy Magazine - January 10th, 2024 [January 10th, 2024]
- The Sky This Week from January 5 to 12: Visitors to the Scorpion - Astronomy Magazine - January 10th, 2024 [January 10th, 2024]
- AAS 243 NRAO Press Announcement - National Radio Astronomy Observatory - January 10th, 2024 [January 10th, 2024]
- Your guide to the sky in 2024 - Astronomy Magazine - January 10th, 2024 [January 10th, 2024]
- The best binoculars for astronomy in 2024 - Popular Science - January 10th, 2024 [January 10th, 2024]
- Are we visible to alien astronomers? This study makes the case - Astronomy Magazine - January 10th, 2024 [January 10th, 2024]
- Mystery of Star Formation Revealed by Hearts of Molecular Clouds - National Radio Astronomy Observatory - January 10th, 2024 [January 10th, 2024]
- Astronomers Solve the Mystery of Giant Radio Circles - AZoQuantum - January 10th, 2024 [January 10th, 2024]
- Early Evolution of Planetary Disk Structures Seen for the First Time - National Radio Astronomy Observatory - January 10th, 2024 [January 10th, 2024]
- XRISM's Revolutionary Insights into X-Ray Astronomy - AZoQuantum - January 10th, 2024 [January 10th, 2024]
- Vatican's chief astronomer talks about stars, beauty, truth - Aleteia - January 10th, 2024 [January 10th, 2024]
- Explore the cosmos in EAC Payson Campus astronomy workshops - Payson Roundup - January 10th, 2024 [January 10th, 2024]
- Neptune is more of a greenish blue than is commonly depicted - NPR - January 10th, 2024 [January 10th, 2024]
- First Yale Gravitational Wave Symposium sparks research innovation | Department of Physics - Yale University - January 10th, 2024 [January 10th, 2024]
- The best expensive telescopes for those ready to splurge - Astronomy Magazine - January 10th, 2024 [January 10th, 2024]
- Dinosaurs and a touch of astronomy | Education | paysonroundup.com - Payson Roundup - January 10th, 2024 [January 10th, 2024]
- Astronomical Illusions: New Images Reveal What Neptune and Uranus Really Look Like - SciTechDaily - January 10th, 2024 [January 10th, 2024]
- Book Review: Things That Go Bump in the Universe, by C. Rene James - The New York Times - December 16th, 2023 [December 16th, 2023]