Archives For Saturn

Photo: Saturn’s rings are perhaps the most recognized feature of any world in our solar system. Cassini spent more than a decade examining them more closely than any spacecraft before it. Credit: NASA/JPL-Caltech/Space Science Institute

Saturn’s rings are perhaps the most recognized feature of any world in our solar system. Cassini spent more than a decade examining them more closely than any spacecraft before it. Image Credit: NASA/JPL-Caltech/Space Science Institute

 

October 4, 2018: New research emerging from the final orbits of NASA’s Cassini spacecraft represents a huge leap forward in our understanding of the Saturn system — especially the mysterious, never-before-explored region between the planet and its rings. Some preconceived ideas are turning out to be wrong while new questions are being raised.

Six teams of researchers are publishing their work Oct. 5 in the journal Science, based on findings from Cassini’s Grand Finale. That’s when, as the spacecraft was running out of fuel, the mission team steered Cassini spectacularly close to Saturn in 22 orbits before deliberately vaporizing it in a final plunge into the atmosphere in September 2017.

Knowing Cassini’s days were numbered, its mission team went for gold. The spacecraft flew where it was never designed to fly. For the first time, it probed Saturn’s magnetized environment, flew through icy, rocky ring particles and sniffed the atmosphere in the 1,200-mile-wide (2,000-kilometer-wide) gap between the rings and the cloud tops. Not only did the flight path push the spacecraft to its limits, the new findings illustrate how powerful and agile the instruments were.

Many more Grand Finale science results are to come, but here are some of today’s highlights:

  • Complex organic compounds embedded in water nanograins rain down from Saturn’s rings into its upper atmosphere. Scientists saw water and silicates, but they were surprised to see also methane, ammonia, carbon monoxide, nitrogen and carbon dioxide. The composition of the organics is different from that found on moon Enceladus — and also different from that on moon Titan, meaning there are at least three distinct reservoirs of organic molecules in the Saturn system.
  • For the first time, Cassini saw up close how rings interact with the planet and observed inner-ring particles and gases falling directly into the atmosphere. Some particles take on electric charges and spiral along magnetic-field lines, falling into Saturn at higher latitudes — a phenomenon known as “ring rain.” But scientists were surprised to see that others are dragged quickly into Saturn at the equator. And it’s all falling out of the rings faster than scientists thought — as much as 22,000 pounds (10,000 kilograms) of material per second.
  • Scientists were surprised to see what the material looks like in the gap between the rings and Saturn’s atmosphere. They knew that the particles throughout the rings ranged from large to small. But the sampling in the gap showed mostly tiny, nanometer-sized particles, like smoke, suggesting that some yet-unknown process is grinding up particles.
  • Saturn and its rings are even more interconnected than scientists thought. Cassini revealed a previously unknown electric-current system that connects the rings to the top of Saturn’s atmosphere.
  • Scientists discovered a new radiation belt around Saturn, close to the planet and composed of energetic particles. They found that while the belt actually intersects with the innermost ring, the ring is so tenuous that it doesn’t block the belt from forming.
  • Unlike every other planet with a magnetic field in our Solar System, Saturn’s magnetic field is almost completely aligned with its spin axis. The new data shows a magnetic-field tilt of less than 0.0095 degrees. (Earth’s magnetic field is tilted 11 degrees from its spin axis.) According to everything scientists know about how planetary magnetic fields are generated, Saturn should not have one. It’s a mystery that physicists will be working to solve.
  • Cassini flew above Saturn’s magnetic poles, directly sampling regions where radio emissions are generated. The findings more than doubled the number of direct measurements of radio sources from the planet, one of the few non-terrestrial locations where scientists have been able to study a radio-generation mechanism that is believed to operate throughout the universe.

For the Cassini mission, the science rolling out from Grand Finale orbits more than justifies the calculated risk of diving into the gap — skimming the upper atmosphere and skirting the edge of the inner rings, said Cassini Project Scientist Linda Spilker.

“Almost everything going on in that region turned out to be a surprise,” Spilker said. “That was the importance of going there, to explore a place we’d never been before. And the expedition really paid off — the data is tremendously exciting.”

Analysis of Cassini data from the spacecraft’s instruments will be ongoing for years to come, helping to paint a clearer picture of Saturn.

“Many mysteries remain, as we put together pieces of the puzzle,” Spilker said. “Results from Cassini’s final orbits turned out to be more interesting than we could have imagined.”

The papers published in Science are:

On Oct. 4, as the Science publication embargo lifts, articles describing research complementary to these findings will post online in Geophysical Research Letters (GRL), a journal of the American Geophysical Union (AGU).

Illustration: Saturn and Some Moons as they will appear at 10 PM, August 18, 2018. Simulation by Gas Giants.

Saturn and Some Moons as they will appear at 10 PM, August 18, 2018. Simulation by Gas Giants.

UPDATE: Thank you to the 38 folks who came out to visit us tonight and enjoy the view – such as it was! Early arrivals had exquisite views of Earth’s Moon; then nice views of Saturn with pastel cloud bands across the planetary body and the Cassini Division visible. Late comers got respectable views of Mars though the Martian dust storm hid details! Unfortunately, atmospheric haze/clouds hid the northern sky from us preventing views of the night’s comet and other wonders. Thanks for your patience, kind visitors, and we will hope for truly clear skies in September!

Stephens Memorial Observatory of Hiram College will be open for public observing Saturday, August 18, from 9:00 to 11:00 PM. Organizers are hoping for clear skies in order to provide visitors with wonderful views of the Moon, Red Planet Mars, and the “ring world” Saturn using the Observatory’s vintage telescope. With clear enough skies, and a little luck finding it, viewers may also have the opportunity to view Comet 21P/Giacobini–Zinner which is currently dim and with only the hint of a tail.

Cloudy skies at the scheduled starting time cancel the event and in that case, the observatory will not open. No reservations are required and there is no admission fee for observatory public nights.

The Observatory is located on Wakefield Road (Rt. 82) less than a quarter of a mile west of Route 700 in Hiram. There is no parking at the Observatory. Visitors may park on permissible side streets near the Post Office, a short distance east of the observatory.

Image: Saturn and a few moons as it will appear the night of July 21. Simulation by "Gas Giants."

Saturn and a few moons as they will appear the night of July 21. Simulation by “Gas Giants.”

 

Stephens Memorial Observatory of Hiram College will be open for public observing Saturday, July 21, from 9:30 to 11:00 PM. Given good skies, visitors will see wonderful views of the Moon, giant planet Jupiter with moons of its own, and the “ring world” Saturn. Other objects of interest, such as star clusters, will also be sought, using the Observatory’s vintage telescope.

Cloudy skies at the scheduled starting time cancel the event and in that case, the observatory will not open. No reservations are required and there is no admission fee for observatory public nights.

The Observatory is located on Wakefield Road (Rt. 82) less than a quarter of a mile west of Route 700 in Hiram. There is no parking at the Observatory. Visitors may park on permissible side streets near the Post Office, a short distance east of the observatory.

 

Image: Jupiter and moon Io as they will appear at about 10 PM on July 21, 2018. The Great Red Spot will be front-and-center. Image: Gas Giants simulation.

Jupiter and moon Io as they will appear at about 10 PM on July 21, 2018. The Great Red Spot will be front-and-center. Image: Gas Giants simulation.

Stephens Memorial Observatory of Hiram College will be open for public observing Saturday, July 22, from 9:30 to 11:00 PM. Featured that night will be Saturn, red supergiant star Antares, and the M4 Star Cluster in the constellation Scorpius. Other objects of interest may also be viewed.

The night’s observing depends upon clear skies and those have been in short supply this season! Cloudy skies at the starting time cancel the event and, in that case, the observatory will not open. No reservations are required and there is no admission fee for observatory public nights.

The Observatory is located on Wakefield Road (Rt. 82) less than a quarter of a mile west of Route 700 in Hiram. There is no parking at the Observatory. Visitors may park on permissible side streets near the Post Office, a short distance east of the observatory.

Photo: Storm over Portage County, Ohio, June 24, 2017 - by James Guilford

Storm over Portage County, Ohio, June 24, 2017 – by James Guilford


 
Saturday night’s Open Night presented “interesting” situations. Shortly after arriving at the observatory, we saw rain arrive and heard thunder. Rain stopped, then started again as another compact thunderstorm passed over the village of Hiram. To the north we could see clear sky just outside the borders of the storm. To the south, over Garrettsville and Manuta, we could spy towering cumulus clouds and radar revealed intense rainfall. All of this weather around 8:30 to 9:00 and even a bit later. But at the appointed hour of 9:30, the sky began to clear overhead and we opened the dome.

There, in the southern shy, was Jupiter shining brightly. Hope? Nope! Storm delays and perhaps a bit of spring growth allowed Jupiter to slip behind the upper branches and leaves of a neighboring tree! Visitors arrived and we looked at mushy images of Jupiter pulled through little gaps between tree leaves. Surprisingly, occasional glimpses were had of the giant planet’s distinctive cloud bands and blurry dots of light — the Galilean Moons — could be seen. Then nothing, as Jupiter arced deeper into the branches. We fished around for a while, looking at a couple of bright stars through the murky atmosphere to the south. Saturn was lost in other trees and the messy air.

The faint, fuzzy Ring Nebula would be impossible, no? No. The sky to the east-northeast, inhabited by Lyra and the Ring, was crisp and clear. We rotated the dome, swung the big scope into position, and quickly found Messier 57 – the Ring Nebula. Of the night’s 19 visitors, those who were able to wait out the passage of clouds and darkening of sky were rewarded with clear, bright views of the famous planetary nebula; the beautiful end to a strange and frustrating evening.

Photo: The Ring Nebula (aka Messier 57). Credit: Walker County Observatory / Science@NASA - http://science.nasa.gov

The Ring Nebula (aka Messier 57). Credit: Walker County Observatory / Science@NASA – http://science.nasa.gov

Stephens Memorial Observatory of Hiram College will be open for public observing Saturday, June 24, from 9:30 to 11:00 PM. Featured that night will be Saturn, Jupiter, and the Ring Nebula. Other objects of interest may also be viewed.

The night’s observing depends upon clear skies and those have been in short supply this season! Cloudy skies at the starting time cancel the event and, in that case, the observatory will not open. No reservations are required and there is no admission fee for observatory public nights.

The Observatory is located on Wakefield Road (Rt. 82) less than a quarter of a mile west of Route 700 in Hiram. There is no parking at the Observatory. Visitors may park on permissible side streets near the Post Office, a short distance east of the observatory.

Image: Saturn: August 12, 10:00 PM EDT - Simulated view via Gas Giants app

Saturn: August 12, 10:00 PM EDT – Simulated view via Gas Giants app

UPDATE: Due to mostly-cloudy to overcast skies and recurring scattered thunderstorms, this event has been CANCELED. — JG, 8/12/16, 8:00 PM.

Stephens Memorial Observatory of Hiram College will be open for public observing Friday, August 12, from 9:30 to midnight. Hoping to catch the end of the annual Perseid Meteor Shower, the observatory is hosting its monthly public event on this Friday rather than on Saturday night.

Visitors are invited to bring personal lawn chairs and sit out beneath the stars watching for meteors (mosquito repellent is strongly recommended) until midnight. Via telescope, views of beautiful Saturn, and other objects will also be offered. Saturn’s famous ring system is nicely tilted allowing for excellent viewing, given clear skies.

No reservations are required and there is no admission fee for observatory public nights. Cloudy skies at the starting time cancel the event and, in that case, the observatory will not open.

The Observatory is located on Wakefield Road (Rt. 82) less than a quarter of a mile west of Route 700 in Hiram. There is no parking at the Observatory. Visitors may park on permissible side streets near the Post Office, a short distance east of the observatory.