The American spacecraft Cassini, completing its mission near Saturn, once again proved that it is not at all necessary to fly to other stars for amazing discoveries, and the amazing is still somewhere nearby - in our still little studied solar system. It is enough just to look.
Just three days ago, on March 7, the device managed to capture one of Saturn's many satellites, tiny Pan, with unprecedented clarity.
Carolyn Porco/NASA
And although scientists had previously guessed about the unusual features of the shape of this small satellite, the reaction of the participants in the mission itself speaks for itself. “These pictures are real! Science turned out to be better than fiction, ”rejoiced from the Cassini mission imaging team.
The tiny satellite, which has a diameter of only 32 kilometers, was named after the ancient Greek god of shepherding and cattle breeding for a reason. He belongs to the so-called shepherd companions. Moving in a circle inside the outer ring A, Pan and similar satellites sweep out the substance of the ring with their attraction, forming a gap around them. The Encke division is just such a gap, inside which Pan rotates. Actually, even before the discovery of Pan, the presence of a gap in the A ring prompted scientists to think about the existence of a satellite in it back in the mid-1980s. However, it itself was not discovered until 1990, when Mark Showalter noticed it while analyzing photographs sent back in 1981 by the Voyager 2 probe.
In November 2016, Cassini, which has been exploring the Saturn system since 2004, at the command of scientists tilted its orbit and began diving through the planet's rings and exploring their least explored and interesting outer edge. Thanks to entering a new orbit with an inclination of 60 degrees from November 30 to April 22, the device began to dive through the rings every seven days (20 times in total).
“We call this phase of the mission ring-grabbing orbits because we will be able to touch the outer edge of the rings,” said Linda Spilker, a mission participant at the Jet Propulsion Laboratory. “In addition, we have two instruments that can take samples of particles and gases as we cross the plane of the rings, so in a sense, Cassini will really touch the rings.”
This has already made it possible to obtain new images of the planet's rings from unusual angles, and now - to obtain images of Pan with unprecedented resolution.
These pictures were taken from a record close distance of 24,572 kilometers.
The photographs clearly show a crest that encircles the entire circumference of an unusual satellite and somehow makes it look either like Saturn itself or really like a flying saucer. A flying saucer, a spaceship, a walnut, ravioli and even a face - that's what people see when they look at the actually rediscovered satellite of Saturn.
According to scientists, this crest is the so-called equatorial accretion disk, consisting of matter that has fallen onto the surface of the satellite, which is part of the surrounding ring. "How different these images are from the barely visible dot I saw in 1990 on Voyager photographs!" “It's nice to finally see Pan up close,” said Showalter, now at the SETI Institute.
Curiously, Pan's flattened shape was also previously known thanks to the first photographs sent by Cassini at the beginning of his mission. IN article, published in Science back in 2007, scientists suggested that its crest formed long before Pan completely cleaned out the hole in the ring around him.
“Its shape is thought by many to be because the moon is constantly sweeping fine dust off the ring,” Showalter explained. “Compared to the size of Pan, the rings are very thin, so the dust settles on his equator.” According to scientists, another satellite of Saturn - Atlas - has a similar shape for the same reason.
Pan- Saturn's inner satellite near the A ring and Encke: photo, the effect of gravity on the rings, discovery, name and myth, parameter table, Cassini study.
Pan is the innermost known moon of Saturn and lies within the Encke division of Saturn's A-ring. He acts as a "shepherd" satellite and is responsible for keeping the Encke division open. The division represents a 325 km (200 miles) passage into Saturn's A ring.
Saturn's moon Pan creates streaks, so-called "vortices", in the ring material on either side of it. Because the ring particles are closer to Saturn than Pan and move faster in their orbits, these particles pass the moon and receive a gravitational "bump" from Pan. This impact causes waves in the division as well as throughout the ring, expanding hundreds of kilometers into the rings. These waves intersect into a downward current that creates vortices - places where the particles of the ring cluster in an orderly fashion due to Pan's gravitational impact.
Pan, like Saturn's moon, has a protruding equatorial ridge that gives the moon its distinctive flying saucer shape.
Pan satellite discovery
Saturn's satellite Pan was discovered by M.R. Schulter in 1990 using images taken by the Voyager 2 spacecraft nine years earlier.
How Pan got its name
Saturn's moons were originally named after the Greco-Roman Titans and their descendants. But as many new moons were discovered, scientists began to pick names from other mythologies, including Gallic, Inuit and Norse stories.
Pan is a satyr (human-like creature with goat's hooves for legs) who is the Greek god of nature and the forest.
Thus, you learned which planet Pan is a satellite of.
See high-quality, high-resolution photos of Saturn's moon Pan from space.
The main parameters of the Pan satellite |
|||||
| Information about the opening | |||||
|---|---|---|---|---|---|
| opening date | July 16, 1990 | ||||
| pioneers | Sheppard, Jewitt Klina, Marsden |
||||
| Orbital characteristics | |||||
| Major axis | ? | ||||
| Eccentricity | 0,0000 | ||||
| Period of circulation | 0.575 days | ||||
| Mood | 0.001° | ||||
| Satellite | Saturn | ||||
| physical characteristics | |||||
| Dimensions | ? | ||||
| Diameter | 26 km | ||||
| Weight | 4.92 10 15 kg | ||||
| Density | ? | ||||
| Albedo | 0,50 | ||||
Photos of satellite Pan
This photo of Cassini was captured on April 3, 2016 at a distance of 373,000 km and at an angle of 140 degrees. Pan and other satellites are seriously affecting the planetary rings. They form gaps, create arcs, and all this due to gravity. Pan spans 28 km in width and is located in the center of the frame, namely in the Encke Gap. Weak arcs are visible at the bottom right. Many satellites produce waves at the far end of the ring, where particles and moons are in resonance. They differ in color and thickness, and their study will help to understand the process of formation of the ring system on giant planets. A narrow-angle camera with visible light was used for the survey. Observations were made on the unlit side of the rings 22 degrees below the plane. The scale is 2 km per pixel. The Cassini program is a joint development of ESA, NASA and the Italian Space Agency. The team is based in JPL. The two cameras on board are also made by them. The obtained photos are processed in Boulder (Colorado).
On March 7, 2017, two prospects for the passage of Cassini past Pan at a distance of 24,600 km were obtained. This is the closest pass with the ability to detail surface features. Here is the northern and southern hemispheres. Researchers believe the moon formed in the planet's rings with material accreting onto it. The rounded shape came about when the outer part of the ring system was younger and denser vertically. As a result, the satellite's ice core is denser than the mantle. It is believed that a thin ridge on the equatorial line formed after the appearance of the satellite and the clearing of the gap between the rings. At the end of the process, the material could have landed on the Pan in this particular area, creating a high ridge. If the body were more massive, then everything would be smoothed out. But gravity is weak, so the particles accumulated. The device is located at a distance of 24583 km (left) and 37335 km (right). Scale: 147 m and 224 m per pixel, respectively. The Cassini program is a joint development of ESA, NASA and the Italian Space Agency. The team is based in JPL. The two cameras on board are also made by them. The obtained images are processed in Boulder (Colorado).
| Shepherd Companions | · · · · · · · · |
| Internal satellites | · · · · · · · |
| Alcyonides | · · |
| External | · · · |
| Irregular | eskimo group: · · · ·
Norwegian group: · · · |
Publication date: 14.03.2017
NASA has released several new images of Pan, Saturn's tiny moon. The images were taken on March 7, 2017 by the Cassini space probe from a distance of about 24,000 kilometers. We see a "moon" of a bizarre shape, which is very similar to a huge dumpling flying in space - or a nut, if you like.
Pan, Saturn's inner moon, also known as Saturn XVIII, was discovered in 1990 by Mark Showalter in Saturn's rings while analyzing photographs taken as early as 1981. Pan received his name in honor of the famous mythological creature.
By dumpling standards, Pan is huge, but by astronomical standards, it’s just a crumb. Its maximum size is about 35 kilometers. It is the second most distant satellite of Saturn and is located in the gap between the rings of Saturn. Pan is a "shepherd" (or "vacuum cleaner") satellite - by acting on its gravity, it cleans the neighborhood of its own orbit from particles of the ring. Pan makes a complete revolution around Saturn in less than 14 hours.
Experts have not yet agreed on why Pan has such a shape.
Imagery from NASA/JPL-Caltech/Space Science Institute.
And here are the same pictures glued into an animated GIF file:
We live in an amazing time, don't we? You launch the camera into the devil knows what space distance and find out that the satellite of Saturn is a shaped dumpling.