Saturn’s Rings: A Beautiful but Fleeting Wonder of the Solar System

Saturn’s rings are one of the jewels of the solar system, but their time seems short and their existence is not eternal.

New study They showed that the rings were between 400 million and 100 million years old – a fraction of the solar system’s age. This means that we are lucky to live in an era when giant planets have their own beautiful rings. Research has also revealed that they could disappear in another 100 million years.

The rings were first observed in 1610 by astronomer Galileo Galilei who, because of limited resolution of his telescopes, initially described them as two smaller planets on each side of Saturn’s main body, appearing to be in physical contact with it.

In 1659, the Dutch astronomer Christiaan Huygens published Systema Saturniumbeing the first to describe it as a thin, flat ring system that does not touch the planets.

It also shows how their appearance changes, as seen from Earth, as the two planets orbit the sun and why they appear to disappear at certain times. This is because the geometry of their vision allows us to see them on Earth at regular intervals.

The rings can be seen by anyone with suitable binoculars or a modest backyard telescope. Casting white against Saturn’s pale yellow sphere, the rings are made up almost entirely of billions of water-ice particles, which glow through scattering sunlight.

Amidst this icy material is a deposit of dark, dusty matter. In space science, the term “dust” usually refers to small details Of rocky, mineral, or carbon-rich material that looks darker than ice. They are also collectively referred to as micrometeorites. These grains penetrate the solar system.

Occasionally, you can see them enter Earth’s atmosphere at night as lightning. The planet’s gravitational field has the effect of magnifying or concentrating the “drop” of the planet’s dust.

Over time, these falls added to the planet’s mass and changed its chemical composition. Saturn is a gas giant with a diameter of about 60,000 km, about 9.5 times that of Earth, and about 95 times that of Earth’s mass. That is, it has a very large “gravitational well” (a gravitational field surrounding objects in outer space) and very effectively directs dust grains towards Saturn.

crash course

The rings stretch from about 2,000 kilometers above Saturn’s cloud tops to about 80,000 kilometers, occupying an enormous amount of space. When falling dust passes through it, it can collide with ice particles in the ring. Over time, the dust gradually darkens the rings and increases their mass.

Cassini-Huygens is a robotic spacecraft launched in 1997. It reached Saturn in 2004 and entered orbit around the planet, where it will remain until the end of the mission in 2017. Cosmic Dust Analyzer (CDA).

Using data from the CDA, the authors in the new paper compared the current dust population in the space around Saturn with the estimated mass of dark dusty material in the rings. They found that the rings are no more than 400 million years old and may be as old as 100 million years. This may seem on a long time scale, but it is less than a tenth of the solar system’s 4.5 billion years.

This also means that the rings did not form at the same time as Saturn or any other planet. They are, in cosmic terms, a recent addition to the solar system. For more than 90% of Saturn’s existence, they did not exist.

Death Star

This leads to another mystery: How did the rings form first, given that all the major planets and moons in the solar system formed much earlier? The total mass of the rings is roughly half that of one of Saturn’s smaller icy moons, many of which display massive impact features on their surfaces.

One in particular, Little Moon mimesnicknamed the Death Star, its surface is a 130-kilometer-wide impact crater called Herschel.

This is by no means the largest crater in the solar system. However, Mimas is only about 400 kilometers across, so it wouldn’t have taken much energy for this impact to obliterate the moon. Mimas is composed of water ice, as are the rings, so it’s possible that the rings could have formed from such a powerful impact.

rain ring

Whatever form it takes, the future of Saturn’s rings is in no doubt. The impact of dust grains on ice particles occurs at very high speeds, separating small pieces of ice and dust from their parent particles.

Ultraviolet rays from the sun cause these parts to become electrically charged photoelectric effect. Like Earth, Saturn has a magnetic field, and once charged, these tiny bits of ice are released from the ring system and trapped by the planet’s magnetic field.

Coordinating with the giant planet’s gravity, they are then directed into Saturn’s atmosphere. This “ring rain” was first observed from afar by the Voyager 1 and Voyager 2 spacecraft during their brief flights over Saturn in the early 1980s.

in the last days Paper from 2018 The scientists used dust tallies, again from the CDA, as Cassini flew between the rings and the cloud tops of Saturn, to see how much ice and dust was lost from the rings over time. The study shows that about one Olympic-sized collection of rings is lost into Saturn’s atmosphere every half hour.

This flow rate has been used to estimate that, given their current mass, the rings will likely disappear in less than 100 million years. This beautiful ring has a turbulent history, and unless it is renewed in some way, it will be devoured by Saturn.

Gareth DorianPostdoctoral Research Fellow in Space Science, University of Birmingham

This article has been republished from Conversation Under Creative Commons License. Read Original article.