Explore the evidence for a possible new moon in Saturn’s rings.
NASA’s Cassini spacecraft has investigated the formation of a small icy object within the rings of
Saturn, which they have informally named “Peggy.” The object may be a new moon. This may be the
birth of an object for the first time.
This disturbance visible at the outer edge of Saturn’s rings from NASA’s Cassini spacecraft, could be
caused by an object in the birth process of forming an icy moon.
Images taken with Cassini’s narrow angle camera on April 15, 2013 show disturbances at the very
edge of Saturn’s A ring, the outermost of the planet’s large, bright rings. One of these disturbances
is a semi-circular region about 20 percent brighter than its surroundings, 1,200 kilometres long and
10 kilometres wide.
Scientists also found unusual disturbances in the usually smooth region of the ring’s outer edge.
Scientists believe that these disturbances are caused by the gravity of a large object.
The object is not expected to grow any larger, and may even be falling apart. But the process of
its formation and an outward movement improves the understanding of how Saturn’s icy moons,
including the cloud-wrapped Titan and ocean-holding Enceladus, may have formed in more
massive rings a long time ago.
Scientists estimate that the object is probably no more than 2 kilometres in diameter. Saturn’s icy
moons range in size depending on their distance from the planet. The farther from the planet,
the larger the moon becomes. Many of Saturn’s moons are comprised primarily of ice, as are the
particles that form Saturn’s rings.
The theory holds that Saturn long ago had a much more massive ring system capable of giving
birth to larger moons. A moon’s formation seems to end near the ring’s edge and the process of
forming all the moons has slowly depleted the rings.
It is possible the process of moon formation in Saturn’s rings has ended with Peggy, as Saturn’s rings
now are, in all likelihood, too depleted to make any more moons.
Endeladus (moon of Saturn)
NASA’s Cassini spacecraft has discovered evidence that Saturn’s moon Enceladus has a large underground ocean. Scientific interest in the moon thinks there is potential for extra-terrestrial microbes.
Scientists said that there was liquid water present in 2005 when Cassini discovered water vapour and ice spewing from vents near the moon’s south pole.
Scientific measurements sent back to Earth by radio suggest a large ocean about 10 kilometres deep, beneath an icy cover of about 30 to 40 kilometres thick. The underground ocean supports including Enceladus among the most likely places in our solar system to host microbial life. Cassini has flown near Enceladus 19 times. There were 3 flybys, from 2010 to 2012.
There is no certainty the underground ocean supplies the water plume spraying out of surface fractures near the south pole of Enceladus, however, scientists suggest it is a real possibility. The fractures may lead down to a part of the moon that is heated by the moon bending and flexing in Saturn’s huge gravitational field.
Much of the excitement about the Cassini mission’s discovery of the Enceladus water plumes stems from the possibility that it may mean a wet and favourable environment for microbial life. This is because material from Enceladus’ south polar jets contains salty water and organic molecules, the basic chemical ingredients for life.
Their discovery increased the understanding of the’habitable zone’ within our solar system and in planetary systems of other stars.
This new idea that an ocean of water under the ground is causing the jets of water furthers improves our understanding about this interesting environment.
NASA’s Wide-field Infrared Survey Explorer (WISE) and Spitzer Space Telescope have discovered what appears to be “brown dwart’A brown-dwarf is a dim, star-like body that emits small amounts of heat and light
The brown dwarf has a chilly temperature between -48°C to minus -13°C. Previous record holders for the coldest brown dwarfs, also found by WISE and Spitzer, were about room temperature.
WISE was able to spot these rare objects because it studied the entire sky three times sometimes looking at areas twice.
Colder objects like brown dwarfs can be hard to see as they don’t give off much heat or light.
Spotting the brown dwarf taken from different positions from Earth while travelling around the Sun, means calculations could be done to determine how far away it is from Earth. The closest stars to Earth are a trio of stars called Alpha Centauri and these are about 4 light-years away. The brown dwarf is only a few light years farther than that and appears to be 3 to 10 times the size of Jupiter.
With such a low mass, it could be a gas giant similar to Jupiter. But scientists think it is probably a brown dwarf rather than a planet since brown dwarfs are known to be fairly common. If this is correct then it is the smallest brown dwarf known.
In March of 2013 WISE discovered a pair of much warmer brown dwarfs at a distance of 6.5 light years, making that system the third closest to the Sun.
NASA continues to search for objects in the night sky like these brown dwarfs. It has also been demonstrated that our outer solar system probably does not contain a large, undiscovered planet, which has been referred to in the past as “Planet X”or”Nemesis:’