Astronomers studied the farthest ring of Saturn

In 2009, astronomers have discovered: in addition to 25 near the rings of Saturn has one more subtle ring located far beyond the others. He was named Ring Phoebe (Phoebe ring), the title of the satellite Phoebe. Presumably, the ring consists of particles of the satellite.

The illustration schematically depicts a giant ring size Phoebe, compared with the planet itself (several points in the center).

This ring is deservedly included in the list of the most bizarre objects in the Universe found so far.

Hoop of dust orbiting gas giant at a distance of about 13 million kilometers, which is almost 50 times more than the other rings.

Ring Phoebe discovered in 2009 by a space observatory "Spitzer", which monitors space in the infrared range and is able to detect particles of about 10 microns. Because of these particles is partially dusty hoop Phoebe (density per cubic meter was initially estimated at 10-20 particles).



The satellite Phoebe, a photo with the device "Cassini» i>

Unfortunately, May 15, 2009 on the telescope "Spitzer" run out of refrigerant, so he could not continue observation.

To continue to examine the ring in June 2010, astronomers headed towards Saturn another infrared telescope lens Wide-field Infrared Survey Explorer (WISE), which is located in Earth orbit. And with it the first time managed to get a picture of the ring Phoebe entirely. In the picture it shows how tenuous dust cloud in the horizontal plane.

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June 10, 2015 in the journal Nature published on исследование, formed a group of scientists from the University of Maryland, the University of Virginia and the Center for processing and analyzing infrared images at the California Institute of Technology. The study analyzed data from the telescope WISE.

The size of the ring and its distance from Saturn were higher than expected. In 2009, the particles were recorded at a distance of 128 to 207 Saturn radii (R <sub>S sub> = 60,330 km) from the planet. The total length of the vertical ring 40 R S sub>. Thus, the ring Phoebe more than ten times more than before is the largest ring E.

The full radial length has not been possible to measure in the pictures with the "Spitzer", as well as the characteristics of the dust particles.

Snapshots from WISE show that Phoebe ring even more than expected: it stretches from the 100 R S sub> as much as 270 R S sub> (6 million kilometers to 16 million kilometers from planet)! That is 30% more than previously thought.

Scientists have made a model of the orbital dynamics of particles aircraft coming from Phoebe in a collision with a foreign space bodies, and constructed a theoretical exponential profiles of particle size distribution. They estimate that up to 10% of the cross-section of the ring are large particles with a radius of more than 10 cm, which can orbit inside the ring does not decrease more than 4, 5 billion years.

Thus, the ring Phoebe significantly older than the inner rings of Saturn. Perhaps it was formed simultaneously with the solar system.

Unfortunately, the telescope WISE also run out of coolant in 2010, and since then no new information about the ring Phoebe, we have not received. According to scientists, is now in space there is no machine that could help in the study of this object.

Source: geektimes.ru/post/251828/</sub>