{"id":13764,"date":"2023-02-09T08:07:53","date_gmt":"2023-02-09T13:07:53","guid":{"rendered":"https:\/\/theness.com\/neurologicablog\/?p=13764"},"modified":"2023-02-15T21:43:14","modified_gmt":"2023-02-16T02:43:14","slug":"dwarf-planet-ring-mystery","status":"publish","type":"post","link":"https:\/\/theness.com\/neurologicablog\/dwarf-planet-ring-mystery\/","title":{"rendered":"Dwarf Planet Ring Mystery"},"content":{"rendered":"

\"\"Scientists love mysteries, because that is where new discoveries lay. It is nice to find evidence consistent with existing theories, providing further confirmation, but it’s exciting to find evidence that cannot be explained with existing theories. Astronomers may have found such a mystery in the dwarf planet Quaoar – it has a ring where one shouldn’t be<\/a>.<\/p>\n

When we think of planetary rings we of course think first of Saturn, which has by far the largest and most impressive ring system in the solar system. But all the gas giants have their own rings, including Jupiter, Uranus, and Neptune. None of the smaller rocky planets have detectable rings. This is likely not a coincidence and relates to how rings form and how long they will last. But smaller bodies can have rings. Saturn’s moon Rhea<\/a> may have a faint ring of its own. There is even an asteroid, Chariklo, which has two faint rings<\/a>.<\/p>\n

Rings are basically linear clouds of dust, ice, and other material that spreads out in an orbit around a planetary body. They form in one of two ways. For large planets like Saturn, if a moon’s orbit decays to the point where it gets within the Roche limit (the point at which tidal forces are so great they tear apart any large object), then the moon will break apart into debris that forms a ring. But anything that spreads dust around a planet can also feed a ring. For example, when meteorites hit the moons of Jupiter they throw up dust which can feed its faint ring system. Because the material that forms rings are close to their host planet they also tend to slowly rain down to the surface, so they have a limited lifetime. Saturn will eventually lose its beautiful rings. But new rings may also form. When Phobos gets too close to Mars one day it will break up and become a Martian ring system.<\/p>\n

Also, the Roche limit works both ways. Moons that fall inside the Roche limit break up into rings. But ring systems outside the Roche limit tend to coalesce into moons. Slight differences in orbital period mean that particles will eventually crash into each other and will be held together by mutual gravity, getting larger and soaking up more and more particles until you have one larger object.<\/p>\n

The Quaoar ring is a mystery because it is far outside the Roche limit of this dwarf planet. It should have coalesced into a moon. Quaoar is a Kuiper belt object, whose orbit varies from 42-45 AU from the sun. It takes 288.8 years to orbit the sun. It has a small moon, Weywot, and now, apparently, a ring. The ring was discovered with data from several ground based telescopes and the orbital telescope Cheops. The ring was not observed directly (it’s too distant for that) but was discovered because it blocked light from stars that passed behind it. The rings were suspected from ground based data, but confirmed with great precision with data from Cheops.<\/p>\n

How, then, could such a ring survive outside the Roche limit of Quaoar? Perhaps the ring it too new to have had time to coalesce into a moon. However, this process can happen within just a few decades. Catching the short life of such a ring is therefore not impossible, just extremely unlikely, which makes it a difficult explanation. If this is the case, however, observations over the next few decades can confirm it as the new ring forms into a small moon. If it does not and the ring remains that will confirm what scientists suspect now as a matter of probability – the ring is a long-lived structure outside the Roche limit.<\/p>\n

The other possibility is that something is keeping the particles in the ring from sticking together and forming a moon. Perhaps it is the extreme cold this distance from the sun, but so far that is just speculation. The presence of a moon can shepherd the particles in a ring. Neptune’s rings are more arcs, kept from spreading out into a full ring by Neptune’s moons, for example. Perhaps an unseen moon in having a gravitational influence.<\/p>\n

Whatever the answer, something new is happening around Quaoar. This will add to our ever-growing list of known astronomical phenomena, increasing our ability to explain what we see out there in the universe.<\/p>\n","protected":false},"excerpt":{"rendered":"

Scientists love mysteries, because that is where new discoveries lay. It is nice to find evidence consistent with existing theories, providing further confirmation, but it’s exciting to find evidence that cannot be explained with existing theories. Astronomers may have found such a mystery in the dwarf planet Quaoar – it has a ring where one […]<\/p>\n","protected":false},"author":7,"featured_media":13765,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[73],"tags":[],"class_list":["post-13764","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-astronomy"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t