An Asteroid with Rings?
Δημοσιεύθηκε στις 28 Μαρ 2014
From ESO, observations made at
telescopes in South America have made the surprise discovery that the
remote asteroid Chariklo is surrounded by two dense and narrow rings.
This is the smallest object to have rings and only the fifth body in the
Solar System — after the much larger planets Jupiter, Saturn, Uranus
and Neptune — to have this feature. The origin of these rings remains a
mystery, but they may be the result of a collision that created a disc
of debris.
The rings of Saturn are one of the most spectacular
sights in the sky, and less prominent rings have also been found around
the other giant planets. Despite many careful searches, no rings had
been found around smaller objects orbiting the Sun in the Solar System.
Now observations of the distant minor planet Chariklo as it passed in
front of a star have shown that this object too is surrounded by two
fine rings.
Chariklo is the largest member of a class known as
the Centaurs and it orbits between Saturn and Uranus in the outer Solar
System. The astronomers found much more than they were expecting. A few
seconds before, and again a few seconds after the main occultation there
were two further very short dips in the star's apparent brightness.
Something around Chariklo was blocking the light! By comparing what was
seen from different sites the team could reconstruct not only the shape
and size of the object itself but also the shape, width, orientation and
other properties of the newly discovered rings.
The team found
that the ring system consists of two sharply confined rings only seven
and three kilometres wide, separated by a clear gap of nine kilometres —
around a small 250-kilometre diameter object orbiting beyond Saturn.
The
rings may prove to be a phenomenon that might in turn later lead to the
formation of a small moon. Such a sequence of events, on a much larger
scale, may explain the birth of our own Moon in the early days of the
Solar System, as well as the origin of many other satellites around
planets and asteroids.
telescopes in South America have made the surprise discovery that the
remote asteroid Chariklo is surrounded by two dense and narrow rings.
This is the smallest object to have rings and only the fifth body in the
Solar System — after the much larger planets Jupiter, Saturn, Uranus
and Neptune — to have this feature. The origin of these rings remains a
mystery, but they may be the result of a collision that created a disc
of debris.
The rings of Saturn are one of the most spectacular
sights in the sky, and less prominent rings have also been found around
the other giant planets. Despite many careful searches, no rings had
been found around smaller objects orbiting the Sun in the Solar System.
Now observations of the distant minor planet Chariklo as it passed in
front of a star have shown that this object too is surrounded by two
fine rings.
Chariklo is the largest member of a class known as
the Centaurs and it orbits between Saturn and Uranus in the outer Solar
System. The astronomers found much more than they were expecting. A few
seconds before, and again a few seconds after the main occultation there
were two further very short dips in the star's apparent brightness.
Something around Chariklo was blocking the light! By comparing what was
seen from different sites the team could reconstruct not only the shape
and size of the object itself but also the shape, width, orientation and
other properties of the newly discovered rings.
The team found
that the ring system consists of two sharply confined rings only seven
and three kilometres wide, separated by a clear gap of nine kilometres —
around a small 250-kilometre diameter object orbiting beyond Saturn.
The
rings may prove to be a phenomenon that might in turn later lead to the
formation of a small moon. Such a sequence of events, on a much larger
scale, may explain the birth of our own Moon in the early days of the
Solar System, as well as the origin of many other satellites around
planets and asteroids.
Κατηγορία:
Άδεια
Τυπική άδεια YouTubeANAΡΤΗΣΗ ΑΠΟ ΤΟ YOUTUBE 28/3/2014
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