October 31, 2011 13:21
Astronomers have reported that a small planet Eris (Eris), which deprived the full title of the planet Pluto, is in fact a cold twin of Pluto. Moreover, in the Kuiper belt may be many such celestial bodies.
A new study has given the most detailed to date features the mysterious planet Eris, which was opened in 2005. This discovery raised many interesting questions about the Kuiper belt — a cluster icy objects beyond Neptune.
Eris discovery caused a sensation among astronomers. Already on the first estimates of the size of this celestial body was comparable to Pluto, for which it had unfortunate consequences. Pluto was discovered in 1930 and has long been a ninth, the smallest planet in the outer Solar System. However, after the discovery of Eris, the International Astronomical Union downgraded Pluto in rank: to level the dwarf planet, ie Now the former planet is in line with a large asteroid Ceres and two other large Kuiper Belt objects — Makemake and Haumea. "Resignation" Pluto has caused public disapproval and is still hotly disputed by many astronomers. Thus the name Eris (after the Greek goddess of discord and disagreement) turned out very successful.
New research Eris was conducted by two giant telescopes in the Atacama Desert in Chile. Due to the passage of Eris star in November 2010, and managed to get a fairly accurate data on the size and surface of the dwarf planet.
It was a real engineering feat since Eris was then about 100 times farther than the distance from Earth to the Sun. Today it is the most distant object in the solar system, which is so well understood.
Astronomers have found the exact dimensions Eris — a spherical object with a diameter 2,326 miles (give or take 12 km), which is lower than previously estimated. Thus, nearly double the size of Eris Pluto, with a diameter estimated at 2300-2400 km. Unusually bright surface of Eris, which suggests the presence of an ice field. Furthermore, the surface is regularly updated, or under the influence of cosmic rays and micrometeorites impacts over time it would lose brightness. Scientists suggest that Eris has a methane-rich atmosphere that periodically freezes and thaws, thus maintaining the brightness of the icy surface of the dwarf planet. Most likely, the surface thaws when Eris reaches closest to the Sun section of its elliptical orbit — it is about 30 astronomical units, ie 30 times farther than Earth is from the Sun. However, the frozen surface warms enough to methane started to evaporate and create a temporary thin atmosphere.
Observations suggest that Eris — a real twin of Pluto, the Sun only dwarf planet becomes longer — 557 years instead of 248 years for Pluto.