Last year we saw Pluto (left with its satellite Charon) booted out of the first division of planets, relegated to “dwarf planet” status. Now it has been confirmed it doesn’t even top the “tiddlers league” A http://news.bbc.co.uk/1/hi/sci/tech/6751975.stm study has confirmed that the dwarf planet Eris - whose discovery prompted Pluto's relegation from planet to dwarf - outranks it in mass.
The discovery of Eris, formerly known as 2003 UB313, marked the beginning of the end for Pluto as a planet. Previous measurements from the Hubble Space Telescope confirmed that Eris was larger in diameter than Pluto, leading the International Astronomical Union (IAU) to rule in 2006 that Pluto could no longer be classed as a planet. A new category of dwarf planets was adopted, into which Pluto, Eris and another body called Ceres, which is located in the asteroid belt, were placed.
Eris (left) lies 14.5 billion km from Earth in the Kuiper Belt. It has a moon, Dysnomia, and scientists used this satellite, to calculate its mass. The researchers, led by Eris' discoverer Mike Brown from the California Institute of Technology, discovered that the more distant world has 27% more mass than Pluto. So in addition to being the largest, Eris is also the most massive known dwarf planet.
Poor Pluto stares into the abyss and the abyss gazes also... over its planetary shoulder at something more interesting - in this case a few pixels!
No comments:
Post a Comment