The Discovery of Eris…Eris was discovered by Mike Brown, Chad Trujilloand David Rabinowitz’s team on 5th January2005, from images taken on 21st October 2003.The discovery was announced on 29th July2005, the same day as Makemake and two daysafter Haumea.
The Orbit of Eris…• Eris has an orbital period of 557 years and as for 2011 it lies 96,6 astronomical units from the Sun, almost its maximum possible distance to orbit the Sun.
The Moon of Eris…Images taken on 10th September 2005 revealeda moon in orbit around Eris. Instead of keepingthe name “Xena”, a nickname already in use forEris, Browns team nicknamed this moon“Gabrielle”. In a conference of the IAU(International Astronomical Unit), Eris receivesits official name and its moon receives the nameDysnomia.
Surface and Atmosphere…Due to the fact that this dwarf planet is in thelimit of the Solar System, it has got negativetemperatures. The medium temperature to thesurface of Eris is -270oC to -217oC.
Bibliografy:• http://en.wikipedia.org/wiki/File:2006-16-a-full-1-.jpg;• http://en.wikipedia.org/wiki/Eris_(dwarf_planet);• http://1.bp.blogspot.com/_n6b9oN2a7Ww/TCpQxM9IIHI/AA AAAAAABK0/rZjzxNs8oPs/s1600/%C3%89ris.jpg;• Geografia Universal – A Astronomia e o Sistema Solar, 2005, de Iniziative Speciali De Agostini;• http://www.astronomytoday.com/astronomy/eris.html;• www.explicatorium.pt/c-f-q-7_ano/astronomia/eris/;• Dicionário por Imagens do Sistema Solar, 1998, de Agnès Vandewiele;