Dysnomia, the moon of Eris



Eris

The discovery of Dysnomia, the moon of Eris, from the W.M. Keck Observatory. Eris appears in the center,

while the moon is the small dot at the 3 o'clock position. Credit: M.E. Brown, W.M. Keck Observatory





How was the moon found?



Artist's concept of Eris and Dysnomia. The sun and other planets appear in the distance. Credit: R. Hurt, IPAC





Why is the discovery of the moon important?







Our best images came from the Hubble Space Telescope, and clearly showed (much to our suprise) that Dysnomia is the only moon around. These images, shown below, are so good that you also can see some of the artifacts caused by the Hubble Space Telescope itself. In particualr, the spikes coming out of Eris, the spotty "ring" around Eris, and the slight elongation to the right of Eris are all expected patterns caused by the telescope itself, rather than from anything going around Eris.









Images of the four largest Kuiper belt objects from the Keck Observatory Laser Guide Star Adaptive Optics system. Satellites are seen

around all except for 2005 FY9. Without the adaptive optics system the images of the Kuiper belt objects would he

smeared out so much by the earth's atmosphere that the satellites would not be visible. Credit: M. Brown/Keck Observatory









Why is the moon called Dysnomia?



What is the moon made out of?



How big is the moon?















