Charon's Cousins

Observations with the Hubble Space Telescope from May of last year show two tiny dots revolving around the same center of gravity as the ninth planet (Pluto) and its largest moon, Charon.

(yes, even the moons have a name!)

"We used Hubble's exceptional resolution to peer close to Pluto and pick out two small moons that had eluded detection for more than 75 years," says Hal Weaver, an astrophysicist at Johns Hopkins University and the discovery team leader.

Based on their brightness--and assuming that their surfaces are about as reflective as Charon's--the scientists believe the two moons are roughly 38 miles and 29 miles in diameter.

Given that they share Pluto's distance from the sun--roughly three billion miles--but are 4,000 times fainter, it is not surprising that the satellites eluded detection until now, the researchers say.

--Thats how large the distances are. If you were looking at your palm, and see the wedges between the palm lines, imagine a palm sitting there with its own palm lines, and do this a 1000 times, thats how small the moons appear when we place the distance between the Sun and Pluto into perspective. Hubble telescope is quite a remakable window to outside of our world.

--How do I know what a solar system is? Is "my world" all that I can see? What if the tenth planet has already given its loyalty to another Sun or a Star?

--From the Scientific American article