When Was Eukelade Discovered?
No one identified Eukelade as a possible moon of Jupiter until 2003. Dr. Scott S. Sheppard led a team of scientists from the University of Hawaii. They conducted research at the Mauna Kea Observatory on the big island of Hawaii. When members of the team looked through the huge telescope at the observatory, they spotted Eukelade orbiting around the planet Jupiter.
How Did Scientists Name Eukelade?
Dr. Sheppard and his team gave the temporary name S/2003 J1 to Eukelade.(2) They planned to study the retrograde “moon” first before assigning a permanent name to it. Eukelade appeared to be a satellite. A “satellite” is an object which orbits around another object.
After more than a year of study, scientists confirmed that S/2003 J1 probably belonged to the Carme Group. An organization called the “International Astronomical Union” (the “IAU”) assigned the name “Eukelade” to the recently discovered satellite in March, 2005.
Many full-time astronomers belong to the IAU. The organization serves as the official authority for assigning names to newly discovered planets, stars, asteroids, and other heavenly bodies. The IAU always gives a retrograde moon a name ending with the letter “e”. This naming rule helps people know immediately that Eukelade maintains an orbit in a retrograde direction.
The Origin of the Name “Eukelade”
The name “Eukelade” comes from an ancient Greek word. It translates as “well sounding”. Some ancient Greeks described Eukelade as a goddess. Some writers referred to her as one of the nine Muses, although she did not always receive inclusion in that list.
Ancient Greeks described Eukelade as one of the daughters of the Greek god Zeus. The ancient Romans referred to “Zeus” as “Jupiter”. Therefore, Eukelade signifies a daughter of Jupiter (a good name for one of the planet Jupiter’s moons!).
How Does Eukelade Appear Through a Telescope?
Through a telescope, all of the moons in the Carme Group (including Eukelade) look pale red in color. However, one of them, Kalyke, differs from the others. It shines more brightly red.
Fun Facts About Eukelade
Like other moons in the Carme Group, Eukelade does not resemble a sphere. Instead, this retrograde moon possesses an irregular shape. It extends across only 4 kilometers in diameter (nearly 2.5 miles). Eukelade’s equator extends around the moon for approximately 12.6 kilometers, or 7.8 miles.(6) Its small circumference means if humans landed on Eukelade they could walk completely around it during a single day. (This is not possible yet, of course, since Eukelade does not possess an atmosphere humans can breathe.)
The moon Eukelade travels in a backwards direction around the large planet Jupiter. It requires roughly 735 Earth days to complete a single orbit.(5) The tiny retrograde moon remains an average of roughly 14.4 million miles away from Jupiter.
Eukelade and other moons in the Carme Group also display another unusual trait. They do not follow circular orbits. Instead, these moons travel in elliptical orbits. Scientists refer to this type of orbit as “eccentric”.
It carries Euklade closer to Jupiter on certain Earth days and much further away from Jupiter at other points in the orbit.
Eukelade ranks as the third largest moon in the Carme Group. Some of the other moons in the Carme Group include: Carme (the largest), Taygete (the second largest), Eirene, Chaldene, Isonoe, Kalyke, Erinome, Aitne, Kale, Pasithee, and a tiny moon called by the temporary name S2003 J9.(7) NASA scientists believe a total of 16 moons belong in the Carme Group.
How Did The Carme Group Come to Exist?
Scientists remain uncertain about the origins of the moons in the Carme Group. These moons share some characteristics in common:
All of them travel in retrograde motion.
All of them possess an irregular shape.
All of them are reddish in color.
All of them orbit close to one another (in astronomical terms, anyway).
These interesting facts cause some scientists to surmise the moons in the Carme Group share a common origin. Some astronomers believe they once formed part of a single object which broke apart.