Autonoe was formed from the creation of the Pasiphae group. When a C-type asteroid from the Asteroid belt was pulled in by Jupiter's gravitational pull, it suffered only one collision. This collision shot debris into space and it became the Pasiphae group, with Pasiphae being the largest of the group.
The surface of Autonoe is possibly grey due to it being a part of the Pasiphae group, with Pasiphae being a very light grey. Autonoe's surface has never been viewed clearly, but shows signs of visible craters. The infrared spectrum shows mountainous areas and color spectra matching those of Sinope, a nearly black-grey satellite of the Pasiphae group.
Autonoe was named after the mother of the Graces of Jupiter according to some authors. It is confirmed by the IAU that all satellite names ending in the letter "e" are outer retrograde satellites.