Anthe (moon of Saturn)

Discovery

The moon was identified by members of the Cassini imaging team in data returned by the Cassini spacecraft. The discovery image was taken on 30 May 2007, and subsequent searches of archived Cassini frames showed the object in earlier observations dating back several years. The discovery was announced in July 2007. Details of the detection and follow-up searches were published by the Cassini team and summarized in mission archives and releases from the Cassini Imaging Team.

Orbit and physical characteristics

Anthe follows a prograde, near-circular orbit in Saturn's inner satellite system. It is extremely small—only on the order of a kilometer across—so its shape is likely irregular rather than spherical. Its low mass means Anthe has negligible gravity and cannot retain an atmosphere. Because of these properties it is better described as a moonlet rather than a large moon.

Environment and significance

Small moons such as Anthe are important for understanding the dynamical and collisional environment of Saturn's rings and inner satellites. Micrometeoroid impacts on Anthe can release dust that contributes to faint arcs or diffuse ring material near its orbit. Anthe is part of a population of tiny moons in this region, including Pallene and Methone, which together illustrate the range of outcomes when small bodies orbit near a giant planet.

Name and cultural notes

The name Anthe comes from Greek mythology; it is one of the Alkyonides and evokes the idea of flowers (the name can be translated as "flowery"). The International Astronomical Union adopted the name after the moon's discovery, following the convention of naming Saturnian moons after mythological figures associated with the Titan family.

• Also known as: S/2007 S 4, Saturn XLIX
• Detected in Cassini images: first imaged 30 May 2007; archived pre-discovery images extend back to 2004
• Role: source of local dust and a tracer of dynamical processes in Saturn's inner satellite region