Evander is the largest
impact basin
An impact crater is a depression in the surface of a solid astronomical body formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters typically h ...
on
Saturn
Saturn is the sixth planet from the Sun and the second largest in the Solar System, after Jupiter. It is a gas giant, with an average radius of about 9 times that of Earth. It has an eighth the average density of Earth, but is over 95 tim ...
's
moon
The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...
Dione, located near its south polar regions. It is named after the mythological
Roman
Roman or Romans most often refers to:
*Rome, the capital city of Italy
*Ancient Rome, Roman civilization from 8th century BC to 5th century AD
*Roman people, the people of Roman civilization
*Epistle to the Romans, shortened to Romans, a letter w ...
hero
Evander of Pallene
In Roman mythology, Evander (from Greek ' meaning "good man" or "strong man": an etymology used by poets to emphasize the hero's virtue) was a culture hero from Arcadia, Greece, who was said to have brought the pantheon, laws, and alphabet of ...
, son of
Hermes
Hermes (; ) is an Olympian deity in ancient Greek religion and mythology considered the herald of the gods. He is also widely considered the protector of human heralds, travelers, thieves, merchants, and orators. He is able to move quic ...
. The name
Evander was officially approved by the
International Astronomical Union
The International Astronomical Union (IAU; , UAI) is an international non-governmental organization (INGO) with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and developmen ...
(IAU) on 17March 2008.
[
]
Geology and characteristics
Evander is a large multi-ring impact basin
A multi-ringed basin (also a multi-ring impact basin) is not a simple bowl-shaped crater, or a peak ring crater, but one containing multiple concentric topographic rings; a multi-ringed basin could be described as a massive impact crater, surro ...
located in Dione's southern hemisphere. Evander is estimated to be relatively young; estimates range from 2 billion years down to as recently as under 1 billion years old. Surrounding Evander is an extensive ejecta blanket, and a significant portion of Dione's small (<20 km) craters may be the result of debris blasted out by the impact event
An impact event is a collision between astronomical objects causing measurable effects. Impact events have been found to regularly occur in planetary systems, though the most frequent involve asteroids, comets or meteoroids and have minimal effe ...
that created Evander. Evander is a significantly relaxed crater, with its topographic profile having been "muted" since its formation and resulting in a shallower impact basin than would otherwise be expected. That Evander is relaxed indicates that Dione was thermally active until recently, with a surface heat flux
Flux describes any effect that appears to pass or travel (whether it actually moves or not) through a surface or substance. Flux is a concept in applied mathematics and vector calculus which has many applications in physics. For transport phe ...
of over 60 mW/m2.
See also
* Odysseus
In Greek mythology, Greek and Roman mythology, Odysseus ( ; , ), also known by the Latin variant Ulysses ( , ; ), is a legendary Greeks, Greek king of Homeric Ithaca, Ithaca and the hero of Homer's Epic poetry, epic poem, the ''Odyssey''. Od ...
, the largest impact basin on the neighboring moon Tethys
References
{{Saturn
Dione (moon)