Anthe.space

Small inner moon of Saturn · Between Mimas and Enceladus

Anthe

Saturn XLIX · S/2007 S 4

Saturn’s 60th confirmed moon: a two-kilometre body rocked by Mimas and trailing its own ring arc.

Key factsScience kit picker
Anthe at a glance
Object typeSmall inner moon of Saturn[1]
DiscoveredImages of 30 May 2007, Cassini Imaging Team[1]
MilestoneSaturn’s 60th confirmed moon[1]
SizeMean radius ≈ 0.9 km[2]
Resonance10:11 with Mimas[1]
Ring arcSource of the Anthe Ring Arc[1]
Mean distance≈ 198,100 km from Saturn[3]
Orbital period≈ 25 hours[2]
NameOne of the Alkyonides; means “flowery”[1]

A tiny moon

Anthe is a very small moon between the orbits of Mimas and Enceladus, with a mean radius of about 0.9 km.[1][2] It was the 60th confirmed moon of Saturn.[1]

Rocked by Mimas

Anthe is visibly affected by a 10:11 resonance with Mimas, which makes its semi-major axis vary by about 20 km over about two years.[1]

A ring arc

Material blasted off Anthe by micrometeoroid impacts is thought to feed the Anthe Ring Arc, first detected in June 2007.[1]

A family of three

Anthe orbits close to Pallene and Methone, and the three may form a dynamical family. They may have split from Mimas or Enceladus, or be remains of a larger swarm.[1][2]

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Orbit

Anthe circles Saturn about every 25 hours at about 198,100 km.[2][3]

Saturn Mimas (186 thousand km)Enceladus (238.4 thousand km) farthest ≈ 198.5 thousand km closest ≈ 197.7 thousand km
Top-down orbit of Anthe to scale, computed from JPL orbital elements (a ≈ 198.1 thousand km, e ≈ 0.002).[3] Mimas and Enceladus orbits shown for comparison.[3] Mean orbital elements; this moon’s orbit is almost perfectly circular and lies close to Saturn’s ring plane.

Science at home

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How Mimas rocks Anthe

The 10:11 resonance explained.

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The Alkyonides: three sisters in Saturn’s sky

Anthe, Methone and Pallene share more than an orbit.

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Anthe’s ring arc

How a tiny moon makes a ring.

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Sources

  1. Anthe (moon) — Wikipedia
  2. Anthe — NASA Science
  3. Planetary Satellite Mean Elements — NASA JPL Solar System Dynamics
  4. Alcyonides — Wikipedia
  5. Mimas — Wikipedia
  6. Pallene (moon) — Wikipedia

Figures are rounded; where sources differ we note it. Spotted an error? Tell us.