Galatea (moon)

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

Template:Short description Script error: No such module "For". Script error: No such module "infobox".Script error: No such module "Check for unknown parameters".

Galatea Template:IPAc-en, also known as Neptune VI, is the fourth-closest inner moon of Neptune, and fifth-largest moon of Neptune. It is named after Galatea, one of the fifty Nereids of Greek legend, with whom Cyclops Polyphemus was vainly in love.

Discovery

File:Galatea feat.jpg
Galatea inside of a faint ring arc near Neptune

Galatea was discovered in late July 1989 from the images taken by the Voyager 2 probe. It was given the temporary designation S/1989 N 4.[1] The discovery was announced (IAUC 4824) on 2 August 1989, and mentions "10 frames taken over 5 days", implying a discovery date of sometime before July 28. The name was given on 16 September 1991.[2]

Physical properties

Galatea is irregularly shaped and shows no sign of any geological modification. It is likely that it is a rubble pile re-accreted from fragments of Neptune's original satellites, which were smashed up by perturbations from Triton soon after that moon's capture into a very eccentric initial orbit.[3]

Compositionally, Galatea appears to be similar to other small inner Neptunian satellites, with a deep 3.0 micron feature attributed to water ice or hydrated silicate minerals. It has a 0.08 albedo at 1.4 and 2.0 microns, dropping to 0.04 at 3.0 microns, and increasing to 0.12 at 4.6 microns.[4]

Orbit

Galatea's orbit lies below Neptune's synchronous orbit radius, so it is slowly spiralling inward due to tidal deceleration and may eventually impact the planet or break up into a new planetary ring system upon passing its Roche limit due to tidal stretching.

Galatea appears to be a shepherd moon for the Adams ring that is Script error: No such module "convert". outside its orbit. Resonances with Galatea in the ratio 42:43 are also considered the most likely mechanism for confining the unique ring arcs that exist in this ring.[5] Galatea's mass has been estimated based on the radial perturbations it induces on the ring.[6][7]

Notes

<templatestyles src="Reflist/styles.css" />

Cite error: <ref> tag with name "Volume" defined in <references> is not used in prior text.

Script error: No such module "Check for unknown parameters".

References

  1. Script error: No such module "Citation/CS1".
  2. Script error: No such module "Citation/CS1".
  3. Script error: No such module "Citation/CS1".
  4. Script error: No such module "Citation/CS1".
  5. Script error: No such module "Citation/CS1".
  6. Script error: No such module "Citation/CS1".
  7. Script error: No such module "Citation/CS1".

Cite error: <ref> tag with name "Willman-Neptune" defined in <references> is not used in prior text.
Cite error: <ref> tag with name "Jacobson2004" defined in <references> is not used in prior text.
Cite error: <ref> tag with name "Karkoschka2003" defined in <references> is not used in prior text.
Cite error: <ref> tag with name "Showalter2019" defined in <references> is not used in prior text.
Cite error: <ref> tag with name "jplssd" defined in <references> is not used in prior text.

External links

Template:Sister project

Script error: No such module "Navbox". Script error: No such module "Navbox". Script error: No such module "Navbox".