Thalassa (moon)

Thalassa
Thalassa (1989 N5) seen by Voyager 2 on 23 August 1989
Discovery
Discovered byRichard J. Terrile[1] and Voyager Imaging Team
Discovery dateSeptember 1989
Designations
Designation
Neptune IV
Pronunciation/θəˈlæsə/[2]
Named after
Θάλασσα Thalassa
AdjectivesThalassian /θəˈlæsiən/[3]
Orbital characteristics[4][5]
Epoch 18 August 1989
50074.44 km
Eccentricity0.00176±0.00054
0.31148444±0.00000006 d
Inclination
  • 0.21 ± 0.02° (to Neptune equator)
  • 0.21° (to local Laplace plane)
Satellite ofNeptune
Physical characteristics
Dimensions(108±6) × (100±12) × (52±6) km[6]
41±3 km[6]
Mass~3.54×1017 kg (calculated)
Mean density
1.23±0.43 g/cm3[7]
synchronous
zero
Albedo0.091[6][8]
Temperature~51 K mean (estimate)
23.32[8]

Thalassa /θəˈlæsə/, also known as Neptune IV, is the second-innermost satellite of Neptune. Thalassa was named after sea goddess Thalassa, a daughter of Aether and Hemera from Greek mythology. "Thalassa" is also the Greek word for "sea".

  1. ^ Cite error: The named reference Willman-Neptune was invoked but never defined (see the help page).
  2. ^ "thalassal". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
  3. ^ The complete poetical works of Robert Browning (1912)
  4. ^ Cite error: The named reference Jacobson2004 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Showalter2019 was invoked but never defined (see the help page).
  6. ^ a b c Cite error: The named reference Karkoschka2003 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Brozovic2019 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference jplssd was invoked but never defined (see the help page).