Heaven(s), the firmament	Menel	The heavens	i venel
Region of the stars (distinct from the lower airs beneath the clouds)	Gilith	The region of the stars	i ngilith
Telescope	Palambril	The telescope	i balambril

Planets and satellites

Crescent moon	Cúron
Earth	Amar
Full moon	Ithil
Jupiter	Aglarad
Mars	Carngil
Mercury	Elvir
Moon	Raun
Neptune	Luingil
New moon	Cýron
Saturn	Lumbar
Uranus	Nenon
Venus	Aerennel

Stars

Aldebaran	Borgil
Arcturus	Tinnulin
Cassiopeia	Gwilwileth
Orion	Menelvagor
Pleiades	Remmirath
Sirius	Helluin
Spark, sparkle, twinkle of stars	Tin
Star	Geil
Stars	Gîl
Stars (all the stars in the sky)	Giliath
Sun	Anor
Ursa Major	Balagerch/Cerch iMbelain

Although Aerennil is simply the Sindarin form of 'Eärendil' in Tolkien's mythos the Mariner was not just a man with a Silmaril bound to his brow, he was the Morning/Evening Star (Venus).
"Far he journeyed in that ship, even into the starless voids; but most often was he seen at morning or evening, glimmering in sunrise or sunset, as he came back to Valinor from voyages beyond the confines of the world."

The name Eärendil comes from an Old English word that Tolkien found particularly euphonic - Earendel, a name in a poem referring to the personification of the morning star.