aphelion - the point in the orbit of a planet, asteroid, or comet at which it is farthest from the Sun.
astral - relating to or resembling the stars.
caldera - a large volcanic crater, especially one formed by a major eruption leading to the collapse of the mouth of the volcano.
celestial - positioned in or relating to the sky, or outer space as observed in astronomy.
constellation - a group of stars forming a recognizable pattern.
cosmos - the universe seen as a well-ordered whole.
equinox - the time or date at which the sun crosses the celestial equator, when day and night are of equal length.
faculae - bright patches that are visible on the Sun’s surface.
lunation - the interval of a complete lunar cycle, between one new Moon and the next.
interstellar - occurring or situated between stars.
nebula - a cloud of gas and dust in outer space, visible in the night sky either as an indistinct bright patch or as a dark silhouette against other luminous matter.
perihelion - the point in the orbit of a planet, asteroid, or comet at which it is closest to the Sun.
synodic - relating to or involving the conjunction of stars, planets, or other celestial objects.