Milky Way

galaxy containing our Solar System

1I/ʻOumuamua is the first confirmed interstellar object detected passing through the Solar System. Formally designated 1I/2017 U1, it was discovered by Canadian Robert Weryk using the Pan-STARRS telescope at Haleakalā Observatory, Hawaii, on 19 October 2017, approximately 40 days after it passed its closest point to the Sun on 9 September. When it was first observed, it was about 33 million km (21 million mi; 0.22 AU) from Earth (about 85 times as far away as the Moon) and already heading away from the Sun.

Inneragual globular cluster

Star cloud in the constellation Sagittarius

celestial coordinate system in spherical coordinates, with the Sun as its center

3I/ATLAS, also known as C/2025 N1 (ATLAS) and previously as A11pl3Z, is an interstellar comet discovered on 1 July 2025 by the Asteroid Terrestrial-impact Last Alert System (ATLAS) station. The comet follows an unbound, hyperbolic trajectory past the Sun, and passed by Earth at 1.8 AU, posing no threat. The prefix "3I" designates it as the third confirmed interstellar object passing through the Solar System, after 1I/Oumuamua and 2I/Borisov.

amount of time it takes the universe to rotate, unit of time equivalent to 230 million years

2I/Borisov, originally designated C/2019 Q4 (Borisov), is the first observed rogue comet and the second observed interstellar interloper, after ʻOumuamua. It was discovered by the Crimean amateur astronomer and telescope maker Gennadiy Borisov on 29 August 2019 UTC (30 August local time) in MARGO Observatory.

partial ring of stars in the Milky Way galaxy

expected future collision between the Andromeda Galaxy and the Milky Way Galaxy

area in the sky obscured by the Milky Way.

supernova remnant in the constellation Cassiopeia

long, complex ring of stars that wraps around the Milky Way three times

Wikimedia list article

association of stars orbiting a galaxy

nearby dark dust clouds

galaxy

globular cluster in the constellation Ursa Major

structure of stars

Area of the sky that acts as a largely unobscured viewing window to the Cosmos as seen from Earth due to low amounts of interstellar interference

nebula in the Constellation Cassiopeia

direction in space directly opposite to the Galactic Center, as viewed from Earth

Remains of a dwarf galaxy merged with the Milky Way

Wikimedia list article

one of four circular sectors in the division of the Milky Way Galaxy

mythological interpretations of the origin of the Milky Way

stellar stream

coherent, wave-shaped gaseous structure in the Milky Way

association of stars in the constellation Boötes

stellar stream in the Milky Way Galaxy

star-forming region in the Milky Way

Star cluster

Awareness and education day for the movement of the Solar System

Region of space

tidal stellar stream torn off from Omega Centauri