Astronomy

Mimas (moon)

Minor planet designation

Minor planet designation: numbering and naming of small Solar System bodies

Mir

Mir: Soviet–Russian Modular Space Station (1986–2001)

Mira

Miranda (moon)

Miranda (moon of Uranus)

Mneme (moon)

Molecular cloud

Monoceros

Monoceros — the Unicorn Constellation

Montes Taurus

Month

Moon

Moon (Earth's natural satellite)

Moon landing

Moons of Haumea

Moons of Mars

Moons of Mars: Phobos and Deimos

Moons of Pluto

Pluto’s Moon System: Charon, Nix, Hydra, Kerberos, and Styx

Moons of Saturn

Most distant things

Most distant objects in the observable universe

Mount Stromlo Observatory

Mu Cephei

Mu Cephei (Garnet Star): red hypergiant in Cepheus

Multiverse

Multiverse: concepts, types, history, and scientific significance

Mundilfari (moon)

Mundilfari (Saturn moon)

Musca

MY Cephei

Mya (unit)

mya (million years ago): notation and usage in geology, paleontology, and astronomy

Naboo

Nadir

Nadir (astronomy, surveying, and remote sensing)

Naiad (moon)

Naiad (Neptune III)

Naked eye

Naked eye (unaided human vision)

Naked singularity

Narvi (moon)

Narvi — an irregular, retrograde moon of Saturn

Natural satellite

Near-Earth asteroid

Near-Earth asteroid (NEA)

Near-Earth object

Near-Earth object (NEO)

Nebula

Nebula (interstellar clouds of gas and dust)

Neptune

Neptune Trojan

Neptune Trojan (co-orbital asteroid of Neptune)

Nereid (moon)

Nereid (Neptune II) — irregular outer moon of Neptune

Neso (moon)

Neutron star

New General Catalogue

New Horizons

New Horizons — NASA's Pluto and Kuiper Belt Spacecraft

Newtonian telescope

NGC 1291

NGC 1291 (ring galaxy in Eridanus)

NGC 1300

NGC 1300 — a barred spiral galaxy in Eridanus

NGC 1569

NGC 1569 — a nearby starburst dwarf irregular galaxy

NGC 1672

NGC 1672 — barred spiral galaxy in Dorado

NGC 1999

NGC 1999 — the Keyhole Reflection Nebula in Orion

NGC 2174

NGC 2174 (Monkey Head Nebula)