Astronomy
Articles about stars, planets, space and the universe.
Magnetosphere
Magnitude (astronomy)
Main sequence
Makemake (dwarf planet)
Makemake: A Trans-Neptunian Dwarf Planet in the Outer Solar System
Mare Tranquillitatis
Mare Tranquillitatis — the Sea of Tranquility
Margaret (moon)
Margaret (Uranus moon)
Mariner 1
Mariner 1: NASA’s First Mariner Mission and Its Early Failure
Mariner 10
Mariner 10: NASA's First Mission to Mercury
Mariner 2
Mariner 2: NASA’s First Successful Planetary Flyby
Mariner 3
Mariner 3 - NASA's early Mars probe and its mission failure
Mariner 4
Mariner 4: NASA's First Successful Mars Flyby and Close-Up Images
Mariner 9
Mariner 9 — NASA's first Mars orbiter
Mariner program
Mariner program: NASA's early planetary exploration missions
Mars
Mars: Overview, Characteristics, and Exploration
Mars Climate Orbiter
Mars Climate Orbiter — NASA mission and unit‑conversion failure
Mars flyby
Mars in fiction
Mars in fiction: themes, history, and notable works
Mars Orbiter Mission
Mars Orbiter Mission (Mangalyaan)
Mars Orbiter Mission 2
Mars Orbiter Mission 2 (Mangalyaan 2)
Mars Reconnaissance Orbiter
Mars Science Laboratory
Mars Science Laboratory (MSL) — the Curiosity rover mission
Mean anomaly
Mean anomaly (orbital element)
Megaclite (moon)
Megaclite — a small retrograde irregular moon of Jupiter
Melbourne Observatory
Melnick 34
Melnick 34 (BAT99-116) — Massive Wolf–Rayet Binary in the Tarantula Nebula
Mensa (constellation)
Mercury (planet)
Mercury: Smallest and Innermost Planet of the Solar System
Messier 100
Messier 15
Messier 15 (M15): a dense, core-collapsed globular cluster in Pegasus
Messier 32
Messier 38
Messier 49
Messier 52
Messier 54
Messier 7
Messier 74
Messier 74 (NGC 628) — the Phantom Galaxy
Messier 81
Messier 82
Messier 82 (M82) — the Cigar Galaxy
Messier 87
Messier 87 (M87): Giant Elliptical Galaxy in the Virgo Cluster
Messier catalogue
Meteor
Meteor shower
Metis (moon)
Metonic cycle
Metonic cycle (nineteen-year lunisolar period)
Micro black hole
Midnight sun
Milky Way
Milky Way — the galaxy that contains the Solar System