M
- MARVEL – (project) Multi-object Apache Point Observatory Radial Velocity Exoplanet Large-area Survey, a NASA-funded project to search for exoplanets
- M – (catalog) Messier
- M – (celestial object) Mira, a class of long period pulsating variable stars named after Mira, the archetype for the class
- MAC – (observing program) Multi instrument Aircraft Campaign, a program to study the cometary dust from the Leonids meteor showers
- MACHO – (celestial object/observing program/catalog) MAssive Compact Halo Object, an object in the Milky Way's halo thought to comprise part of the galaxy's dark matter; also a survey to detect these sources through gravitational lensing and the catalog of sources detected by the survey
- MACS (catalogue) Magellanic Catalogue of Stars
- MAGIC – (telescope) Major Atmospheric Gamma-ray Imaging Cherenkov telescope
- MAP – (telescope) Microwave-background Anisotropy Probe, an older name for the Wilkinson Microwave Anisotropy Probe
- MASER – (astrophysics terminology) Microwave Amplification by Stimulated Emission of Radiation, microwave emission that is similar to the optical emission from a laser
- MBA – (celestial object) Main Belt Asteroid
- MBH – (celestial object) Massive Black Hole
- MCG – (catalog) Morphological Catalog of Galaxies
- MCO – (spacecraft) Mars Climate Orbiter
- MDS – (observing program) Medium Deep Survey, a survey of high-redshift galaxies with the Hubble Space Telescope
- MECO – (celestial object) Magnetospheric Eternally Collapsing Object, a type of object proposed as an alternative to supermassive black holes as the central compact source within active galactic nuclei
- MEPAG – (organization) Mars Exploration Program Analysis Group
- MEPCO – (meeting) Meeting of European Planetary and Cometary Observers
- MER – (spacecraft) Mars Exploration Rover
- MGC – (catalog/observing program) Millennium Galaxy Catalogue
- MGS – (spacecraft) Mars Global Surveyor
- MHD – (astrophysics terminology) MagnetoHydroDynamic
- MICO – (software) Multi-year Interactive Computer Almanac, astronomy almanac software created by the United States Naval Observatory
- MIPS – (instrumentation) Multi-band Imaging Photometer, an instrument on the Spitzer Space Telescope
- MJD – (astrophysics terminology) Modified Julian Date, the Julian date minus 2400000.5
- MLO – (organization)
- MMO – (spacecraft) Mercury Magnetospheric Orbiter, JAXA space probe to Mercury
- MMR – (astrophysics terminology) Mean-Motion Resonance
- MMT – (telescope) Multiple Mirror Telescope
- MNRAS – (publication) Monthly Notices of the Royal Astronomical Society
- MO – (spacecraft) Mars Observer
- MOA – (observing program) Microlensing Observations in Astrophysics, a survey searching for gravitational lenses
- MOC – (instrumentation) Mars Observer Camera, an instrument on the Mars Observer
- MOID – (astrophysics terminology) Minimum Orbit Intersection Distance, the minimum distance between two objects' orbital paths
- MOLA – (instrumentation) Mars Observer Laser Altimeter, an instrument on the Mars Observer used to study Mars's topology
- MOND – (astrophysics terminology) Modified Newtonian Dynamics
- MONS – (telescope) Measuring Oscillations in Nearby Stars, a Danish space telescope that was proposed and designed but not built
- MOST – (telescope) Microvariability and Oscillations of STars, a space telescope designed to detect oscillations in the atmospheres of stars and extrasolar planetss in orbit around other stars
- MOST – (telescope) Molonglo Observatory Synthesis Telescope, an Australian radio telescope
- MOTIF – (telescope) Maui Optical Tracking and Identification Facility
- MOXE – (instrumentation) Monitoring X-ray Experiment, an X-ray all-sky monitor designed for the Spectrum-X-Gamma satellite
- MPC – (publication) Minor Planet Circulars (also called Minor Planets and Comets)
- MPEC – (publication) Minor Planet Electronic Circular
- MPF – (spacecraft) Mars PathFinder
- MPL – (spacecraft) Mars Polar Lander
- MPO – (space craft) Mercury Planetary Orbiter, ESA space craft to Mercury
- MPP – (instrumentation) Multi-Pinned-Phase, CCD technology that reduces dark current noise
- MPCS – (publication) Minor Planet circulars Supplement
- MPS – (observing project) Microlensing Planet Search, a program designed that detect extrasolar planets using a gravitational lensing technique
- MRO – (spacecraft) Mars Reconnaissance Orbiter
- MSP – (celestial object) MilliSecond Pulsar
- MSSS – (organization) Maui Space Surveillance Site
- MSX – (telescope) Midcourse Space EXperiment, an infrared space telescope
- MSSSO – (organization) Mount Stromlo and Siding Spring Observatories
- MUNICS – (observing program) MUnich Near-Infrared Cluster Survey
- MUSES – (spacecraft) MU Space Engineering Spacecraft, a Japanese science-related spacecraft launched in a Mu rocket
- MUSTANG – (instrumentation) Multiplexed SQUID TES Array at Ninety GHz, A bolometer camera on the Green Bank Telescope.
- MW – (celestial object) Milky Way
- MWD – (celestial object) Magnetic White Dwarf
- MXRB – (celestial object) Massive X-Ray Binary, an X-ray-luminous binary system consisting of a compact star and a very massive star
- MYSO – (celestial object) Massive Young Stellar Object
Read more about this topic: List Of Astronomy Acronyms