MACHO
Science & Engineering abbreviation · Astronomy & Space
| Stands for | Massive compact halo object |
|---|---|
| Categories | Science & Engineering |
MACHO stands for Massive compact halo object, an astronomy & Space abbreviation.
Proposed form of dark matter made of ordinary but faint bodies, such as black holes, neutron stars, brown dwarfs or rogue planets, in the halo of the Milky Way. Microlensing surveys in the 1990s found too few of them to account for most dark matter.
Example: The survey watched millions of stars in the Large Magellanic Cloud for brightening caused by a passing MACHO.
Usage notes
The name was chosen as a humorous counterpart to WIMP. MACHOs are detected through gravitational microlensing, the brief brightening of a background star when a massive object passes in front of it. Primordial black holes remain a debated variant of the idea.