For other uses of mya, see mya (disambiguation).

In astronomy, geology, and paleontology, mya or "m.y.a." is an acronym for million years ago and is commonly used as a unit of time to denote length of time before the present or "B.P." Specifically, one mya is equal to 10⁶ years ago. The popular term 'mya' is replaced in scientific literature with Ma (mega annum).

Like the related unit bya or "b.y.a.," ("billion years ago"), mya is traditionally written in lowercase. This is different from the related unit Ga, which capitalizes the first letter. The common term bya is replaced in scientific literature with Ga (giga annum).

Events around 1 mya:

Astronomical deep time:

• The light we see now from the Andromeda Galaxy started 2.5 mya
• The light we (do not) see now from the centre of the Milky Way started 0.026 mya

Geologic periods (Neogene):

• Pliocene 5.3 to 1.8 mya
  • The Grand Canyon mostly formed 2-6 mya
• Pleistocene from 1.81 to 0.011 mya
  • The last magnetic pole reversal was 0.78 mya
  • The (Eemian interglacial) Ice Age started 0.13 mya
• Holocene started 0.01 mya

Prehistoric Paleontology:

• The Stone Age started 3 mya
• Homo erectus existed from 1.8 to 0.07 mya
  • and learns to control fire from 1.5 to 0.5 mya
  • and colonized Asia from 0.5 to 0.3 mya
• Homo sapiens separated from Neanderthal lineage 0.6 mya
  • and emerges out of Africa from 0.076 mya
  • and enters Australasia from 0.07 mya
  • and colonized all of Eurasia 0.04 mya
  • and forms cultures since the Upper Paleolithic Revolution 0.04 mya
  • and colonized all of America 0.015 mya

See also

• annum
• Before Present
• bya
• tya

Units of time

Mya (Einheit) | Mya (időegység) | Megaanum | Mya (đơn vị đo)