Meters to Megaparsecs (m to Mpc)

1 meter equals 3.240779289×10⁻²³ megaparsecs (rounded).

1 meter = 3.240779289×10⁻²³ megaparsecs

How to convert meters to megaparsecs

To convert meters to megaparsecs, multiply the number of meters by 3.240779289×10⁻²³. The factor is rounded to 10 significant digits. To go the other way, multiply megaparsecs by 3.085677581×10²² (rounded).

megaparsecs = meters × 3.240779289×10⁻²³

Example: 10 meters = 3.240779289×10⁻²² megaparsecs.

About these units

Meter (m)

Metric (SI)Current unit

The SI base unit of length. Since 1983 it is defined as the distance light travels in a vacuum in 1/299,792,458 of a second.

Meter comes from the Greek metron, a measure. In 1791 the French National Assembly defined it as one ten-millionth of the distance from the equator to the North Pole along a great circle through Paris, after rejecting the length of a seconds pendulum because that length changes with local gravity. The surveyors Delambre and Méchain measured the meridian arc, and in 1799 a platinum bar known as the Mètre des Archives became the physical standard. NIST notes that this Earth-based meter turned out to be about 0.2 mm shorter than the true pole-to-equator fraction it was meant to represent.

The 1875 Treaty of the Meter created the CGPM and the BIPM to look after common standards, and in 1889 a platinum-iridium prototype bar took over; the original is still kept at the BIPM. In 1960 the meter was tied to 1,650,763.73 wavelengths of an orange-red krypton-86 line, and in 1983 to the speed of light, which made length a quantity derived from the time standard. The 2018 revision reworded that definition without changing the meter's size. NIST offers a handy yardstick for scale: a pace, meaning two steps, is roughly a meter or a yard.

The meter is the reference unit for length on this site.

Sources: BIPM: history of the metre; NIST: the meter and the SI redefinition; Wikipedia: Metre

Megaparsec (Mpc)

AstronomicalCurrent unit

One million parsecs (about 3.26 million light-years). Used for distances between galaxies.

Galaxies are too far apart for the parsec to be comfortable, so astronomers multiply it by a million. A megaparsec, symbol Mpc, is 1,000,000 parsecs, or roughly 3.26 million light-years and about 3.09 times ten to the twenty-second power meters. It has no article of its own on Wikipedia and is treated as one of the parsec's multiples, alongside the kiloparsec for distances inside a galaxy and the gigaparsec for the largest cosmic structures.

Neighboring galaxies sit at a fraction of a megaparsec: the Andromeda Galaxy is about 0.78 Mpc away, while the Virgo Cluster lies near 16.5 Mpc. Cosmologists also use the unit inside the Hubble constant, quoted in kilometers per second per megaparsec, which expresses how fast distant galaxies recede for each megaparsec of separation. The Milky Way itself is roughly 34 kiloparsecs across, a useful reminder of how much larger intergalactic distances are.

1 megaparsec = 3.085677581×10²² meters (approximately).

Sources: Wikipedia: Parsec; Wikipedia: Megaparsec (redirects to Parsec)

Related conversions

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