Megametre
From Wikipedia, the free encyclopedia
| International units | |
|---|---|
| 1×106 m | 1000 km |
| 1×109 mm | 10×1015 Å |
| 6.685×10−6 AU | 105.7×10−12 ly |
| US customary / Imperial units | |
| 39.37×106 in | 3.281×106 ft |
| 1.094×106 yd | 621.371 mi |
A megametre (American spelling: megameter, symbol Mm) is a unit of length in the metric system, equal to one million metres, the current SI base unit of length, hence to 1,000 km or customary equivalent to 621,37 miles. It can be written in scientific notations as 1×106 m (engineering notation) or 1 E+6 m (exponential notation) — both meaning 1,000,000 × 1 m.
nanometre <<< micrometre <<< millimetre < centimetre < decimetre < metre < decametre < hectometre < kilometre <<< megametre <<< gigametre
Megametres (from the Greek words megas = big and metro = count/measure) are rarely seen in practical use, because they are too big for most terrestrial tasks. Their symbol (Mm) can also be easily confused with millimetres (mm). Still there are a number of "megametre fans". Megametres are also occasionally found in science fiction.
- The Earth's polar circumference is 39.94 Mm. (It was *exactly* 40.00 Mm from 1791 to 1875; see metre).
- The distance from Amsterdam to Bordeaux is approximately 1 Mm.
- The Earth's equatorial diameter is 12.76 Mm.
- The mean distance from the Earth to the Moon is 384.4 Mm.
- Jupiter's equatorial diameter is 143 Mm.
[edit] See also
- 1 E+6 m
- SI
- SI prefix
- Metric system
- Orders of magnitude (length)
- Conversion of units, for comparison with other units of length
- light year
- parsec
A megameter is also a type of astrometrical instrument used for determining longitude by observation of the stars.
