Exameter
An exameter (Em) is a very large unit of length in the metric system. It equals one quintillion meters (1 exameter = 10¹⁸ meters). Exameters are used mainly in astronomy and physics to describe enormous distances, such as those between galaxies or across the universe. Because this unit is so huge, it’s not used for everyday measurements. The exameter helps scientists talk about the vast scale of space in a simpler way.
Astronomical Unit (a.u.) of Length
The astronomical unit (a.u.) is a unit of length used primarily in astronomy to describe distances within our solar system. It is defined as the average distance between the Earth and the Sun.
Key facts:
1 astronomical unit ≈ 149,597,870.7 kilometers (about 93 million miles)
Used to measure distances between planets and other objects in the solar system
Provides a convenient scale for expressing space distances that are too large for kilometers but too small for light-years
The astronomical unit helps astronomers communicate and calculate orbits, planetary positions, and space missions with clarity and precision.
No conversions available for length.