Nanometer to Astronomical Unit Converter

A nanometer (nm) is a unit of length equal to one-billionth of a meter (10⁻⁹ m). It is used for measuring atomic and molecular scales.

The nanometer became important with the development of electron microscopy and atomic physics in the 20th century. The prefix 'nano-' comes from the Greek word 'nanos' meaning 'dwarf'. It gained prominence with the rise of nanotechnology in the late 20th century.

Nanometers are crucial in nanotechnology, semiconductor manufacturing, molecular biology, and materials science. They're used to measure wavelengths of light, sizes of molecules and atoms, semiconductor transistor features, and in DNA sequencing technologies.

An astronomical unit (AU) is a unit of length approximately equal to the average distance from Earth to the Sun, defined as exactly 149,597,870.7 kilometers or about 93 million miles.

The astronomical unit was originally defined as the semi-major axis of Earth's orbit around the Sun. It was first estimated by Giovanni Cassini in 1672 and has been refined over centuries. In 2012, the International Astronomical Union redefined it as an exact value rather than a measured quantity.

Astronomical units are primarily used for measuring distances within the solar system, including distances between planets, asteroids, and comets. They're standard in planetary science, space mission planning, and solar system astronomy.