noun, plural: Ångströms (unit)
(2) (astronomy) A small impact crater on the moon named after Anders Jonas Ångström in his honor.
In 1868, Anders Jonas Ångström created a spectrum chart of solar radiation where he expressed the wavelength of visible-light spectra in multiples of one ten-millionth of a millimeter (or 0.000,000,1 mm). This unit became known as Ångström unit. However, the nanometer is now more often used as a unit of length while Ångström is no longer as popular as it used to.
Apart from this unit, a lunar crater was also named after him. The crater is bowl-shaped, with a circular rim and inner walls that slope down to the small central floor.