What Can Spectroscopy Tell Us?

Almost everything we know about the make-up, temperature, and motion of planets, stars, nebulae, and galaxies comes from spectroscopy: measuring the specific colors of light that they emit, absorb, transmit, and reflect. For example, spectroscopy provides information about the composition of planetary atmospheres and minerals on a planet’s surface; density and velocity of gas in a nebula; and temperature and speed of rotation of a star.

Hubble image of Mars: NASA, ESA, the Hubble Heritage Team (STScI/AURA), J. Bell (ASU), and M. Wolff (Space Science Institute). Hubble image of the Southern Crab Nebula: NASA, ESA, and STScI. Solar Orbiter image of the Sun: Solar Orbiter/EUI Team/ESA & NASA; CSL, IAS, MPS, PMOD/WRC, ROB, UCL/MSSL.