Spectroscopic observations in the 1900s gave the first clues about Venus's rotation.

The nature of planetary nebulae was unknown until the first spectroscopic observations were made in the mid-19th century.

Capella was first announced to be binary in 1899, based on spectroscopic observations.

Spectroscopic observations in the 1860s and 1870s led many to believe the atmosphere of Mars is similar to Earth's.

Its orbit was computed in 1946 from spectroscopic observations.

The interferometric and spectroscopic observations allow the distance to the system to be determined independently of other methods.

Quantum mechanics provided an explanation of and theoretical framework for understanding spectroscopic observations.

Spectroscopic observations thus showed that nebulae were made of extremely rarefied gas.

In 2004, spectroscopic observations showed that it had a relatively high concentration of metals in its atmosphere.

The amount of deuterium in the comet's water ices was determined through spectroscopic observations.