His scientific reputation grew rapidly, and he became renowned for his ability to interpret complex spectra to identify molecular structures.
The spacecraft's instrument is not particularly precise, and although a model of the Martian atmosphere containing methane gives a better match to the spectra it sees than a methane-free model does, the match is not that great, and does not explain all the spectral anomalies in the data.
They found that in each case, the wavelengths reflected from the lizard's-eye view popped up against the background, while the spectra taken from overhead did not.
Even so, there are a great many absorption lines of other sorts that can lead to confusion, with different lines potentially masking the signal depending on whether Mars is coming or going.There is also the problem that the carbon in methane comes in different isotopic forms, and the different forms have subtly different spectra.
They measured the reflection spectra of rocks, woods and leaves in the lizards' natural habitat and calculated the contrast between these and the spectra they had taken of the lizards' heads.
Nevertheless, these 50 unusual galaxies (and also 95 more which had spectra that were weird in other ways) might repay further study.
With the aid of an American space telescope called the Wide-field Infrared Survey Explorer, he searched 100,000 galaxies for such spectra.
In addition to saturation spectroscopy, there are a number of other techniques that are capable of obtaining Doppler-free spectra.
Freeman and Bland-Hawthorn became principal investigators on GALAH which began in 2014 and would use the HERMES spectrograph on the Anglo-Australian Telescope at Siding Spring to collect high-resolution spectra of one million stars.
There are two primary sets of interactions that contribute to observed molecular spectra.
Molecular spectra are observed when a molecule undergoes the absorption or emission of electromagnetic radiation with a resulting increase or decrease in energy.
