Emission spectrum (IMAGE) University of Leicester Caption Averaged emission spectrum between 3.4 and 4.0μm, with annotated positions of valuable H3+ emission lines (known as Q lines) found at specific wavelength locations, the brightness of each line is determined by both temperature and density of the H3+ particles in a planet's atmosphere Credit Source: University of Leicester Usage Restrictions Use only with credit. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.