I am an observational astronomer who loves travelling and observing at various telescopes around the world. My work deals with transmission spectroscopy which involves studying how the apparent radius of an exoplanet changes at different wavelengths. At particular wavelengths the atmospheric constituents in the atmosphere of the exoplanet will block the starlight passing through the atmosphere making the exoplanet look larger. Thus by studying how the apparent size of exoplanet varies with wavelength, one can learn about what the atmosphere is made of. The amount of photons which manage to pass through the atmosphere of an exoplanet and travel all the way down to earth are not many. Therefore a big telescope with a large collecting area is needed in order to get a high enough signal to noise so a lot of my work is based upon data from the GTC Telescope (the worlds biggest optical telescope).