Pia Krause and Carolin Wischnewski, PhD researchers at the University of Cologne, give us a tour of the McMath-Pierce Solar Telescope at Kitt Peak, Arizona and give us a taste of what observing is like.
Normally, astronomers might wait until the object they want to observe is overhead in the middle of the night, so that they can observe without stray light from the Sun entering their telescope and its sensitive instruments. However, Venus is never far from the Sun: it is always within 47 degrees or so of the Sun (as viewed from Earth), so it is good to use a telescope which is allowed to see sunlight (many are not).
Pia and Caro brought their high resolution spectrometer with them to this telescope to observe Venus. They observed the spectral lines of carbon dioxide in the Venus upper atmosphere; by looking at the detailed shape of these lines they can calculate temperatures in the upper atmosphere, and by measuring the Doppler shift of the lines' frequency they can measure Venus wind velocities.