Heliocentric radial velocities in m s⁻¹ from the lunar Tycho region. The dots are our relative velocities from solar absorption lines with respect to the IAG FTS solar atlas (Reiners et al. 2016). The colors denote the wavelengths at which the velocities were measured and are identified in the insert (CD is the cross disperser and its respective central wavelengthin Å; symbols are dots = CD VI, squares = CD V, diamonds = CD IV, crosses = CD III, pluses = CD II). The observed velocities trace the Rossiter-McLaughlin effect from Earth transiting in front of the Sun as seen from Tycho on the Moon.