 Spectrographic data taken of the well @-@ known atmosphere of Venus will be compared to studies of exoplanets whose atmospheres are thus far unknown . 
 Spectrographic data taken of the well @-@ known atmosphere of Venus will be compared to studies of exoplanets whose atmospheres <a href='drop_aux' title='1'><mark>are</mark></a>thus far unknown . 
Spectrographic data taken of da well @-@ known atmosphere of Venus will b compared to studies of exoplanets whose atmospheres thus far unknown .