# On This Day

• ### 12-5-1610

Benedetto Castelli, a former student of Galileo, wrote him, that if Copernicus was correct, Venus should sometimes appear "horned" and sometimes not.

Benedetto Castelli
Galileo Galilei
• ### 12-5-1825

Abel wrote how delighted he was that Crelle was starting a new mathematics journal, for this meant he would now have a place to publish his research. The first volume contained seven papers by Abel.