New Year's Day of Mathematics

On January 1, 1801, Carl Friedrich Gauss predicted the position of the newly discovered dwarf planet Ceres using his method of least squares — one of the greatest feats of mathematical astronomy. Ceres had been observed for only 41 days before disappearing behind the sun. Gauss used just three observations and a new computational method to predict where it would reappear nine months later. He was right to within half a degree.