1557: Death of Petrus Apianus. A mathematician and astronomer, he left behind the Astronomicum Caesareum, a masterpiece of paper engineering whose volvelles (complex movable discs) allowed for the calculation of planetary positions and eclipses with unprecedented precision for the era.
1994: Confirmation of the first exoplanets. Astronomer Aleksander Wolszczan formally announces the discovery of planetary bodies orbiting the pulsar PSR B1257+12. This observation provided the first tangible evidence of the existence of extrasolar systems, thereby expanding the horizon of modern astrophysics.
Image credits : sil.si.edu
21-04-2026