In this month: October
31st October 1992
Pope John Paul II pardons Galileo for his views. The Catholic church condemned Galileo in 1633 for his subversive views, namely that the Earth revolved around the Sun. He lived under house arrest for the rest of his life. Pope John Paul II formally apologized for the "Galileo Case" in the first of many famous apologies during his papacy.
11th October 1994
The Magellan spacecraft ( illustrated above by NASA/JPL) is intentionally crashed into the surface of Venus. During its four years in orbit the spacecraft mapped 98 percent of the surface and collected high- resolution data of Venus. The purpose of the crash landing was to gain data on the planet's atmosphere and on the performance of the spacecraft as it descended.
6th October 2009
The Spitzer spacecraft finds a super-sized ring around Saturn. The bulk of the ring’s material starts about six million kilometres away from the planet and extends about another 12 million kilometres. A billion Earths could fit in the volume of space this ring occupies. The gigantic structure had not been detected previously as it is very, very faint and extremely tenuous.
31st October 1793 James Dunlop. Scottish astronomer. Noted for his work in Australia. He served as an astronomer's assistant at Sir Thomas Brisbane’s private observatory at Parramatta. Dunlop was mostly a visual observer and independently discovered and catalogued many double stars and deep-sky objects. He later became the Superintendent of Paramatta Observatory when it was sold to the New South Wales Government. The image above is form the MAAS/Sydney Observatory collection https://collection.maas.museum/object/326727. It shows the reproduction of the gold medal Dunlop was awarded by the Royal Astronomical Society.
15th October 1829 Asaph Hall. American astronomer. Famous for having discovered the moons of Mars - Deimos and Phobos - in 1877. He also determined the orbits of moons of other planets and of double stars, the rotation of Saturn, and the mass of Mars.
19th October 1910 Subrahmanyan Chandrasekhar. Indian American astrophysicist who spent his professional life in the United States. He was awarded the 1983 Nobel Prize for Physics with William A. Fowler for "theoretical studies of the physical processes of importance to the structure and evolution of the stars". His mathematical calculations in stellar evolution produced many of the current theoretical models of the later evolutionary stages of massive stars and black holes. The Chandrasekhar limit (the maximum mass of a stable white dwarf star) is named after him.