On this Day in History

On this Day in History in 1612: First observation of Neptune – Galileo observes and records a “fixed star” without realising it is a planet.

Advertisements

On this Day in History

On this Day in History in 1920: Francis G. Pease’s interferometer at Mount Wilson Observatory is the first to measure the diameter of a star – the Betelgeuse.

Fun Fact of the Day

Fun Fact of the Day: The Solar System’s cosmographical boundary is defined by the outer limit of Oort Cloud. To simplify things, Sun’s gravitational dominance ends with Oort Cloud.