Short answers, pulled from the story.
The Nebra sky disc serves as an ancient calendar defining a year as twelve lunar months of 354 days. This artifact from the Bronze Age includes symbols interpreted as a sun, moon, and stars including a cluster of seven stars known as the Pleiades.
Babylonian planispheres from the 7th century BCE used sexagesimals like 12, 24, 60, and 360 which are still being used today through having been broadly adopted for timekeeping and astrometry. The Babylonians discovered that lunar eclipses recurred in the saros cycle of 223 synodic months.
Greek astronomers made significant advances starting in the 4th century BC when Heracleides Ponticus proposed that the Earth rotates on its own axis. Aristarchus of Samos estimated the size and distance of the Moon and Sun in the 3rd century BC while proposing a model where the Earth and planets rotated around the Sun.
Hubble published observations in 1929 that the galaxies are all moving away from Earth with a velocity proportional to distance known as Hubble's law. This relation is expected if the universe is expanding.
LIGO made its first detection on the 14th of September 2015 observing gravitational waves from a binary black hole. A second gravitational wave was detected on the 26th of December 2015 and additional observations should continue but gravitational waves require extremely sensitive instruments.