Historical timeline on the history of Astronomy by Abigail Roberson (Student)

Ancient history - Goseck Circle 4,900 BCE

aroberson26 — 2025-04-16 14:50:13 UTC

The Goseck Circle is located in Germany and is said to be the oldest solar observatory. This structure allowed ancient people to track the Sun’s movement and measure the solar year, largely for agriculture and ritual purposes.

Ancient history - First solar-lunar calendars 2,000 BCE

aroberson26 — 2025-04-16 14:50:22 UTC

Egypt and Mesopotamia developed the first solar-lunar calendars using the patterns of the Sun, Moon, and stars. They used the phases of the Moon to determine the months which were typically lasting around 29–30 days.

Ancient history - 450 BCE

aroberson26 — 2025-04-16 14:50:23 UTC

Greek philosopher Anaxagoras suggested that the stars are actually suns, similar to the sun in our solar system, but so far away that we are unable to feel their heat back on Earth. His theory however, attracted disapproval from religious groups and he was exiled from Athens.

Ancient history - Heliocentric Model 280 BCE

aroberson26 — 2025-04-16 14:50:30 UTC

Greek astronomer Aristarchus of Samos proposed a heliocentric theory of the universe, which means the Earth and planets revolving around a stationary Sun. However, his theory was not popular and it would be nearly 1800 years before it was finally accepted.

Renaissance period - 1609

aroberson26 — 2025-04-16 14:50:48 UTC

By using a newly invented telescope, Galileo was able to make some incredible astronomical observations, including viewing the planet Jupiter’s rotating moon system, and noting there were objects in space that didn’t revolve around the Earth. He also was able to discover 4 Jovian moons, the Moon's craters and the Milky Way galaxy.

Renaissance period - 1668

aroberson26 — 2025-04-16 14:50:50 UTC

Sir Isaac Newton invented the first reflecting telescope which used a curved mirror instead of a lens to look further into space. He later went onto publish his book called ‘Philosophiae Naturalis Principia Mathematica’ in which he agrees that the Earth rotates around the Sun and explains the reasons behind Kepler’s three laws.

Modern space travel - General Theory of Relativity 1905

aroberson26 — 2025-04-16 14:51:02 UTC

Albert Einstein introduced a Special Theory of Relativity. This theory suggests nothing can travel faster than the speed of light. As the speed of an object approaches the maximum limit set by the speed of light, the other variables in the equation start to change with distances becoming shortened relative to time which becomes lengthened.

Modern space travel - Sputnik 1 satellite 1957

aroberson26 — 2025-04-16 14:51:07 UTC

The Russian Sputnik 1 satellite becomes the first man-made object to orbit the Earth marking the beginning of the space age. Sputnik 2, launched on November 3, 1957 and carried the dog Laika, the first living creature to be shot into space and orbit Earth.

Modern space travel - Apollo 11 mission 1969

aroberson26 — 2025-04-16 14:51:11 UTC

During the Apollo 11 mission, Neil Armstrong and Buzz Aldrin were the first to walk on the surface of the Moon. During the Apollo missions, there were nearly 400,000 highly skilled people directly involved in designing, building, testing, and operating all of the project’s components and equipment.

Modern space travel - Mars exploration 2004

aroberson26 — 2025-04-16 14:51:16 UTC

NASA’s Mars Exploration Rover mission successfully lands Spirit and Opportunity on Mars. Both rovers exceed above and beyond their expectations by delivering invaluable data about Martian geology and climate, leading to the discovery of past water activity on the planet.

aroberson26 — 2025-04-16 15:40:05 UTC

"The First Calendar Systems: Tracking Time In The Ancient World." The Archaeologist, February 16, 2025. https://www.thearchaeologist.org/blog/the-first-calendar-systems-tracking-time-in-the-ancient-world
Miller, James. "Black Holes, Relativity And Time Travel," Astronomy Trek. May 19, 2013. https://www.astronomytrek.com/black-holes-relativity-and-time-travel/
The Editors of Encyclopaedia Britannica. "Sputnik". Encyclopedia Britannica, 29 Mar. 2025, https://www.britannica.com/technology/Sputnik. Accessed 16 April 2025.
Miller, James. "10 Interesting Facts about the Apollo Missions," Astronomy Trek. November 3, 2017. https://www.astronomytrek.com/10-interesting-facts-about-the-apollo-missions/
Miller, James. "Important Dates In The Timeline Of Astronomy," Astronomy Trek. March 28, 2013. https://www.astronomytrek.com/important-dates-in-the-timeline-of-astronomy/
Astronomy timeline.pdf. https://teideastro.com/assets/files/Astro/Astronomy%20timeline.pdf Accessed April 16 2025.