Portal:Astronomy/Anniversaries/July

• 1 July 2004 – The Cassini spacecraft arrives at Saturn after entering orbit
• 4 July 1997 – Mars Pathfinder and its rover, Sojourner, land on Mars, with the latter becoming the first rover to successfully travel the planet
• 5 July 1687 – Sir Isaac Newton's Philosophiæ Naturalis Principia Mathematica, which formulated the laws of motion and universal gravitation and applied them to celestial bodes, is first published
• 13 July 2007 – Gran Telescopio Canarias undergoes first light, becoming the largest telescope in the world
• 20 July 1969 – As part of the Apollo 11 mission, Americans Neil Armstrong and Buzz Aldrin become the first men to walk on the Moon
• 20 July 1976 – Viking 1 becomes the first spacecraft to successfully land on Mars and perform its mission
• 26 July 1971 – Apollo 15 launches with lunar rover payload