- 4 August 2007 – The Phoenix Mars Lander is launched from Cape Canaveral, carrying science instruments to analyze soil samples of the Martian northern polar region
- 6 August 2012 – The Mars rover Curiosity lands on the Red Planet as part of NASA's Mars Science Laboratory mission
- 7 August 1996 – Announcement of possible microfossils found in ALH84001 Martian Meteorite
- 20 August 1977 – Voyager 2 space probe is launched by NASA to study the outer planets and interstellar space beyond the Sun's heliosphere
- 21 August 2017 – NASA.gov conducts a broadcast of the total solar eclipse with more than 50 million views of the live broadcast, and almost 31 million unique views on Facebook before and after the eclipse
- 24 August 2006 – The International Astronomical Union votes to approve a new definition of "planet" that excludes Pluto
- 25 August 2003 – The Spitzer Space Telescope (SIRTF) is launched, dedicated to infrared astronomy
- 27 August 1962 – Mariner 2 launches on a journey to Venus, and is the first robotic space probe to conduct a successful planetary encounter
- 31 August 1913 – Bernard Lovell, a British physicist and radio astronomer is born
