Viking 1 lands on Mars
DOI: 10.1063/PT.5.031268
On this date, 20 July 1976, Viking 1 landed on Mars, becoming the first spacecraft to successfully do so. Launched in August 1975 it was originally intended to land on 4 July to mark the US bicentennial, but upon entry into orbit the landing site was determined to be too rough. After landing, Viking 1 returned the first clear images from the surface of Mars. It also carried instruments for sampling the Martian soil to look for organic compounds, and the data it collected showed mixed results that are still being debated and reanalyzed in light of data collected by more recent landers. The lander operated for 2245 Martian days until a faulty command sent from Earth caused a loss of contact. It was the longest active Martian surface mission until the Opportunity rover broke the record in 2010.
Date in History: 20 July 1976
