page_title: Timeline of Solar System exploration
section_title: 1960s
hierarchical_section_title: Timeline of Solar System exploration / 1960s
caption_attribution_description: English: Mariner 2 was the world's first successful interplanetary spacecraft. Launched August 27, 1962, on an Atlas-Agena rocket, Mariner 2 passed within about 34,000 kilometers (21,000 miles) of Venus, sending back valuable new information about interplanetary space and the Venusian atmosphere. Mariner 2 recorded the temperature at Venus for the first time, revealing the planet's very hot atmosphere of about 500 degrees Celsius (900 degrees Fahrenheit). The spacecraft's solar wind experiment measured for the first time the density, velocity, composition and variation over time of the solar wind.
context_page_description: This is a timeline of Solar System exploration ordered by date of spacecraft launch. It includes:
  All spacecraft that have left Earth orbit for the purposes of Solar System exploration, including lunar probes.
  A small number of pioneering or notable Earth-orbiting craft.
  It does not include:
  Centuries of terrestrial telescopic observation.
  The great majority of Earth-orbiting satellites.
  Space probes leaving Earth orbit that are not concerned with Solar System exploration.
  Probes that failed at launch.
  The dates listed are launch dates, but the achievements noted may have occurred some time later—in some cases, a considerable time later.
caption: Mariner 2 – First successful Venus flyby
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