Mariner 4
- id: PRB-002
- launch_year: 1964
- launch_date: 1964-11-28
- operated_by: NASA, Jet Propulsion Laboratory
- visited: Mars
- carried: Mariner 4 television camera
- status: completed
- confidence: believed-correct
- sources: NASA NSSDCA Master Catalog, JPL missions
Mariner 4 launched on 28 November 1964 and performed the first successful flyby of Mars, passing the planet on 14–15 July 1965. Built and operated by JPL for NASA, it returned the first close-up photographs of another planet.
Its television camera recorded 21 complete pictures to an onboard tape recorder, which then played them back to Earth at about eight bits per second. The images showed a cratered, Moon-like surface — a result that ended the era of imagined Earthlike Mars and reshaped planetary science overnight.