Decades-old idea brought to fruition: a mission to Mercury

Excerpt from the February 6, 1965 issue of Science News Letter

Messenger maps

GLOBAL COVERAGE  The MESSENGER probe created these maps of Mercury based on thousands of images.

NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Mercury flyby proposed — An unmanned space probe that would pass 1,100 miles from Venus and then come within 4,700 miles of Mercury has been proposed. Planned for launching in late July or August of 1970, the spacecraft would need less than a third as much thrust as one going directly to Mercury without visiting Venus…. Neither NASA nor JPL are as yet planning such a mission as this, but the techniques involved are applicable to other multi-planet flights.
 — Science News Letter, February 6, 1965


Mariner 10 launched in 1973 and the next year became the first probe to visit Mercury and the first to use the gravity of another planet — Venus — to help it on its way. Images revealed a barren terrain riddled with craters. No spacecraft visited again until MESSENGER, which in 2013 completed the maps begun nearly 40 years earlier (SN: 1/12/13, p. 17). Now out of fuel, that mission will end this spring, when the probe crashes into Mercury’s surface.

Christopher Crockett is an Associate News Editor. He was formerly the astronomy writer from 2014 to 2017, and he has a Ph.D. in astronomy from the University of California, Los Angeles.

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