NASA's Voyager 2 spacecraft gave humanity its first glimpse of Neptune and its moon Triton in the summer of 1989. This picture of Neptune was produced from the last whole planet images taken through the green and orange filters on the Voyager 2 narrow angle camera on Aug. 20, 1989. NASA hide caption

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NASA

A NASA poster imagines what it might be like to "planet hop" from the planet called TRAPPIST-1e, 40 light-years from Earth. NASA-JPL/Caltech hide caption

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NASA-JPL/Caltech

Vintage American history photo of a nuclear weapon test by the American military at Bikini Atoll, Micronesia on July 25, 1946. The explosion was part of Operation Crossroads. John Parrot/Stocktrek Images/Getty Images hide caption

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John Parrot/Stocktrek Images/Getty Images

President Barack Obama speaks during the dedication ceremony for the Smithsonian Museum of African American History and Culture in Washington, DC, on Sept. 24, 2016. Pablo Martinez Monsivais/AP hide caption

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Pablo Martinez Monsivais/AP

From left, Octavia Spencer, Janelle Monae and Taraji P. Henson accept the award for outstanding performance by a cast in a motion picture for Hidden Figures at the 23rd annual Screen Actors Guild Awards on Jan. 29 in Los Angeles. Chris Pizzello/Invision/AP hide caption

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Chris Pizzello/Invision/AP

This artist's impression shows the surroundings of a supermassive black hole, typical of that found at the heart of many galaxies. The black hole itself is surrounded by a brilliant accretion disc of very hot, infalling material and, further out, a dusty torus. There are also often high-speed jets of material ejected at the black hole's poles that can extend huge distances into space. L. Calçada/ESO hide caption

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L. Calçada/ESO

This artist's view shows an exoplanet orbiting the young star Beta Pictoris. The exoplanet has an eight-hour day — and a much faster rotation than any planet in the solar system. L. Calçada/N. Risinger/ESO hide caption

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L. Calçada/N. Risinger/ESO

Taking Stock In The Search For Aliens

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