The SpaceX Falcon 9, carrying a Dragon capsule, lifts off the launch pad at Launch Complex 40 at Cape Canaveral on Dec. 8, 2010. NASA hide caption

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Ronald McNair (third in line) and his fellow Challenger astronauts head to the launch pad at Kennedy Space Center to board the space shuttle on Jan. 27, 1986. Steve Helber/AP hide caption

itoggle caption Steve Helber/AP

The space shuttle Challenger explodes shortly after lifting off from the Kennedy Space Center in Cape Canaveral, Fla., on Jan. 28, 1986. Bruce Weaver/AP hide caption

itoggle caption Bruce Weaver/AP

The supermassive black hole at the center of our galaxy. Smithsonian Institute/via Flickr hide caption

itoggle caption Smithsonian Institute/via Flickr

A Hubble telescope image of Hanny's Voorwerp. NASA hide caption

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The planet Kepler-10b, seen in this artist's drawing, is about 1.4 times the size of Earth and is the smallest planet ever discovered outside of our solar system. NASA hide caption

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This is what researchers at the ATLAS detector at the Large Hadron Collider expect data from a Higgs boson to look like. The Higgs boson is the subatomic particle that scientists say gives everything in the universe mass. ATLAS Experiment/CERN hide caption

itoggle caption ATLAS Experiment/CERN