Australia's giant Parkes radio telescope detected a "fast radio burst," or FRB, last May. Researchers call FRBs, whose origins haven't been explained, "tantalizing mysteries of the radio sky." CSIRO/EPA/Landov hide caption

itoggle caption CSIRO/EPA/Landov

A negative image of Kks3, made using the Advanced Camera for Surveys on the Hubble Space Telescope. The core of the galaxy is the right hand dark object at the top center of the image. D. Makarov/Royal Astronomical Society hide caption

itoggle caption D. Makarov/Royal Astronomical Society

A blast from the past: Using data from four telescopes, NASA created this image of the first documented sighting of a supernova, made by Chinese astronomers in 185 A.D. NASA/JPL-Caltech/B. Williams hide caption

itoggle caption NASA/JPL-Caltech/B. Williams

International Space Station Commander Barry "Butch" Wilmore holds up the first object made in space with 3-D printing on Nov. 25. NASA hide caption

itoggle caption NASA

The Rosetta spacecraft, which orbits the comet, captured this series of images of the Philae lander bounding off the surface. The precise spot the lander came to a stop remains unknown. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA hide caption

itoggle caption Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA