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

The spiral galaxy known as NGC 3521 lies in the constellation of Leo, a mere 35 million light-years away. Now go flush and see if you understand the connection between the two. O. Maliy/ESO hide caption

itoggle caption O. Maliy/ESO

An artist's impression of a gamma-ray burst, a powerful jet of energy lasting from less than a second to several minutes. The most powerful events in the universe, they are thought to be mostly associated with the explosion of stars that collapse into black holes. A. Roquette/ESO hide caption

itoggle caption A. Roquette/ESO

The Warp in this Spiral Galaxy was probably the result of a cosmic collision with another galaxy. Hubble Heritage Team (STScI/AURA), C. Conselice (U. Wisconsin/STScI) et al., NASA hide caption

itoggle caption Hubble Heritage Team (STScI/AURA), C. Conselice (U. Wisconsin/STScI) et al., NASA