This Hubble Space Telescope shot of the Horsehead Nebula, released April 19, was taken in celebration of the telescope's 23rd anniversary. Pictured in infrared wavelengths for the first time, the Horsehead is part of the larger constellation Orion.
Depending on the time of year, watching for aurora borealis—or the northern lights—can be a popular activity in high latitudes. Here, the lights were visible in Stockholm, Sweden, on March 13 following a solar storm, and could be seen in the sky just before dusk. (See more pictures of auroras.)
The SN 1006 supernova was created by an exploding star in the year 1006, according to historical accounts. It was most likely a white dwarf that sucked up material from a companion star and exploded, or two white dwarf stars that merged and subsequently exploded.
A composite of ten x-ray images taken by NASA's Chandra x-ray observatory, released April 17, pieces together a tapestry of what the white dwarf star likely looked like when it exploded.
This conceptual artist rending, released April 18, shows Kepler-62f, an Earth-like planet nearly 1,200 light-years away. NASA scientists believe it orbits in the habitable zone for humans.
The planet is 40 percent larger than Earth and orbits its star, which is slightly cooler than Earth's sun, every 267 days.
The planet is believed to have a similar composition of water and land mass as our planet, but its exact components and mass are unknown, as is its current condition. Images and data received now of the planet capture light that left the planet more than a millennium ago.