NASA mysterious signal: Detected by two NASA spacecraft, X-ray emissions of unknown origin could lend insight into dark matter, a mysterious substance thought to compose more than 80 percent of all matter in the known universe.
The huge orbit of a Jupiter-like gas giant has researchers scratching their heads over how the thing could ever form so far from the nearest star and the star's accompanying debris disk. But they've got some intriguing theories.
The star collections known as galaxies formed much sooner in the early universe than previously estimated, according to an analysis of data from the Hubble Space Telescope. Galaxies were well established within 2.5 billion years of the big bang.
The Hubble Space Telescope helped scientists to identify the blue color of an exoplanet, giving researchers another piece in their understanding of the distant world. The alien planet has fierce winds and high temperatures, which turn rain into glass.