In this image from NASA's Spitzer Space Telescope, "cometary knots" on the Helix Nebula show blue-green heads caused by excitation of their molecular material from shocks or ultraviolet radiation.

The Helix Nebula. Credit: X-ray: NASA/CXC/SAO/Univ Mexico/S. Estrada-Dorado et al.; Ultraviolet: NASA/JPL; Optical: NASA/ESA/STScI (M. Meixner)/NRAO (T.A. Rector ...

The rapidly spinning neutron star embedded in the center of the nebula is the dynamo powering the nebula's eerie interior bluish glow. The Bubble Nebula is 7 light-years across and resides 7,100 ...

Since 2004, I have worked on PCMag’s hardware team, covering at various times printers, scanners, projectors, storage, and monitors. I currently focus my testing efforts on 3D printers, pro and ...