Both the Orion (left) and the Horsehead (right) Nebulae light up a winter's night over Tehran, Iran.
The Orion Nebula—located 1,300 light-years away from Earth—is an area where new stars are forming. To the naked eye, it appears as a tiny smudge below the belt in the Orion constellation.
The Horsehead Nebula—officially known as Barnard 33—also acts as a stellar nursery, giving birth to low-mass stars. Researchers at Harvard College Observatory first imaged this famous celestial object in 1888, but they didn't discover it. That honor goes to Williamina Fleming, a maid in the home of astronomy professor Edward Pickering, who hired her to catalog the stars he was imaging. It seems the astronomy professor wasn't satisfied by the work done by his male employees, and stated that his maid could do a better job. (See "6 Women Scientists Who Were Snubbed Due to Sexism.")
Fleming developed a star classification system—now known as the Pickering-Fleming system—based on a star's spectra, or how its light refracts through a prism. She went on to catalog 10,000 stars over nine years. (See "Why It's Crucial to Get More Women Into Science.")
—By Jane J. Lee, photo gallery by Sherry L. Brukbacher
Week's Best Space Pictures: Curiosity Drills, Nebulae Illuminate, and Hubble Peers
Curiosity makes its third foray into Martian soil, nebulae light up a winter night, and Hubble peers into deep space in this week's best space photos.