Chandra X-ray Observatory Reference Libraries
X-Ray Astronomy -- Although the more energetic X-rays (E > 30 keV) can penetrate the air at least for distances of a few meters (they would never have been detected and medical X-ray machines would not work if this was not the case) the Earth's atmosphere is thick enough that virtually none are able to penetrate from outer space all the way to the Earth's surface. X-rays in the 0.5 - 5 keV...
Chandra X-ray Observatory -- NASA's Chandra X-ray Observatory, which was launched and deployed by Space Shuttle Columbia on July 23, 1999, is the most sophisticated X-ray observatory built to date. Chandra is designed to observe X-rays from high-energy regions of the universe, such as the remnants of exploded stars. The Observatory has three major parts: (1) the X-ray telescope, whose...
- A Roman unit of weight, 1⁄1728 of a pound.
- A weight of four grains used in weighing gold and precious stones; a carat.
- In anatomy, a formation suggesting a husk or pod.
- The lowest unit in the Roman coinage, the twenty-fourth part of a solidus.
- A coin of base silver of the Gothic and Lombard kings of Italy.