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I want to introduct something about Sky Spotlight. Skycenter technology hk, co., ltd who is a manufactory, are special produce 1: 1w 3w 5w 10w high power spot light, like: , mr16 gu10 e27 b22 par38. 2: 1w 3w 5w 10w 50w high power led, . Lcd, led lighting, diod led, lamps, 3: 1w 3w high powe led flashlight 4, the oem of led simi-finished and finished lighting product 5: The manufactory of kinds of lighting product The boundaries between the Earth's surface and outer space, at the Km line, 100 km (62 mi) & exosphere at 690 km (430 mi). Outer space (often called space) comprises the relatively empty regions of the universe outside the atmospheres of celestial bodies. Outer space is used to distinguish it from airspace and terrestrial locations. There is no clear boundary between Earth's atmosphere and space as the density of the atmosphere gradually decreases as the altitude increases. Nevertheless, the Fation Aonautique Internationale has established the Km line at an altitude of 100kilometres (62mi) as a working definition for the boundary between aeronautics and astronautics. This is used because above an altitude of roughly 100kilometres (62mi), as Theodore von Km calculated, a vehicle would have to travel faster than orbital velocity in order to derive sufficient aerodynamic lift from the atmosphere to support itself. The United States designates people who travel above an altitude of 50miles (80km) as astronauts. During re-entry, roughly 120kilometres (75mi) marks the boundary where atmospheric drag be comes noticeable, depending on the ballistic coefficient of the vehicle. Contrary to popular understanding, outer space is not completely empty (i.e. a perfect vacuum), but contains a low density of particles, predominantly hydrogen plasma, as well as electromagnetic radiation. Hypothetically, it also contains dark matter and dark energy. The term outer space was first recorded by H. G. Wells in his novel First Men in the Moon in 1901. The shorter term space is actually older, first used to mean the region beyond Earth's sky in John Milton's Paradise Lost in 1667. Contents 1 Environment 2 Space versus orbit 3 Regions 3.1 Geospace 3.2 Interplanetary 3.3 Interstellar 3.4 Intergalactic 4 See also 5 References 6 External links // Environment See also: Space exposure Outer space is the closest natural approximation of a perfect vacuum. It has effectively no friction, allowing stars, planets and moons to move freely along ideal gravitational trajectories. But no vacuum is truly perfect, not even in intergalactic space where there are still a few hydrogen atoms per cubic centimeter. (For comparison, the air we breathe contains about 1019 molecules per cubic centimeter.) The deep vacuum of space could make it an attractive environment for certain industrial processes, for instance those that require ultraclean surfaces; Stars, planets, asteroids, and moons keep their atmospheres by gravitational attraction, and as such, atmospheres have no clearly delineated boundary: the density of atmospheric gas simply decreases with distance from the object. The Earth's atmospheric pressure drops to about 1 Pa at 100kilometres (62mi) of altitude, the Km line which is a common definition of the boundary with outer space. Beyond this line, isotropic gas pressure rapidly becomes insignificant when compared to radiation pressure from the sun and the dynamic pressure of the solar wind, so the definition of pressure becomes difficult to interpret. The thermosphere in this range has large gradients of pressure, temperature and composition, and varies greatly due to space weather. Astrophysicists prefer to use number density to describe these environments, in units of particles per cubic centimetre. All of the observable universe is filled with large numbers of photons, the so-called cosmic background radiation, and quite likely a correspondingly large number of neutrinos. The current temperature of this radiation is about 3K (?270.15; ?454.27). Contrary to popular belief, a person suddenly exposed to the vacuum would not explode, freeze to death or die from boiling blood, but would take a short while to die by asphyxiation (suffocation). Air would immediately leave the lungs due to the enormous pressure gradient. Any oxygen dissolved in the blood would empty into the lungs to try to equalize the partial pressure gradient. Once the deoxygenated blood arrives at the brain, death would quickly follow. Humans and animals exposed to vacuum will lose consciousness after a few seconds and die of hypoxia within minutes. Blood and other body fluids do boil when their pressure drops below 6.3 kPa, the vapor pressure of water at body temperature. This condition is called ebullism. The steam may bloat the body to twice its normal size and slow circulation, but tissues are elastic and porous enough to prevent rupture. Ebullism is slowed by the pressure containment of blood vessels, so some blood remains liquid. Swelling and ebullism can be reduced by containment in a flight suit. Shuttle astronauts wear a fitted elastic garment called the Crew Altitude Protection Suit (CAPS) which prevents ebullism at pressures as low as 2 kPa. Water vapor would also rapidly evaporate off from exposed areas...(and so on) To get More information , you can visit some products about tanker ship, touch screen car stereo, electric air filter, folding container, fashion scarves, embroidery cotton, bird feeder station, centrifugal casting machine, dirt bike quad, sculpture antique, . 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