Search results
Results From The WOW.Com Content Network
A light-year, alternatively spelled light year (ly or lyr[3]), is a unit of length used to express astronomical distances and is equal to exactly 9,460,730,472,580.8 km (Scientific notation: 9.4607304725808 × 10 12 km), which is approximately 5.88 trillion mi.
A light-year is the distance light travels in one Julian year, around 9461 billion kilometres, 5879 billion miles, or 0.3066 parsecs. In round figures, a light year is nearly 10 trillion kilometres or nearly 6 trillion miles. Proxima Centauri, the closest star to Earth after the Sun, is around 4.2 light-years away. [89]
Parsecs are used in astronomy to measure interstellar distances. A parsec is approximately 3.26 light-years or about 3.086×10 16 m (1.917×10 13 mi). Combining it with the "atto-" prefix (×10 −18) yields attoparsec (apc), a conveniently human-scaled unit of about 3.086 centimetres (1.215 in) that is used only humorously.
A proper motion of 1 arcsec per year 1 light-year away corresponds to a relative transverse speed of 1.45 km/s. Barnard's Star's transverse speed is 90 km/s and its radial velocity is 111 km/s (perpendicular (at a right, 90° angle), which gives a true or "space" motion of 142 km/s. True or absolute motion is more difficult to measure than the ...
Google Maps is available as a mobile app for the Android and iOS mobile operating systems. The first mobile version of Google Maps (then known as Google Local for Mobile) was launched in beta in November 2005 for mobile platforms supporting J2ME. [186] [187] [188] It was released as Google Maps for Mobile in 2006. [189]
The cosmic distance ladder (also known as the extragalactic distance scale) is the succession of methods by which astronomers determine the distances to celestial objects. A direct distance measurement of an astronomical object is possible only for those objects that are "close enough" (within about a thousand parsecs) to Earth.
Animated 3D map of the nearest stars, centered on the Sun. 3D red green glasses are recommended to view this image correctly. A radar map of the distances ( ) and positions ( ) of all known stellar bodies or systems within 9 light years (ly) (for within 12 ly see this map).
Light-year: 63,241 – Distance light travels in one Julian year (365.25 days) – Oort cloud: 75,000: ± 25,000: Distance of the outer limit of Oort cloud from the Sun (estimated, corresponds to 1.2 light-years) – Parsec: 206,265 – One parsec. The parsec is defined in terms of the astronomical unit, is used to measure distances beyond the ...