Astronomical Unit

An Astronomical Unit is a unit of measurement of distance, frequently used to measure inter-planetary distances.

• It is an astrographic scale measurement.
• It is a standard Imperial metric.

Description (Specifications)

One Imperial Astronomical Unit is defined to be exactly 150 million Imperial standard kilometers. The original Solomani Astronomical Unit of Old Terra, based on the Terra-Sol average orbital distance from which it was derived, is 149,597,870.691 ± .030 kilometers, or about 93 million miles (Old Terran Customary Units).

• The standard abbreviation is AU.
• One Imperial Astronomical Unit is equal to exactly 500 light-seconds.
• One Imperial Standard Parsec is exactly equal to 200,000 AU.

History & Background (Dossier)

Because the definition of a Parsec originally relied upon the Astronomical Unit, the AU has become a standard unit of measurement within the Imperium.

Imperial vs. Solomani Astronomical Unit Usage

The Solomani define the Astronomical Unit as the distance between Terra and Sol, the system's primary star, yielding a value of almost precisely 499 light-seconds.

Modern Imperial usage defines the AU to be exactly 150 million Imperial standard kilometers, which by extension yields a distance calculation of exactly 500 ls. Given the closeness of the calculated historic value of the old Terran parsec at slightly more than 200,000 AUs, the Imperial Science Union and Imperial Bureau of Standards have defined the Imperial Standard Metric Parsec to be exactly 200,000 AUs. This yields a value of ~ 3.171 ly.

This definition of the AU was broadly adopted following the Solomani Rim War, in order to avoid the use of specifically Terracentric metrics.

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Library Data Referral Tree

Please refer to the following AAB Library Data for more information:
Metrics & Terminology:

• Speed of Travel

• NAFAL (STL) - (Not As Fast As Light) / (Slower Than Light)
• Light Speed (c)
• FTL - (Faster Than Light) - "Superluminal"

• Astronomical Unit (AU)

» Imperial Standard Astronomical Unit

• Light-second (ls)
• Light-minute (lm)
• Light-hour (lh)
• Light-day (ld)
• Light-week (lw)
• Light-year (ly)
• Parsec (pc)

» Solomani Parsec

» Vilani Parsec ("Deshi")

» Imperial Standard Parsec

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References & Contributors (Sources)

This page uses content from Wikipedia. The original article was at Astronomical_unit. The list of authors can be seen in the page history. The text of Wikipedia is available under the Commons Attribution-ShareAlike 3.0 Unported License.

This list of sources was used by the Traveller Wiki Editorial Team and individual contributors to compose this article. Copyrighted material is used under license from Mongoose Publishing or by permission of the author. The page history lists all of the contributions.

• Marc Miller. Imperial Encyclopedia (Game Designers Workshop, 1987), TBD.
• EXTERNAL LINK: A Kuiper Belt Glossary by Jeol Parker
• Traveller Wiki Editorial Team
• Author & Contributor: Lord (Marquis) and Master of Sophontology Maksim-Smelchak of the Ministry of Science