terasecond

Terasecond is an SI-derived unit of time equal to 10^12 seconds. It is formed by applying the prefix tera- to the base unit second (s). While mathematically valid within the SI system, teraseconds are not commonly used in routine measurements, and many guidelines discourage introducing large time units for everyday timing.

Symbol and usage considerations often vary. The proposed symbol for terasecond is Ts, derived from the tera- prefix and the second unit, but usage is not universal and can be ambiguous with other symbols in practice. Consequently, many texts simply refer to teraseconds by the numeric value in seconds rather than adopting a dedicated symbol.

Conversions and scale. 1 Ts equals 1,000,000,000,000 seconds. In more familiar terms, 1 Ts is about 31,688 years, roughly 11.57 million days, or about 277.8 million hours. This places teraseconds in a very long timescale, useful for comparisons with geological, astronomical, or cosmological durations rather than everyday events.

Context and relation to other units. Teraseconds sit above megaseconds (10^6 s) and gigaseconds (10^9 s) in the SI prefix hierarchy. For perspective, the age of the Earth is about 4.5 billion years, roughly 1.4 × 10^17 seconds or about 1.4 × 10^5 teraseconds. Teraseconds are therefore most relevant in discussions of processes spanning tens of thousands of years to hundreds of millions of years.

See also: SI prefixes, seconds, gigasecond, megasecond.