01
The universe is approximately 13.8 billion years old according to current astronomical measurements.
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02
The observable universe is about 92 billion light-years across, while the total size of the entire universe is not known.
supported03
A light-year is a unit of distance equal to the distance light travels through vacuum in one year, about 9.5 trillion kilometers.
supported04
Proxima Centauri, the nearest known star to the Sun, is about 4.25 light-years away.