Proxima Centauri, the nearest star to the Sun, is 4.2 light-years away. A probe travels toward it at one tenth of the speed of light. How many years does the journey take?

Astrophysics Challenge #2 — Light-Years

Light-years to
Proxima Centauri.

Astrophysics Easy

Problem

Proxima Centauri, the nearest star beyond the Sun, lies 4.2 light-years away. A probe cruises toward it at a constant one tenth of the speed of light. How many years does the journey take?

Distance\( 4.2 \) light-years
Probe speed\( 0.1c \)
Answer inyears

A light-year measures distance, not time — that is the whole puzzle.

Hint: light covers one light-year per year, by definition. At a tenth of that speed, how long does the probe need for each light-year?

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years

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Light-years toProxima Centauri.

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Light-years to
Proxima Centauri.