Name: Lightime (App)
Author: JuliensLab

NOW AS AN APP FOR ALL CURRENT WATCHES (fēnix 7/8, tactix 8, epix, Venu 2/3/4, Forerunner 255/265/965/970, vívoactive 5/6, Instinct 3...) as well as older models. This is the successor of the "Lightime" widget: Connect IQ 4+ watches have no widget loop any more, so the app comes as a new listing with a glance.

Ever wondered how long it will take your kids to get your email once they settled on Mars? Lightime shows how long light (and therefore information) takes to travel between the Earth and the Sun, the Moon, the planets, Pluto - and the Tesla Roadster sent in 2018 by a Falcon Heavy on a heliocentric orbit.

DISTANCE, LIGHT TIME AND VELOCITY OF THE SELECTED BODY RELATIVE TO THE EARTH - LIVE.

When the app starts, the last selected body is shown. Light time is displayed in the center; below it the distance in km or miles (million) and in AU (astronomical units, the average Sun-Earth distance of about 150 million km), and the relative speed.
Press SELECT to enter selection mode: UP/DOWN pick the body.
Press SELECT again for date mode: UP/DOWN shift the date (1 day per click) to explore future/past.
Press MENU to come back to now.

Positions are computed on the watch from JPL/Standish orbital elements (valid 1800-2050); the Tesla Roadster orbit was refreshed from JPL Horizons in 2026. No internet connection needed.

Keywords: Space, Planet, Planets, Light, Mercury, Venus, Earth, Moon, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto, Tesla, Starman