Observed arrival · 2026-09-19

Sunset Visualiser

observable.science Visit website

Editorial interest 78/100 Selection signal · not a rating of the site

An open solar model compares how the Sun appears to set on a globe Earth versus a flat Earth.

Landing page captured for the 2026-09-19 issue.

For: Science communicators and curious skywatchers
Worth noticing: It compares angular diameter and its rate of change, with shrinking represented as negative arcseconds per minute.

Field notes

The interface accepts geographic coordinates and a date, then fixes the Sun's starting position and path for the selected location. It offers four model/view combinations and reports solar height, angular diameter, and change over time, including a data-table option. A lens loupe supports 400 mm, 800 mm, and 1600 mm settings. The page also exposes verification tests, mathematical notes, and a GitHub source link rather than hiding the calculation behind a black box.

Observed signals

Read the marks

Editorial observations of this landing page, not a rating.

○OpenPublic substance visible

✦PrettyNotable craft visible

●ProPolished or operationally mature

◎NicheUnusually specific use

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Filed Under: Missing Tooth

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