Move the depression-angle dial to sweep a bright ring across the civil, nautical and astronomical twilight bands, or move the latitude and season controls to find where white nights happen.
The globe looks straight down the Sun-Earth line, so daylight is the bright cap at the top and full night is the dark cap at the bottom - this is not the usual side-on Earth view, it is chosen so all three twilight bands are visible at once as complete rings.
Drag to orbit the scene and scroll or pinch to zoom. The bright thin ring marks the exact depression angle set by the dial; the small glowing marker shows the latitude and season point you picked.
Twilight Types 3D Explorer: Civil, Nautical & Astronomical
Move the depression-angle dial to sweep a bright ring across the civil, nautical, and astronomical twilight bands drawn around Earth's terminator, then move the latitude and season controls to find where white nights happen.
Twilight is graded by how many degrees the Sun's center sits below the horizon: 0-6 degrees is civil twilight, 6-12 degrees is nautical twilight, and 12-18 degrees is astronomical twilight, per the U.S. Naval Observatory's definitions. Past 18 degrees the sky reaches full night. Near the tropics the Sun sets almost straight down, so it crosses all three bands quickly; near the poles in summer the Sun's path runs nearly parallel to the horizon, so twilight can stretch for hours - or never end at all.
- Move the depression-angle dial (0-18 degrees) to see which twilight band a given angle falls in, marked by a bright ring on the globe
- Move the latitude slider to place a marker at that latitude's local-midnight point
- Click a season button (June solstice, equinox, December solstice) to change how far the Sun's overhead point sits from the equator
- Read the facts panel to see whether that latitude and season combination gets a "white night" - continuous civil twilight with no true darkness
- Drag to orbit the scene and scroll or pinch to zoom
- Runs fully in the browser with the vendored three.js engine - no account, no upload
| Twilight type | Sun's depression below horizon |
|---|---|
| Civil twilight | 0 to 6 degrees |
| Nautical twilight | 6 to 12 degrees |
| Astronomical twilight | 12 to 18 degrees |
| Full night | more than 18 degrees |
These boundary figures come from the U.S. Naval Observatory's Rise, Set, and Twilight Definitions (aa.usno.navy.mil/faq/RST_defs) and the U.S. National Weather Service's Definitions of Twilight (weather.gov/fsd/twilight). Near the equator, total twilight from sunset to full astronomical darkness lasts roughly 70 minutes year-round, because the Sun's path meets the horizon at a steep angle. Near latitude 60.5 degrees North or South around that hemisphere's summer solstice, the Sun's center never drops the full 6 degrees below the horizon at local midnight - the classic "white nights" seen in cities like Saint Petersburg and Reykjavik, where the sky stays in civil twilight all night instead of reaching true darkness. This page's latitude and season controls compute that same midnight-depression figure using standard spherical astronomy (90 degrees minus latitude minus solar declination), assuming a flat sea-level horizon with no atmospheric refraction.
This page grades the twilight transition zone itself into its three defined bands and shows how latitude changes their duration. For the shape of the day/night line and a live approximate sun position on a rotating Earth, see Earth 3D Globe: Live Day/Night Map. For how Earth's 23.4-degree axial tilt drives the seasons that shift those bands through the year, see Seasons on Earth 3D Explorer. For the specific date and duration of an eclipse rather than everyday twilight, see Solar Eclipse 3D Explorer.
Everything renders on your device with WebGL. The 3D engine loads once (about 0.7 MB) and is cached.
This is an educational approximation, not a physical simulation: the scene assumes a flat sea-level horizon and ignores atmospheric refraction, haze, and local terrain, all of which shift real twilight times by a few minutes. The latitude/season midnight-depression figure uses the standard idealized spherical-astronomy formula rather than a full-precision ephemeris, and the globe is viewed pole-on to the Sun so all three bands render as complete rings - it is not meant as a realistic day-side view of Earth. The cited degree boundaries and the roughly-70-minute equatorial figure are accurate to the referenced sources.
Frequently Asked Questions
What are civil, nautical, and astronomical twilight?
They are the three official twilight bands, graded by how many degrees the Sun's center sits below the horizon: civil twilight is 0-6 degrees, nautical twilight is 6-12 degrees, and astronomical twilight is 12-18 degrees, per the U.S. Naval Observatory's definitions.
What happens past 18 degrees below the horizon?
The sky reaches full night - no further twilight banding is defined past astronomical twilight.
Why is twilight shorter near the equator?
Near the equator the Sun sets almost straight down relative to the horizon, so it crosses all three twilight bands quickly - total twilight from sunset to full astronomical darkness lasts roughly 70 minutes year-round.
What is a "white night"?
A white night happens when the Sun's center never drops the full 6 degrees below the horizon at local midnight, so the sky stays in civil twilight all night instead of reaching true darkness. This starts around latitude 60.5 degrees North or South near that hemisphere's summer solstice - the effect known in cities like Saint Petersburg and Reykjavik.
How does this page compute the white-night threshold?
It uses the standard spherical-astronomy formula: the Sun's depression below the horizon at local midnight is about 90 degrees minus the latitude minus the Sun's declination (its angle from the equator for the chosen season), assuming a flat sea-level horizon with no atmospheric refraction.
Why does the globe show daylight as a cap at the top instead of a side view?
The scene looks straight down the Sun-Earth line so all three twilight bands render as complete rings at once - a side-on view would only show a thin arc of each band along the terminator.
Does this page simulate real orbital or atmospheric physics?
No. It is an educational approximation: it ignores atmospheric refraction, haze, and terrain, and uses an idealized formula rather than a full-precision ephemeris. The cited degree boundaries and the roughly-70-minute equatorial figure are accurate to the referenced U.S. Naval Observatory and National Weather Service sources.