One large, real-time world map that switches between the data NovelNumbers' other apps compute per-location -- Golden Hour's light bands (golden hour, blue hour, and each stage of twilight), Stargaze's live aurora probability, Stargaze's meteor activity, Stargaze's estimated light pollution, Stargaze's zodiacal light visibility, and Sun & Moon's upcoming solar eclipse paths -- so you can see how they're distributed across the whole globe at once instead of one place at a time.
Page help ⌄
How to use this page: pick which overlay is shown with the Overlay dropdown above the map -- NovelEarth shows one at a time, so switching never leaves two sets of bands layered confusingly on top of each other. Each overlay's own controls (time of day, which bands are shown, evening or morning) appear in its own box below the toggle -- and an overlay only shows the controls it actually uses, so Zodiacal Light offers a date to navigate but no time-of-day slider, because it scores every point at that point's own local dusk rather than at one shared moment. Solar Eclipses offers no date at all, just Prev/Next and a dropdown to pick which of the upcoming eclipses (through 2055) to show, since an eclipse only happens on its own specific day rather than existing for any date you might navigate to. Switch between 2D and 3D (globe) with the toggle in the top right, use the full-screen button on the map itself for a maximized view, and pan/zoom like any other map. Overlays shown here mirror the same live data as their home tab in Golden Hour, Stargaze, or Sun & Moon -- switching overlays here doesn't change anything about those apps' own pages.
Key Definitions
- Auroral oval
- The ring-shaped zone around each magnetic pole, marked on the map with a pink dot, where the aurora is most active -- it expands toward the equator during stronger geomagnetic activity.
- Bortle scale
- The standard 1-9 scale (Bortle, 2001) astronomers use to describe how dark a sky actually is -- Class 1 is the best a sky can naturally get, Class 9 is a bright inner-city sky. Its class boundaries aren't perfectly standardized across sources, which is why the hover readout also shows the underlying ALR and SQM numbers, not just the class.
- Central line
- The line through the middle of an eclipse's shadow path where it lasts longest at any given point along the path.
- Contrast
- How much brighter the cone is than the sky immediately around it. This, rather than absolute brightness, is what decides whether the eye can pick it out -- which is why the sharply tapering cone is a relatively easy object while the near-flat zodiacal band, barely fainter in absolute terms, needs a superb site.
- Ecliptic angle
- The angle the plane of the solar system makes with the horizon once the sky is fully dark. It decides whether the cone stands up out of the horizon haze or lies flat along it, depends only on latitude and date, and is the reason the zodiacal light is a spring-evening and autumn-morning object at northern mid-latitudes, a year-round one in the tropics, and a difficult one near the poles.
- Evening and morning zodiacal light
- The same dust cone seen on opposite sides of the sky: in the west after astronomical twilight ends, or in the east before it begins. The two peak in opposite seasons at any given latitude, which is why this overlay makes you choose one rather than blending them into a single number.
- Light pollution
- Artificial light scattered by the atmosphere back down toward the ground, brightening the sky and washing out fainter stars -- the Light Pollution overlay models it by propagating real NASA/NOAA satellite measurements of night-time light emissions through an atmospheric-scattering model, the same way a real ground observer's sky actually works.
- Meteor activity
- The Meteor Activity overlay's combined rate from every currently-active shower at once, scaled from Gold (low) to Blue (high) relative to the best rate any of them could theoretically reach that night -- a relative comparison across the selected night's sky, not an absolute meteors-per-hour scale.
- Overlay
- One data layer NovelEarth can show on the shared map -- Golden Hour's light bands, Stargaze's aurora tracker, Stargaze's meteor activity map, Stargaze's estimated light pollution map, Stargaze's zodiacal light visibility, and Sun & Moon's eclipse paths today, with more planned as the site grows.
- SQM (Sky Quality Meter reading)
- Sky brightness in magnitudes per square arcsecond, the unit a real handheld Sky Quality Meter reports -- lower numbers mean a brighter sky. A pristine natural sky reads about 22; a bright city center can read below 18.
- Terminator
- The moving boundary line between the day side and night side of the Earth -- the edge between the Golden Hour overlay's light bands, the Aurora overlay's shaded night/twilight regions, and the Meteor Activity overlay's colored density.
- Twilight
- The period between full daylight and full darkness, split into civil, nautical, and astronomical stages as the sun sinks progressively lower.
- Umbra / antumbra
- The Moon's full shadow, inside which a total eclipse's Sun is completely covered -- or, when the Moon is too far away to fully cover the Sun, the narrower antumbra, inside which a ring of sunlight remains visible (an annular eclipse). A hybrid eclipse shifts between the two along its own path. Both are drawn the same way here, as the shaded band.
- Zodiacal light
- A broad cone of sunlight scattered off interplanetary dust orbiting in roughly the plane of the planets, leaning up from where the sun set or from where it is about to rise. From a genuinely dark site the base of the cone outshines the Milky Way, and it is often mistaken for a distant town's light pollution. The overlay scores how visible it would be at each point on Earth on the selected date, each point measured at its own local dusk or dawn rather than at one shared instant.
How this works: the Golden Hour overlay calculates sun position for every point on the map using the NOAA/Meeus solar position algorithm, the same reduced-precision method NOAA publishes for its own sunrise/sunset calculator, accurate to about a minute anywhere on Earth. The Aurora overlay draws on NOAA's OVATION model, which forecasts global aurora probability from real-time solar wind and geomagnetic measurements and refreshes every few minutes. The Meteor Activity overlay combines each currently-active shower's official ZHR with the radiant's height above the horizon and the current moonlight at every point on the globe, the same real-but-simplified correction the Meteor Activity tab already applies to a single location. The Light Pollution overlay takes real NASA/NOAA VIIRS satellite measurements of night-time light emissions (a 2025 annual composite, so every town, industrial site, and highway that actually emits light shows up, not just large cities) and propagates them through an atmospheric-scattering model (Duriscoe et al. 2018, built on Garstang's radiative-transfer physics) into the same ALR (All-sky Light Pollution Ratio) and SQM metrics the Dark Skies tab computes -- the raw satellite measurement alone only shows light escaping upward into space, not how much of it scatters back down to a ground observer's eye, which is why the modeled glow extends smoothly around cities and even out over open water near a lit coast. Its own "Recent Satellite Imagery" toggle overlays a separate, real-time NASA VIIRS night-lights satellite pass for comparison, a single night's raw imagery rather than the modeled baseline the main layer uses. Color blends continuously between the 9 Bortle class colors rather than stepping at each class boundary, because sky glow itself falls off smoothly -- a hard edge would draw a line where the sky has none; hovering the map reads out the exact class at that point and highlights it in the legend. The Zodiacal Light overlay combines the geometry of the ecliptic against the horizon at every latitude with the real measured surface brightness of the dust cone from Leinert et al. (1998), the standard reference tabulation professional sky-background models are built on, and scores the result as a contrast ratio against the sky it has to compete with -- because a low-surface-brightness glow is seen or lost on contrast, not on brightness. Each point is evaluated at its own local dusk (or dawn) on the selected date rather than at a single shared instant, so the whole globe answers "is tonight a good night here" at once. Its color assumes a genuinely dark site and deliberately leaves local light pollution out, since that is exactly what the Light Pollution overlay next to it already shows; hovering adds the real Bortle class at that point so the two can be read together. The Solar Eclipses overlay draws real published shadow-path data (Xavier Jubier's Google Earth files, built on NASA/Fred Espenak's Five Millennium Canon of Solar Eclipses) rather than a model of its own -- the same path geometry the Solar Eclipses tab's map shows, picked from a dropdown instead of a date since these are specific future events rather than something to compute for an arbitrary day. All six overlays are the same underlying data and math that power Golden Hour's Map tab, Stargaze's Aurora, Meteor Activity, Dark Skies, and Zodiacal Light tabs, and Sun & Moon's Solar Eclipses tab respectively -- NovelEarth just presents them full-screen, one at a time, with more room to pan and zoom around the globe.