AstroShort vs Astrelia

Astro Explorer was built together — with curiosity, a sense of social connection, learning and education at its heart. It began as a gift from a dad to his kid, and grew into a hand-built universe for curious minds of every age. THE WHOLE UNIVERSE, BY TOUCH Fly between the Sun, all eight planets and the Moon. Zoom from a planet up close all the way out to the Milky Way — and the real black hole at its heart, Sagittarius A*, shown as the 2022 Event Horizon Telescope image. Nothing here needs reading to explore — a child who can't read yet can pilot the entire universe with a fingertip. DEEP FACTS ON EVERY PLANET Tap any planet — all eight, plus Pluto — to open its observation plate: its moons, its weather, the missions we've sent, and how it truly sizes up. The facts go deep, in plain language, and every one is sourced straight from NASA fact sheets and JPL. GO INSIDE REAL WORLDS Earth, Mars and the Moon aren't just spheres. Drill down to real places — the Grand Canyon, Olympus Mons, the Sea of Tranquility — meet animals, visit landmarks, and watch each place come alive with its own animated scene. Every fact carries its source, straight from NASA planetary fact sheets and the International Astronomical Union. TWO WAYS TO EXPLORE - Explorer mode (the default): a clean, premium look where grown-up facts, side-by-side planet comparisons and a daily discovery feed are one tap away. - Kid mode: a playful skin made for little hands — bigger buttons, a gentler pace, and deeper content tucked safely behind a parent hold-gesture. BUILT BY ITS EXPLORERS Here's the part we love most. Have an idea for the app? A child can simply say it out loud. Their words are turned into text right on your device, a grown-up reads it and decides whether to send it — anonymously, never any audio, never any account. On the Builders Board inside the app you can watch ideas from explorers around the world come together: what's being considered, what's being built, and what just shipped. Great ideas can become real features in days. This app is built by its explorers. HONEST BY DESIGN - Works fully offline — every planet, place and fact, with zero connection. - No accounts. No ads. No analytics. No tracking. Ever. - The only thing that ever touches the internet is the daily discovery feed: a single anonymous download of the same public file everyone gets, with no identifiers and no cookies. Offline, it shows the last feed with a visible date. - Facts are sourced and scale is honest: planets are stylized so small worlds stay visible, but the truths always hold — Jupiter is always the biggest, Mercury always closest to the Sun. Made for families. A friendly narrator reads names and facts aloud, so a pre-reader can explore and learn by ear. Safe for the youngest explorer to use alone, deep enough for the most curious adult.

Raise your phone toward the sky and Astrelia shows you what is actually up there: stars, planets, the Moon and the Sun, placed for your exact location and this exact instant. Tap anything and it tells you everything it knows. POINT AT THE SKY Around 8,900 naked-eye stars, sized and coloured the way the eye sees them. Constellation lines, the ecliptic with the live planets, and a Sun and Moon computed with topocentric parallax and atmospheric refraction, so they sit where you can genuinely see them. Pinch to zoom and more names appear. Tap any star to identify it. Scrub time twelve hours forward or back and watch the whole sky move. Aim at something bright and align, and the compass error that ruins most sky apps is cancelled out. TONIGHT One screen for what is happening: the Moon's phase, sunrise and sunset, which planets are up right now and which are below the horizon, meteor showers near their peak, and what is coming — eclipses, oppositions, solstices, greatest elongations. All of it searched out of the live ephemeris, not read from a hardcoded list. NUMBERS THAT MEAN SOMETHING Every object opens into real astrophysics: distance, spectral class, temperature, luminosity, derived radius, orbital elements. Next to them, plain language — the year the light you are looking at left that star, how many Suns it would take to match it, what you would weigh on that planet, where the star falls on the HR diagram, and a one-line biography of its life. Anything unfamiliar has a glossary entry a tap away. THE GALAXY MAP Leave Earth entirely and free-fly a 3D map built from real data: about 25,000 catalogued stars at their true distances, the Milky Way as its real barred spiral, and deep-sky landmarks at their real positions, distances and sizes. Twenty-seven nebulae are built from public-domain telescope photographs, so their shape and colour are the ones the telescope saw — fly into them and they hold up in three dimensions. Fly to a star and its confirmed exoplanets are there, orbiting it. At the galactic centre, Sagittarius A* is rendered by tracing light through curved spacetime: the galaxy behind it genuinely bends around it. CONSTELLATIONS All 88 IAU constellations, plus asterisms, historical figures and cultural skies, each drawn over its real stars. Open any of them in 3D and the familiar shape falls apart into deep space, because a constellation is a line of sight rather than a thing. Astrelia computes all of it on your device from catalogs that ship inside the app. No account, no subscription, no ads, no tracking, and no network needed to use it. Every dataset, algorithm and image behind it is credited in About → Sources. Astrelia has a sister app, Selenia, which reads the same real sky the astrological way.