APOD Explorer vs Sideris

Every day, NASA publishes a new astronomy picture or video, with an explanation written by a professional astronomer. APOD Explorer brings it to you with an experience built for exploring the universe, not just looking at it. THE FULL ARCHIVE SINCE 1995 Over 11,000 photos and videos, from the very first APOD to today. Full-text search across titles and explanations, curated tag collections (galaxies, nebulae, eclipses, Earth from space, and many more), and an "On This Day" section showing what was published on this date across the years. READINGS TAILORED TO YOU, ON DEVICE With Apple Intelligence, every explanation can be generated at different reading levels: quick, general, for kids, or for experts. NASA's original explanation can also be translated right on your device — nothing is sent to any server. FAVORITES THAT SYNC Save the photos you love and access them from any of your devices through iCloud. No one else can see them. WIDGETS AND LOCK SCREEN Two widgets — "Picture of the Day" and "Today's Sky" — that refresh themselves every morning, on the Lock Screen too. SHARE WHAT YOU DISCOVER Share the photo or, when the day's APOD is a video, a poster generated from it, straight from the detail view or from the widgets extension. NO ACCOUNTS, NO ADS, NO TRACKING APOD Explorer doesn't require sign-up and doesn't show ads. If you enjoy the app, you can leave a voluntary tip from Settings — a gesture of support that never unlocks features. A daily window into the universe, with NASA's complete archive always in your pocket.

Sideris is a plate solver for astrophotography with simple gear: a camera, a lens or a telescope, and a star tracker without go-to functionality. You aim at a galaxy and take a test shot, but the camera's screen only shows stars. Is your target in the frame, or just outside it? Take a photo of the screen with your phone (or tablet), and Sideris tells you exactly where your camera is pointing. Your shot appears on the interactive sky map, next to the target you are aiming for, so you know which way to move. No go-to mount, no laptop and no internet needed at your dark site. HOW IT WORKS 1. Take a test shot with your camera. 2. Photograph the camera's screen with your phone, or import the photo itself. 3. Crop it, and Sideris solves it in seconds, right on your device. 4. See your photo on the sky map, and how far you are from your target. PLATE SOLVING, FULLY OFFLINE • Solving runs on your phone, so it works where there is no signal. • Most photos solve with nothing but the picture. If one struggles, add your sensor size, focal length or target to help it. • From camera lenses to telescopes of about 1,200 mm on a full-frame camera. • A solve that fails does not use up a free solve. FRAME YOUR SHOT Add your cameras and your lenses or telescopes, and the framing tool shows your exact field of view on the sky map. Turn the frame to match your camera and plan the composition before you shoot. MORE THAN 21,000 DEEP-SKY OBJECTS • Messier, Caldwell, Herschel 400, NGC and IC, plus Sharpless, Barnard and Lynds nebulae, planetary nebulae, supernova remnants, star clusters and galaxy groups. • Show the 500 best known, the 2,500 within reach of a camera lens, or all of them. • Search any object by name or number, filter by type, catalog, magnitude, size or altitude, and sort the list by what matters tonight. • Every object has an altitude curve for the night, and the 110 Messier objects have NASA and ESA photographs. AN INTERACTIVE SKY MAP • 364,000 stars, the planets, and the Moon in its real phase. • Point your phone at the sky and the map follows. Select an object, and arrows guide you to it. • Constellation lines, an equatorial or azimuthal grid, and the sky at any date and time. TOOLS FOR THE FIELD • Polar scope: a Polaris reticle for the polar alignment of your star tracker. • Night mode: turns on at sunset to protect your night vision, with an all-red option for the darkest sites. • Moon phase calendar: phase, illumination, moonrise and moonset for every night. • White screen: a dimmable panel for flat frames. • Location from the GPS, or chosen on an offline world map. LEARN IT ON REAL PHOTOS A guided tutorial walks you through two real solves on example photos, with an animation of the whole process. ONE PURCHASE, NO SUBSCRIPTION Your first 10 solves are free. After that, a single one-time purchase unlocks unlimited plate solving on all your devices. No subscription, no ads, no account. I built Sideris for my own nights under the stars, after spending too many hours trying to find my targets. I hope it can help you take beautiful photos as well. Clear skies!