Live alerts
Know when the clear window opens, the Moon sets, or an ISS pass begins.
StellaKnow what’s worth the drive tonight
Coming soonStella for iPhone — join the launch list
Know what’s worth going outside for tonight.
Stella turns clarity, moonlight, and darkness into one plan: when to go, where to go, and what to see.
442+DARK-SKY DESTINATIONS
75COUNTRIES MAPPED
1–9LIVE BORTLE LAYER
Tonight score & best window Bortle dark-sky map Live Activities & alerts Point-and-identify AR14 bookable stays
Built on trusted sky data
- NASA
- NOAA SWPC
- Celestrak
- The Space Devs
- DarkSky International
- Open-Meteo
Tonight, live
See tonight for your own sky.
Search a city or dark-sky place. Stella combines live clouds, transparency, smoke, wind, moonlight, astronomical darkness, and nearby dark-sky quality into one decision.
Tonight atCherry Springs, PA
Moonlight and darkness are computed for this location. The live score adds cloud, humidity, visibility, smoke, haze, and wind.
Tonight score…
–out of 100
Best moon-free windowMoon up most of the night
Loading live sky conditions…
CloudsLoading…
TransparencyLoading…
Smoke & hazeLoading…
WindLoading…
Moonlight–
Moon-free dark–
Darkness–
Nearest dark site–
How it works
From couch to clear sky in three steps.
Stella turns a pile of forecasts into one decision — then takes you from the verdict to the dark site to the stars themselves.
- 1
Check tonight's score
Open Stella and one number tells you if the sky is worth it — clouds, transparency, seeing, moonlight, and darkness, weighed together.
- 2
Find your dark site
The Bortle dark-sky map shows the darkness near you and routes you to the closest genuinely dark spot — parks, reserves, and observing sites.
- 3
Point & identify
Raise your phone and the AR sky map names the stars, planets, and satellites overhead — then drops into a full planetarium to explore.
Real dataBuilt on the live night sky
A hundred billion stars — and the few worth chasing tonight.
Stella models the real sky overhead: the stars, planets, satellites, meteor showers, and dark-sky places above you right now — then tells you what’s actually worth going outside for. Tap a landmark to explore it in 3D.
Built for the field
One decision, then the tools to act on it.
Point and identify
Raise your phone to name stars, planets, constellations, and satellites.
Dark-sky routing
Compare Bortle class, distance, and nearby observing places before leaving.
Explore Stella
Go deeper when the night becomes a trip.
Dark-sky places490 parks, reserves, and observing sites.Astronomy staysHotels and lodges where the sky is the amenity.Sky eventsEclipses, meteor showers, launches, and passes.Trip boardsKeep sites, stays, timing, and gear together.CertificationHow Stella verifies darkness and sky access.GuidesPractical field notes for better nights outside.
Stella event supportComing soon
Bring the sky to your event.
Stella is developing event support for community star parties, schools, festivals, private gatherings, hospitality programs, and brand events. Register your interest while we shape the equipment, facilitation, media, and app experience.
Star partiesSolar observingPrivate eventsCommunity programs
Night sky
Staffed telescope observing
Stella plans to bring telescopes, shape a target list for the date and location, and help first-time observers enjoy the view without needing their own gear.
Daytime
Solar telescope experiences
The planned service can add a safe daytime astronomy program with purpose-built solar telescopes, guided viewing, and approachable science for your audience.
Storytelling
Photo and video coverage
Planned coverage can document the people, telescopes, and sky for event recaps, social clips, interviews, and partner storytelling.
In the app
Stella Event Mode + Ultra window
The planned app experience gives registered attendees one event hub plus temporary Ultra access during an agreed event window.
Pricing
Start free. Go deeper when the sky pulls you in.
Free handles tonight. Pro and Ultra unlock deeper planning and imaging tools.
Free
$0
Free forever
Everything to decide on tonight.
- Tonight score & best window
- 3-day conditions forecast
- AR identify & planetarium
- Saved sites & observing log
Preview what it unlocks
Download StellaMost popular
Pro
$39.99/ yearSave 16%
Just $3.99/mo, billed annually
For the regular stargazer.
- Everything in Free
- 10-day & hourly astronomy forecasts
- Dark-sky map with Bortle layer & routing
- Live Activities, alerts & widgets
- Stella Destinations & trip boards
Preview what it unlocks
Go ProUltra
$99/ yearSave 8%
Just $8.99/mo, billed annually
For astrophotographers & rigs.
- Everything in Pro
- Telescope & mount workflows
- Plate-solving & imaging planner
- Advanced camera & capture tools
- Priority new-feature access
Preview what it unlocks
Get UltraFAQ
Questions, answered.
Is Stella free?
Yes. The Tonight score, best observing window, a 3-day conditions forecast, AR identify, the planetarium, and your saved sites are all free, forever. Pro and Ultra unlock deeper forecasts, the dark-sky map, alerts, and imaging tools.
What's the difference between Pro and Ultra?
Pro is for the regular stargazer — 10-day and hourly astronomy forecasts, the dark-sky map with the Bortle layer and routing, Live Activities, alerts, widgets, Destinations, and trip boards. Ultra adds the serious imaging stack: telescope and mount control, plate-solving, an imaging planner, and advanced capture tools.
Why is the web price cheaper than the App Store?
Subscribing on the web skips the app-store fee, so we pass the savings on — up to 43% off. Your membership unlocks automatically in the app the next time you open it; nothing extra to set up.
How accurate is the Tonight score?
Stella blends astronomy-grade cloud, transparency, and seeing forecasts with precisely computed moonlight and the astronomical-darkness window for your exact location. Like any forecast it isn't a guarantee, but it's tuned to answer one question well: is tonight worth the drive?
Does it work without signal at a dark site?
Yes. Trip boards bundle your targets, timing, gear, and the night's plan so the essentials work when there's no signal. The AR sky map and planetarium also run from on-device ephemeris.
Can I control my telescope and camera?
On the Ultra tier, yes — Stella includes mount and telescope workflows, plate-solving to confirm where you're pointed, an imaging planner, and advanced camera and capture tools.
What devices does Stella run on?
iPhone and iPad, with companion experiences on Apple Watch, Mac, and CarPlay — so the plan follows you from the couch to the car to the field.
Where does Stella's sky data come from?
From trusted public sources — NASA, NOAA's Space Weather Prediction Center for aurora, Celestrak and The Space Devs for satellites and launches, plus astronomy-grade weather and dark-sky datasets — all combined into one plan.
Tonight is either worth it, or it isn’t.
Stella tells you which—and exactly where to go when it is.