Support & frequently asked questions
SkyWatchNEO shows near-Earth asteroid flybys for the week ahead, using public tracking data published by NASA. You can browse each day's close approaches, save objects to a watchlist, and get a daily notification summarizing what's passing by.
I read every message and usually reply within a few days.
All flyby data comes from NASA's Near Earth Object Web Service (NeoWs), which is maintained by the Center for Near-Earth Object Studies at NASA's Jet Propulsion Laboratory. You can browse the same data at cneos.jpl.nasa.gov. SkyWatchNEO is an independent app and is not affiliated with, endorsed by, or sponsored by NASA or JPL.
A potentially hazardous asteroid (PHA) is one that comes within 0.05 AU (about 7.5 million km) of Earth's orbit and is larger than about 140 meters across. This classification does not mean an impact is expected or imminent — it means the object is large enough and close enough that scientists monitor it carefully. Objects flagged in the app are being tracked, not predicted to hit anything.
One Lunar Distance is the average gap between Earth and the Moon, about 384,400 km. SkyWatchNEO shows miss distances in LD by default because it gives a more intuitive sense of scale than raw kilometers. A flyby at 1 LD is very close in astronomical terms but still enormously far away. You can switch to kilometers in Settings.
SkyWatchNEO reads live data from NASA, so it needs a connection. If the list is empty or you see "Unable to load", check that you're online and pull to refresh — NASA's service is occasionally down for maintenance, and the app will pick up again once it returns.
Yes, though you shouldn't need to. The app ships with its own key and there's nothing to set up. The option exists for anyone who wants their requests to go through their own key, or in the unlikely event the app's shared allowance runs short at a busy moment.
Keys are free and take about a minute:
Your key is stored only on your device and is used solely to make requests to NASA's API. Clear the field at any time to go back to the built-in key.
Open Settings and enable hazard notifications. iOS will ask for permission the first time. Once enabled, you'll get one notification per day at 9:00 AM summarizing that day's flybys and how many are classified as potentially hazardous. Tapping it opens that day in the app.
Check that notifications are allowed for SkyWatchNEO in iOS Settings → Notifications →
SkyWatchNEO. Notifications are also skipped for days that have already passed, so if you enable
the setting late in the day the first one may not arrive until tomorrow morning. Low Power Mode
can delay the background refresh that keeps the schedule current.
Open any asteroid and save it. Saved objects appear on the Watchlist tab and stay there until you remove them. The watchlist is stored on your device only — it isn't synced to an account or backed up to a server, so it won't carry over to a new phone.
Delete the app. Everything SkyWatchNEO stores — your settings, your watchlist, and your API key if you entered one — lives on the device and is removed with it. There's no account to close and no server-side copy.
SkyWatchNEO is an educational app for general interest. It is not an emergency alerting tool and should not be relied on for safety-critical decisions. For authoritative information about near-Earth objects, consult NASA CNEOS directly.