Where every numberon POLARIS comes from

The Earth Observatory Natural Event Tracker curates events from agencies such as InciWeb and IRWIN for US wildfires, the Joint Typhoon Warning Center and NOAA for storms, and the Smithsonian for volcanoes. Each event carries dated positions; a storm carries one per advisory, which is what the globe draws as its track and what the timeline replays.

EONET is curated, not instant. A fire may appear hours or days after ignition, and an event can stay open long after its last update. POLARIS shows events by their last reported observation inside the window you choose.

Every earthquake of magnitude 2.5 or more worldwide, from the USGS Earthquake Hazards Program’s real-time feed, with the previous week from its event service. Each carries the USGS magnitude type, depth, review status, tsunami flag and PAGER alert level exactly as published.

“Automatic” solutions come from algorithms and are revised when a seismologist reviews them, so a magnitude can change after we show it.

Positions broadcast by aircraft transponders (ADS-B and Mode S) and picked up by receivers that OpenSky’s volunteers run. POLARIS uses anonymous access, which allows one worldwide snapshot about every 15 minutes, so an aircraft on the globe is where it was at the snapshot time shown beside it, not where it is now.

Coverage follows the receivers: dense over Europe and North America, thin over oceans, Africa and parts of Asia. Aircraft that do not broadcast, or fly out of every receiver’s range, do not appear. We show only the broadcast identifiers and never look up owners, passengers or flight histories. The short trail on a selected aircraft joins only the snapshots this server saw, kept in memory for at most eight snapshots.

Orbital element sets for space stations, the brightest satellites, and weather, GPS and science missions. Positions are SGP4 estimates computed in your browser, with the element epoch shown beside each one. They are estimates from a model, not observations.

By day the Earth is Sentinel-2 cloudless 2024 by EOX IT Services, a 10 m mosaic made from Copernicus Sentinel-2 data (CC BY-NC-SA 4.0, used here non-commercially); the night side shows VIIRS city lights from the 2016 Black Marble composite. Optional layers add the latest daily VIIRS true-colour swaths, GOES and Himawari cloud infrared every ten minutes, and GPM IMERG precipitation estimates, each labelled with the time GIBS published it. The pictures beside events are VIIRS true colour for the day of observation.

“Weather here now” is Open-Meteo’s blend of national weather models for that point and that hour, not a reading from a station. Place search uses Open-Meteo’s geocoding of GeoNames. Both are called only when you ask, and cached briefly so repeated questions do not reach the provider.

Natural events: NASA Earth Observatory Natural Event Tracker (EONET). Earthquakes: U.S. Geological Survey. Aircraft: The OpenSky Network, opensky-network.org. Orbital elements: CelesTrak. Base imagery: Sentinel-2 cloudless by EOX (contains modified Copernicus Sentinel data 2024). Other imagery: we acknowledge the use of imagery from NASA’s Global Imagery Browse Services (GIBS), part of NASA’s Earth Science Data and Information System (ESDIS). Weather and geocoding: Open-Meteo.com (CC BY 4.0) and GeoNames. Borders and place names: Natural Earth. Globe engine: CesiumJS. Icons: Lucide.