Astrochron
Astronomy through time.
See what is happening in the sky from your location.
Astrochron brings together astronomical events, object visibility, and observing information in one place. Explore the planets, Sun, Moon, International Space Station, meteor showers, and deep-sky objects, with times and observing circumstances calculated for the location you choose.
What’s up tonight
See relevant observing opportunities for the current night without searching through separate calendars or ephemerides.
Explore the sky
Planetary events
Follow the changing appearance and visibility of the planets. Astrochron tracks events such as oppositions, greatest elongations, conjunctions, planetary phases, apparent diameters, and other useful observing information.
Jupiter includes detailed timing for Great Red Spot visibility, Galilean moon transits, and shadow transits. Saturn’s page follows the changing appearance and orientation of its ring system alongside the planet’s visibility and apparent size.
The Sun and Moon
Follow lunar phases, eclipses, occultations, and the changing position of the Moon throughout the night.
Solar information includes the Sun’s changing position, sunspots, visibility, and upcoming astronomical events involving the Sun.
International Space Station
Follow the International Space Station as it moves around Earth and check its position and visibility from your location.
Astrochron provides orbital and observing information for the ISS alongside the rest of the sky.
Meteor showers
View upcoming meteor shower peaks, radiant information, and observing circumstances. Timing and sky position are shown alongside other astronomical events occurring around the same date.
Deep-sky objects
Explore galaxies, nebulae, star clusters, and other deep-sky objects. Object pages provide position and visibility information to help determine when a target is well placed from your location.
Explore the sky through time
Planetary positions, apparent diameters, phases, and visibility change continuously. The Moon moves across the sky from night to night, Jupiter rotates in less than ten hours, and the International Space Station circles Earth many times each day.
Move through time, inspect an object, or open an upcoming event to see its circumstances from your location.
Astronomy for your location
An object’s altitude, direction, rise and set times, and event visibility depend on the observer’s location.
Astrochron uses the location you select to present astronomical information in local time and show how objects and events appear from that part of Earth.