Perigee

• perigee_find — Looks up objects by name or identifier (English or French, accents optional): planets, moons, missions beyond Earth orbit, featured science satellites, any acti
• perigee_object — Facts about an object: name, agency, country, launch date, status, mission goals and notes, identifiers (NORAD, COSPAR, Horizons), official website, sources and
• perigee_state — Position (km, ICRF/J2000 equatorial axes) and velocity (km/s) of an object at a date, relative to a centre (default: the body it orbits or stands on), with dist
• perigee_orbit — Orbit of an object: perigee and apogee altitudes (periapsis/apoapsis), period, inclination, eccentricity, semi-major axis. Earth satellites: the mean elements o
• perigee_passes — When an Earth satellite (ISS = 25544, Tiangong = 48274, Hubble = 20580, or any NORAD number) passes over a place: rise, highest point and set times with directi
• perigee_sky — What is in the sky from a place at a date (default: now): day, twilight or night; the Sun with its next rise, set and twilights; the Moon with its phase, illumi
• perigee_events — Events over a period (default: the next 30 days, at most 31): Moon phases (super and micro full Moons), lunar perigee and apogee, lunar and solar eclipses (with
• perigee_tonight — What there is to see tonight from a place (the coming night, or the current one): the night's start and end, the Moon (phase, illuminated share, rise and set),
• perigee_sky_conjunctions — Apparent close pairings seen from a place over a period (default 7 days, at most 7): the Moon and the planets with each other and with the bright stars near the
• perigee_shadow — Whether an object is in sunlight, in the penumbra or in the umbra of the body it orbits (Earth satellites: the Earth's shadow; lunar and Martian orbiters: the M
• perigee_ground_track — The path on the ground below an Earth satellite over one or two orbits: a list of points (time, latitude, longitude, height) and a GeoJSON MultiLineString split
• perigee_close_approach — The closest distance between two objects in space over a period (default 1 day, at most 1): when, how close (timed to a fraction of a second) and, for two Earth
• perigee_stats — Counts of the active satellites: total, by owner (country or organisation, e.g. US, PRC, CIS, ESA), by operator (SpaceX, OneWeb, Amazon Kuiper…), by CelesTrak g
• perigee_distance — Centre-to-centre distance between two objects at a date (km and astronomical units) and the light travel time, with the provenance of both positions. Example: f
• perigee_distance_series — Distances between two objects sampled evenly over a period (for a table or a chart), with the closest and farthest samples. The step limits their precision: use
• perigee_view — Link to Perigee showing an object (optionally at a date, paused or accelerated, followed), and an iframe snippet for a lesson page: the live 3D view without bar
• perigee_describe_view — Turns a Perigee link or embed URL (from perigee_view or a shared link) into words: a one-sentence alternative text for the image or iframe, and a description fo
• perigee_define — Student-level definitions (secondary school) of the terms shown in Perigee: NORAD number, COSPAR id, apogee and perigee, inclination, orbital period, element ep
• perigee_about — What every answer rests on: data sources and when they were fetched, the models and their typical accuracy, catalogue sizes, frame, attribution and the educatio

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