A Halley-type comet that goes round the Sun every 33 years, at perihelion about May 2031
Not in reach from Georgetown on this return: it is forecast too faint or too low.
Not in reach from Georgetown on this return: it is forecast too faint or too low.
Tonight it does not climb 10 degrees above the horizon while the sky is dark from Georgetown.
From Lethem, under a dark interior sky: Not in reach from Lethem on this return: it is forecast too faint or too low.
Nobody has reported its brightness to COBS in the last 30 days, so every number here is a forecast.
No one has followed this comet through a return like this one, so the forecast is a catalogue estimate with a wide range.
A comet's light is spread over a fuzzy patch, so it is harder to see than a star of the same magnitude. That is why the gear rungs ask for a magnitude in hand.
55P/Tempel-Tuttle passes closest to the Sun (perihelion) about 22 May 2031, at 0.976 au, where 1 au is the Earth's distance from the Sun. One orbit takes 33 years. The orbit is tilted 162.5 degrees to the Earth's and its eccentricity is 0.9055 (0 is a circle, 1 an open curve).
Orbit: NASA/JPL Horizons osculating elements, solution JPL#J985/69, retrieved 8 October 2026. Positions on this page are computed from them in your browser and agree with JPL's own tables to half an arcminute.
The parent of the Leonid meteors of November, on a 33-year orbit.
55P/Tempel-Tuttle is a Halley-type comet that goes round the Sun every 33 years. The "P" in 55P marks a periodic comet, and the number is the order in which its return was first confirmed.
Its dust is the source of the Leonids meteors: each year the Earth crosses the trail it has left along its orbit.
Orbits: NASA/JPL Horizons (Giorgini, JD and the JPL Solar System Dynamics Group), data retrieved 2026-10-08.
Catalogue brightness laws: JPL Small-Body Database and the IAU Minor Planet Center.
Observed brightness: COBS Comet Observation Database (https://cobs.si) and its contributing observers, CC BY-NC-SA 4.0.
Data updated 8 October 2026. "Early forecast" means: A catalogue estimate. Early predictions are often wrong in both directions.
Gear rungs and ranges are estimates for a typical observer: your eyes, your sky and the night will differ.