A short-period comet that goes round the Sun every 6.4 years, at perihelion about April 2028
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.
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.
The forecast comes from past returns (2009, 2015, 2021): a law fitted to 161 eye estimates before perihelion and 413 after, with the Earth's distance at the time removed and this return's put in. Comets do change between returns.
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.
67P/Churyumov-Gerasimenko passes closest to the Sun (perihelion) about 9 April 2028, at 1.212 au, where 1 au is the Earth's distance from the Sun. One orbit takes 6.43 years. The orbit is tilted 3.9 degrees to the Earth's and its eccentricity is 0.6495 (0 is a circle, 1 an open curve).
Orbit: NASA/JPL Horizons osculating elements, solution JPL#K284/1, 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.
67P/Churyumov-Gerasimenko is a short-period comet that goes round the Sun every 6.4 years. The "P" in 67P marks a periodic comet, and the number is the order in which its return was first confirmed.
Brightest eye estimate reported to COBS on each past return: 2009: magnitude 9.3, 53 days after perihelion, 1.40 au from the Sun and 1.92 au from Earth; 2015: magnitude 11.1, 40 days after perihelion, 1.33 au from the Sun and 1.79 au from Earth; 2021: magnitude 7.4, 31 days after perihelion, 1.27 au from the Sun and 0.43 au from Earth. How bright a return looks depends as much on how near the Earth it passes as on the comet.
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. "Forecast" means: Not measured yet this return. Based on how this comet behaved on past returns.
Gear rungs and ranges are estimates for a typical observer: your eyes, your sky and the night will differ.