Comets visible tonight from your location
Heard that a comet is in the sky and want to know where to look? This comets visible tonight finder takes the latest orbits of the brightest comets, works out where each one is for your place and time, and tells you in plain words: which comets are above the horizon in a dark sky, how bright they are expected to be, when they are highest and which direction to face.
Each comet gets a card with its predicted magnitude, the equipment you will probably need, altitude and compass direction at your chosen time, right ascension and declination, its distance from the Sun and Earth and the details of its orbit. A small all-sky map shows the comets that are up, with their tails pointing away from the Sun. All of the orbital maths runs in your browser; nothing about your location is sent anywhere.
How to use the Comets Visible Tonight
- Choose a Place (cities and dark-sky sites) or enter Latitude, Longitude and Time zone. Use my location reads your position only when pressed.
- Set the Night of date and the clock time for Positions at, or press Tonight, now.
- Pick how faint to go with Show comets down to: magnitude 6 for the naked eye, 9 for binoculars, 12 for a small telescope, or every comet in the list.
- Read the summary, then each card’s best time and direction; use the RA/Dec with a planetarium app or a GoTo telescope.
Comets Visible Tonight features
Real orbits
Elements from the NASA/JPL Small-Body Database, propagated with a two-body solver that handles elliptic, parabolic and hyperbolic paths.
Checked against JPL Horizons
For 12P/Pons-Brooks, C/2023 A3 (Tsuchinshan-ATLAS), C/2026 A2 (Bok) and C/2024 T5 (ATLAS), positions agree to about 0.01° and magnitudes to 0.01.
Finder directions
Best time, altitude and compass direction tonight, plus the window when the comet is at least 10° up in a dark sky.
Honest magnitudes
Brightness from the standard total-magnitude law, clearly marked as uncertain, with a hint about binoculars or telescope size.
Sky map
An all-sky view for your time with each comet’s tail direction and the Moon.
Dated data
The download date, the elements’ epoch and the orbit fit date are shown, and a warning appears when your date is far from the data.
How the positions are worked out
A comet’s orbit is described by six osculating elements: perihelion distance q, eccentricity e, inclination, longitude of the ascending node, argument of perihelion and the time of perihelion. Most bright comets move on near-parabolic paths with e close to 1, which ordinary Kepler equations handle badly, so this tool uses the universal-variable formulation with Stumpff functions — one method for ellipses, parabolas and hyperbolas.
The comet’s heliocentric position is combined with the Earth’s (from Meeus’s solar theory), corrected for light travel time and converted to astrometric J2000 right ascension and declination, then precessed to the date and turned into altitude and azimuth for your place, with refraction. Planetary perturbations are not modelled, which is why the data are refreshed regularly.
Why comet magnitudes are uncertain
Predicted brightness uses m = M1 + 5 log Δ + K1 log r, where Δ is the distance from Earth and r from the Sun in astronomical units. M1 and K1 are fitted by JPL to past observations, but comets brighten by releasing gas and dust, and that activity changes: outbursts can add several magnitudes overnight, and some comets fade or break up near perihelion. Treat every value as a guide, check recent observer reports, and remember that a comet’s light is spread over a fuzzy coma, so it looks fainter than a star of the same magnitude.
| Magnitude | What you need |
|---|---|
| Brighter than 4 | Naked eye, even from suburbs |
| 4 – 6 | Naked eye from a dark site |
| 6 – 9 | Binoculars (7×50 or 10×50) |
| 9 – 11 | Small telescope, 80–100 mm |
| 11 – 13 | 150–200 mm telescope, dark sky |
| Fainter than 13 | Large telescope or a camera |
Data source and refresh
The list is a dated snapshot of the JPL Small-Body Database, chosen as the comets predicted to reach magnitude 14 or brighter within about eight months. The date appears above the results. A newly discovered comet will not appear until the next refresh, so check news of new discoveries too. For the rest of the night sky use planets visible tonight and the star chart; the moon phase calculator shows when moonlight will wash out faint comets.
Comets Visible Tonight FAQ
Is there a comet visible tonight?
Choose your place and press Tonight, now. The summary says which comets are above the horizon in a dark sky and brighter than your chosen magnitude; if none is bright enough for the naked eye it says so.
Which direction should I look for the comet?
Each card gives the best time, the altitude in degrees and the compass direction, such as “22° in the west-northwest”. Comets near the Sun are usually low in the west after sunset or low in the east before dawn.
Can I see a comet with the naked eye?
Only when it is brighter than about magnitude 5–6 and you are away from city lights. Most comets are fainter and need binoculars or a telescope.
How accurate are the comet positions?
Near the date of the orbital elements they agree with JPL Horizons to about 0.01°, far better than a finder needs. Months away, planetary perturbations can shift them more.
Why is the predicted magnitude different from what I see?
Comet brightness depends on how much gas and dust the comet releases, which changes unpredictably. Predictions are often off by one to three magnitudes.
Does this tool use my location?
Only in your browser. The calculation is local and your coordinates are never sent anywhere.