Comet C/2021 S3 (PANSTARRS)
Comet C/2021 S3 (PANSTARRS) is in the constellation of
Andromeda,
at a distance of
Finder Charts
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High precision deep sky finder chart, 60 arcmin wide, showing where Comet C/2021 S3 (PANSTARRS) is right now. Click on the image to see a more detailed fullscreen tracker view.


Also check out Where is Comet C/2021 S3 (PANSTARRS)?, a page that provides all the information needed to find Comet C/2021 S3 (PANSTARRS) in the sky and additional links to sky charts.
Celestial Coordinates
Apparent
J2000
Additional Information
The observed values of Magnitude, Coma Diameter and Tail Length are derived from the most recent observation recorded at the Comet Observers Database. The value of Predicted Magnitude comes from the JPL Horizons ephemerides service and, in the case of comets, might be inaccurate given the highly dynamic and unpredictable behavior of these objects. When available, please refer to the Observed Magnitude value and consider the Predicted Magnitude as a directional indication. We acknowledge with thanks the comet observations from the COBS Comet Observation Database contributed by observers worldwide and used in this table to report recent comet observations.
Rise and Set Times
Today's rise, transit and set times of Comet C/2021 S3 (PANSTARRS) from Greenwich, UK (all times relative to the local timezone Europe/London):
- C/2021 S3 (PANSTARRS) is above the horizon from Greenwich, UK.
- Right now it is placed in the North-West direction at an altitude of 13.70° above the horizon.
- Given its current magnitude, C/2021 S3 (PANSTARRS) is visible only through long exposure photography.
- Go to interactive sky chart
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Distance from Earth
The distance of Comet C/2021 S3 (PANSTARRS) from Earth is currently
The following chart shows the distance of Comet C/2021 S3 (PANSTARRS) from Earth as a function of time. In the chart the distance data is measured in Astronomical Units and sampled with an interval of 1 day.
The value of the reported distance might be somewhat inaccurate around the times of closest approach for objects passing extremely close to Earth. The value of the distance of C/2021 S3 (PANSTARRS) from Earth is also available as a real time updated value in the Live Position and Data Tracker.
Closest Approach
Between 1 January 2000 and 31 December 2099, the closest approach of Comet C/2021 S3 (PANSTARRS) to Earth happens on Fri Mar 15 2024 at a distance of 1.297866 Astronomical Units, or 194,157,991 kilometers:
NOTE: values for the closest approach are computed with a sampling interval of 1 day.
Light Curve
The following chart is the predicted light curve (visual magnitude as a function of time) of Comet C/2021 S3 (PANSTARRS), according to the most recent ephemerides data. Magnitude data is sampled with a 2 days interval and there might be inaccuracies for objects changing brightness very rapidly during the course of a few days. For comets there could be large discrepancies between the observed and predicted brightness because of their highly dynamic behaviour.
Orbital Elements
The following table lists the orbital elements of Comet C/2021 S3 (PANSTARRS) at epoch 20 February 2024 00:00 UTC (JD: 2460361.5). Source: JPL Small-Body Database
Element | Symbol | Value |
---|---|---|
Orbit eccentricity | e | 1.00024971 |
Orbit inclination | i | 58.53283988° |
Perihelion distance | q | 1.32020916 AU 197,500,480 km |
Aphelion distance | Q | n.a. |
Semi-major axis | a | n.a. |
Orbital period | period | n.a. |
Date of perihelion transit | Tp | 2024-Feb-14 17:04:47 2,460,355.2117 JD |
Argument of perihelion | peri | 6.8550833032033° |
Longitude of the ascending node | node | 215.62077864739° |
Mean anomaly | M | 1.6122560840752E-5° |
Mean motion | n | 0.00000256°/day |
View Comet C/2021 S3 (PANSTARRS) in the 3D Solar System Simulator
15 Days Ephemeris
The following table lists the ephemerides of Comet C/2021 S3 (PANSTARRS) computed for the past and next 7 days, with a 24 hours interval. Apparent celestial coordinates are provided.
Date | Right AscensionR.A. | DeclinationDec. | MagnitudeMag | Constellation |
---|---|---|---|---|
2025 May 10 | 23h 29m 51s | +38° 19’ 06” | 17.91 | Andromeda |
2025 May 11 | 23h 30m 25s | +38° 25’ 08” | 17.91 | Andromeda |
2025 May 12 | 23h 30m 59s | +38° 31’ 11” | 17.92 | Andromeda |
2025 May 13 | 23h 31m 32s | +38° 37’ 13” | 17.92 | Andromeda |
2025 May 14 | 23h 32m 05s | +38° 43’ 15” | 17.92 | Andromeda |
2025 May 15 | 23h 32m 37s | +38° 49’ 17” | 17.93 | Andromeda |
2025 May 16 | 23h 33m 09s | +38° 55’ 19” | 17.93 | Andromeda |
2025 May 17 | 23h 33m 40s | +39° 01’ 21” | 17.93 | Andromeda |
2025 May 18 | 23h 34m 10s | +39° 07’ 23” | 17.94 | Andromeda |
2025 May 19 | 23h 34m 40s | +39° 13’ 25” | 17.94 | Andromeda |
2025 May 20 | 23h 35m 09s | +39° 19’ 26” | 17.94 | Andromeda |
2025 May 21 | 23h 35m 37s | +39° 25’ 27” | 17.95 | Andromeda |
2025 May 22 | 23h 36m 05s | +39° 31’ 27” | 17.95 | Andromeda |
2025 May 23 | 23h 36m 33s | +39° 37’ 27” | 17.95 | Andromeda |
Additional Resources on TheSkyLive
- Comet C/2021 S3 (PANSTARRS): Complete reference information on TheSkyLive.com
- Where is Comet C/2021 S3 (PANSTARRS)?: Key information on locating Comet C/2021 S3 (PANSTARRS) in the sky.
- Distance from Earth: Find out how far Comet C/2021 S3 (PANSTARRS) is from Earth right now.
- How Bright is Comet C/2021 S3 (PANSTARRS)?: Current visual brightness (magnitude) and apparent size.
- Rise and Set Times: Comet C/2021 S3 (PANSTARRS)'s rise and set times from your location.
- Interactive Sky Map: planetarium-style interactive visualization of Comet C/2021 S3 (PANSTARRS)'s position in the sky.
- Live Position Tracker: high precision position tracker with deep space imagery.
- Ephemeris: 15 days Comet C/2021 S3 (PANSTARRS)'s computed ephemeris.
- Orbital elements: information about Comet C/2021 S3 (PANSTARRS) orbital parameters.
- Orbit Visualization. 3d interactive visualization showing the orbit of Comet C/2021 S3 (PANSTARRS) with respect to the major Solar System objects.