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public Observing fromLocation: Greenwich, United Kingdom edit_location_alt
north SunriseRise: 7:54  
clear_day Transit: 11:51  
SunsetSet: 15:49 south
wb_twilight Nautical TwilightWhat's Visible Now?
Comets » 

Comet C/2021 P4 (ATLAS)

Altitude: -61.9°   Azimuth: 119.6°   Direction: East-South-East

Comet C/2021 P4 (ATLAS) is currently in the constellation of Indus.

The current Right Ascension of Comet C/2021 P4 (ATLAS) is 21h 14m 45s and the Declination is -56° 38’ 20” (topocentric coordinates computed for the selected location: Greenwich, United Kingdom edit_location_alt). The current estimated magnitude of Comet C/2021 P4 (ATLAS) is 21.10 (JPL).

21h 14m 45s
-56° 38’ 20”

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.

Today's rise, transit and set times of Comet C/2021 P4 (ATLAS) from Greenwich, United Kingdom edit_location_alt (all times relative to the local timezone Europe/London):

Today Comet C/2021 P4 (ATLAS) is not visible from Greenwich, United Kingdom edit_location_alt

  • C/2021 P4 (ATLAS) is below the horizon from Greenwich, United Kingdom edit_location_alt.
  • Given its current magnitude, C/2021 P4 (ATLAS) is visible only through long exposure photography.
  • Go to interactive sky chart

If you need to access this information frequently for your observations, you can create a simple customized Quick Access page, so that you can easily bookmark it in your browser favorites or add a shortcut to your mobile phones' home screen.

Available Resources

Comet C/2021 P4 (ATLAS) Position and Finder Charts

Below we provide Comet C/2021 P4 (ATLAS) finder charts showing where the object is right now in the sky with respect to the brightest stars. The first finder chart has a field of view of 50 degrees, while the second one has a field of view of 10 degrees. Click on each finder chart to access a full screen interactive Online Planetarium.

Finder chart of C/2021 P4 (ATLAS) in Indus on December,11 2023
Map showing Comet C/2021 P4 (ATLAS) in Indus on December, 11 2023
Field of view: 50x30 degrees
View fullscreen
Finder chart of C/2021 P4 (ATLAS)
Map showing Comet C/2021 P4 (ATLAS) in Indus on December, 11 2023
Field of view: 10x6 degrees
View fullscreen

Higher precision deep sky finder chart, 60 arcmin wide, showing where Comet C/2021 P4 (ATLAS) is right now. Click on the image to see a more detailed fullscreen tracker view.

C/2021 P4 (ATLAS)
RA: 21h 14m 45s
Dec: -56° 38’ 20”
Deep sky finder chart for Comet C/2021 P4 (ATLAS)
Field of view: 60x40 arcmins
View fullscreen

Also check out Where is Comet C/2021 P4 (ATLAS)?, a page that provides all the information needed to find Comet C/2021 P4 (ATLAS) in the sky and additional links to sky charts.

Comet C/2021 P4 (ATLAS) Distance from Earth

The distance of Comet C/2021 P4 (ATLAS) from Earth is currently 974,867,569 kilometers, equivalent to 6.516587 Astronomical Units. Light takes 54 minutes and 11.8082 seconds to travel from Comet C/2021 P4 (ATLAS) and arrive to us.

54 minutes and 11.8082 seconds

The following chart shows the distance of Comet C/2021 P4 (ATLAS) 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.

Chart of the distance of Comet C/2021 P4 (ATLAS) from Earth in Astronomical Units (au)

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 P4 (ATLAS) from Earth is also available as a real time updated value in the Live Position and Data Tracker.

Closest Approach of Comet C/2021 P4 (ATLAS) to Earth

Between 1 January 2013 and 30 December 2100, the closest approach of Comet C/2021 P4 (ATLAS) to Earth happens on Wed Jul 13 2022 at a distance of 1.957861 Astronomical Units, or 292,891,805 kilometers:

Wed Jul 13 2022

NOTE: values for the closest approach are computed with a sampling interval of 1 day.

Comet C/2021 P4 (ATLAS) Brightness and Light Curve

The following chart is the predicted light curve (visual magnitude as a function of time) of Comet C/2021 P4 (ATLAS), 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.

Chart of the magnitude of Comet C/2021 P4 (ATLAS) as a function of time

Comet C/2021 P4 (ATLAS) Orbital Elements

The following table lists the orbital elements of Comet C/2021 P4 (ATLAS) at epoch 09 January 2022 00:00 UTC (JD: 2459589.5). Source: JPL Small-Body Database

Element Symbol Value
Orbit eccentricity e 0.99656500
Orbit inclination i 56.31079673°
Perihelion distance q 1.08046264 AU
161,634,911 km
Aphelion distance Q 628.00921043 AU
93,948,840,848 km
Semi-major axis a 314.54483653 AU
47,055,237,879 km
Orbital period period 5,578.6876 years
2,037,615.6490 days
Date of perihelion transit Tp 2022-Jul-30 09:00:37
2,459,790.8754 JD
Next perihelion transit 7601-May-19 00:35
4,497,406.5245 JD
Argument of perihelion peri 175.82241494569°
Longitude of the ascending node node 348.09486623284°
Mean anomaly M 359.96442157471°
Mean motion n 0.00017668°/day

Visualization of Comet C/2021 P4 (ATLAS) Orbit

This 3d orbit diagram is a feature of our 3D Solar System Simulator and shows the orbit of Comet C/2021 P4 (ATLAS) with respect of the Sun and the orbits of the major planets. The position of Comet C/2021 P4 (ATLAS) and the planets along their orbits in this diagram accurately represents the current configuration of the objects in the Solar System. This is an experimental feature and it requires a WebGL enabled browser. Please provide us feedback!

Orbit Diagram of Comet C/2021 P4 (ATLAS)
View Comet C/2021 P4 (ATLAS) in the 3D Solar System Simulator

Comet C/2021 P4 (ATLAS) 15 Days Ephemeris

The following table lists the ephemerides of Comet C/2021 P4 (ATLAS) computed for the past and next 7 days, with a 24 hours interval. Click on each row of the table to locate Comet C/2021 P4 (ATLAS) in our Online Planetarium at the chosen date.

Date Right AscensionR.A. DeclinationDec. MagnitudeMag Constellation
2023 Dec 04 21h 09m 07s -57° 37’ 36” 21.02 Indus
2023 Dec 05 21h 09m 52s -57° 29’ 20” 21.03 Indus
2023 Dec 06 21h 10m 37s -57° 21’ 06” 21.04 Indus
2023 Dec 07 21h 11m 24s -57° 12’ 55” 21.05 Indus
2023 Dec 08 21h 12m 10s -57° 04’ 47” 21.06 Indus
2023 Dec 09 21h 12m 56s -56° 56’ 43” 21.08 Indus
2023 Dec 10 21h 13m 44s -56° 48’ 41” 21.09 Indus
2023 Dec 11 21h 14m 30s -56° 40’ 41” 21.10 Indus
2023 Dec 12 21h 15m 19s -56° 32’ 45” 21.11 Indus
2023 Dec 13 21h 16m 06s -56° 24’ 52” 21.12 Indus
2023 Dec 14 21h 16m 55s -56° 17’ 03” 21.13 Indus
2023 Dec 15 21h 17m 44s -56° 09’ 15” 21.14 Indus
2023 Dec 16 21h 18m 33s -56° 01’ 32” 21.15 Indus
2023 Dec 17 21h 19m 23s -55° 53’ 52” 21.16 Indus