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🌎  Greenwich, United Kingdom [change]

Comet C/2021 E3 (ZTF)

Comet C/2021 E3 (ZTF) is currently in the constellation of Ophiucus. The current Right Ascension of Comet C/2021 E3 (ZTF) is 18h 35m 20s and the Declination is +10° 58’ 08” (topocentric coordinates computed for the selected location: Greenwich, United Kingdom [change]). The current estimated magnitude of Comet C/2021 E3 (ZTF) is 15.38 (JPL) while the latest observed magnitude is 16.2 (COBS).

Summary of key facts about Comet C/2021 E3 (ZTF) [tip: you can also create a Quick Access page for this data if you access it frequently and would like to have a simpler view]:

18h 35m 20s
+10° 58’ 08”
  • C/2021 E3 (ZTF) is above the horizon from Greenwich, United Kingdom [change].
  • It is visible looking in the South-East direction at an altitude of 39° above the horizon.
  • Given its current magnitude, C/2021 E3 (ZTF) is visible only through long exposure photography.
  • See also C/2021 E3 (ZTF) rise and set times.
  • 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.

Additional information about Comet C/2021 E3 (ZTF) available on TheSkyLive:

Available Resources

Comet C/2021 E3 (ZTF) Position and Finder Charts

Below we provide Comet C/2021 E3 (ZTF) 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.

Map showing Comet C/2021 E3 (ZTF) in Ophiucus on October, 16 2021
Field of view: 50x30 degrees
View fullscreen
Map showing Comet C/2021 E3 (ZTF) in Ophiucus on October, 16 2021
Field of view: 10x6 degrees
View fullscreen
 = visible to the naked eye
 = binocular, brighter than 10th magnitude
= current altitude ≥ 30°   = current altitude < 30°   = below the horizon
Location: Greenwich, United Kingdom [change]

Higher precision deep sky finder chart, 60 arcmin wide, showing where Comet C/2021 E3 (ZTF) is right now. Click on the image to see a more detailed fullscreen tracker view.

C/2021 E3 (ZTF)
RA: 18h 35m 20s
Dec: +10° 58’ 08”
Deep sky finder chart for Comet C/2021 E3 (ZTF)
Field of view: 60x40 arcmins
View fullscreen

Also check out Where is Comet C/2021 E3 (ZTF)?, a page that provides all the information needed to find Comet C/2021 E3 (ZTF) in the sky and additional links to sky charts.

Comet C/2021 E3 (ZTF) Distance from Earth

The distance of Comet C/2021 E3 (ZTF) from Earth is currently 507,921,322 kilometers, equivalent to 3.395244 Astronomical Units. Light takes 28 minutes and 14.2432 seconds to travel from Comet C/2021 E3 (ZTF) and arrive to us.

28 minutes and 14.2432 seconds

The following chart shows the distance of Comet C/2021 E3 (ZTF) 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.

Distance of Comet C/2021 E3 (ZTF) from Earth between January 2013 and December 2100

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 E3 (ZTF) from Earth is also available as a real time updated value in the Live Position and Data Tracker.

Closest approach of Comet C/2021 E3 (ZTF) to Earth

Between January 2013 and December 2100, the closest approach of Comet C/2021 E3 (ZTF) to Earth happens on Wed Jun 1 2022 at a distance of 1.214462 Astronomical Units, or 181,680,939 kilometers:

Wed Jun 1 2022

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

Comet C/2021 E3 (ZTF) brightness

The current visual magnitude of Comet C/2021 E3 (ZTF) is 15.38.


The observed magnitude and coma diameter values are derived from the Comet Observers Database by averaging the values reported in recent observations (more recent than 4 days), when available. The Estimated Magnitude comes from the JPL Horizons ephemerides service and might be inaccurate given the highly dynamic and unpredictable behavior of comets. When available, please refer to the Observed Magnitude value and consider the Estimated 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.

The following chart is the predicted light curve (visual magnitude as a function of time) of Comet C/2021 E3 (ZTF), 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.

Predicted magnitude of Comet C/2021 E3 (ZTF) between January 2013 and December 2100

Comet C/2021 E3 (ZTF) rise and set times

Location: Greenwich, United Kingdom [change]
Latitude: 51° 28’ 47” N
Longitude: 0° 00’ 00” E
Timezone: Europe/London

Today's Comet C/2021 E3 (ZTF) rise, transit and set times from Greenwich, United Kingdom [change] are the following (all times relative to the local timezone Europe/London):

Azimuth: 79.0°
Max altitude: 49.5°
Azimuth: 280.8°

The rise and set times are defined as the time at which the upper limb of Comet C/2021 E3 (ZTF) touches the horizon, considering the effect of the atmospheric refraction. As the atmospheric conditions cannot be modeled precisely the times reported here should be considered correct with an approximation of few minutes.

Comet C/2021 E3 (ZTF) Orbital Elements

The following table lists the orbital elements of Comet C/2021 E3 (ZTF) at epoch 01 June 2021 00:00 UTC (JD: 2459367.5). Source: JPL Small-Body Database

Element Symbol Value
Orbit eccentricity e 1.00049963
Orbit inclination i 112.56846631°
Perihelion distance q 1.77731132 AU
265,881,990 km
Aphelion distance Q n.a.
Semi-major axis a n.a.
Orbital period period n.a.
Date of perihelion transit Tp 2022-Jun-11 23:12:15
2,459,742.4669 JD
Argument of perihelion peri 228.85511512973°
Longitude of the ascending node node 104.45771799794°
Mean anomaly M -0.0017418958297581°
Mean motion n 0.00000465°/day

Visualization of Comet C/2021 E3 (ZTF) Orbit

This 3d orbit diagram is a feature of our 3D Solar System Simulator and shows the orbit of Comet C/2021 E3 (ZTF) with respect of the Sun and the orbits of the major planets. The position of Comet C/2021 E3 (ZTF) 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 E3 (ZTF)
View Comet C/2021 E3 (ZTF) in the 3D Solar System Simulator

Comet C/2021 E3 (ZTF) 15 Days Ephemeris

The following table lists the ephemerides of Comet C/2021 E3 (ZTF) 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 E3 (ZTF) in our Online Planetarium at the chosen date.

Date Right AscensionR.A. DeclinationDec. MagnitudeMag Constellation
2021 Oct 09 18h 35m 44s +13° 27’ 59” 15.49 Hercules
2021 Oct 10 18h 35m 38s +13° 07’ 51” 15.47 Hercules
2021 Oct 11 18h 35m 31s +12° 47’ 53” 15.46 Hercules
2021 Oct 12 18h 35m 26s +12° 28’ 00” 15.45 Hercules
2021 Oct 13 18h 35m 22s +12° 08’ 13” 15.43 Hercules
2021 Oct 14 18h 35m 21s +11° 48’ 36” 15.42 Ophiucus
2021 Oct 15 18h 35m 20s +11° 29’ 04” 15.40 Ophiucus
2021 Oct 16 18h 35m 20s +11° 09’ 42” 15.39 Ophiucus
2021 Oct 17 18h 35m 21s +10° 50’ 26” 15.37 Ophiucus
2021 Oct 18 18h 35m 23s +10° 31’ 18” 15.36 Ophiucus
2021 Oct 19 18h 35m 26s +10° 12’ 18” 15.34 Ophiucus
2021 Oct 20 18h 35m 31s +09° 53’ 26” 15.33 Ophiucus
2021 Oct 21 18h 35m 36s +09° 34’ 41” 15.31 Ophiucus
2021 Oct 22 18h 35m 44s +09° 16’ 05” 15.30 Ophiucus