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TimezoneEurope/London
Sunrise: 4:51 
Transit: 13:04 
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Comet 110P/Hartley

Below the horizon.  Rise: 21:23 | Tran: 1:12 | Set: 4:56
Alt: -41.18°   Az: 283.80°   Direction: West-North-West

Comet 110P/Hartley is in the constellation of Sagittarius, at a distance of 555,749,003.0 kilometers from Earth. The current Right Ascension is 19h 01m 17s and the Declination is -23° 47’ 20” (apparent coordinates). The estimated magnitude of comet 110P/Hartley, computed using JPL Horizons's data, is 25.21).

Finder Charts

The sky charts below show, at different resolutions, the position of comet 110P/Hartley in the sky. Click on each chart to access the interactive star map tool.

Star map showing the position of comet 110P/Hartley in the constellation of Sagittarius on F, d Y. Field of view: 50x30 degrees. View interactive star map.
Star map showing the position of comet 110P/Hartley in the constellation of Sagittarius on F, d Y. Field of view: 15x9 degrees. View in interactive star map.

The following map uses photographic imagery from the Digitized Sky Survey (DSS) to realistically visualize the precise position of comet 110P/Hartley against the stars in the background. The horizontal size of the map measures 60 arcminutes. Click on the image to access a more detailed full-screen view.

110P/Hartley
RA: 18h 59m 44s
Dec: -23° 49’ 33”
Simplified high-resolution deep sky chart showing the current position of comet 110P/Hartley. Field of view: 60 x 40 arcminutes. Go to the dedicated page

Equatorial Coordinates

Apparent

19h 01m 17s
-23° 47’ 20”
08h 27m 57s
03h 29m 15s

J2000

18h 59m 44s
-23° 49’ 33”

Additional Information

Sagittarius
n/a
n/a
n/a
n/a
25.21

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

The following table lists today's rise, transit and set times of comet 110P/Hartley from Greenwich, UK (all times relative to the local timezone Europe/London):

Azimuth: 113.8°
Max altitude: 14.7°
Azimuth: 246.2°

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.

Distance from Earth

The distance of comet 110P/Hartley from Earth is currently 555,749,003.0 kilometers, equivalent to 3.7149526287 Astronomical Units. Light takes 30m 53.779s to travel from comet 110P/Hartley and arrive to us.

555,749,003.0
3.7149526287
30m 53.779s

The following graph shows the distance of comet 110P/Hartley from Earth as a function of time. In the chart the distance is measured in Astronomical Units and the data is sampled with an interval of 1 day.

Chart of the distance of comet 110P/Hartley from Earth in Astronomical Units (au)
Note: The values in this chart may not be entirely accurate around the time of closest approach for objects passing very close to Earth at high speed (e.g., Near-Earth Objects).

The value of the distance of 110P/Hartley from Earth is also available as a real time updated value in the live position tracker.

Closest Approach to Earth

In the period between January 1, 2000 and December 31, 2099, the closest approach of comet 110P/Hartley to Earth happened on Wednesday 31 December 2014 at a distance of 1.494126 Astronomical Units, or 223,518,038 kilometers:

Wednesday 31 December 2014
223,518,038
1.494126

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

Light Curve

The following chart shows the light curve of comet 110P/Hartley, i.e., its apparent magnitude as a function of time. The curve is calculated using the latest ephemerides provided by JPL Horizons. The magnitude data is sampled with the interval of 2 days. Because of this sampling, inaccuracies may occur for objects that have large variations of brightness over a few days. For comets, large discrepancies can arise between the calculated brightness and the observations due to their highly dynamic, and not always precisely predictable, behavior.

Chart of the magnitude of comet 110P/Hartley as a function of time

Orbital Elements

The following table lists the orbital elements of comet 110P/Hartley at epoch May, 07 2018 00:00 UTC (JD: 2458246.5). Source: JPL Small-Body Database

Element Symbol Value
Orbit eccentricity e 0.31628027
Orbit inclination i 11.69836175°
Perihelion distance q 2.46445016 AU
368,676,497 km
Aphelion distance Q 4.74449837 AU
709,766,855 km
Semi-major axis a 3.60447426 AU
539,221,676 km
Orbital period period 6.8434 years
2,499.5471 days
Date of perihelion transit Tp December 16, 2014
2,457,008.1774 JD
Next perihelion transit October 20, 2021
2,459,507.7245 JD
Argument of perihelion peri 167.39561172405°
Longitude of the ascending node node 287.52957296521°
Mean anomaly M 178.35076247938°
Mean motion n 0.14402609°/day

Orbit Visualization

The following chart is a 3D animated visualization of the orbit of comet 110P/Hartley relative to the other major objects in the Solar System. You can access more advanced features using our 3D Solar System Viewer.

15 Days Ephemeris

The following table lists the ephemerides of comet 110P/Hartley 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
Jun 27 2025 19h 06m 28s -23° 48’ 18” 25.22 Sagittarius
Jun 28 2025 19h 05m 46s -23° 48’ 13” 25.22 Sagittarius
Jun 29 2025 19h 05m 04s -23° 48’ 07” 25.22 Sagittarius
Jun 30 2025 19h 04m 22s -23° 48’ 00” 25.21 Sagittarius
Jul 01 2025 19h 03m 40s -23° 47’ 52” 25.21 Sagittarius
Jul 02 2025 19h 02m 57s -23° 47’ 44” 25.21 Sagittarius
Jul 03 2025 19h 02m 14s -23° 47’ 34” 25.21 Sagittarius
Jul 04 2025 19h 01m 32s -23° 47’ 24” 25.21 Sagittarius
Jul 05 2025 19h 00m 49s -23° 47’ 12” 25.20 Sagittarius
Jul 06 2025 19h 00m 06s -23° 47’ 00” 25.20 Sagittarius
Jul 07 2025 18h 59m 23s -23° 46’ 46” 25.20 Sagittarius
Jul 08 2025 18h 58m 40s -23° 46’ 32” 25.20 Sagittarius
Jul 09 2025 18h 57m 57s -23° 46’ 17” 25.20 Sagittarius
Jul 10 2025 18h 57m 15s -23° 45’ 59” 25.20 Sagittarius

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