Find it in the Sky
Chose a date & time and view the position of comet C/1861 G1 (Thatcher) in the sky on our interactive planetarium.
In Evidence
Comet C/1861 G1 (Thatcher)
Comet C/1861 G1 (Thatcher) is in the constellation of Andromeda, at a distance of
Finder Charts
The sky charts below show, at different resolutions, the position of comet C/1861 G1 (Thatcher) in the sky. Click on each chart to access the interactive star map tool.
The following map uses photographic imagery from the Digitized Sky Survey (DSS) to realistically visualize the precise position of comet C/1861 G1 (Thatcher) 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.
Equatorial 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
The following table lists today's rise, transit and set times of comet C/1861 G1 (Thatcher) from Greenwich, UK (all times relative to the local timezone Europe/London):
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 C/1861 G1 (Thatcher) from Earth is currently
The following graph shows the distance of comet C/1861 G1 (Thatcher) 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.
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 C/1861 G1 (Thatcher) 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, 1900 and December 31, 2099, the closest approach of comet C/1861 G1 (Thatcher) to Earth happened on Monday 1 January 1900 at a distance of 55.191654 Astronomical Units, or 8,256,553,921 kilometers:
Note: the values for the closest approach are computed with a sampling interval of 1 day.
Light Curve
Orbital Elements
The following table lists the orbital elements of comet C/1861 G1 (Thatcher) at epoch UTC (JD: 2400920.5). Source: JPL Small-Body Database
| Element | Symbol | Value |
|---|---|---|
| Orbit eccentricity | e | 0.98346500 |
| Orbit inclination | i | 79.77330000° |
| Perihelion distance | q | 0.92070000 AU 137,734,760 km |
| Aphelion distance | Q |
110.44307380 AU 16,522,048,707 km |
| Semi-major axis | a |
55.68188690 AU 8,329,891,734 km |
| Orbital period | period |
415.0000 years 151,578.7500 days |
| Date of perihelion transit | Tp | June 3, 1861 2,400,930.3899 JD |
| Next perihelion transit | June 6, 2276 2,552,509.1399 JD |
|
| Argument of perihelion | peri | 213.4496° |
| Longitude of the ascending node | node | 31.8674° |
| Mean anomaly | M | -0.0234598° |
| Mean motion | n | 0.00237210°/day |
Orbit Visualization
The following chart is a 3D animated visualization of the orbit of comet C/1861 G1 (Thatcher) 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 C/1861 G1 (Thatcher) 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 |
|---|---|---|---|---|
| Jul 10 2025 | 01h 34m 53s | +43° 22’ 42” | N.A. | Andromeda |
| Jul 11 2025 | 01h 34m 54s | +43° 23’ 01” | N.A. | Andromeda |
| Jul 12 2025 | 01h 34m 54s | +43° 23’ 20” | N.A. | Andromeda |
| Jul 13 2025 | 01h 34m 54s | +43° 23’ 39” | N.A. | Andromeda |
| Jul 14 2025 | 01h 34m 54s | +43° 23’ 58” | N.A. | Andromeda |
| Jul 15 2025 | 01h 34m 55s | +43° 24’ 16” | N.A. | Andromeda |
| Jul 16 2025 | 01h 34m 55s | +43° 24’ 35” | N.A. | Andromeda |
| Jul 17 2025 | 01h 34m 55s | +43° 24’ 53” | N.A. | Andromeda |
| Jul 18 2025 | 01h 34m 55s | +43° 25’ 11” | N.A. | Andromeda |
| Jul 19 2025 | 01h 34m 55s | +43° 25’ 30” | N.A. | Andromeda |
| Jul 20 2025 | 01h 34m 55s | +43° 25’ 47” | N.A. | Andromeda |
| Jul 21 2025 | 01h 34m 54s | +43° 26’ 05” | N.A. | Andromeda |
| Jul 22 2025 | 01h 34m 54s | +43° 26’ 23” | N.A. | Andromeda |
| Jul 23 2025 | 01h 34m 54s | +43° 26’ 40” | N.A. | Andromeda |
Additional Resources on TheSkyLive
- Comet C/1861 G1 (Thatcher): Complete reference information on TheSkyLive.com.
- Where is comet C/1861 G1 (Thatcher)?: Key information on where to find comet C/1861 G1 (Thatcher) in the sky.
- Distance of comet C/1861 G1 (Thatcher) from Earth: Find out how far comet C/1861 G1 (Thatcher) is from Earth right now.
- How Bright is comet C/1861 G1 (Thatcher)?: Current visual brightness (magnitude) and apparent size.
- Rise and Set Times: Rise and set times of comet C/1861 G1 (Thatcher) from your location.
- Interactive Sky Map: Planetarium-style interactive visualization of comet C/1861 G1 (Thatcher)'s position in the sky.
- Live Position Tracker: High precision real time tracker of comet C/1861 G1 (Thatcher)'s position using deep space imagery.
- Ephemeris: 15 days comet C/1861 G1 (Thatcher)'s computed ephemeris.
- Orbital elements: Information about comet C/1861 G1 (Thatcher) orbital parameters.
- Orbit Visualization: 3D interactive visualization showing the orbit of comet C/1861 G1 (Thatcher) with respect to the major Solar System objects.