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Comet

Bus

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C/1981 H1 (Bus)

Bus is a comet in the Comet orbit class. Its orbit takes it from 2.46 AU to 4,315.82 AU from the Sun; one orbit takes 100,329.5 years. Orbit from the JPL solution of 15 April 2021.

Where is it now

Distance from Sun
68.759 AU
True anomaly
158.37°
Distance from Earth
67.769 AU
As of
25 October 2026

Two-body Kepler propagation — accurate to ~0.1% for major planets over decades, less so for highly-perturbed bodies. Use JPL Horizons for high precision.

Sun Earth — 0.994 AU from the Sun Earth Bus — 68.759 AU from the Sun Bus
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Bus is 67.769 AU from Earth today (9.4 light-hours).

In the sky

Right ascension
02h 17m 51s
Declination
+09° 37′ 22″
Constellation
Cetus
Distance from Earth
67.77 AU
Elongation from the Sun
175.24° — near opposition — up most of the night

Visible from both hemispheres.

From your location

See how high it is right now, whether it is up after civil twilight, and when it rises and sets where you are.

How do I find my coordinates?

Google Maps on a computer

  1. Right-click the spot where you'll be observing.
  2. The first line of the menu is the coordinates, e.g. 51.50722, -0.12758 — click it and they're copied.
  3. Paste them above.

Google Maps on a phone

  1. Press and hold the spot to drop a pin.
  2. The coordinates appear in the search bar (or on the pin's card) — tap to copy, then paste above.

A full Google Maps link works too, but the short maps.app.goo.gl share links don't carry coordinates — copy the numbers instead. We round to about a kilometre; that's all the sky calculation needs.

Know your what3words address? Paste it, e.g. ///filled.count.soap. This is optional — the three words are sent to what3words to convert them, and we don't store the address or the result.

Your location stays in your browser and is sent only for this calculation. Using a what3words address is optional; if you do, the three words go to what3words to be converted and we don't record them. Set a location first, then you can save an email alert for this object. See our privacy policy.

Two-body approximation, good to about a degree for the planets — enough to find the constellation and know whether it is up.

Orbital elements

Semi-major axis
2,159.137 AU
Eccentricity
0.9989
Inclination
160.66°
Orbital period
100,329.5 years
Perihelion
2.458 AU
Aphelion
4,315.816 AU
Longitude of ascending node
24.26°
Argument of periapsis
189.85°
Epoch · J2000
2444756.5
Orbit class · COM
Comet
Earth MOID · 567.9 LD
1.4593 AU
Tisserand (Jupiter)
-1.831

Orbit quality

Observations used
26
Data arc
265 days
First observed
26 April 1981
Last observed
16 January 1982
Residual RMS
0.73 ″
Solution · Otto Matic
15 April 2021

Visual & observation

Absolute magnitude (H)
10.7
Total magnitude M₁ · K₁ 10
10.7

Discovery & classification

Also known as 1981 H1

Named

Sources