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Comet

Kowal-Mrkos

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143P/Kowal-Mrkos

Where is it now

Distance from Sun
2.759 AU
True anomaly
315.99°
Distance from Earth
3.51 AU
As of
22 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.

Orbit of Mercury Orbit of Venus Orbit of Mars Sun Earth — 0.995 AU from the Sun Earth Kowal-Mrkos — 2.759 AU from the Sun Kowal-Mrkos
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Kowal-Mrkos is 3.51 AU from Earth today (29.2 light-minutes).

In the sky

Right ascension
11h 33m 52s
Declination
-01° 10′ 04″
Constellation
Leo
Distance from Earth
3.5 AU
Elongation from the Sun
35.7° — near the Sun — look low at dusk or dawn

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
4.294 AU
Eccentricity
0.4099
Inclination
4.69°
Orbital period
8.9 years
Perihelion
2.534 AU
Aphelion
6.055 AU
Longitude of ascending node
245.31°
Argument of periapsis
320.84°
Epoch · J2000
2457483.5
Orbit class · JFc
Jupiter-family comet (P < 20 y)
Earth MOID · 596.2 LD
1.5321 AU
Tisserand (Jupiter)
2.863

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
1,485
Data arc
42.04 years
First observed
23 April 1984
Last observed
7 May 2026
Residual RMS
0.42 ″
Solution · Otto Matic
7 August 2026

Visual & observation

Absolute magnitude (H)
14.5
Total magnitude M₁ · K₁ 4.5
14.5

Discovery & classification

Also known as 143P · 143P/1984 H1 · 143P/1984 JD · 143P/2000 ET90 · 1984 X · 1984n

Named

Close approaches 14 on record

When (UTC) Body Distance Lunar distances Relative speed
2091-02-07 09:53:00 Juptr 1.5534 AU 604.6 LD 3.2 km/s
2092-12-04 19:37:00 Juptr 1.325 AU 515.7 LD 4.1 km/s
2107-06-10 00:30:00 Juptr 0.3704 AU 144.2 LD 7 km/s
2107-06-10 00:30:00 Jupiter 0.3704 AU 144.2 LD 7 km/s
2142-11-05 03:05:00 Juptr 1.3618 AU 530.0 LD 9.6 km/s
2164-03-13 16:31:00 Juptr 0.7002 AU 272.5 LD 6.7 km/s
2200-01-25 09:04:00 Juptr 1.9748 AU 768.5 LD 10.8 km/s

Next ten from today. 1 lunar distance = 384,400 km. Source: JPL close-approach data.

Sources