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Comet Near-Earth

SOHO

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321P/SOHO

Where is it now

Distance from Sun
3.815 AU
True anomaly
185.8°
Distance from Earth
4.669 AU
As of
11 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 — 0.998 AU from the Sun Earth SOHO — 3.815 AU from the Sun SOHO
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. SOHO is 4.669 AU from Earth today (38.8 light-minutes).

In the sky

Right ascension
11h 25m 09s
Declination
+03° 13′ 22″
Constellation
Leo
Distance from Earth
4.66 AU
Elongation from the Sun
28.32° — 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
2.427 AU
Eccentricity
0.9807
Inclination
19.74°
Orbital period
3.78 years
Perihelion
0.047 AU
Aphelion
4.806 AU
Longitude of ascending node
165.27°
Argument of periapsis
172.41°
Epoch · J2000
2453458.5
Orbit class · JFc
Jupiter-family comet (P < 20 y)
Earth MOID · 33.5 LD
0.086 AU
Tisserand (Jupiter)
2.396

Orbit quality

Orbit reasonably well determined (uncertainty code 3).

Observations used
91
Data arc
15.16 years
First observed
1 May 1997
Last observed
30 June 2012
Residual RMS
0.11 ″
Solution · Otto Matic
15 April 2021

Discovery & classification

Also known as 321P · 321P/1997 J6 · 321P/2001 D1 · 321P/2004 X7 · 321P/2008 S2 · 321P/2012 M2

Near-Earth Object Named

Close approaches 30 on record

Flyby geometry
Ecliptic flyby of SOHO at 2031-04-01 04:36 UTC Top-down view of the ecliptic, Earth at the centre, for the 2031-04-01 04:36 UTC close approach of SOHO. Catalogue miss distance 124.3 LD · 4.78 × 10⁷ km. The curve is the geocentric path from 2031-03-29 to 2031-04-04, with a mark at UTC midnights and an arrow for the direction of motion. The circle is the Moon’s mean orbit; the Moon is plotted at closest approach. A ray shows the Sun’s direction. The labelled distance is the full separation. The drawn radius is the part that lies in the ecliptic plane. At closest approach the object is north of the ecliptic. The path is a geocentric ecliptic ephemeris from JPL Horizons. The inset is a heliocentric view and is approximate. Sun 124.3 LD · 4.78 × 10⁷ km 2031-04-01 04:36 UTC Earth Moon Heliocentric, approximate

Top-down view of the ecliptic, Earth at the centre, for the 2031-04-01 04:36 UTC close approach of SOHO. Catalogue miss distance 124.3 LD · 4.78 × 10⁷ km. The curve is the geocentric path from 2031-03-29 to 2031-04-04, with a mark at UTC midnights and an arrow for the direction of motion. The circle is the Moon’s mean orbit; the Moon is plotted at closest approach. A ray shows the Sun’s direction. The labelled distance is the full separation. The drawn radius is the part that lies in the ecliptic plane. At closest approach the object is north of the ecliptic. The path is a geocentric ecliptic ephemeris from JPL Horizons. The inset is a heliocentric view and is approximate.

JPL Horizons

When (UTC) Body Distance Lunar distances Relative speed
2031-04-01 04:36:00 Earth 0.3194 AU 124.3 LD 34.4 km/s
2035-01-28 07:12:00 Venus 0.0746 AU 29.0 LD 47.3 km/s
2035-02-09 11:34:00 Merc 0.0466 AU 18.1 LD 75.1 km/s
2035-02-09 11:34:00 Mercury 0.0466 AU 18.1 LD 75.1 km/s
2039-11-20 09:36:00 Juptr 1.7972 AU 699.4 LD 14.8 km/s
2050-03-11 02:14:00 Earth 0.2307 AU 89.8 LD 49.4 km/s
2051-07-11 19:17:00 Juptr 1.1308 AU 440.1 LD 12.3 km/s
2063-04-21 07:50:00 Juptr 0.7522 AU 292.7 LD 11 km/s
2075-02-24 20:37:00 Juptr 0.6286 AU 244.6 LD 10.8 km/s

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

Sources