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Comet

LONEOS

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201P/LONEOS

Where is it now

Distance from Sun
3.774 AU
True anomaly
225.8°
Distance from Earth
3.945 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 LONEOS — 3.774 AU from the Sun LONEOS
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. LONEOS is 3.945 AU from Earth today (32.8 light-minutes).

In the sky

Right ascension
18h 05m 51s
Declination
-29° 46′ 10″
Constellation
Sagittarius
Distance from Earth
3.95 AU
Elongation from the Sun
72.27° — well clear of the Sun

Favours the southern hemisphere; low or below the horizon from far north.

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
3.461 AU
Eccentricity
0.6129
Inclination
7.04°
Orbital period
6.44 years
Perihelion
1.34 AU
Aphelion
5.583 AU
Longitude of ascending node
35.29°
Argument of periapsis
24.95°
Epoch · J2000
2456055.5
Orbit class · JFc
Jupiter-family comet (P < 20 y)
Earth MOID · 139.3 LD
0.358 AU
Tisserand (Jupiter)
2.783

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
865
Data arc
13.68 years
First observed
9 August 2001
Last observed
16 April 2015
Residual RMS
0.76 ″
Solution · Otto Matic
15 April 2021

Visual & observation

Absolute magnitude (H)
13
Total magnitude M₁ · K₁ 15.3
13

Discovery & classification

Also known as 201P · 201P/2001 R1 · 201P/2008 Q4

Named

Close approaches 22 on record

Flyby geometry
Ecliptic flyby of LONEOS at 2097-11-26 04:59 UTC Top-down view of the ecliptic, Earth at the centre, for the 2097-11-26 04:59 UTC close approach of LONEOS. Catalogue miss distance 143.2 LD · 5.5 × 10⁷ km. The curve is the geocentric path from 2097-11-23 to 2097-11-29, 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. The path is a geocentric ecliptic ephemeris from JPL Horizons. The inset is a heliocentric view and is approximate. Sun 143.2 LD · 5.5 × 10⁷ km 2097-11-26 04:59 UTC Earth Moon Heliocentric, approximate

Top-down view of the ecliptic, Earth at the centre, for the 2097-11-26 04:59 UTC close approach of LONEOS. Catalogue miss distance 143.2 LD · 5.5 × 10⁷ km. The curve is the geocentric path from 2097-11-23 to 2097-11-29, 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. 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
2030-09-17 23:24:00 Jupiter 0.4429 AU 172.4 LD 5.3 km/s
2030-09-17 23:24:00 Juptr 0.4429 AU 172.4 LD 5.3 km/s
2042-01-04 08:37:00 Juptr 0.5114 AU 199.0 LD 6.2 km/s
2097-11-26 04:59:00 Earth 0.3679 AU 143.2 LD 3.3 km/s
2102-05-30 05:26:00 Juptr 0.724 AU 281.8 LD 7.4 km/s
2114-01-25 08:15:00 Juptr 0.2475 AU 96.3 LD 5.8 km/s
2114-01-25 08:15:00 Jupiter 0.2475 AU 96.3 LD 5.8 km/s
2122-11-22 19:17:00 Earth 0.4119 AU 160.3 LD 7.1 km/s
2125-02-16 12:38:00 Juptr 1.0742 AU 418.0 LD 7.1 km/s
2135-11-30 05:51:00 Earth 0.4937 AU 192.2 LD 6.9 km/s

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

Sources