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Comet Near-Earth

LONEOS

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P/1999 RO28 (LONEOS)

Where is it now

Distance from Sun
2.492 AU
True anomaly
106.37°
Distance from Earth
2.787 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 — 2.492 AU from the Sun LONEOS
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. LONEOS is 2.787 AU from Earth today (23.2 light-minutes).

In the sky

Right ascension
09h 08m 45s
Declination
+12° 10′ 22″
Constellation
Cancer
Distance from Earth
2.78 AU
Elongation from the Sun
63.07° — well clear of the Sun

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
3.525 AU
Eccentricity
0.6501
Inclination
8.19°
Orbital period
6.62 years
Perihelion
1.233 AU
Aphelion
5.817 AU
Longitude of ascending node
148.43°
Argument of periapsis
219.83°
Epoch · J2000
2452876.5
Orbit class · JFc
Jupiter-family comet (P < 20 y)
Earth MOID · 96.9 LD
0.249 AU
Tisserand (Jupiter)
2.714

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
120
Data arc
25.87 years
First observed
7 September 1999
Last observed
20 July 2025
Residual RMS
0.53 ″
Solution · Otto Matic
9 June 2026

Visual & observation

Absolute magnitude (H)
20.2
Total magnitude M₁ · K₁ 9.3
20.2

Discovery & classification

Also known as 1999 RO28 · P/2025 N3

Near-Earth Object Named

Close approaches 21 on record

Flyby geometry
Ecliptic flyby of LONEOS at 2044-09-30 02:15 UTC Top-down view of the ecliptic, Earth at the centre, for the 2044-09-30 02:15 UTC close approach of LONEOS. Catalogue miss distance 70.0 LD · 2.69 × 10⁷ km. The curve is the geocentric path from 2044-09-27 to 2044-10-03, 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 approximate: a two-body Kepler propagation of the catalogue orbital elements, not a numerical integration. The Moon’s position is approximate. The inset is a heliocentric view and is approximate. approximate Sun 70.0 LD · 2.69 × 10⁷ km 2044-09-30 02:15 UTC Earth Moon Heliocentric, approximate

Top-down view of the ecliptic, Earth at the centre, for the 2044-09-30 02:15 UTC close approach of LONEOS. Catalogue miss distance 70.0 LD · 2.69 × 10⁷ km. The curve is the geocentric path from 2044-09-27 to 2044-10-03, 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 approximate: a two-body Kepler propagation of the catalogue orbital elements, not a numerical integration. The Moon’s position is approximate. The inset is a heliocentric view and is approximate.

When (UTC) Body Distance Lunar distances Relative speed
2028-06-06 13:46:00 Jupiter 0.3999 AU 155.6 LD 5.9 km/s
2028-06-06 13:46:00 Juptr 0.3999 AU 155.6 LD 5.9 km/s
2040-01-23 13:22:00 Juptr 1.078 AU 419.5 LD 8.9 km/s
2044-09-30 02:15:00 Earth 0.1799 AU 70.0 LD 6.1 km/s
2088-06-13 16:51:00 Juptr 1.5732 AU 612.3 LD 10.4 km/s
2100-04-26 02:58:00 Juptr 0.343 AU 133.5 LD 6.1 km/s
2100-04-26 02:58:00 Jupiter 0.343 AU 133.5 LD 6.1 km/s
2102-10-06 13:33:00 Earth 0.1915 AU 74.5 LD 7.2 km/s
2111-02-19 02:58:00 Juptr 0.7749 AU 301.6 LD 7.2 km/s
2122-07-01 03:53:00 Mars 0.0631 AU 24.6 LD 9.4 km/s

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

Sources