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Comet

Swift-Gehrels

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64P/Swift-Gehrels

Where is it now

Distance from Sun
4.694 AU
True anomaly
223.43°
Distance from Earth
5.367 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 Swift-Gehrels — 4.694 AU from the Sun Swift-Gehrels
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Swift-Gehrels is 5.367 AU from Earth today (44.6 light-minutes).

In the sky

Right ascension
16h 42m 00s
Declination
-27° 13′ 04″
Constellation
Scorpius
Distance from Earth
5.37 AU
Elongation from the Sun
42.85° — near the Sun — look low at dusk or dawn

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
4.456 AU
Eccentricity
0.6873
Inclination
8.95°
Orbital period
9.41 years
Perihelion
1.393 AU
Aphelion
7.519 AU
Longitude of ascending node
300°
Argument of periapsis
97.14°
Epoch · J2000
2458096.5
Orbit class · JFc
Jupiter-family comet (P < 20 y)
Earth MOID · 171.3 LD
0.4401 AU
Tisserand (Jupiter)
2.496

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
3,436
Data arc
18.36 years
First observed
22 December 2000
Last observed
4 May 2019
Residual RMS
0.45 ″
Solution · Davide Farnocchia
21 December 2023

Physical properties

Mean radius
1.60 km

Visual & observation

Absolute magnitude (H)
14.5
Total magnitude M₁ · K₁ 6
14.5

Discovery & classification

Discovered by
Swift, Lewis
Discovery date
16 November 1889
Discovery site
Warner Observatory, Rochester, New York

Also known as 64P · 1889 VI · 1889f · 1972 VII · 1973d · 1981 XIX · 1981j · 1991 II

Named

Close approaches 13 on record

Flyby geometry
Ecliptic flyby of Swift-Gehrels at 2092-10-27 05:00 UTC Top-down view of the ecliptic, Earth at the centre, for the 2092-10-27 05:00 UTC close approach of Swift-Gehrels. Catalogue miss distance 174.2 LD · 6.7 × 10⁷ km. The curve is the geocentric path from 2092-10-24 to 2092-10-30, 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 174.2 LD · 6.7 × 10⁷ km 2092-10-27 05:00 UTC Earth Moon Heliocentric, approximate

Top-down view of the ecliptic, Earth at the centre, for the 2092-10-27 05:00 UTC close approach of Swift-Gehrels. Catalogue miss distance 174.2 LD · 6.7 × 10⁷ km. The curve is the geocentric path from 2092-10-24 to 2092-10-30, 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
2054-08-17 15:50:00 Juptr 1.0969 AU 426.9 LD 11 km/s
2076-02-13 18:31:00 Juptr 1.0556 AU 410.8 LD 9.9 km/s
2090-03-04 11:53:00 Juptr 1.6167 AU 629.2 LD 6.3 km/s
2092-10-27 05:00:00 Earth 0.4476 AU 174.2 LD 3.7 km/s
2123-08-02 16:04:00 Juptr 1.6508 AU 642.4 LD 6.3 km/s
2137-10-13 20:09:00 Juptr 0.5401 AU 210.2 LD 9.3 km/s
2159-02-28 20:18:00 Juptr 1.2852 AU 500.2 LD 10 km/s
2173-05-11 13:35:00 Juptr 1.2218 AU 475.5 LD 6.6 km/s

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

Sources