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Comet

Giacobini

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205P/Giacobini-A

Where is it now

Distance from Sun
4.778 AU
True anomaly
208.69°
Distance from Earth
5.744 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 Giacobini — 4.778 AU from the Sun Giacobini
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Giacobini is 5.744 AU from Earth today (47.8 light-minutes).

In the sky

Right ascension
12h 20m 32s
Declination
-01° 30′ 55″
Constellation
Virgo
Distance from Earth
5.74 AU
Elongation from the Sun
13.71° — too close to the Sun to observe

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
3.539 AU
Eccentricity
0.5687
Inclination
15.3°
Orbital period
6.66 years
Perihelion
1.526 AU
Aphelion
5.552 AU
Longitude of ascending node
179.63°
Argument of periapsis
154.22°
Epoch · J2000
2454766.5
Orbit class · JFc
Jupiter-family comet (P < 20 y)
Earth MOID · 207.1 LD
0.5321 AU
Tisserand (Jupiter)
2.779

Orbit quality

Orbit reasonably well determined (uncertainty code 4).

Observations used
1,143
Data arc
163 days
First observed
11 September 2008
Last observed
21 February 2009
Residual RMS
0.81 ″
Solution · Otto Matic
14 September 2011

Visual & observation

Absolute magnitude (H)
12
Total magnitude M₁ · K₁ 17
12

Discovery & classification

Also known as 205P-A

Named

Close approaches 3 on record

When (UTC) Body Distance Lunar distances Relative speed
2039-12-12 00:57:00 Juptr 1.0689 AU 416.0 LD 8.4 km/s
2169-11-24 22:03:00 Juptr 0.881 AU 342.9 LD 5.6 km/s

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

Sources