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Comet

Vaisala

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40P/Vaisala 1

Where is it now

Distance from Sun
3.806 AU
True anomaly
111.03°
Distance from Earth
4.035 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 Vaisala — 3.806 AU from the Sun Vaisala
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Vaisala is 4.035 AU from Earth today (33.6 light-minutes).

In the sky

Right ascension
18h 38m 43s
Declination
-19° 10′ 41″
Constellation
Sagittarius
Distance from Earth
4.05 AU
Elongation from the Sun
69.08° — 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
4.904 AU
Eccentricity
0.6325
Inclination
11.5°
Orbital period
10.86 years
Perihelion
1.802 AU
Aphelion
8.006 AU
Longitude of ascending node
134.48°
Argument of periapsis
47.31°
Epoch · J2000
2455788.5
Orbit class · JFc
Jupiter-family comet (P < 20 y)
Earth MOID · 323.2 LD
0.8304 AU
Tisserand (Jupiter)
2.535

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
1,268
Data arc
22.79 years
First observed
25 September 2003
Last observed
11 July 2026
Residual RMS
0.79 ″
Solution · Davide Farnocchia
17 July 2026

Physical properties

Mean radius
2.10 km

Visual & observation

Absolute magnitude (H)
11.5
Total magnitude M₁ · K₁ 13.5
11.5

Discovery & classification

Discovered by
Vaisala, Y.
Discovery date
8 February 1939
Discovery site
Turku, Finland

Also known as 40P · 1939 IV · 1939b · 1949 V · 1949h · 1959i · 1960 IV · 1970q

Named

Close approaches 8 on record

When (UTC) Body Distance Lunar distances Relative speed
2116-03-12 18:09:00 Juptr 0.5923 AU 230.5 LD 11.3 km/s
2127-12-02 04:16:00 Juptr 0.0957 AU 37.3 LD 10.2 km/s
2127-12-02 04:16:00 Jupiter 0.0957 AU 37.3 LD 10.2 km/s
2141-12-24 23:01:00 Juptr 0.6634 AU 258.2 LD 10 km/s

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

Sources