Skip to content
Public Universe
Comet Near-Earth

PANSTARRS

Add to an observing list or journal →

P/2021 HS (PANSTARRS)

Where is it now

Distance from Sun
7.362 AU
True anomaly
186.98°
Distance from Earth
7.684 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 PANSTARRS — 7.362 AU from the Sun PANSTARRS
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. PANSTARRS is 7.684 AU from Earth today (1.1 light-hours).

In the sky

Right ascension
09h 25m 57s
Declination
+05° 18′ 46″
Constellation
Hydra
Distance from Earth
7.67 AU
Elongation from the Sun
68.09° — 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
4.196 AU
Eccentricity
0.8102
Inclination
12.17°
Orbital period
8.59 years
Perihelion
0.796 AU
Aphelion
7.595 AU
Longitude of ascending node
262.4°
Argument of periapsis
46.09°
Epoch · J2000
2459398.5
Orbit class · JFc
Jupiter-family comet (P < 20 y)
Earth MOID · 16.5 LD
0.0423 AU
Tisserand (Jupiter)
2.269

Orbit quality

Orbit reasonably well determined (uncertainty code 4).

Observations used
181
Data arc
243 days
First observed
10 April 2021
Last observed
9 December 2021
Residual RMS
0.41 ″
Solution · Otto Matic
17 December 2021

Visual & observation

Absolute magnitude (H)
20.6
Total magnitude M₁ · K₁ 4.5
20.6

Discovery & classification

Also known as 2021 HS

Near-Earth Object Named

Close approaches 22 on record

Flyby geometry
Ecliptic flyby of PANSTARRS at 2047-05-18 03:31 UTC Top-down view of the ecliptic, Earth at the centre, for the 2047-05-18 03:31 UTC close approach of PANSTARRS. Catalogue miss distance 85.6 LD · 3.29 × 10⁷ km. The curve is the geocentric path from 2047-05-15 to 2047-05-21, 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 85.6 LD · 3.29 × 10⁷ km 2047-05-18 03:31 UTC Earth Moon Heliocentric, approximate

Top-down view of the ecliptic, Earth at the centre, for the 2047-05-18 03:31 UTC close approach of PANSTARRS. Catalogue miss distance 85.6 LD · 3.29 × 10⁷ km. The curve is the geocentric path from 2047-05-15 to 2047-05-21, 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
2047-05-18 03:31:00 Earth 0.2199 AU 85.6 LD 25.4 km/s
2049-05-24 16:31:00 Juptr 1.1599 AU 451.4 LD 8.8 km/s
2062-12-24 01:42:00 Juptr 1.2023 AU 467.9 LD 12.1 km/s
2089-10-30 08:40:00 Earth 0.4993 AU 194.3 LD 33.4 km/s
2106-10-24 18:54:00 Earth 0.3622 AU 141.0 LD 29.2 km/s
2108-09-28 14:43:00 Juptr 1.3516 AU 526.0 LD 8.6 km/s
2122-02-04 07:39:00 Juptr 1.5169 AU 590.3 LD 14 km/s
2131-10-25 12:07:00 Earth 0.3214 AU 125.1 LD 28.9 km/s
2132-10-30 00:07:00 Juptr 1.6593 AU 645.8 LD 15.2 km/s
2145-12-18 13:34:00 Juptr 1.8342 AU 713.8 LD 8.3 km/s

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

Sources