C/2021 O3 (PanSTARRS)
C/2021 O3 (PanSTARRS) is an Oort cloud comet, discovered on 26 July 2021 by the Pan-STARRS sky survey. It will come to perihelion on 21 April 2022 at 0.287 AU (42.9 million km). from the Sun. It might reach apparent magnitude 5 by late April 2022, but will only be 15 degrees from the Sun.[3][4] C/2021 O3 will make its closest approach to Earth on 8 May 2022 at a distance of 0.60 AU (90 million km).[5] As a dynamically new comet from the Oort cloud there is a high risk of disintegration.
Discovery | |
---|---|
Discovered by | Pan-STARRS |
Discovery date | 26 July 2021 |
Orbital characteristics A | |
Epoch | 2021-Aug-21 |
Observation arc | 53 days |
Number of observations | 279 |
Orbit type | Oort cloud[1] |
Perihelion | 0.287 AU[2] |
Eccentricity | 1.00005 (epoch 1950)[1] 1.002 (epoch 2021)[2] 1.0001 (epoch 2100)[1] |
Inclination | 56.75° |
Node | 189.03° |
Argument of periapsis | 299.97° |
TJupiter | 0.446 |
Earth MOID | 0.062 au[2] |
Jupiter MOID | 2.16 au |
Comet total magnitude (M1) | 10.6 |
Next perihelion | 21 April 2022 |
Orbit

With a short observation arc of 7 days, the Minor Planet Center used an assumed eccentricity of 1.0 for the orbit solution.[6] Due to statistics of small numbers, with a short 10 day arc JPL had an eccentricity of 0.99595±0.00444 which could be as high as 1.00039 or as low as 0.99151.[7] With an observation arc of 53 days, JPL Horizons shows both an inbound and outbound eccentricity greater than 1.[1]
C/2021 O3 probably took millions of years to arrive from the outer Oort cloud and may be ejected from the Solar System.[1]
References
- "JPL Horizons On-Line Ephemeris for 2021 O3 at epoch 1950 and 2100 (barycentric)". JPL Horizons On-Line Ephemeris System. Jet Propulsion Laboratory. Retrieved 29 September 2021. Solution using the Solar System Barycenter. Ephemeris Type:Elements and Center:@0 (To be outside planetary region, inbound epoch 1950 and outbound epoch 2100. Aphelia/orbital periods defined while in the planetary-region are misleading for knowing the long-term inbound/outbound solutions.)
- "JPL Small-Body Database Browser: C/2021 O3 (PANSTARRS)". Jet Propulsion Laboratory. Retrieved 28 September 2021.
- "Electronic Telegram No. 5009". Central Bureau Electronic Telegrams. 1 August 2021.
- "C/2021 O3 ( PanSTARRS )". Seiichi Yoshida.
- "Closest Approach to Earth 2022" (Closest Earth approach occurs when deldot flips from negative to positive). JPL Horizons. Retrieved 2021-09-29.
- "MPEC 2021-P05 : COMET C/2021 O3 (PANSTARRS)] (7-day arc)". Minor Planet Electronic Circulars. Minor Planet Center. 1 August 2021.
- Archive of JPL #2 (with a 10 day arc)