C/2022 E3 (ZTF)

C/2022 E3 (ZTF)
C/2022 E3 (ZTF) on 27 January 2023
Discovery
Discovered byZwicky Transient Facility
Discovery date2 March 2022[1]
Orbital characteristics
Observation arc456 days
Number of
observations		3382
Orbit typeLong-period comet
Aphelion≈2800 AU (barycentric epoch 1950)[2]
Perihelion1.112 AU[3]
Eccentricity0.999988 (barycentric epoch 2050)[4]
Orbital period≈50,000 yr (inbound)[2]
Possible Ejection (outbound)[4]
Inclination109.17°
Last perihelion12 January 2023[3]
Earth MOID0.221 AU (33.1 million km)[3]
Jupiter MOID1.743 AU (260.7 million km)
Physical characteristics
Dimensions≈1 km[5]
Comet total
magnitude (M1)		10.5±0.6[3]

C/2022 E3 (ZTF) is a non-periodic comet from the Oort cloud that was discovered by the Zwicky Transient Facility (ZTF) on 2 March 2022.[1] The comet has a bright green glow around its nucleus, due to the effect of sunlight on diatomic carbon and cyanogen.[6][5] The comet's systematic designation starts with C to indicate that it is not a periodic comet, and "2022 E3" means that it was the third comet to be discovered in the first half of March 2022.[5]

The comet nucleus was estimated to be about a kilometer in size,[7] rotating every 8.5[8] to 8.7 hours.[9] Its tails of dust and gas extended for millions of kilometers and, during January 2023, an anti-tail was also visible.[10]

The comet reached its perihelion on 12 January 2023, at a distance of 1.11 AU (166 million km; 103 million mi), and the closest approach to Earth was on 1 February 2023, at a distance of 0.28 AU (42 million km; 26 million mi). The comet reached magnitude 5 and was visible with the naked eye under moonless dark skies.[11][12][13][14]

  1. ^ a b Cite error: The named reference MPEC2022-F13 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference pre-perihelion-barycenter was invoked but never defined (see the help page).
  3. ^ a b c d "JPL Small-Body Database Browser: C/2022 E3". JPL. Archived from the original on 19 January 2023. Retrieved 24 August 2022.
  4. ^ a b Cite error: The named reference post-perihelion-barycenter was invoked but never defined (see the help page).
  5. ^ a b c "A rare green comet is becoming visible in northern skies. How to see it without a telescope". www.usatoday.com. 15 January 2023. Archived from the original on 2 February 2023. Retrieved 2 February 2023.
  6. ^ Georgiou, Aristos (10 January 2023). "What makes the green comet green?". Newsweek. Archived from the original on 25 January 2023. Retrieved 25 January 2023.
  7. ^ "Once in 50,000-year comet may be visible to the naked eye". France 24. 7 January 2023. Archived from the original on 2 February 2023. Retrieved 2 February 2023.
  8. ^ "ATel #15909: Rotation period and Morphological Structures in the inner coma of comet C/2022 E3 (ZTF)". The Astronomer's Telegram. Retrieved 22 February 2023.
  9. ^ "ATel #15879: Rotation period of comet C/2022 E3 ZTF from CN morphology". The Astronomer's Telegram. 30 January 2023. Archived from the original on 2 February 2023. Retrieved 2 February 2023.
  10. ^ "Understanding the Tails of Comet ZTF (C/2022 E3)". Sky & Telescope. 1 February 2023. Archived from the original on 2 February 2023. Retrieved 2 February 2023.
  11. ^ Cite error: The named reference COBS was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference S&T20230116 was invoked but never defined (see the help page).
  13. ^ Hall, Shannon (20 January 2023). "How to Watch the 'Green Comet' in Night Skies. - Comment". The New York Times. Archived from the original on 24 January 2023. Retrieved 21 January 2023.
  14. ^ Mack, Eric (23 January 2023). "Bright Green Comet Passing Earth Is Visible Now in Dark Skies". CNET. Archived from the original on 23 January 2023. Retrieved 24 January 2023.