Skip to content
Q67328765

File:Comet-2IBorisov-HubbleST-20191016_(cropped).png · Wikimedia Commons · See Wikimedia Commons

EntityQ67328765· pop 40· linked from 653 articles

Also known as ISO 2I/Borisov, ISO 2I

2I/Borisov, originally designated C/2019 Q4 (Borisov), is the first observed rogue comet and the second observed interstellar interloper, after ʻOumuamua. It was discovered by the Crimean amateur astronomer and telescope maker Gennadiy Borisov on 29 August 2019 UTC (30 August local time) in MARGO Observatory.

Key facts

Comet.name
2I/Borisov
Comet.image
Comet-2IBorisov-HubbleST-20191016 (cropped).png
Comet.caption
Comet Borisov in October 2019
Comet.discoverer
Gennadiy Borisov
Comet.discovery_date
29 August 2019
Comet.discovery_site
MARGO Observatory, Crimea
Comet.mpc_name
C/2019 Q4
Comet.designations
gb00234
Comet.epoch
5 January 2020 (JD 2458853.5)
Comet.observation_arc
964 days
Comet.obs
3,360
Comet.earliest_precovery_date
13 December 2018
Comet.semimajor
–0.8515 AU
Comet.inclination
44.053°
Comet.eccentricity
3.3565
Comet.asc_node
308.15°
Comet.arg_peri
209.12°
Comet.Earth_moid
1.093 AU

via Wikipedia infobox

~15 min read

Encyclopedic overview

16 sections
Contents
  • Nomenclature
  • Characteristics
  • Size and shape
  • Rotation
  • Chemical makeup and nucleus structure
  • Trajectory
  • Observation
  • Discovery
  • Observation
  • Comet chemistry
  • Suspected nucleus fragmentation
  • Exploration
  • See also
  • Notes
  • References
  • External links

2I/Borisov, originally designated C/2019 Q4 (Borisov), is the first observed rogue comet and the second observed interstellar interloper, after ʻOumuamua. It was discovered by the Crimean amateur astronomer and telescope maker Gennadiy Borisov on 29 August 2019 UTC (30 August local time) in MARGO Observatory.

2I/Borisov has a heliocentric orbital eccentricity of 3.36 and is not bound to the Sun. The comet passed through the ecliptic of the Solar System at the end of October 2019, and made its closest approach to the Sun at just over on 8 December 2019. The comet passed closest to Earth on 28 December 2019. In November 2019, astronomers from Yale University said that the comet's tail was 14 times the size of Earth, and stated, "It's humbling to realize how small Earth is next to this visitor from another solar system."

Excerpted from Wikipedia’s “Q67328765” article, available under the CC BY-SA 4.0 licence.

Gallery (11)