What are the closest comet encounters with Earth?
This table provides a list of known comet close encounters with Earth, for objects whose orbits are known well enough to be confident of the approach distances. Encounters occurring after 1950 are highlighted as the modern era, which signifies the time that scientific studies began to focus on the physics and chemistry of comets, rather than just qualitative descriptions of their behavior.
Note that the distance from Earth is not necessarily an indicator of brightness. Of the comets on the modern-era list, only #4 IRAS-Araki-Alcock and #5 252P/LINEAR (and hopefully #10 46P/Wirtanen) reached naked eye brightness, while many of the others were not detected because they were too faint (#8 323P/SOHO)
Rank Rank Distance Distance Date (TT) Permanent designation all Modern (LD) (AU) ---- ------- -------- ------- ----------- ---------------------------------- 1 1 4.70 0.0120 1999 Jun 12 P/SOHO 5 (1999 J6) 2 5.88 0.0151 1770 Jul 1 D/Lexell (1770 L1) 3 8.91 0.0229 1366 Oct 26 55P/Tempel-Tuttle 4 2 9.22 0.0237 2016 Mar 22 P/PANSTARRS 51 (2016 BA14) 5 3 9.68 0.0248 2003 Dec 11 289P/Blanpain 6 4 12.14 0.0312 1983 May 11 C/IRAS-Araki-Alcock (1983 H1) 7 13.00 0.0334 837 Apr 10 1P/Halley 8 5 13.93 0.0358 2016 Mar 21 252P/LINEAR 9 14.24 0.0366 1805 Dec 9 3D/Biela 10 15.18 0.0390 1743 Feb 8 C/1743 C1 11 15.33 0.0394 1927 Jun 26 7P/Pons-Winnecke 12 15.88 0.0408 1930 Jun 3 73P/Schwassmann-Wachmann 3 13 17.01 0.0437 1702 Apr 20 C/1702 H1 14 18.46 0.0474 1947 Apr 11 322P/SOHO 1 15 6 21.60 0.0555 2014 May 29 209P/LINEAR 41 16 7 22.60 0.0581 2000 Jan 13 323P/SOHO 2 17 8 23.50 0.0604 1966 Jan 16 323P/SOHO 2 18 9 24.44 0.0628 1983 Jun 12 C/Sugano-Saigusa-Fujikawa (1983 J1) 19 26.54 0.0682 1760 Jan 8 C/1760 A1 (Great comet) 20 10 30.23 0.0775 2018 Dec 16 46P/Wirtanen 21 11 30.63 0.0787 2006 May 12 73P/Schwassmann-Wachmann 3 22 12 32.37 0.0831 2017 Feb 11 45P/Honda-Mrkos-Pajdusakova 23 32.65 0.0839 1853 Apr 29 C/Schweizer (1853 G1) 24 34.21 0.0879 1797 Aug 16 C/Bouvard-Herschel (1797 P1) 25 34.40 0.0884 374 Apr 1 1P/Halley 26 13 34.58 0.0888 2011 Aug 11 45P/Honda-Mrkos-Pajdusakova 27 34.69 0.0891 1904 Jun 6 300P/Catalina 3 28 34.95 0.0898 607 Apr 19 1P/Halley 39 36.23 0.0931 1926 Jun 16 300P/Catalina 3 30 36.35 0.0934 1763 Sep 23 C/Messier (1763 S1) 31 37.52 0.0964 1864 Aug 8 C/Tempel (1864 N1) 32 14 38.09 0.0979 1997 Apr 22 249P/LINEAR 53 33 38.22 0.0982 1862 Jul 4 C/Schmidt (1862 N1)
Future Close Approaches (chronologic order)
Distance Distance Date (TT) Permanent designation Est
(LD) (AU) Mag
-------- ------- ----------- ---------------------------------- ---
30.23 0.0775 2018 Dec 16 46P/Wirtanen 3-8
34.55 0.0888 2020 Jan 11 289P/Blanpain 18
22.10 0.0568 2029 Nov 4 249P/LINEAR 53 10
37.86 0.0973 2032 Mar 5 252P/LINEAR 12 12
38.63 0.0993 2035 Nov 4 289P/Blanpain 18
24.71 0.0635 2036 Jun 8 300P/Catalina 3 12
19.18 0.0493 2060 Oct 27 15P/Finlay 11
34.09 0.0876 2061 Jan 2 104P/Kowal 2 5
22.72 0.0584 2071 Nov 4 249P/LINEAR 53 10
19.10 0.0491 2076 Apr 23 249P/LINEAR 53 9
22.61 0.0581 2080 Mar 1 323P/SOHO 2 --
Notes:
The list of past close approaches was updated on Feb 9, 2017 using information from the list provided at the Minor Planet Center and the list generated from the JPL NEO website. Where discrepancies exist, the JPL information was adopted, as it is more complete due to the criteria used for an objects' inclusion on the two lists.)
The list of future close approaches was derived from numbered periodic comets (and a few recent non-numbered comets) using JPL Horizons to compute the approach distances. Only those with C/A distances less than 0.1 AU before 2100 are included. The calculation assumes no non-gravitational forces, so the actual approach distances may be different. The list may also be incomplete due to these assumptions, and to new comets being discovered.