C/2016 U1 (NEOWISE)
Discovered byNEOWISE project
Discovery siteNEOWISE
Discovery dateFriday 21 October 2016[1]
Orbital characteristics
Epoch2457723.5 (2016-Dec-01.0) TDB[1] Reference: JPL 4 (heliocentric ecliptic J2000)[1]
Perihelion0.3191 AU[1]
Semi-major axis−3477.5728 AU[1]
Inclination46.4292 deg[1]
61.4214 deg[1]
Argument of
162.7640 deg[1]
Last perihelion14 January 2017
Next perihelionejection
Comet total
Comet nuclear
magnitude (M2)

C/2016 U1 (NEOWISE) is a hyperbolic comet discovered 21 October 2016 by NEOWISE, the asteroid-and-comet-hunting portion of the Wide-Field Infrared Survey Explorer (WISE) mission.[1][2][3] The comet brightened to magnitude +6.8[4] and could be observed with binoculars,[5] during the first week of 2017 and it was closest to the Sun on 14 January 2017.[2][6]

It was closest to the Earth on 13 December 2016 at 106,000,000 km (66,000,000 mi)[5] away; it is not considered a threat to Earth.[2] The aphelion of the comet lies at the inner edge of the Oort cloud and it is possible that the 2017 perihelion was not the first and that during a previous perihelion planetary perturbations pushed the comet towards the Oort cloud. Despite its small size, the comet survived perihelion and was observed for days from the SWAN instrument on board SOHO.[7]

Orbit of C/2016 U1 (NEOWISE) on 14 January 2017, closest approach to the Sun.[1][3]


  1. ^ a b c d e f g h i j k l m Park, Ryan S.; Chamberlin, Alan B. (30 December 2016). "JPL small-body database browser – C/2016 U1 (NEOWISE)". JPL. Retrieved 30 December 2016.
  2. ^ a b c Agle, DC; Cantillo, Laurie; Brown, Dwayne (29 December 2016). "NASA's NEOWISE mission spies one comet – maybe two". NASA. Retrieved 29 December 2016.
  3. ^ a b Dickinson, David (28 December 2016). "Comet U1 NEOWISE – a possible binocular comet?". Phys.org. Retrieved 30 December 2016.
  4. ^ "Weekly Information about Bright Comets (2017 Jan. 14: North)". www.aerith.net. Retrieved 15 October 2022.
  5. ^ a b MacDonald, Fiona (31 December 2016). "A rare comet is zooming past Earth right now, and you should be able to see it with binoculars". ScienceAlert.com. Retrieved 31 December 2016.
  6. ^ Williams, Matt (30 December 2016). "NASA'S NEOWISE mission spots new comets". Universe Today. Retrieved 31 December 2016.
  7. ^ Sekanina, Zdenek (2019). "1I/'Oumuamua and the Problem of Survival of Oort Cloud Comets Near the Sun". arXiv:1903.06300 [astro-ph.EP].