C/2017 K2 (PANSTARRS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	13 Jul 2022	8.9	2.643 AU	1.791 AU	16h59m	-03°45'	139.0°	14.6°	119°
Perihelion	17 Dec 2022	8.5	1.800 AU	2.485 AU	17h51m	-60°22'	37.1°	19.2°	176°
Today	14 Mar 2026	17.1	10.777 AU	10.734 AU	05h28m	+31°16'	89.8°	5.3°	87°

The interactive orbit chart above shows the comet's path through the solar system and its position at the given date. Green and blue lines are shown perpendicular to the ecliptic plane: Green if the path is above the ecliptic plane, blue if it is below. (Left-click and drag to rotate the view; Right-click and drag to move the view; Use scroll wheel to zoom in our out.)

Light curve

The light curve chart below shows the estimated development of the comet's magnitude. Blue and black dots are visual and photometric CCD observations from COBS. This lightcurve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 4.7 + 5 log[∆] + 7.0 log[r]). An additional green curve is displayed when an increase in apparent brightness is expected due to forward scattering of sunlight, which occurs when a dust-rich comet is located between the Earth and the Sun. (See Marcus 2007)

Charts

The all-sky chart below shows the path of the comet over the same period as the light curve. The comet's current position is marked yellow.

The following chart shows the short-term path of the comet in a field of view that is optimized for (~10x50) binoculars and finderscopes.

Orbital elements

The orbital elements of C/2017 K2 (PANSTARRS) are:

    e (Eccentricity)                : 0.9984910
    q (Perihelion distance)         : 1.8003040
    i (Inclination)                 : 87.63960
    Ω (Longitude of ascending node) : 88.22170
    ω (Argument of perihelion)      : 236.15020
    L (Longitude of perihelion)     : 91.73559
    B (Latitude of perihelion)      : -56.07779
    T (Time of perihelion passage)  : 2459931.49230
    P (Orbital period in years)     : 41208.32

    Epoch                           : 2026 Mar 13
    Reference                       : MPEC 2026-E44

    Classification(s):              : Nearly isotropic; Returning (a < 10000 AU); External (P > 200 years)

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-03-13 00:00 UT   05 28 29.2   +31 16 11    10.701   10.767   91.1    5.3    87   17.1 
2026-03-14 00:00 UT   05 28 29.6   +31 16 23    10.725   10.774   90.2    5.3    87   17.1 
2026-03-14 09:46 UT   05 28 29.8   +31 16 28    10.734   10.777   89.8    5.3    87   17.1 
2026-03-15 00:00 UT   05 28 30.3   +31 16 35    10.749   10.781   89.2    5.3    87   17.1 
2026-03-16 00:00 UT   05 28 31.5   +31 16 48    10.772   10.787   88.2    5.3    87   17.1 
2026-03-17 00:00 UT   05 28 33.1   +31 17 00    10.796   10.794   87.2    5.3    86   17.1 
2026-03-18 00:00 UT   05 28 35.2   +31 17 14    10.820   10.801   86.2    5.3    86   17.1 
2026-03-19 00:00 UT   05 28 37.7   +31 17 27    10.844   10.808   85.3    5.3    86   17.1 
2026-03-20 00:00 UT   05 28 40.7   +31 17 41    10.868   10.814   84.3    5.3    86   17.1 
2026-03-21 00:00 UT   05 28 44.0   +31 17 55    10.891   10.821   83.3    5.2    86   17.1 
2026-03-22 00:00 UT   05 28 47.8   +31 18 09    10.915   10.828   82.3    5.2    86   17.1 
2026-03-23 00:00 UT   05 28 52.0   +31 18 24    10.939   10.834   81.4    5.2    86   17.1 
2026-03-24 00:00 UT   05 28 56.6   +31 18 39    10.962   10.841   80.4    5.2    86   17.1 

    Terminology:
            
    delta:  distance between comet and earth in AU
    radius: distance between comet and sun in AU
    magn:   magnitude (brightness) estimate    
    ra:     right ascension in hours (24h = 360deg)
    dec:    declination in degrees
    elong:  elongation in degrees (angle sun-earth-comet)    
    phase:  phase angle in degrees (angle sun-comet-earth)        
    AU:     Astronomical Unit (mean distance between earth and sun: 149597870.7 km      
    

Orbital elements usually provided by the MPC (Minor Planet Center).
Observations contributed by observers worldwide, via COBS (Comet Observation Database) or the MPC (Minor Planet Center)
Calculations by a modified version of AAPlus, a C# implementation of the AA+ project by PJ Naughter from the algorithms presented in the book "Astronomical Algorithms" by Jean Meeus.
NGC2000 dso catalog and star labels from VizieR as provided by the Strasbourg astronomical Data Center.
Tycho2 catalog from the ESO archive.