C/2018 N1 (NEOWISE)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	27 Jul 2018	9.0	1.310 AU	0.306 AU	20h24m	-37°13'	161.9°	13.9°	2°
Perihelion	3 Aug 2018	9.5	1.306 AU	0.397 AU	17h20m	-29°14'	130.2°	36.4°	89°
Today	19 Oct 2025	29.8	19.675 AU	20.180 AU	10h18m	+22°40'	58.3°	2.5°	299°

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 10.4 + 5 log[∆] + 10.0 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/2018 N1 (NEOWISE) are:

    e (Eccentricity)                : 0.9974900
    q (Perihelion distance)         : 1.3062340
    i (Inclination)                 : 159.38870
    Ω (Longitude of ascending node) : 292.59000
    ω (Argument of perihelion)      : 354.74820
    L (Longitude of perihelion)     : 297.50734
    B (Latitude of perihelion)      : -1.84650
    T (Time of perihelion passage)  : 2458333.93300
    P (Orbital period in years)     : 11871.92

    Epoch                           : 2023 Sep 24
    Reference                       : MPEC 2022-M21

    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
2025-10-18 00:00 UT   10 18 06.7   +22 40 52    20.191   19.668   57.1    2.4   299   29.8 
2025-10-19 00:00 UT   10 18 12.6   +22 40 47    20.182   19.673   58.0    2.5   299   29.8 
2025-10-19 05:43 UT   10 18 14.0   +22 40 46    20.180   19.675   58.3    2.5   299   29.8 
2025-10-20 00:00 UT   10 18 18.4   +22 40 43    20.172   19.679   59.0    2.5   298   29.8 
2025-10-21 00:00 UT   10 18 24.0   +22 40 41    20.163   19.684   59.9    2.5   298   29.8 
2025-10-22 00:00 UT   10 18 29.4   +22 40 40    20.153   19.689   60.9    2.5   298   29.8 
2025-10-23 00:00 UT   10 18 34.7   +22 40 40    20.144   19.694   61.8    2.6   298   29.8 
2025-10-24 00:00 UT   10 18 39.8   +22 40 41    20.134   19.699   62.8    2.6   297   29.8 
2025-10-25 00:00 UT   10 18 44.7   +22 40 43    20.124   19.705   63.8    2.6   297   29.8 
2025-10-26 00:00 UT   10 18 49.5   +22 40 47    20.114   19.710   64.7    2.6   297   29.8 
2025-10-27 00:00 UT   10 18 54.1   +22 40 52    20.103   19.715   65.7    2.6   297   29.8 
2025-10-28 00:00 UT   10 18 58.5   +22 40 59    20.093   19.720   66.6    2.7   297   29.8 
2025-10-29 00:00 UT   10 19 02.7   +22 41 06    20.082   19.726   67.6    2.7   296   29.8 

    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.