C/2018 N1 (NEOWISE)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	28 Jul 2018	8.8	1.296 AU	0.294 AU	20h26m	-38°19'	160.7°	15.0°	2°
Perihelion	4 Aug 2018	9.4	1.292 AU	0.391 AU	17h12m	-29°14'	127.8°	38.3°	90°
Today	24 Mar 2026	30.0	20.486 AU	19.731 AU	09h59m	+24°55'	138.2°	1.9°	124°

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)                : 0.9972580
    q (Perihelion distance)         : 1.2921300
    i (Inclination)                 : 159.33050
    Ω (Longitude of ascending node) : 292.71350
    ω (Argument of perihelion)      : 354.66320
    L (Longitude of perihelion)     : 297.70858
    B (Latitude of perihelion)      : -1.88138
    T (Time of perihelion passage)  : 2458334.59850
    P (Orbital period in years)     : 10229.59

    Epoch                           : 2026 Mar 16
    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
2026-03-23 00:00 UT   09 59 41.3   +24 55 13    19.706   20.478  139.8    1.8   125   29.9 
2026-03-24 00:00 UT   09 59 30.0   +24 55 41    19.722   20.483  138.8    1.8   124   29.9 
2026-03-24 14:58 UT   09 59 23.1   +24 55 58    19.731   20.486  138.2    1.9   124   30.0 
2026-03-25 00:00 UT   09 59 18.9   +24 56 08    19.737   20.488  137.8    1.9   124   30.0 
2026-03-26 00:00 UT   09 59 07.9   +24 56 33    19.754   20.493  136.9    1.9   124   30.0 
2026-03-27 00:00 UT   09 58 57.0   +24 56 57    19.770   20.498  135.9    1.9   123   30.0 
2026-03-28 00:00 UT   09 58 46.3   +24 57 20    19.786   20.504  134.9    2.0   123   30.0 
2026-03-29 00:00 UT   09 58 35.8   +24 57 42    19.803   20.509  133.9    2.0   122   30.0 
2026-03-30 00:00 UT   09 58 25.4   +24 58 02    19.820   20.514  132.9    2.0   122   30.0 
2026-03-31 00:00 UT   09 58 15.2   +24 58 21    19.837   20.519  131.9    2.1   121   30.0 
2026-04-01 00:00 UT   09 58 05.1   +24 58 39    19.855   20.524  131.0    2.1   121   30.0 
2026-04-02 00:00 UT   09 57 55.2   +24 58 56    19.872   20.529  130.0    2.1   121   30.0 
2026-04-03 00:00 UT   09 57 45.5   +24 59 11    19.890   20.534  129.0    2.2   120   30.0 

    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.