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	23 Apr 2026	30.0	20.641 AU	20.298 AU	09h55m	+24°59'	108.6°	2.6°	114°

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
2026-04-22 00:00 UT   09 55 14.5   +25 00 07    20.260   20.632  110.4    2.6   115   30.0 
2026-04-23 00:00 UT   09 55 08.5   +24 59 58    20.281   20.637  109.4    2.6   114   30.0 
2026-04-23 19:35 UT   09 55 03.8   +24 59 50    20.298   20.641  108.6    2.6   114   30.0 
2026-04-24 00:00 UT   09 55 02.7   +24 59 48    20.302   20.642  108.4    2.6   114   30.0 
2026-04-25 00:00 UT   09 54 57.1   +24 59 36    20.323   20.647  107.4    2.7   114   30.0 
2026-04-26 00:00 UT   09 54 51.7   +24 59 24    20.344   20.652  106.5    2.7   114   30.1 
2026-04-27 00:00 UT   09 54 46.5   +24 59 10    20.365   20.657  105.5    2.7   114   30.1 
2026-04-28 00:00 UT   09 54 41.5   +24 58 55    20.386   20.663  104.5    2.7   113   30.1 
2026-04-29 00:00 UT   09 54 36.7   +24 58 39    20.408   20.668  103.6    2.7   113   30.1 
2026-04-30 00:00 UT   09 54 32.1   +24 58 22    20.429   20.673  102.6    2.7   113   30.1 
2026-05-01 00:00 UT   09 54 27.7   +24 58 04    20.450   20.678  101.6    2.7   113   30.1 
2026-05-02 00:00 UT   09 54 23.5   +24 57 45    20.472   20.683  100.7    2.7   112   30.1 
2026-05-03 00:00 UT   09 54 19.5   +24 57 25    20.494   20.688   99.7    2.8   112   30.1 

    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.