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	0.392 AU	17h12m	-29°13'	127.8°	38.4°	90°
Today	10 Mar 2026	29.9	20.411 AU	19.526 AU	10h02m	+24°47'	152.3°	1.3°	135°

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)                : 0.9972610
    q (Perihelion distance)         : 1.2922140
    i (Inclination)                 : 159.33050
    Ω (Longitude of ascending node) : 292.71340
    ω (Argument of perihelion)      : 354.66440
    L (Longitude of perihelion)     : 297.70735
    B (Latitude of perihelion)      : -1.88096
    T (Time of perihelion passage)  : 2458334.60970
    P (Orbital period in years)     : 10247.40

    Epoch                           : 2026 Mar 09
    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
2026-03-09 00:00 UT   10 02 32.2   +24 46 31    19.514   20.406  153.3    1.3   136   29.9 
2026-03-10 00:00 UT   10 02 19.3   +24 47 16    19.526   20.411  152.3    1.3   135   29.9 
2026-03-10 01:13 UT   10 02 18.7   +24 47 18    19.526   20.411  152.3    1.3   135   29.9 
2026-03-11 00:00 UT   10 02 06.5   +24 47 60    19.538   20.416  151.4    1.3   134   29.9 
2026-03-12 00:00 UT   10 01 53.8   +24 48 43    19.550   20.421  150.5    1.4   133   29.9 
2026-03-13 00:00 UT   10 01 41.2   +24 49 24    19.563   20.426  149.5    1.4   132   29.9 
2026-03-14 00:00 UT   10 01 28.7   +24 50 05    19.576   20.432  148.5    1.5   131   29.9 
2026-03-15 00:00 UT   10 01 16.3   +24 50 44    19.590   20.437  147.6    1.5   130   29.9 
2026-03-16 00:00 UT   10 01 04.0   +24 51 22    19.603   20.442  146.6    1.5   129   29.9 
2026-03-17 00:00 UT   10 00 51.8   +24 51 58    19.617   20.447  145.7    1.6   129   29.9 
2026-03-18 00:00 UT   10 00 39.8   +24 52 34    19.631   20.452  144.7    1.6   128   29.9 
2026-03-19 00:00 UT   10 00 27.8   +24 53 08    19.646   20.457  143.7    1.7   127   29.9 
2026-03-20 00:00 UT   10 00 16.0   +24 53 41    19.660   20.462  142.7    1.7   127   29.9 

    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.