C/2020 M3 (ATLAS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	25 Oct 2020	8.3	1.279 AU	0.416 AU	05h09m	-16°38'	124.8°	39.7°	298°
Nearest approach	14 Nov 2020	8.3	1.313 AU	0.369 AU	05h26m	+05°22'	146.3°	24.7°	295°
Today	13 Mar 2026	33.6	14.937 AU	14.072 AU	13h27m	+14°09'	149.5°	1.9°	251°

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 8.5 + 5 log[∆] + 16.5 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/2020 M3 (ATLAS) are:

    e (Eccentricity)                : 0.9532060
    q (Perihelion distance)         : 1.2786400
    i (Inclination)                 : 23.47590
    Ω (Longitude of ascending node) : 71.15150
    ω (Argument of perihelion)      : 328.74220
    L (Longitude of perihelion)     : 42.04426
    B (Latitude of perihelion)      : -11.92942
    T (Time of perihelion passage)  : 2459147.82310
    P (Orbital period in years)     : 142.84

    Epoch                           : 2026 Mar 12
    Reference                       : MPEC 2026-E44

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-03-12 00:00 UT   13 27 21.6   +14 07 21    14.074   14.931  148.5    2.0   253   33.6 
2026-03-13 00:00 UT   13 27 09.3   +14 09 11    14.072   14.936  149.3    1.9   252   33.6 
2026-03-13 08:22 UT   13 27 05.0   +14 09 50    14.072   14.937  149.5    1.9   251   33.6 
2026-03-14 00:00 UT   13 26 56.9   +14 11 01    14.071   14.941  150.0    1.9   250   33.6 
2026-03-15 00:00 UT   13 26 44.3   +14 12 50    14.070   14.946  150.7    1.9   249   33.6 
2026-03-16 00:00 UT   13 26 31.5   +14 14 38    14.070   14.951  151.4    1.8   247   33.6 
2026-03-17 00:00 UT   13 26 18.7   +14 16 25    14.069   14.956  152.0    1.8   245   33.6 
2026-03-18 00:00 UT   13 26 05.6   +14 18 11    14.069   14.961  152.7    1.7   243   33.6 
2026-03-19 00:00 UT   13 25 52.5   +14 19 57    14.069   14.966  153.3    1.7   242   33.6 
2026-03-20 00:00 UT   13 25 39.2   +14 21 41    14.070   14.971  153.9    1.7   240   33.6 
2026-03-21 00:00 UT   13 25 25.9   +14 23 24    14.071   14.976  154.4    1.6   238   33.6 
2026-03-22 00:00 UT   13 25 12.4   +14 25 06    14.072   14.981  155.0    1.6   235   33.6 
2026-03-23 00:00 UT   13 24 58.8   +14 26 47    14.073   14.986  155.5    1.6   233   33.6 

    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.