C/2020 M3 (ATLAS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	25 Oct 2020	8.3	1.280 AU	0.419 AU	05h10m	-16°21'	124.6°	39.7°	298°
Nearest approach	14 Nov 2020	8.3	1.314 AU	0.372 AU	05h27m	+05°38'	146.1°	24.9°	295°
Today	4 Sep 2026	34.4	15.805 AU	16.615 AU	13h14m	+12°40'	35.5°	2.1°	85°

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)                : 0.9531650
    q (Perihelion distance)         : 1.2797570
    i (Inclination)                 : 23.47240
    Ω (Longitude of ascending node) : 71.16670
    ω (Argument of perihelion)      : 328.74130
    L (Longitude of perihelion)     : 42.05795
    B (Latitude of perihelion)      : -11.92803
    T (Time of perihelion passage)  : 2459147.63030
    P (Orbital period in years)     : 142.84

    Epoch                           : 2026 May 29
    Reference                       : MPC194168

    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
2026-09-03 00:00 UT   13 14 25.9   +12 43 05    16.595   15.798   36.6    2.2    86   34.3 
2026-09-04 00:00 UT   13 14 37.7   +12 41 08    16.608   15.803   35.9    2.1    85   34.4 
2026-09-04 13:24 UT   13 14 44.3   +12 40 03    16.615   15.805   35.5    2.1    85   34.4 
2026-09-05 00:00 UT   13 14 49.6   +12 39 11    16.621   15.807   35.1    2.1    84   34.4 
2026-09-06 00:00 UT   13 15 01.7   +12 37 15    16.634   15.812   34.4    2.1    83   34.4 
2026-09-07 00:00 UT   13 15 13.8   +12 35 19    16.646   15.817   33.6    2.0    82   34.4 
2026-09-08 00:00 UT   13 15 26.1   +12 33 23    16.658   15.822   32.9    2.0    81   34.4 
2026-09-09 00:00 UT   13 15 38.5   +12 31 28    16.670   15.827   32.2    1.9    80   34.4 
2026-09-10 00:00 UT   13 15 51.0   +12 29 33    16.682   15.832   31.4    1.9    79   34.4 
2026-09-11 00:00 UT   13 16 03.6   +12 27 39    16.693   15.837   30.7    1.9    78   34.4 
2026-09-12 00:00 UT   13 16 16.4   +12 25 45    16.705   15.841   30.0    1.8    77   34.4 
2026-09-13 00:00 UT   13 16 29.2   +12 23 51    16.716   15.846   29.3    1.8    76   34.4 
2026-09-14 00:00 UT   13 16 42.1   +12 21 59    16.726   15.851   28.7    1.7    75   34.4 

    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.