C/2020 M5 (ATLAS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	19 Aug 2021	15.0	3.000 AU	3.627 AU	12h29m	+43°14'	45.2°	13.8°	59°
Nearest approach	2 Mar 2022	15.0	3.556 AU	2.598 AU	12h02m	+10°26'	162.6°	4.8°	260°
Today	9 Dec 2025	23.9	12.561 AU	12.580 AU	08h58m	-56°41'	86.6°	4.5°	308°

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 7.5 + 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/2020 M5 (ATLAS) are:

    e (Eccentricity)                : 1.0000730
    q (Perihelion distance)         : 3.0003790
    i (Inclination)                 : 93.16350
    Ω (Longitude of ascending node) : 351.99610
    ω (Argument of perihelion)      : 126.24700
    L (Longitude of perihelion)     : 356.30073
    B (Latitude of perihelion)      : 53.63408
    T (Time of perihelion passage)  : 2459446.14990

    Epoch                           : 2025 Dec 08
    Reference                       : MPEC 2023-FK0

    Classification(s):              : Nearly isotropic; New (a > 10000 AU)

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-12-08 00:00 UT   08 58 37.1   -56 35 45    12.581   12.553   86.1    4.5   307   23.9 
2025-12-09 00:00 UT   08 58 12.8   -56 39 54    12.581   12.559   86.5    4.5   308   23.9 
2025-12-09 10:00 UT   08 58 02.5   -56 41 37    12.580   12.561   86.6    4.5   308   23.9 
2025-12-10 00:00 UT   08 57 48.0   -56 43 60    12.580   12.565   86.8    4.5   309   23.9 
2025-12-11 00:00 UT   08 57 22.6   -56 48 02    12.579   12.571   87.2    4.5   310   23.9 
2025-12-12 00:00 UT   08 56 56.7   -56 52 00    12.579   12.577   87.6    4.5   311   23.9 
2025-12-13 00:00 UT   08 56 30.2   -56 55 55    12.578   12.583   88.0    4.5   312   23.9 
2025-12-14 00:00 UT   08 56 03.1   -56 59 47    12.577   12.589   88.4    4.5   313   23.9 
2025-12-15 00:00 UT   08 55 35.5   -57 03 35    12.577   12.595   88.8    4.5   314   23.9 
2025-12-16 00:00 UT   08 55 07.4   -57 07 18    12.576   12.601   89.2    4.5   315   24.0 
2025-12-17 00:00 UT   08 54 38.7   -57 10 58    12.575   12.607   89.6    4.5   316   24.0 
2025-12-18 00:00 UT   08 54 09.5   -57 14 34    12.575   12.613   89.9    4.5   317   24.0 
2025-12-19 00:00 UT   08 53 39.8   -57 18 06    12.574   12.619   90.3    4.5   318   24.0 

    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.