C/2018 E1 (ATLAS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	7 Mar 2018	17.4	2.723 AU	2.740 AU	04h27m	-45°21'	78.6°	20.9°	94°
Perihelion	18 Apr 2018	17.5	2.689 AU	2.868 AU	05h44m	-27°54'	69.7°	20.5°	115°
Today	9 May 2025	27.4	17.521 AU	17.221 AU	15h38m	+56°40'	105.6°	3.2°	188°

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.)

The orbital elements of C/2018 E1 (ATLAS) are:

            e (Eccentricity)                : 0.9501030
            q (Perihelion distance)         : 2.6893810
            i (Inclination)                 : 72.48750
            Ω (Longitude of ascending node) : 146.79020
            ω (Argument of perihelion)      : 299.27380
            L (Longitude of perihelion)     : 118.56342
            B (Latitude of perihelion)      : -56.29063
            T (Time of perihelion passage)  : 2458227.05560
            P (Orbital period in years)     : 395.70

            Epoch                           : 2023 Sep 24
            Reference                       : MPC114602

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

The light curve chart below shows the estimated development of the comet's magnitude. Blue and black dots are visual and photometric CCD observations respectively from COBS or the MPC. The gray curve is based on the absolute magnitude and slope parameter as calculated from the original MPEC, or the latest values provided by the MPC (10.50 + 5 log[∆] + 10.00 log[r]), whereas the red curve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 11.96 + 5 log[∆] + 7.48 log[r]).

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.
A more printer-friendly version of the same chart can be found further down this page as well.

The following chart shows the current location of the comet in a smaller, upside-down telescopic field of view.

A printable version of the short-term path of the comet in a field of view that is optimized for (~10x50) binoculars and finderscopes.

Ephemerides:

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-05-09 00:00 UT   15 38 08.2   +56 40 11    17.219   17.519  105.7    3.2   189   27.4 
2025-05-09 07:41 UT   15 38 01.6   +56 40 23    17.221   17.521  105.6    3.2   188   27.4 
2025-05-10 00:00 UT   15 37 47.6   +56 40 47    17.227   17.524  105.5    3.2   188   27.4 
2025-05-11 00:00 UT   15 37 26.9   +56 41 20    17.235   17.529  105.3    3.2   187   27.4 
2025-05-12 00:00 UT   15 37 06.3   +56 41 49    17.243   17.534  105.1    3.2   185   27.4 
2025-05-13 00:00 UT   15 36 45.6   +56 42 15    17.251   17.539  104.9    3.2   184   27.4 
2025-05-14 00:00 UT   15 36 24.9   +56 42 37    17.260   17.544  104.7    3.2   183   27.4 
2025-05-15 00:00 UT   15 36 04.1   +56 42 56    17.268   17.548  104.5    3.2   182   27.5 
2025-05-16 00:00 UT   15 35 43.4   +56 43 11    17.276   17.553  104.3    3.2   181   27.5 
2025-05-17 00:00 UT   15 35 22.7   +56 43 22    17.285   17.558  104.0    3.2   180   27.5 
2025-05-18 00:00 UT   15 35 02.0   +56 43 30    17.294   17.563  103.8    3.2   179   27.5 
2025-05-19 00:00 UT   15 34 41.3   +56 43 35    17.302   17.568  103.6    3.2   178   27.5 

    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.