(85) Io
ephemeris	date	magn	radius	delta	ra	dec	elong	phase
Today	20 Sep 2026	13.8	2.956 AU	3.337 AU	07h51m	+10°28'	59.5°	17.0°
Opposition	22 Jan 2027	12.5	3.102 AU	2.148 AU	08h03m	+02°50'	162.8°	5.4°

The interactive orbit chart above shows the body'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 Io are:

            e (Eccentricity)                : 0.1929889
            a (Semimajor axis)              : 2.6535067
            i (Inclination)                 : 11.95950
            Ω (Longitude of ascending node) : 203.03593
            ω (Argument of perihelion)      : 122.96267
            M (Mean anomaly)                : 93.83602
            Epoch                           : 2026 Jun 09

            L (Longitude of perihelion)     : 146.57512
            B (Latitude of perihelion)      : 10.01250
            P (Orbital period in years)     : 4.32            
        

The light curve chart below shows the estimated development of the minor planet's magnitude.

The all-sky chart below shows the path of the minor planet over the same period as the light curve. The current position is marked yellow.

The following chart shows the path of the minor planet in the next few days. The field of view is optimized for (~10x50) binoculars and finderscopes.

Ephemerides:

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-09-20 00:00 UT   07 51 05.0   +10 28 11     3.337    2.956   59.5   17.0   275   13.8 
2026-09-20 05:43 UT   07 51 21.2   +10 26 46     3.334    2.957   59.7   17.0   275   13.8 
2026-09-21 00:00 UT   07 52 12.8   +10 22 12     3.326    2.958   60.2   17.1   275   13.8 
2026-09-22 00:00 UT   07 53 20.0   +10 16 11     3.316    2.959   60.8   17.2   275   13.8 
2026-09-23 00:00 UT   07 54 26.5   +10 10 08     3.305    2.961   61.5   17.3   275   13.8 
2026-09-24 00:00 UT   07 55 32.4   +10 04 04     3.294    2.962   62.2   17.4   276   13.8 
2026-09-25 00:00 UT   07 56 37.7   +09 57 58     3.283    2.964   62.9   17.5   276   13.8 
2026-09-26 00:00 UT   07 57 42.2   +09 51 51     3.272    2.965   63.6   17.6   276   13.8 
2026-09-27 00:00 UT   07 58 46.1   +09 45 41     3.261    2.966   64.2   17.7   276   13.8 
2026-09-28 00:00 UT   07 59 49.3   +09 39 31     3.250    2.968   64.9   17.8   277   13.8 
2026-09-29 00:00 UT   08 00 51.8   +09 33 19     3.239    2.969   65.6   17.9   277   13.8 
2026-09-30 00:00 UT   08 01 53.6   +09 27 05     3.228    2.971   66.3   18.0   277   13.8 
2026-10-01 00:00 UT   08 02 54.7   +09 20 51     3.216    2.972   67.0   18.1   277   13.8 
2026-10-02 00:00 UT   08 03 55.1   +09 14 35     3.205    2.974   67.7   18.2   278   13.8 
2026-10-03 00:00 UT   08 04 54.7   +09 08 18     3.194    2.975   68.4   18.2   278   13.8 
2026-10-04 00:00 UT   08 05 53.6   +09 01 60     3.182    2.976   69.1   18.3   278   13.8 
2026-10-05 00:00 UT   08 06 51.7   +08 55 41     3.170    2.978   69.9   18.4   278   13.8 
2026-10-06 00:00 UT   08 07 49.1   +08 49 21     3.159    2.979   70.6   18.5   278   13.7 
2026-10-07 00:00 UT   08 08 45.6   +08 42 60     3.147    2.981   71.3   18.5   279   13.7 
2026-10-08 00:00 UT   08 09 41.4   +08 36 38     3.135    2.982   72.0   18.6   279   13.7 
2026-10-09 00:00 UT   08 10 36.4   +08 30 16     3.123    2.983   72.7   18.7   279   13.7 
2026-10-10 00:00 UT   08 11 30.5   +08 23 54     3.111    2.985   73.5   18.7   279   13.7 
2026-10-11 00:00 UT   08 12 23.9   +08 17 30     3.099    2.986   74.2   18.8   280   13.7 
2026-10-12 00:00 UT   08 13 16.3   +08 11 07     3.087    2.988   74.9   18.8   280   13.7 
2026-10-13 00:00 UT   08 14 08.0   +08 04 43     3.075    2.989   75.7   18.9   280   13.7 
2026-10-14 00:00 UT   08 14 58.7   +07 58 19     3.063    2.990   76.4   18.9   280   13.7 
2026-10-15 00:00 UT   08 15 48.6   +07 51 55     3.051    2.992   77.2   19.0   280   13.7 
2026-10-16 00:00 UT   08 16 37.7   +07 45 31     3.038    2.993   77.9   19.0   281   13.7 
2026-10-17 00:00 UT   08 17 25.8   +07 39 07     3.026    2.994   78.7   19.1   281   13.7 
2026-10-18 00:00 UT   08 18 13.0   +07 32 44     3.014    2.996   79.4   19.1   281   13.7 
2026-10-19 00:00 UT   08 18 59.3   +07 26 20     3.001    2.997   80.2   19.1   281   13.7 
2026-10-20 00:00 UT   08 19 44.7   +07 19 57     2.989    2.998   81.0   19.1   282   13.7 

    Terminology:
            
    delta:  distance between minor planet and earth in AU
    radius: distance between minor planet 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-minor planet)    
    phase:  phase angle in degrees (angle sun-minor planet-earth)        
    AU:     Astronomical Unit (mean distance between earth and sun: 149597870.7 km
    

Orbital elements provided by 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.