Information about STEREO-A close approach to Earth, August 2023

Positions of STEREO A and B for 2-Apr-2025 02:00 UT

This figure plots the current positions of the STEREO Ahead (red) and Behind (blue) spacecraft relative to the Sun (yellow) and Earth (green). The dotted lines show the angular displacement from the Sun. Units are in A.U.

When the two spacecraft are close to Earth, an expanded view of the region around Earth will appear on the right, in the same orientation as the Sun-centered view.

Other resources:

• STEREO Orbit Tool
• STEREO-A Fly-by Orbit Tool for Summer 2023
• STEREO-A roll angle during Fly-By
• STEREO orbit simulations
• Satellite Situation Center (SSCWeb)
• HelioWeb
• Attitude and orbit text files (CalTech)
• Early orbit summary
• Connections with Parker Solar Probe
• Explanation of coordinate systems

                                STEREO-B           Earth        STEREO-A       Parker SP   Solar Orbiter     BepiColombo

Heliocentric distance (AU)      1.006169        0.999530        0.958054        0.399054        0.296157        0.443578
Semidiameter (arcsec)            953.744         960.079        1001.642        2404.757        3240.269        2163.382

HCI longitude                     78.077         116.655         148.628         221.970         205.814         143.929
HCI latitude                      -7.061          -6.487          -3.764           2.616          -5.331          -3.209

Carrington longitude             278.179         316.757         348.730          62.072          45.916         344.032
Carrington rotation number      2296.227        2296.120        2296.031        2295.828        2295.872        2296.044

Heliographic (HEEQ) longitude    -38.578           0.000          31.973         105.315          89.159          27.274
Heliographic (HEEQ) latitude      -7.061          -6.487          -3.764           2.616          -5.331          -3.209

HAE longitude                    153.934         192.237         224.191         297.753         280.787         219.586

Earth Ecliptic (HEE) longitude   -38.302          -0.000          31.955         105.517          88.551          27.349
Earth Ecliptic (HEE) latitude      0.038          -0.000           0.024          -2.241          -8.450           1.067

Roll from ecliptic north           0.045                          -0.040
Roll from solar north              1.539                          -6.227

Light travel time to Earth (min)           5.473           4.494                   9.741           8.611           5.315

Separation angle with Earth               38.302          31.955                 105.504          88.566          27.368
Separation angle A with B                         70.257

Carrington rotation 2296 runs from 2025-03-29 19:19 (DOY  88.80) to
2025-04-26 01:47 (DOY 116.07), as seen from Earth.

Last Revised: Wednesday, 02-Apr-2025 02:01:07 UTC
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