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

Positions of STEREO A and B for 26-Mar-2025 08:00 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)      1.003892        0.997604        0.958801        0.193729        0.316616        0.419636
Semidiameter (arcsec)            955.908         961.932        1000.862        4953.442        3030.891        2286.810

HCI longitude                     71.312         109.944         141.550         198.244         156.757         122.328
HCI latitude                      -6.815          -6.820          -4.514           1.251         -15.572          -2.604

Carrington longitude               7.159          45.791          77.397         134.091          92.604          58.175
Carrington rotation number      2295.980        2295.873        2295.785        2295.628        2295.743        2295.838

Heliographic (HEEQ) longitude    -38.632           0.000          31.606          88.300          46.813          12.384
Heliographic (HEEQ) latitude      -6.815          -6.820          -4.514           1.251         -15.572          -2.604

HAE longitude                    147.215         185.563         217.092         274.024         230.858         198.125

Earth Ecliptic (HEE) longitude   -38.348          -0.000          31.529          88.461          45.295          12.563
Earth Ecliptic (HEE) latitude      0.060           0.000           0.008          -1.026         -12.613           3.523

Roll from ecliptic north           0.072                          -0.016
Roll from solar north              2.390                          -5.689

Light travel time to Earth (min)           5.468           4.432                   8.410           6.766           4.960

Separation angle with Earth               38.348          31.529                  88.461          46.648          13.040
Separation angle A with B                         69.877

Carrington rotation 2295 runs from 2025-03-02 11:51 (DOY  61.49) to
2025-03-29 19:19 (DOY  88.80), as seen from Earth.

Last Revised: Wednesday, 26-Mar-2025 08:01:06 UTC
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