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

Positions of STEREO A and B for 13-Mar-2025 06:00 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)      1.000892        0.993915        0.960323        0.388478        0.472122        0.351334
Semidiameter (arcsec)            958.773         965.503         999.276        2470.224        2032.583        2731.385

HCI longitude                     58.155          96.849         127.824         277.487          95.623          69.756
HCI latitude                      -6.071          -7.201          -5.760           3.822         -13.392           0.120

Carrington longitude             179.581         218.276         249.250          38.913         217.049         191.182
Carrington rotation number      2295.501        2295.394        2295.308        2295.892        2295.397        2295.469

Heliographic (HEEQ) longitude    -38.695           0.000          30.974        -179.363          -1.227         -27.094
Heliographic (HEEQ) latitude      -6.071          -7.201          -5.760           3.822         -13.392           0.120

HAE longitude                    134.120         172.561         203.365         353.249         171.267         145.366

Earth Ecliptic (HEE) longitude   -38.441          -0.000          30.804        -179.312          -1.294         -27.194
Earth Ecliptic (HEE) latitude      0.101          -0.000          -0.022          -3.368          -6.174           6.923

Roll from ecliptic north           0.124                           0.033
Roll from solar north              3.943                          -4.406

Light travel time to Earth (min)           5.462           4.325                  11.494           4.385           5.850

Separation angle with Earth               38.441          30.804                 176.563           6.307          27.996
Separation angle A with B                         69.246

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: Thursday, 13-Mar-2025 06:01:06 UTC
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