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

Positions of STEREO A and B for 4-Jun-2025 15:00 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)      1.043443        1.014477        0.954287        0.495160        0.865601        0.334355
Semidiameter (arcsec)            919.674         945.934        1005.597        1938.017        1108.626        2870.083

HCI longitude                    139.460         178.143         215.422         269.920         358.978          55.283
HCI latitude                      -4.877          -0.233           4.344           3.861          12.039           0.958

Carrington longitude             158.262         196.945         234.224         288.722          17.780          74.084
Carrington rotation number      2298.560        2298.453        2298.349        2298.198        2298.951        2298.794

Heliographic (HEEQ) longitude    -38.683          -0.000          37.279          91.777        -179.165        -122.861
Heliographic (HEEQ) latitude      -4.877          -0.233           4.344           3.861          12.039           0.958

HAE longitude                    214.984         253.894         291.418         345.686          73.211         130.763

Earth Ecliptic (HEE) longitude   -38.910          -0.000          37.524          91.792         179.317        -123.131
Earth Ecliptic (HEE) latitude     -0.151           0.000           0.123          -3.391          11.816           6.913

Roll from ecliptic north          -0.189                          -0.158
Roll from solar north             -5.694                          -6.062

Light travel time to Earth (min)           5.705           5.288                   9.504          15.554          10.217

Separation angle with Earth               38.910          37.524                  91.789         168.165         122.860
Separation angle A with B                         76.434

Carrington rotation 2298 runs from 2025-05-23 07:15 (DOY 143.30) to
2025-06-19 12:06 (DOY 170.50), as seen from Earth.

Last Revised: Wednesday, 04-Jun-2025 15:01:06 UTC
Responsible NASA Official:
Accessibility
Privacy Policy and Important Notices
Feedback and comments: webmaster