Positions of STEREO A and B for 16-Sep-2026 09:00 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)      1.083095        1.005433        0.965109        0.435915        0.593464        0.457504
Semidiameter (arcsec)            886.005         954.443         994.320        2201.408        1616.993        2097.527

HCI longitude                    209.805         277.450         346.896         224.718         313.604         151.475
HCI latitude                       3.453           7.191           1.588           2.749          16.847          -3.318

Carrington longitude              59.669         127.314         196.760          74.582         163.468           1.339
Carrington rotation number      2315.834        2315.646        2315.453        2315.793        2315.546        2315.996

Heliographic (HEEQ) longitude    -67.644          -0.000          69.446         -52.732          36.154        -125.974
Heliographic (HEEQ) latitude       3.453           7.191           1.588           2.749          16.847          -3.318

HAE longitude                    285.752         353.156          62.567         300.501          28.118         227.065

Earth Ecliptic (HEE) longitude   -67.405          -0.000          69.411         -52.655          34.961        -126.091
Earth Ecliptic (HEE) latitude     -0.169           0.000          -0.061          -2.361          11.539           0.156

Roll from ecliptic north          -0.069                           0.024
Roll from solar north             -6.357                           7.086

Light travel time to Earth (min)           9.654           9.336                   6.806           5.292          11.041

Separation angle with Earth               67.405          69.411                  52.692          36.584         126.091
Separation angle A with B                        136.815

Carrington rotation 2315 runs from 2026-08-29 18:07 (DOY 241.75) to
2026-09-26 00:28 (DOY 269.02), as seen from Earth.

Last Revised: Wednesday, 16-Sep-2026 09:01:07 UTC
Responsible NASA Official:
Accessibility
Privacy Policy and Important Notices
Feedback and comments: webmaster