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

Positions of STEREO A and B for 23-Jun-2025 13:00 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)      1.056068        1.016362        0.954733        0.223045        0.900070        0.430466
Semidiameter (arcsec)            908.680         944.179        1005.127        4302.386        1066.170        2229.278

HCI longitude                    156.664         196.079         235.490         203.319          14.542         132.867
HCI latitude                      -3.065           2.022           6.112           1.570           8.407          -2.950

Carrington longitude             267.145         306.559         345.970         313.799         125.022         243.347
Carrington rotation number      2299.258        2299.148        2299.039        2299.128        2298.653        2299.324

Heliographic (HEEQ) longitude    -39.414          -0.000          39.411           7.240         178.463         -63.212
Heliographic (HEEQ) latitude      -3.065           2.022           6.112           1.570           8.407          -2.950

HAE longitude                    232.242         271.968         311.479         279.100          89.156         208.608

Earth Ecliptic (HEE) longitude   -39.726           0.000          39.511           7.132         177.188         -63.360
Earth Ecliptic (HEE) latitude     -0.181          -0.000           0.124          -1.308          10.163           2.367

Roll from ecliptic north          -0.220                          -0.148
Roll from solar north             -6.875                          -4.249

Light travel time to Earth (min)           5.865           5.562                   6.617          15.872           7.560

Separation angle with Earth               39.726          39.511                   7.251         169.459          63.384
Separation angle A with B                         79.238

Carrington rotation 2299 runs from 2025-06-19 12:06 (DOY 170.50) to
2025-07-16 16:54 (DOY 197.70), as seen from Earth.

Last Revised: Monday, 23-Jun-2025 13:01:06 UTC
Responsible NASA Official:
Accessibility
Privacy Policy and Important Notices
Feedback and comments: webmaster