A note that the transLunar orbit insertion burn at 3 April ~00:01 UTC (duration 5m 45s) might be visible from Europe. It will generate a sunlit exhaust cloud that could be visible in binoculars, perhaps even naked eye. I have checked for our new TU Delft MISO telescope site and we have it 11 deg above our horizon (the Netherlands, 52N): more south in Europe will have it higher in the sky. - Marco ------ Dr Marco Langbroek Lecturer in optical Space Situational Awareness (SSA) TU Delft, Faculty of Aerospace Engineering section Astrodynamics and Space Missions ------ Op 28-3-2026 om 13:13 schreef Ted Molczan via Seesat-l: > Artemis II is scheduled for launch from KSC on 2026 Apr 01 at 22:24 UTC. Mission duration is 10 days. > > JPL Horizons has ephemerides of the spacecraft. I did not check Horizons for any other pieces from > the launch. > > https://ssd.jpl.nasa.gov/horizons/app.html > > Horizons does not have magnitude estimates for Artemis II, so I have made rough estimates. > > Based on dimensions published by NASA, I have estimated standard magnitude (1000 km range, 90 deg phase > angle) of 4.6 for the Orion spacecraft, and 3.9 for the final stage of the SLS booster plus spacecraft > adapter. The estimated uncertainty of both is 2 magnitudes. > > Below are magnitude estimates for a variety of ranges, for 100% illumination and 50% illumination. Since > Horizons states range in astronomical units, I have done likewise and included the km equivalent. > Note: Horizons uses the term delta for range. > > Range Estimated Magnitude > AU km 100% Ill. 50% Ill. > 0.00001 1496 4.2 5.5 > 0.00002 2992 5.7 7.0 > 0.00003 4488 6.6 7.9 > 0.00004 5984 7.2 8.5 > 0.00005 7480 7.7 9.0 > 0.00006 8976 8.1 9.4 > 0.00007 10472 8.5 9.7 > 0.00008 11968 8.7 10.0 > 0.00009 13464 9.0 10.2 > 0.00010 14960 9.2 10.5 > 0.00020 29920 10.7 12.0 > 0.00030 44879 11.6 12.9 > 0.00040 59839 12.2 13.5 > 0.00050 74799 12.7 14.0 > 0.00060 89759 13.1 14.4 > 0.00070 104719 13.5 14.7 > 0.00080 119678 13.7 15.0 > 0.00090 134638 14.0 15.2 > 0.00100 149598 14.2 15.5 > 0.00110 164558 14.4 15.7 > 0.00120 179517 14.6 15.9 > 0.00130 194477 14.8 16.0 > 0.00140 209437 15.0 16.2 > 0.00150 224397 15.1 16.3 > 0.00160 239357 15.2 16.5 > 0.00170 254316 15.4 16.6 > 0.00180 269276 15.5 16.7 > 0.00190 284236 15.6 16.9 > 0.00200 299196 15.7 17.0 > 0.00210 314156 15.8 17.1 > 0.00220 329115 15.9 17.2 > 0.00230 344075 16.0 17.3 > 0.00240 359035 16.1 17.4 > 0.00250 373995 16.2 17.5 > 0.00260 388954 16.3 17.5 > 0.00270 403914 16.4 17.6 > > Uncertainty = 2 magnitudes > Subtract 0.7 mag for rocket body > > Happy hunting! > Ted Molczan > > > > > _______________________________________________ > Seesat-l mailing list > https://lists.seesatmail.org/mailman/listinfo/seesat-l -- ---- Dr Marco Langbroek e-mail: marco_at_langbroek.org web: www.langbroek.org Twitter: _at_Marco_Langbroek ---- _______________________________________________ Seesat-l mailing list https://lists.seesatmail.org/mailman/listinfo/seesat-lReceived on Sat Mar 28 2026 - 08:59:10 UTC
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