Martian Moons Explorer, 21 October 2026

On the evening (UK time) of 19 October 2026, JAXA (Japan Aerospace Exploration Agency) launched Martian Moons eXplorer (MMX) from the Tanegashima Space Centre. The craft is designed to return the first samples from the Martian moon Phobos, with samples due to arrive on Earth in 2031.

In the early hours of 21 October, an opportunity arose to image the probe and its carrier rocket. The latter was easy to capture, even without predictions of its trajectory. Although the MMX space probe itself was bound to be nearby, I searched for it in vain, even checking that star trails had not hidden it.

The carrier rocket was tumbling, and I estimated an average magnitude of 16.8. Subsequent to my observations, predictions for visibility of MMX became available on ProjectPluto; they put the probe at magnitude 19. However, I think it is fainter than this and beyond my ability to image.

Nigel Evans.