By chance, two meteoroids flew across the foreground of this image of the Andromeda Galaxy. They are out of focus because they are too close. The brighter meteoroid changes intensity partway across. The arc shaped shadow on the left side is a ghost image of a bright star located just outside the field of view. To the right of center you can see a separate ghost image caused by the x-shaped ‘spiders’ which support the telescope’s secondary mirror. By analyzing images like this one, we learned that the light trails of typical micrometeoroids are only a few millimeters across.

Text by: Masnori Iye (Subaru Telescope, TMT Project Office)
Translation by: Ramsey Lundock (NAOJ)