Compare Hubble’s two observations of a portion of the Trifid Nebula, one taken in 2026 with the telescope’s current Wide Field Camera 3 and the other in 1997 with an earlier instrument (the Wide Field and Planetary Camera 2).

This portrait of star formation spotlights Herbig-Haro 399, a jet of plasma periodically ejected by an actively forming star to produce the long, wiggling line pointing to the top left. The 29 years between these observations show how the jet has expanded. Its counter jet is within the dark brown dust, and shows up as jagged orange and red lines where a natural V appears in the brown dust.

Other changes are evident near the bottom right, specifically the rippling angled line that begins in bright orange and ends in blazing red. The newer observation shows it has expanded toward the right.

The pinker stars in the scene also appear to twinkle or move. This is because stars’ positions change from our line of sight, ever so slightly, over decades. This effect is known as proper motion.

Credit:

NASA, ESA, STScI, J. DePasquale (STScI)