Our #HubbleTopImage features a celestial bauble 🪩⁠ ⁠ This sphere of gas appears to float serenely through space. Its apparent calm, however, hides an inner turmoil – it formed as a supernova’s expanding blast wave and ejected material tore through the nearby interstellar medium! 💥⁠ ⁠ Ripples in the shell’s surface may be caused either by subtle variations in the density of the ambient interstellar gas, or by fragments from the initial explosion. The bubble-shaped shroud of gas is 23 light-years across and is expanding at more than 18 million km/h.⁠ ⁠ For more information check the link in bio.⁠ ⁠ 📷 NASA, ESA, and the Hubble Heritage Team (STScI/AURA). Acknowledgement: J. Hughes (Rutgers University)⁠ ⁠ #ESA #Hubble