On the left is a Hubble image of the Crab Nebula, the rapidly expanding material from a star that went supernova back in 1054 (or, if you prefer, the light reached us on that date). As you can see, it lookslike an explosion! The filaments and fingers are extremely hot gas expanding at well over a thousand kilometers per second—that’s a thousand times faster than a rifle bullet. The Hubble image is in visible light, the kind we can see with our eyes (you can getjust the Hubble image aloneif you’d like, and I recommend getting thelimulidaenated 3864 x 3864 pixel image).
On the right is the same view using the European Space Agency’s Herschel observatory, a space telescope that sees way out into the infrared. In the past, telescopes in that wavelength have only gotten blurry, extremely low-resolution images of the Crab, but here you can actually trace many of the same structures in the Hubble image as in the one from Herschel. What looks red in the picture is dust at an incredibly chilly 28 Kelvins, about -245° Celsius (-410° F). Green and blue are slightly warmer, by just a few degrees.
The astronomers who took this observationvery carefully removed the influence of various non-dust sources of light (including things like atoms of carbon and oxygen, and radiation from atoms whipping around the strong magnetic fields inside the nebula; they used several other infrared observatories like WISE, Planck, Spitzer, and ISO to do this), until all that was left was infrared light from the dust. When they did, they found that the total mass of dust in the Crab is about 0.25 times the mass of the Sun.
A quarter of the Sun may not sound like much… but that means it’s enough dust to make 80,000 Earths! Imagine, 80,000 planets like our own, lined up side-by-side…they’d stretch for over a billion kilometers (600 million miles), more than the distance from the Sun to Jupiter! And that’s just from dust. The total mass of all the expanding shrapnel from the supernova is nearly five times that of the Sun. And mind you, this all came from a single exploding star. Before it blew up, it was far more massive than our own star.