In approximately ten billion years, our Sun will cease to exist, that much is clear. But astronomers, of course, are thinking even farther out – they wonder what will become of our mother star. Nine out of ten stars will leave behind a planetary nebula, a massive, illuminated cloud of interstellar gas and dust, when they transition from red giants to white dwarves. A nebula can contain almost half the mass of its former star; the nebula is visible for approximately 10,000 years, as long as the core is still hot enough to light up the cloud from inside.…