The remains of a water-rich asteroid have been found splattered across the face of a "zombie" star about 150 light years away. It is first time that we have seen chemical evidence for water on rocky worlds orbiting other stars. The discovery was made on a white dwarf star: what's left of a star like our sun when it dies. It supports the idea that our galaxy hosts many life-friendly exoplanets akin to Earth. It also hints that some watery rocks in our solar system could remain after our sun burns out, to be a resource for spacefaring humans of the distant future. Water, a key ingredient for life as we know it, has been spotted in the atmospheres of gas-giant exoplanets. We expect it to exist on some of the smaller, rocky planets in the habitable zone of other stars-where temperatures are warm enough for it to be in liquid form.
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