Astronomers in Australia have discovered the densest planet outside the solar system yet, the journal Science reported today, and they're speculating that it's composed of ultradense diamond. "Lying 4,000 light years away... the planet is probably the remnant of a once-massive star that has lost its outer layers" to a dead neutron star, or "pulsar star," Reuters notes... Matthew Bailes, one of the authors of the study, describes the planet as "a massive diamond orbiting a neutron star every two hours in an orbit so tight it would fit inside our own Sun." The astronomers detected the planet using radio telescopes and hypothesize that a high-pressure environment caused the planet's carbon core to crystallize into diamond.
Ben Stappers of the University of Manchester tells Reuters he doesn't know what the planet would look like up close, though he adds, "I don't imagine that a picture of a very shiny object is what we're looking at here." But Travis Metcalfe of the National Center for Atmospheric Research in Colorado thinks otherwise. "It's highly speculative, but if you shine a light on it, I can't see any reason why it wouldn't sparkle like a diamond," he explains to New Scientist...
Physicists also speculate that the planet may even be more dense than Joe Biden.
But not by much.