It’s a world like no other: a metal-rich asteroid that could be the remnants of a small planet, or perhaps an entirely new type of celestial body unknown to science. A NASA probe is set to blast off Friday bound for Psyche, an object 2.2 billion miles (3.6 billion kilometers) away that could offer clues about the interior of planets like Earth. Weather conditions were rated as 85 percent favorable for the launch on Friday morning. “We’ve visited either in person or robotically worlds made of rock, worlds made of ice and worlds made of gas… but this will be our first time visiting a world that has a metal surface,” lead scientist Lindy Elkins-Tanton told reporters during a briefing this week. NASA and SpaceX are targeting 10:19 am Eastern Time (1419 GMT) for launch from the Kennedy Space Center, aboard a SpaceX Falcon Heavy rocket, with a backup window on Saturday if necessary. Trailing a blue glow from its next-generation electric propulsion system and flanked by two large solar arrays, the van-sized probe should arrive at its destination in the Asteroid Belt, between Mars and Jupiter, in July 2029.