NASA to journey to a metal-rich asteroid

CAPE CANAVERAL, Fla.

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 was set to blast off on Oct. 12 bound for Psyche, an object 2.2 billion miles (3.5 billion kilometers) away that could offer clues about the interior of planets like Earth.

"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.

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.

Over the following two years, it will deploy its suite of advanced instruments to look for evidence of an ancient magnetic field, probe its chemical composition, and study the minerals and topography of Psyche.

Scientists think Psyche, named after the goddess of the soul in Greek mythology, could be part of the iron-rich core of a "planetesimal," a building block of all rocky planets.

It could also be something else, a leftover piece of an iron-rich, primordial solar system object that's not yet been documented.

"This is our one way to see a core," said Elkins-Tanton. "We say tongue in cheek that we're going to outer space to explore inner space."

Psyche is thought to have an irregular, potato-like shape, measuring 173 miles (280 kilometers) across at its widest point though it's never actually been seen up close.

Until recently, scientists thought it was overwhelmingly composed of metal but analyses based on reflected radar and light now indicate that metal probably comprises between 30-60 percent, with the rest being rock.

The Psyche spacecraft, named after the asteroid, will test out next generation communications based on lasers, rather than radio waves, a step NASA compares to upgrading old telephone lines on Earth to fiber optics.