US space agency Nasa and Elon Musk's aerospace company are all set to send a probe to a metal-rich asteroid to study the origins and evolution of the celestial rock about which the astronomers were unaware, calling it an entirely new phenomenon.
It is anticipated by astronomers that the space rock could be a part of a small planet.
The probe is to fly Friday bound for Psyche, an object 2.2 billion miles (3.5 billion kilometres) 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.
Nasa and Elon Musk's company scheduled the flight Friday at 10:19am Eastern Time from Kennedy Space Center, using a SpaceX Falcon Heavy rocket, with a backup window Saturday if weather conditions did not allow.
Trailing a blue glow from its next-generation electric propulsion system and flanked by two large solar arrays, the van-sized mission 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 kilometres) 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%, with the rest being rock.
The mission will include several technological innovations.
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 fibre optics.
Deep Space Optical Communications, as the system is called, "was designed to demonstrate 10 to 100 times the data-return capacity of state-of-the-art radio systems used in space today," said Abi Biswas of Nasa's Jet Propulsion Laboratory in a statement.
Psyche also uses a special kind of propulsion system called "Hall-effect thrusters" that harnesses the energy from solar panels to create electric and magnetic fields that, in turn, expel charged atoms of xenon gas.
The thrust it exerts is roughly equal to the weight of an AA battery in your hand. But in the void of space, the spacecraft will accelerate continuously to tens of thousands of miles per hour.
Such systems avoid the need to carry thousands of pounds of chemical fuel into space, and Psyche will be the first time they are used beyond lunar orbit.