Save articles for later

Add articles to your saved list and come back to them any time.

In the asteroid belt that separates the warm inner planets of our solar system from the cold, gassy giants of the deep, there’s a body that stands out.

When sunlight reaches this misshapen lump, it gleams. Unlike nearly all asteroids in our solar system, this lump is almost entirely made of metal.

An artist’s impression of the Psyche asteroid.Credit: NASA / Supplied

Astronomers believe it is the dead metal core of an ancient failed planet. They christened it Psyche, after the Greek goddess of the soul.

This Thursday, weather permitting, we will attempt to visit it. A SpaceX rocket will deliver the spacecraft from a Florida launchpad into orbit – and then via a spiralling path past Mars and on to Psyche.

”Every single planet, moon and asteroid that we have visited so far was made of rock or ice or gas,” said Professor Fred Jourdan, an asteroid researcher based at Curtin University. “We’ve never visited one made of metal.”

And when it arrives in 2029, we’ll also get our first direct look at what the core of a planet looks like.

“To get down to the base building block, the core, on Earth is an impossibility. Now we’ve got an object we can go out and actually do it,” said Glen Nagle, spokesman for the Canberra Deep Space Communication Complex, which will run comms during the spacecraft’s crucial early hours.

NASA is focused solely on the science. But those with commercial agendas will also be watching closely – tantalised by the idea of a pure lump of iron and platinum bigger than the state of Massachusetts.

“Even if you produced all the iron ore, nickel and cobalt on Earth, you couldn’t get the same amount of metal,” said Professor Serkan Saydam, a mining engineer who studies deep space mining at the University of NSW.

SpaceX’s Falcon Heavy rocket, the type to be used to launch Psyche.Credit: SpaceX

A failed planet

Planets, said Jourdan, form by increments: “sand, then pebble, then boulder”.

Rocks tumble and crunch together in the chaos of space. These lumps get larger and larger until they can exert their own gravitational forces to gather even more material.

Eventually, this material reaches a critical mass and starts to heat up. The heat melts any veins of metal that may be in the rock; the molten metal drips down into the centre of the planetoid, forming a hot lump.

If that lump is large enough, its spin generates a magnetic field that can hold gases to the surface of the planetoid – forming an atmosphere.

Technicians at work inside the clean room at Astrotech Space Operations facility in Titusville, Florida.Credit: NASA / Supplied

You can see why scientists are fascinated by Earth’s core – and frustrated, as we can only really measure it indirectly. “It’s 3000 kilometres deep – we will never go there,” Jourdan said.

Psyche, astronomers think, is a core that didn’t quite make it. Perhaps it got to protoplanet size and then struck another mass – maybe another protoplanet – tearing off its rocky surface. And, unable to generate enough gravity to suck in more material, the core cooled into a frozen lump.

Or something else that astronomers really don’t understand is going on.

Psyche

The spacecraft that will visit it, also known as Psyche, is about the size of a small van. A tennis-court-sized solar panel array powers four electric engines, which use charge to accelerate atoms and generate thrust.

Its instrument package lets it test the asteroid’s magnetic field, chemical makeup and gravity.

The ship will also test an important new communications technology.

All spacecraft communicate with Earth using radio. “Scientists always want to get back more information – and radio as a bandwidth has some limitations,” said Nagle said.

Psyche will test out optical-based communications, encoding data in streams of photons.

If it works, it has the potential to increase bandwidth by 100 times – turning grainy space images into high-definition.

Liam Mannix’s Examine newsletter explains and analyses science with a rigorous focus on the evidence. Sign up to get it each week.

Most Viewed in National

From our partners

Source: Read Full Article