Jules Verne, a French author, enthralled readers in the 19th century with the intriguing idea that it was possible to go to the center of the Earth.
Scientists have known for a long time that Verne’s fictional expedition was strictly science fiction. People aren’t allowed to go too far under the Earth due to the incredibly high temperatures (the core is about 10,000 degrees Fahrenheit/5,537 degrees Celsius) and the crushing pressure (millions of times greater than at the surface).
Nevertheless, a few things concerning the Earth’s interior are understood. For instance, geophysicists have found that the Earth’s core is made up of a solid iron and nickel sphere that spans 20% of its radius and is encased in a shell of molten iron and nickel that extends an additional 15% of its radius.
That and the rest of our knowledge about the interior of our planet were discovered by indirect means, such as through observing the Earth’s magnetic field or the way earthquake waves reflect off different layers under the surface of the planet.
However, indirect discovery has some drawbacks. How might researchers learn more about the interior of our planet?
I and other planetary scientists believe that space travel is the ideal place to learn about the inside Earth.
The robotic journey to a world made of metal that NASA is planning to launch on October 5th, 2023. The name of the mission, the spacecraft going there, and the planet it will explore are all Psyche. I’ve also been a member of NASA’s Psyche team for the past six years.
About the asteroid Psyche
Asteroids are tiny planets, some of which are the size of small cities while others are comparable to those of small nations. They are the surviving building components from the early, violent phase of planetary formation in our Solar System.
Perhaps 20% of asteroids are metal-rich worlds with a composition comparable to that of the Earth’s core, however the majority are rocky, icy, or a combination of the two.
So it’s tempting to think that these metallic asteroids are fragments of the interiors of formerly extant planets, torn apart by long-ago cosmic collisions. Perhaps by examining these fragments, researchers will be able to directly learn what a planetary core is like.
The largest known metallic asteroid is called Psyche. Psyche, a major asteroid belt object discovered in 1852, is the breadth of Massachusetts, has a pincushion-like squashed spherical shape, and orbits between Mars and Jupiter. With a backyard telescope, an amateur astronomer can observe Psyche, but it only shows up as a single point of light.
About the Psyche mission
The $1 billion trip to Psyche was approved by NASA in the beginning of 2017. The unmanned spacecraft won’t need to touch down in order to complete its mission; instead, it will orbit the asteroid regularly and systematically, beginning at a distance of 435 miles (700 km) and down to a distance of 46 miles (75 km), and possibly much lower.
The mission will spend 26 months surveying the asteroid’s geology, terrain, and gravity after it arrives there in August 2029. It will also look for signs of a magnetic field and compare the asteroid’s composition to what we now know about the composition of Earth’s core.
These are the main inquiries: Is the core of Psyche really exposed? What exactly is the asteroid—a single massive chunk of bedrock, a jumble of smaller rocks, or something else entirely? Are there any indications that this small world’s crust and mantle were once brutally removed in the past? And perhaps most importantly: Can we use what we discover about Psyche to extrapolate some of the Earth’s key mysteries?
About the spacecraft Psyche
The body of the probe is roughly the size and mass of a large SUV. The cameras, spectrometers, and other equipment are powered by solar panels that are slightly broader than a tennis court.
Psyche will be launched into space by a SpaceX Falcon Heavy rocket. The remaining distance will be traveled by Psyche using ion propulsion, which uses the mild pressure of ionized xenon gas blasting out of a nozzle to drive spacecraft into the Solar System.
It will take over six years to complete the 2.5 billion mile (4 billion km) leisurely spiral, which includes a flyby of Mars with the aid of gravity. The Psyche team at Arizona State University in Tempe and the NASA Jet Propulsion Laboratory in Pasadena, California, will communicate frequently with the spacecraft throughout the mission. Using the massive radio antennae of NASA’s Deep Space Network, our team will transmit and receive data.
Even if it turns out that Psyche is not an ancient planetary core, our understanding of the solar system and how planets originate will undoubtedly increase as a result. After all, Psyche is still a realm that has never been encountered by humans.
Although it’s possible that we won’t be able to travel to the Earth’s core anytime soon, robotic avatars to places like Psyche can help solve the mysteries that lie deep within all of the planets, including our own.
Jim Bell, Professor of Earth and Space Exploration, Arizona State University
This article is republished from The Conversation under a Creative Commons license. Read the original article.
