French novelist Jules Verne captivated readers in the 19th century with his incredible tale of a journey to the center of the Earth. While Verne’s story was purely fiction, scientists have long acknowledged the impossibility of such a feat due to the extreme conditions of the Earth’s interior. The intense temperatures and crushing pressures prevent any human exploration to these depths. However, there are still many unknowns about our world’s interior. In an attempt to unveil the hidden secrets of our planet’s deep core, planetary scientists have turned their attention to space exploration. This article delves into NASA’s upcoming mission to a metal world called Psyche, which aims to shed light on the mysteries of inner Earth.
The Quest for Inner Earth
Traditionally, scientists have relied on indirect methods to study the Earth’s interior. This includes analyzing the Earth’s magnetic field and observing how earthquake waves interact with various layers beneath the Earth’s surface. While these methods have provided valuable insights, they have their limitations. To gain a deeper understanding of the Earth’s core, planetary scientists propose that the best approach is to explore outer space.
Scheduled for launch on October 5, 2023, NASA’s Psyche mission involves the exploration of a metallic asteroid with the same name. Asteroids, small celestial bodies, are remnants from the early stages of our Solar System’s formation. Approximately 20% of these asteroids are composed of metal, similar in composition to the Earth’s core. It is believed that studying these metallic asteroids could provide significant information about planetary cores.
Psyche, discovered in 1852, is the largest-known metallic asteroid. Its dimensions are comparable to Massachusetts, and it orbits between Mars and Jupiter in the main asteroid belt. While it can be seen with a telescope, Psyche appears as a mere pinpoint of light. In early 2017, NASA approved a US$1 billion mission to explore this intriguing asteroid.
Rather than landing on Psyche’s surface, the spacecraft will orbit the asteroid repeatedly, steadily moving closer to its core. Starting from a distance of 435 miles (700 kilometers), the probe will ultimately reach as close as 46 miles (75 km) from the surface. Upon arrival in August 2029, the spacecraft will spend 26 months mapping the asteroid’s geology, topography, and gravity. Scientists will also search for evidence of a magnetic field and compare Psyche’s composition with our current understanding of Earth’s core.
The Psyche mission aims to answer essential questions about the nature of Psyche and its relationship to planetary cores. Is Psyche truly an exposed planetary core, or is it something else entirely? Scientists are eager to determine whether the asteroid is a solid bedrock boulder, a conglomerate of smaller boulders, or an entirely different formation. By studying Psyche’s structure, researchers hope to uncover clues about the violent history of this small world. Did it experience a catastrophic event that stripped away its outer layers, including the crust and mantle? And perhaps most crucially, can the knowledge gained from studying Psyche be used to solve the mysteries of Earth’s core?
The spacecraft assigned to the Psyche mission resembles a large SUV in size and mass. Solar panels, spanning a width greater than a tennis court, power the numerous tools and instruments onboard. A SpaceX Falcon Heavy rocket will launch Psyche into space, while ion propulsion, using ionized xenon gas, will propel the spacecraft through the solar system. This efficient and low-cost method allows for precise and controlled movement over long distances.
The journey to Psyche covers a distance of approximately 2.5 billion miles (4 billion km). It involves a slow spiral trajectory, including a gravity-assist flyby past Mars. The duration of the mission will be nearly six years. Throughout the journey, the Psyche team at NASA’s Jet Propulsion Laboratory and Arizona State University will maintain regular contact with the spacecraft, exchanging data via NASA’s Deep Space Network.
Even if the Psyche mission reveals that the asteroid is not an ancient planetary core, it will undoubtedly contribute significantly to our knowledge of the solar system and planetary formation. Psyche remains a unique world that no human has ever visited. Robotic exploration, like the Psyche mission, presents an incredible opportunity to unravel the deep mysteries concealed within our planets.
While a journey to the center of the Earth may still be out of reach for now, missions like Psyche offer a glimmer of hope in our quest for understanding. By exploring the far reaches of our solar system, we bring ourselves closer to unlocking the secrets of our own planet and beyond.