Credit By: PBS
In a pioneering effort to unveil the elusive metal core hidden deep within Earth, NASA is embarking on an audacious mission: dispatching a spacecraft to study an asteroid a staggering 280 million miles away.
The Heart of the Matter Earth took shape approximately 4.5 billion years ago, emerging from the amalgamation of dust and gas encircling our sun. Initially, these materials possessed immense heat, but with cooling, denser elements settled at the planet’s center over time, culminating in the formation of Earth’s core.
Scientists postulate that electric currents circulating within Earth’s searing metal core generate the planet’s magnetic field. This magnetic shield is indispensable in Earth’s habitability, safeguarding our atmosphere and deflecting the solar wind.
Eftyhia Zesta, Chief of NASA’s Geospace Physics Laboratory, emphasizes, “Devoid of a magnetic field, our atmosphere would be altered dramatically, potentially rendering it inhospitable for life as we recognize it.”
16 Psyche: A Portal to Unveiling Earth’s Core As a direct observation of Earth’s core remains an impossible challenge—the core begins a whopping 1,800 miles beneath the surface, while our deepest drilling to date barely reached 7.5 miles—NASA has devised an alternative strategy. The agency is orchestrating a spacecraft mission to investigate a colossal metallic asteroid suspected to be the remnants of a “planetesimal,” a solid entity potentially serving as a planet’s foundational base.
This celestial body, designated as 16 Psyche, orbits roughly 280 million miles away. Interestingly, if transported to Earth, 16 Psyche would harbor an astonishing $10,000 quadrillion worth of nickel (though this theoretical scenario disregards the subsequent plummet in the metal’s value due to oversupply).
However, NASA’s intention isn’t mineral extraction from 16 Psyche but rather a comprehensive examination.
“This mission presents an opportunity to explore an extraordinary realm—distinct from the realms of rock and ice—constituted by metal,” declared Lindy Elkins-Tanton, Principal Investigator of the Psyche mission, when NASA greenlit the project in 2017.
Elkins-Tanton elaborated, “Among all objects identified within our solar system, 16 Psyche stands as a solitary exemplar of its kind. Moreover, this voyage represents humanity’s sole prospect of encountering a core firsthand. Our insight into inner space is rooted in our exploration of outer space.”
The Mission Blueprint The Psyche mission is primed to commence with the launch of the Psyche spacecraft on October 5. Navigating an energy-efficient trajectory spanning 2.5 billion miles, the craft is projected to reach 16 Psyche in 2026. Once there, it will engage in a 26-month orbit around 16 Psyche at four distinct altitudes.
During this phase, Psyche will employ advanced instruments to capture images of the asteroid and measure its gravitational forces, magnetic field, and electromagnetic radiation. These measurements will contribute to NASA’s assessment of whether 16 Psyche represents a planetary core.
Henry Stone, Project Manager for Psyche, explains, “If Psyche retains traces of a residual magnetic field, this would substantially reinforce the hypothesis that it once constituted a core. This stands as a compelling indicator.”
Beyond the Core: Technological Advances Beyond delving into the core mystery, the Psyche mission is a testing ground for innovative communication and propulsion systems.
For decades, NASA has predominantly relied on radio signals for spacecraft communication. However, the limitations of this method—requiring 30 minutes to several hours to transmit a high-resolution color image from a Mars rover to Earth—underscore the need for faster communication as we contemplate sending humans to distant planets.
NASA is experimenting with optical communication systems utilizing invisible lasers to transmit data, substantially boosting data transmission rates compared to traditional radio methods.
To this end, Psyche will demonstrate the Deep Space Optical Communications (DSOC) system. This system will facilitate communication with the spacecraft every week or two until it approaches Mars, a journey anticipated to span approximately two years.
The Psyche mission also pioneers a solar electric propulsion system featuring Hall thrusters for deep space travel. Powered by expansive solar arrays generating electricity, the spacecraft’s Hall thrusters will accelerate charged atoms from neutral xenon gas, creating propulsion. This highly efficient technology enables Psyche to attain speeds up to 124,000 mph relative to Earth.
Lindy Elkins-Tanton underscores the significance of solar electric propulsion: “Solar electric propulsion was ingrained in our mission design from its inception in 2012. It’s an integral part of the Psyche mission, necessitating a specialized team to calculate orbits using this innovative propulsion method.”
A Glimpse into the Future NASA researchers are on the brink of completing the preparatory stages of the Psyche mission. A successful trial and installation of the spacecraft’s solar array occurred on August 3, boasting dimensions comparable to five parking spaces when fully expanded. Around mid-August, the spacecraft will be loaded with nearly 2,400 pounds of xenon propellant.
To align with the plan, a SpaceX rocket carrying Psyche could launch as early as 10:38 a.m. EDT on October 5. This event marks the commencement of the spacecraft’s extensive voyage towards uncovering the enigma concealed within Earth’s (albeit distant) core.