Is asteroid Psyche really mostly a block of metal? Could this object, roughly the width of Massachusetts, be the core of a baby planet whose rocky outer layers were stripped away in a cataclysmic impact in the early days of our solar system?
All astronomers can say for now is maybe, probably not.
NASA launched the Psyche probe on Friday morning to explore the asteroid belt between Mars and Jupiter.
“We’re really going to see some new objects, which means a lot of our ideas were wrong,” said Lindy Elkins Tanton, a professor of Earth and space exploration at Arizona State University. will be proven,” he said. Chief researcher of the mission.
Being proven wrong, she added, “I think is the most exciting thing in science.”
The search for answers began at 10:19 a.m. ET on Friday. The Falcon Heavy, the largest of SpaceX’s operational rockets, lifted off from Kennedy Space Center in Florida, setting the giant spacecraft on a journey that would last nearly six years and cover billions of miles.
Friday’s flight was a seemingly perfect flight, overcoming an unfavorable early morning weather forecast. About eight minutes into flight, the rocket’s upper stage will enter a 45-minute coasting period during which it will prepare the spacecraft for its flight away from Earth. You can watch the flight in progress in the video player above or on his NASA YouTube channel.
The asteroid named Psyche has long been an interesting mystery. Discovered in 1852 by Italian astronomer Annibale de Gasparis, it was named after the Greek goddess of the soul and was just his 16th asteroid to be discovered. Early observations showed that it was a star-like point of light orbiting the sun, and nothing more, like other asteroids.
In the early 1960s, astronomers observed with telescopes that Psyche’s color resembled that of an iron meteorite that had fallen to Earth, said Jim Bell, a professor of Earth and Space Exploration at Arizona State University who will lead research on the asteroid. It is said that he discovered that Spacecraft camera equipment. Astronomers reflected radar pulses off Psyche, and the reflections back to Earth were brighter than those coming from other small objects in the asteroid belt.
“It’s become pretty clear that there are parts of the surface that are very reflective of radar,” Dr. Bell said. “And the easiest way to do that is with a piece of metal.”
And when scientists observed Psyche passing relatively close to a larger world, its orbit was deflected in a way that suggested something very large and potentially much denser than rock. It was done.
Most rocks, such as granite, have a density of 2 to 3 grams per cubic centimeter. Water, whether liquid or ice, weighs about 1 gram per cubic centimeter. Metals like iron are much denser, between 6 and 9 grams per cubic centimeter.
“Some of the early estimates were like, wow, this is really unusual,” Dr. Bell said.
Psyche looked almost like pure metal. Earth’s core is made of iron and nickel, and Psyche’s measurements led to the idea that it could be the remains of a similar core that belonged to a baby planet. Such worlds are known as planetesimals, and the temperature is high enough that dense metals melt and fall to the center.
It’s impossible to explore the center of a planet like Earth, which lies 1,800 miles below the Earth’s surface, but a trip to Psyche could provide more information about what lies at the center of the Earth. there is.
Or the hypothesis could be completely wrong.
“Psyche could be something completely different,” says Dr. Elkins-Tanton. “I really want to surprise you.”
Recent measurements have lowered estimates of the asteroid’s density, just below 4 grams per cubic centimeter. It’s still higher than rock and ice, but not as high as metal. It suggests that Psyche is made of metal and something else, perhaps rock, perhaps empty space.
“Based on the data we have, my best guess is that more than half is metal,” Dr. Elkins-Tanton said.
If Psyche turns out to be full of valuable metals, it is too far away to mine using current technology. Dr Elkins Tanton said Psyche is about 150 million miles from Earth at its closest approach, which is about five times the distance from Earth to Mars if the two planets were as close as possible. It points out that it does.
Psyche’s mission was scheduled to begin a year ago. The spacecraft had already been transported to Kennedy Space Center. But testing the navigation software that guides the spacecraft around the solar system has been problematic. These were due to incompatibilities between the flight software and the programs used to check it. Engineers no longer have time to resolve the issue before the launch period ends.
An independent review of the launch failure commissioned by NASA found that changes in leadership, communication failures, heavy workloads, and the COVID-19 pandemic “made it difficult for missions like Psyche to cope with staffing.” It concluded that this contributed to an environment in which he did not receive the attention he needed. and the challenges faced by experienced personnel. ”
The project is back on track for 2023 by hiring new mission staff, minimizing remote work, and implementing other recommendations from the review.
There were other crashes on the way to the launch pad. Psyche was scheduled to launch on October 5, but tests showed that the thrusters used to orient the spacecraft during flight shot out cold nitrogen gas, generating higher-than-expected temperatures. As it turned out, the launch was postponed again. NASA officials said they solved the problem by planning to run the thrusters at lower power levels to prevent them from overheating in space.
Once launched, the Psyche spacecraft will head to Mars, orbiting by the Red Planet in May 2026, and using its gravity as a slingshot toward the asteroid Psyche, traveling 2.2 billion miles and arriving in August 2029. arrive.
During the journey, Psyche will exchange laser messages with Earth as part of an experiment called Deep Space Optical Communications. Current spacecraft communicate using radio waves, but switching to lasers could increase the bandwidth of deep space communications by as much as 100 times. This laser experiment will be the first demonstration of this new technology at distances far beyond the moon.
Once it reaches the asteroid, the spacecraft will spend at least 26 months in orbit, using a variety of instruments to study Psyche.
The mission’s camera, known as the Multispectral Imager, will provide the first close-up look at Psyche, revealing surface features not visible from Earth. The spacecraft’s magnetometer will look for traces of ancient magnetic fields, such as those sourced from Earth’s core, that may be etched into the asteroid’s terrain.
And a gamma-ray spectrometer detects the high-energy gamma rays and neutrons produced when cosmic rays hit the asteroid’s surface. These particles contain information about the composition and distribution of metals and rocks throughout Psyche’s otherworldly landscape.
Finally, the spacecraft’s radio antenna will be used to map the asteroid’s gravitational field by measuring small changes in the frequency of the signal’s Doppler shift, rising as it approaches Earth and falling as it moves away. Masu. This experiment could detect differences in the density of asteroids, which could help elucidate their origins.
Ben Weiss, the mission’s deputy chief scientist, said at a press conference Thursday that “there is no instrumentation that can independently determine whether Psyche is nuclear or not.” “It’s a combination of data from all these different instruments.”