On International Women’s Day, we recognize women’s achievements in education and work around the globe. This year, under the theme “DigitALL: Innovation and Technology for Gender Equality,” the U.N. is celebrating the women in STEM fields who are closing the gender gap in technology and science. We were honored to have one of these pioneering women, planetary scientist Lindy Elkins-Tanton, make a virtual visit to TCS. Lindy is only the second woman to serve as principal investigator on a NASA mission, following in the footsteps of Maria Zuber, who led the GRAIL mission to create a gravity map of the moon.
Lindy talked to the children about the soon-to-launch Psyche mission, named for the unusual asteroid, (16) Psyche, that it will explore. Lindy studies how planets form, and this asteroid intrigues her because it’s one of only nine, out of the 1.5 million asteroids we’ve looked at, that has a metal surface. It’s also large—not as big as a planet, but as big as several New England states. And it’s very, very old, likely forming just after the first solids appeared in our solar system, about 4.568 billion years ago. Its an outlier of an asteroid, a mysterious object, and Lindy is excited to find out more about it as the principal investigator for the Psyche mission.
The way humans explore distant places in space, like the asteroid belt near Jupiter, is to send a robot. We’ve landed spacecraft on rocky planets like Mars and the moon, and flown by Jupiter, the outside of which is made of gas, and its moon Europa, whose surface is made of ice. But we haven’t yet examined a space object made mostly of metal. Lindy thinks that Psyche may be the remnant of a planet from the beginning of the solar system that was broken apart, and only its metal core is left. Sending a robot to examine Psyche is a unique opportunity for humans to analyze a metal core that is similar to the metal core inside Earth, which is too deep below for us to observe.
The children were curious about what kinds of metal the surface of (16) Psyche could be made of, and Lindy explained that the metal nature makes is iron. We sometimes find meteorites, or bits of rock from the asteroid belt that have landed in Earth, that are made of metal. And metallic meteorites are always composed of iron, with maybe some nickel and copper mixed it. So we’re pretty sure that Psyche is mostly iron, but there could be metals up there that we don’t know about.
Lindy shared an artist’s rendering of (16) Psyche that shows a gray metal surface with some patches of yellow sulfur. But that image is probably incorrect, because space is always more than what we imagine. We use our imagination to predict what this asteroid might be like, and then we figure out how to measure it. But everything might be proven wrong when we get there!
It was exciting and challenging to build the spacecraft that will orbit (16) Psyche for two years and analyze its surface from high above. The children wondered why we weren’t going to land on the asteroid, and Lindy explained that landing would be too complicated: the asteroid is a funny shape, like a potato, and we don’t know anything about its gravity. But this mission is more complex than a flyby. The Psyche spacecraft has huge solar panels for power, which will unfold in space to the size of a tennis court, as well as a large radio antenna to communicate with Earth and instruments for sensing the asteroid’s surface. Lindy noted that the team will send the approach pictures as soon as they arrive by radio waves—and put those pictures up live on the internet. Most missions hold on to their pictures, but her team wants to share the images right away.
One heartbreak for her has been the delay of Psyche’s launch. If it had launched last year, as hoped, it would have taken only three years to get to the asteroid. But it proved too difficult to complete a new spacecraft during Covid. The new launch is scheduled for October, with the first possible launch date being October 5 at 10 a.m. With the delay of the launch date to make sure everything on Psyche is working perfectly, the spacecraft won’t arrive at the asteroid until 2029, six years from now.
Lindy noted that space exploration always takes a long time; by the time the Psyche spacecraft reaches the asteroid, she will have worked on the mission for 17 years. But she has enjoyed every step of the process, saying that the best part of being in planetary science for her is working with a team of people who all have the same goal. “Think of building something so complicated!” she said. “It takes hundreds of people around the world to make it. And it has to work perfectly in space for years because no one can repair it.” The reward for all their planning will be the science that comes in 2029.
The children asked if she had a favorite planet, and if she thinks we will find life in outer space. Lindy said that she has done science on Mercury, Venus, Earth and Mars as well as exoplanets, which are planets that orbit around other stars. But her favorite planets are the ones that are far away, like Uranus and Pluto. They are so mysterious and different from Earth, and she is looking forward to NASA’s missions in the next 10 to 15 years to those distant places. As for finding life off Earth, she thinks that the No. 1 science question for humanity is, Are we alone? Although no one has yet found life in space, she hopes we’ll discover life buried under rocks on Mars or beneath the ice of Europa. “It would be the biggest discovery of our lifetimes, by far,” she exclaimed, “and I hope we find it!”
With inspiration from scientists like Lindy Elkins-Tanton, it could be one of TCS’s budding scientists who help make such a momentous discovery! We look forward to watching the Psyche mission launch to the asteroid belt in October, and to finding out what this enigmatic metal object reveals about the ancient history of our solar system.