Perseverance’s Martian crust samples won’t arrive until 2031, but Dr Meenakshi Wadhwa is improving our understanding of the red planet using meteorites and volcanic rocks.
“Please say CREWED mission, not manned,” Dr Meenakshi Wadhwa breaks off mid-thought to stress the point. “I am certain that the first such mission will have women on the team.” We are discussing the likelihood of human beings stepping foot on
. As chair of the Science Committee in NASA’s Advisory Council, Wadhwa knows what she’s talking about.
She heads the School of Earth and
Exploration at Arizona State University, and after studying space rocks – some of them from Mars – for years, she also knows more about the red planet than most experts. In fact, she is the recipient of this year’s J. Lawrence Smith Medal – the highest honour in the field of meteoritics (science of meteors, meteorites and meteoroids).
Now that NASA has landed its Perseverance rover on Mars, what does she think of SpaceX CEO Elon Musk’s hopes of a ‘crewed’ mission to Mars by
? “I think that landing humans on Mars in that time frame is quite ambitious, but I certainly hope that will happen sometime in the 2030s,” she says.
(Photo: Arizona State University)
That hope hinges on the retrieval of Martian rock samples for a better understanding of the planet. But samples collected by Perseverance aren’t expected back until 2031. So, meteorites collected by Wadhwa and other space rock hunters will fill in until then.
(A Martian meteorite. Photo: Wikipedia)
It sounds strange but some of the meteorites found on Earth are actually bits of Mars. They were dislodged when large objects collided with the planet, and flew millions of kilometres to reach Earth. Martian meteorites, Wadhwa says, provide “insights into the planet’s origin and geologic evolution. To prepare for a crewed mission, we need to have a good understanding of the conditions and potential hazards on Mars.”
A keen trekker and explorer, Wadhwa has been on meteorite collecting expeditions in Antarctica and has picked volcanic samples that are considered to be analogues of Martian volcanic rocks, in other faraway places like Iceland. But, as a teenager surrounded by Le Corbusier’s modernist buildings in 1980s’ Chandigarh, all she wanted to be was an architect.
“At that time I had just read The Fountainhead by Ayn Rand. The book inspired in me a glorified image of an architect. That image was not based on reality, but I was in love with it, which is part of the danger implicit in having to make such a big decision at 17. I wanted to be an architect, and I shut out everything else from my radar screen,” she told
Geology happened when she could not get a seat at the architecture college. The geology department at Panjab University was a lonely place for a woman at the time, but in the same Discover article she says, “I’m glad I followed my instincts.”
Space, and Mars, weren’t on Wadhwa’s trajectory at first, although she was in awe of an older family friend, Kalpana Chawla, who was studying aerospace engineering at Punjab Engineering College. Wadhwa was a 13-year-old student at Chandigarh’s Carmel Convent School for girls when she first knew Chawla. “She was always a source of great inspiration for me,” she says of the late NASA astronaut who died in the Space Shuttle Columbia disaster in 2003. They never met after Chawla left Chandigarh, but years later, Wadhwa married astronaut Dr. Scott Parazynski, who had known Chawla well as “they shared an office at NASA’s Johnson Space Center for a time.”
Wadhwa became deeply interested in Mars when she learned about Martian meteorites as a graduate student. “I was immediately intrigued by these rocks, and all that they could reveal about the geologic evolution of Mars.”
Over the years, her studies have improved the understanding of the composition and evolution of Mars’s crust and mantle, and the evolution of water on it. She is credited with “refining” the age of the solar system. Scientists estimate the age of meteorites and ancient rocks on Earth by measuring the uranium-235 and uranium-238 isotopes in them. These isotopes decay into lead with time. Wadhwa’s research group calculated a more precise ratio of the uranium isotopes, thus improving the accuracy of the “uranium-lead clock”.
“Work in my laboratory has led to a better understanding of the time scales of the formation of the earliest solids, and of accretion and large-scale melting of asteroidal bodies that were the precursors of the rocky planets like Earth and Mars,” she says.
Back in 2004, her dream was to “have, within my lifetime, actual rocks picked up from the surface of Mars to examine in my laboratory.” The Perseverance mission has put it within reach. But has she never dreamt about flying to her favourite planet?
(Photo: Dr. Dan Britt, University of Central Florida)
“I have always been fascinated by airplanes and spacecraft,” she says (she has a pilot’s licence). “With all the developments in commercial space, it will become easier for many more people to experience space travel. So I’m not counting myself out just yet – it is possible that I may experience space flight sometime in the future!”
Meanwhile, the asteroid 8356 Wadhwa – named after her in 1999 – continues to buzz Mars every 3.8 years. She hasn’t gotten around to seeing it though.