The origin of life on Earth continues to be a scientific mystery to this day. Our understanding of planet formation, though expansive, still attempts to understand how an astronomical body can harbor life-essential elements in an accessible way to support life as we know it. The mechanisms by which these elements began to be distributed on our planet date as far back as 4 billion years ago. This is the history that researchers like Aindrila Pal, a graduate student in Earth, environmental and planetary sciences, focus on.
Aindrila’s interest in planets started with her fascination with outer space, along with a childhood dream of being an astronaut. Originally from Kolkata, India, her journey began by studying geology. “I started with geology, because it teaches us about planet Earth, and I leveraged that to shift into planetary science, since it is necessary to understand planets,” she explained. “It's a tool we use to understand not only Earth, but also other planets.” Still, her interest in space urged her to pursue a degree in planetary sciences, and her expertise in petrology led her to Rajdeep Dasguspta's research group at Rice.
“We focus on life-essential elements,” Aindrila said. “There are six essential elements: carbon, oxygen, hydrogen, nitrogen, sulfur and phosphorus. These are the six major elements needed for life to form — the basic constituents of life.” By tracing the evolution of these elements through Earth’s formation, Aindrila aims to understand how the planet became capable of fostering life. “In simple terms, we want to understand how Earth gained the ingredients for life.” Comprehending Earth’s transformations may then lead to the discovery of other habitable planets.
It might sound abstract to think about the changes our planet withstood billions of years ago, but Aindrila’s work is very much experimental in nature. She can reproduce the composition of one of Earth’s layers at a certain point in time by mixing different chemical reagents. This mixture is packed into a small capsule the size of a lentil, and it is subjected to incredible amounts of pressure at a controlled temperature to mimic the conditions of Early Earth. “What we do with my experiments is we go back into the past, and it is very tangible,” she said. These experiments can also be designed to mimic other planets. “We are traveling back in time and going to different planets just by sitting in our lab.” Studying the fate of life-essential elements throughout Earth’s formation is a feat that transcends both space and time.
More specifically, Aindrila studies the fate of nitrogen along Earth’s evolution. “In our research group, all of us start by focusing on one element,” she described. “First, we try to understand a single element, and then we look at the interplay with other elements and how they influence the behavior of that element.” Understanding the cycles of all life-essential elements together is necessary to identify which planets are habitable.
Aindrila’s work seeks to explore the origin of life from the perspective of planet formation, a question that also impacts many other scientific fields. “One of the fundamental questions in science is trying to understand how life formed. In that way, everyone is interested in planetary science.” And although most of Aindrila’s experiments focus on Earth’s formation, her understanding of our planet helps in assessing the ability of other planets to sustain life. “Nowadays, people are planning to move to different planets,” she said. “What we are doing right now might seem like very fundamental research, but in the future, it can definitely play a big role in life.”
—Andrés Sánchez