Every few months, a new headline flashes across our screens: a mysterious signal or a strange molecule on a far away planet. The possibility of finding life beyond Earth feels closer than ever, and for a moment, people let themselves wonder: What if we’re not alone?
In July, a global team of astronomers discovered a third interstellar comet, 3I/ATLAS. Harvard physicist Avi Loeb said in an article published in Medium post the object could instead be a man-made object in disguise because it doesn’t resemble a typical comet.
“Insisting that 3I/ATLAS must be a comet is unwise because it does not exhibit a cometary tail, and its trajectory is fine-tuned to align with the orbital plane of the planets around the Sun,” Loeb said in the article. “As of now, the glow of light ahead of 3I/ATLAS can be maintained for six months by the ablation of a millimeter-thick layer of dirt on the surface of a 20-kilometer object.”
However, this idea is facing skepticism from the broader scientific community. Nicolas Lee, a Stanford senior lecturer of aeronautics and astronautics, said the evidence for Loeb’s hypothesis is lacking.
“There hasn’t really been any evidence beyond just hypothesis, more wild guessing, that it’s anything other than just a rock,” Lee said.
Anton Ermakov, a Stanford assistant professor who specializes in aeronautics and astronautics, geophysics, and earth and planetary sciences, said while the object’s shape is unusual, interstellar comets are unlikely to be proof of extraterrestrial life.
“I don’t think there’s anything in the observations of the three interstellar objects observed so far that requires an explanation involving biological activity or life or aliens or alien technology.” Ermakov said.
However, in recent months, scientists have shifted their search for life away from interstellar objects, which are unlikely to be proof of life. Instead, they have focused on targets much closer to home: Mars and the icy moons in our solar system.
In September, NASA announced that its Perseverance rover had analyzed a Martian rock sample revealing a pattern of leopard spots.
“NASA’s recent discovery on Mars is one of the most compelling signs that life would have existed there,” Lee said.
He said the next major step for Mars exploration is sample collection.
“If we can get samples of Martian rock and bring it back to Earth, that would give us a huge opportunity to put it under a much better microscope,” Lee said.
The search for life, whether on Mars or elsewhere, is guided by the principle of following the water. The potential for past life on Mars exists since there’s evidence the planet once had liquid water.
Ermakov said this principle has led scientists to look beyond Mars to the icy moons of the outer solar system.
“(Europa and Enceladus) have liquid water, an energy source, and the rocky interior could have the chemical elements critical for life,” Ermakov said. “These three necessary ingredients could be present in these ocean worlds.”
Lee said the future of exploring moons like Europa and Enceladus lies in new spacecraft designed to study them up close.
“NASA’s Juno mission is currently orbiting Jupiter and imaging Europa, while the European Space Agency’s JUICE mission is on its way to Jupiter for a dedicated study of Jupiter’s icy moons,” Lee said.
However, Lee also said the search on Mars and the icy moons is built on the assumption life elsewhere will be like life on Earth, requiring water and a specific chemistry.
“If life evolved completely separate from our form of life, our water-based DNA-based life, then we may completely miss it because our sensors are looking for the wrong thing,” Lee said.
For sophomore Oscar Varodayan, who’s interested in astrophysics, it’s the uncertainty that makes the search so compelling.
“I know it’s still a very nebulous field,” Varodayan said. “What if there was never even life out there to begin with? But the thrill and idea that there could possibly be life beyond Earth is what makes me excited and interested in the field.”
Given these challenges, Lee said progress is measured in small steps, not giant leaps.
“I don’t think it’s going to be a yes or no we have found life,” Lee said. “It’s probabilities, and it’s going to be … we’ll have more and more mounting evidence that there’s likely life.”
Ermakov said this slow accumulation of evidence and possibilities means the question of whether or not there’s extraterrestrial life remains open.
“We’re closer than we have ever been, but we can still be infinitely far,” Ermakov said.
Public attention is often dominated by speculation, and Lee said this gap between scientific probability and public excitement exposes a need to clarify what finding life actually means.
“The first thing that comes to my mind when I hear the word alien are the creepy green figures with big black eyes that I see on TV,” Varodayan said.
However, Lee said if life were to be found on Mars, it wouldn’t be as the media portrays it.
“When we say we found life on Mars, it’s not going to be little green aliens running around,” Lee said. It’s going to be like bacteria or microbes.”
Beyond the public attention, though, Lee said researchers face another obstacle: securing money.
“Funding is always a problem,” Lee said. “The big problem is that we all keep saying Mars is the ultimate goal, but it’s always going to cost too much to just go there.”
Lee said lack of funding often forces difficult choices between different paths of exploration.
“We keep fighting over what the first step should be,” Lee said. “Do we want to go back to the moon to try things out before going to Mars? If we go to the moon, do we want to land on the surface or do we just want to orbit it?”
But Ermakov said for students dreaming of working in space exploration, this uncertainty isn’t a reason to feel discouraged. Every unanswered question leaves room for the next generation to discover answers, and he said the key is to approach these challenges with a practical mindset.
“Don’t be scared about working on big complex projects, which when they first look at them, look very overwhelming, and try to split them into many, many simpler tasks,” Ermakov said.
Lee also said STEM and physics-related clubs are a good way to get involved in high school by learning new skills and exploring potential majors.
“School clubs and teams are a really good opportunity for skill building,” Lee said. “Something like a FIRST Robotics team is the sort of thing that leads to competitions where you get to meet other people and see what college majors they’re applying to.”
Senior Kishor Rajmohan, co-captain of the Science Olympiad team said Scioly is how he got his start.
“I love Scioly because there’s so many events. So as long as you’re interested in STEM, there’s going to be a topic that interests you,” Rajmohan said. “It’s what exposed me to astrophysics, and I’m forever grateful for that.”
Additionally, Ermakov said students interested in space science could even get started with a hands-on project.
“I would suggest buying a camera and a telescope to take images of the night sky and do some basic image processing,” Ermakov said. “In doing this, you kind of repeat the main steps of scientific research. You have your instrument, you collect data, and then you try to analyze data … It’s very similar to working with real data from space missions.”
Rajmohan said observing the sky from his own telescope as a teen is how his interest in astrophysics began.
“I got a telescope in high school,” Rajmohan said. “And when it’s a nice full moon, and the moon is very bright, It’s great to observe the moon. You can see a lot of comets and a lot of detail.”
Rajmohan said telescopes don’t have to be fancy or expensive.
“You can get some really basic telescopes,” Rajmohan said. “As you start looking up at the sky and seeing that there’s actually really amazing, beautiful stuff there, then you’ll see how amazing astronomy is as a field.”
Still, owning a telescope can present other challenges, so Varodayan said he also makes use of community resources to fuel his interest in space.
“I don’t have my own telescope, but Stanford sometimes holds night-time events and sometimes I’d go and look through their telescopes.” Varodayan said.
Ultimately, Ermakov said curiosity is at the heart of astronomy and astrophysics.
“Don’t be afraid to ask questions, even if you think it’s a stupid question,” Ermakov said.
Lee said it’s this curiosity that will empower the next era of space discovery.
Lee said, “There is still so much to explore, and room for the next generation to improve.”
