‘Success is not a destination, it’s like chasing the horizon’

One cool evening in Delhi, a young Ritika pressed her eye to a school telescope and gasped—there it was, Saturn’s shimmering rings and Jupiter’s fiery Great Red Spot. That moment of wonder stitched itself into her heart, setting her on a journey that would one day take her across galaxies. Today, as a PhD student at MIT University and a 2025 Quad Fellow, Ritika Sethi proudly explores the strangest of worlds—planets so light they’re nicknamed “Cotton Candy.” From that first telescope to the frontiers of Astrophysics, Ritika’s story is one of courage, curiosity, and cosmic dreams. In this conversation, she welcomes us into her universe, where science and imagination shine equally side by side.  

Being an astrophysicist sounds both royal and daunting at the same time! Could you simplify your work for us—what does your day with galaxies and planets really look like?

Well, it does sound grand, but most of my work can really be described as playing detective and solving the mysteries of the universe. I study Exoplanets- these are the planets outside of our solar system. So far, we’ve discovered about 5,800 of these exotic worlds, and they come in an incredible variety.

Some exoplanets are giant like Jupiter or cold and icy like Neptune, but others are truly bizarre. There are lava worlds covered in molten magma, and even planets with densities as low as Styrofoam. Naturally, this raises a lot of big questions- Why do these planets exist in the first place? What makes them so different from the planets in our solar system? And how do we scientifically explain their formation and properties? These are the kind of mysteries that I try to solve.

Another part of my research focuses on the orbital architecture of planetary systems. If you imagine our solar system, it looks pretty flat, eight planets orbiting neatly in a disk around the Sun. That’s what we expect from the laws of physics because planets form in protoplanetary disks which are disks of gas and dust around young stars. But here’s where things get puzzling: we’ve discovered planets whose orbits are highly misaligned, tilted at nearly 90 degrees relative to their stars. These are called polar planets, and they challenge our understanding of physics.

I use a mix of coding, simulations, and telescope data, combining them with theoretical models to push the boundaries of what we understand about the universe and learn a little more about the unknown. In short, I study the diversity and demographics of exoplanets and build dynamical models of their formation and evolution to explain both their physical properties and their orbital architectures.

As a PhD student, my days are a mix of reading research papers, running simulations, coding, and discussing ideas with my group and advisor. Some days are intense, others are more relaxed. And to stay creative, I make time for things I love like going on hikes, visiting the beach, or just sitting by a river. Often, my best ideas come from those quiet moments away from my desk.

The answer seems like a crash course on Astro Physic. It is so profound! We wonder were the seeds of your cosmic curiosity planted in Apeejay School, Pitampura?

I clearly remember when I was in sixth grade, our school offered a 10-session ‘space’ workshop. We even got a little kit with solar goggles and a small telescope. From the very first session, whenever they spoke about the universe, the solar system, and what lies beyond, I would get goosebumps.

One evening during an observation session, we looked through the telescope and saw Jupiter’s Great Red Spot and Saturn’s rings. That day remains so special to me, because I think it was that moment when I truly knew this is what I want to do for the rest of my life. Of course, like most kids, I had wanted to be many things before that, a doctor, an athlete, a pilot but from that night onwards, my dream was clear: I wanted to be a scientist.

Wow, that is quite an anecdote! So it must have been Science and Math at school that nudged you towards the universe beyond Earth?

I always loved Science and Math. Physics fascinated me too, and I could spend hours solving the equations and problems. In fact, I would go through every NCERT problem three times, and I finished extra books just for fun. These subjects taught me to be curious, to ask questions, and to think analytically and logically.

But what might surprise you is that the subject which truly sparked my imagination was literature– in both Hindi and English. I especially loved poetry, because it allowed me to create whole fantasy worlds in my mind, free from logic or rules.

Looking back, I think it was this blend of creativity from literature and analytical thinking that shaped me into the scientist I am today.

Is there a piece of advice or a classroom moment from your teachers that still guides you in your research today?

There are so many moments from Apeejay School, Pitampura that continue to guide me, because the school really shaped who I am today.

In classes 11 and 12, I was going through some personal challenges and wasn’t performing at my best. But my teachers never judged me by my scores, they looked past the marks and saw me as a person. From them, I learned two of the biggest lessons of my life: empathy and courage. Empathy taught me the value of kindness and understanding others. And courage taught me that no matter how difficult life gets, I can face challenges head-on and fight through them.

I was especially close to my chemistry teacher who gave me confidence and believed in my potential. She told me that if I truly set my mind to something, nothing could stop me from achieving it. Even today, whenever I feel lost, her words echo in my mind. They remind me that I have the strength to overcome any challenge and keep moving forward.

And it wasn’t just her, I was fortunate to feel the care and encouragement of many teachers who didn’t just teach subjects, but also taught me lessons for life.

And you’re truly blessed! Congratulations on the Quad Fellowship! Could you share what this milestone means for your career and the exciting research avenues it has opened up?

Thank you so much! Getting the Quad Fellowship truly means a lot to me. I feel proud to be among the only five US-based Indian fellows to receive this prestigious award.

Yet this fellowship is just the beginning for me. The Quad Fellowship brings together some of the brightest people across all fields of STEM, not just astrophysics, but also AI/ML, Biotechnology, Environmental Science, Neuroscience, and more. It gives me the chance to interact, learn, and collaborate with peers who are making an impact in areas far beyond my own field. I want to leverage this platform to broaden the scope of my research and learn how scientific thinking can contribute to solving global challenges.

Another exciting aspect is the fellowship’s connection to policymakers, diplomats, and international stakeholders. We’re trained to think about how science can help shape policy, and I hope to use this experience one day to contribute to scientifically informed policies in India, helping spark a new wave of scientific progress in the country.

Finally, being part of this strong network of current and past Quad Fellows inspires me to think about outreach. I’d love to collaborate with high schools and universities back in India to conduct talks and workshops, exposing students to cutting-edge research in fields that often feel inaccessible. My dream is to inspire the next generation of scientists and show them how transformative research can be. So, for me, the Quad Fellowship is not just an award, it’s a platform to learn, collaborate, and give back!

Ritika, we not only admire your vision towards a better world but also your creativity. We heard you work on so-called Cotton Candy planets– that’s such a delightful name! What inspired it, and what makes this planet so unique?

Yes, Cotton Candy planets is one of my favorite nicknames! These are a type of exoplanet that are incredibly puffy and lightweight compared to their size. Imagine a planet as big as Jupiter, but with a density so low it’s almost like Styrofoam; or as astronomers like to say, Cotton Candy. The nickname comes from this strange property: when we measure their mass and compare it to their size, they’re far too light for what we would expect.

What makes them so fascinating is that we still don’t fully understand how they exist. Their low density suggests that they have huge, extended atmospheres, but again one wonders what puffed them up so much, and how are they managing to stay that way?

Studying Cotton Candy planets helps us test our theories of planetary structure and evolution, and they remind us that the universe is endlessly creative and can make worlds far stranger than anything we see in our own solar system.

Life at MIT University must have been a galaxy of experiences in itself—what was it like juggling intense research with life on campus?

I feel so fortunate to study at MIT, it was my dream college, and it still feels surreal to actually be here. MIT is an incredible place to do cutting-edge science, but it can also feel daunting to be surrounded by so many brilliant people. At times you feel lost, but that’s also the beauty of it, you’re constantly learning and growing just by being around them. As they say, studying at MIT is like drinking from a firehose!

Coming from IISER Berhampur, which was still a very young university with no astrophysics faculty when I studied there, the contrast was huge. Back then, I had to create opportunities for myself, whereas here at MIT there are so many opportunities that it’s impossible to grab them all. The challenge has been learning to choose wisely and focusing on what matters most for my long-term growth while letting go of the rest.

And yes, juggling research, coursework, and life at MIT is challenging but it’s also the challenge I chose and the one I live for. To me, studying astrophysics and learning from the best of the best feels like a luxury, not a burden.

What has made this journey truly special are the people—my advisor, professors, mentors, and senior PhD students who not only guide me scientifically but also make the experience fun and fulfilling. Their support has helped me balance intense research with life on campus and made MIT feel like home.

If you could invite one scientist—past or present—for a coffee chat about the universe, who would it be and why?

That has to be Marie Curie for me! Even today, women in STEM (Science, Technology, Engineering and Mathematics) face challenges, but she achieved not one but two Nobel Prizes, and in two distinct fields-Physics and Chemistry. That too, at a time when women were not even allowed proper access to higher education. Her discoveries of polonium and radium revolutionised science, and her pioneering work on radioactivity laid the foundation for both medical treatments and nuclear physics.

What inspires me most is not just her contributions to science, but her courage and perseverance. She worked in incredibly difficult conditions, sometimes in makeshift labs with hardly any resources and yet she never let obstacles define her. She also refused to patent her radium-isolation process, because she believed science should belong to everyone, not just individuals. For me, she embodies both scientific brilliance and human strength. To sit with her over coffee and hear how she kept her determination alive, while breaking barriers for women like me, would be the most inspiring conversation I could imagine.

Beyond the lab and telescope, what do you do for fun? Any hobbies or interests that balance your scientific world with a lighter side?

Definitely, that balance is so important, I’d go crazy without it! I love going to the gym regularly, and I’ve recently started taking Aikido classes. Sometimes I also play tennis with friends. Basically, I enjoy anything sporty and outdoorsy because it keeps me happy and healthy. On the calmer side, I like reading books, doing art, and building Lego or crafty projects. Those creative hobbies give me a break from work, and remind me that play and imagination are just as important as science.

Finally, what’s your message for today’s students who dream of chasing stars, discovering planets, and perhaps naming one of their own someday?

This feels like a full circle moment. I want to pass on the same advice that Apeejay School, Pitampura gave me when I finished school in 2018: Courage and Empathy.

There’s no single path to your dreams, you define success on your own terms, shaped by your own experiences. I know this from my own journey, where I often had to carve out opportunities when none existed. So, be courageous. Have the spirit to rise when you fall, to take unconventional paths, and to stand up for what is right even when it’s not the popular opinion. And pair that with empathy, because success means little if you can’t uplift others along the way.

Remember, success is not a destination, it’s like chasing the horizon. What matters is to keep moving forward, learning, growing, and pushing your boundaries. Celebrate milestones, but never stop striving for more. That’s how you truly chase your stars.