Aswin Sekhar: From Ottapalam to Outer Space

THE ASTEROID IS FOUR KILOMETRES IN DIAMETER. You could say it is far away and that would be an understate­ment. The distance between the earth and the sun is called an astronomical unit and this asteroid is four astronomical units away. That translates to about 600 million kilometres. Something so small, so remote is a celestial needle in the haystack and yet, the wonders of powerful modern telescopes make it possible to view it. Aswin Sekhar was pleasantly surprised when his friend, Robert Weryk, a Canadian observational astronomer of some renown, recently contacted him and said that using the PanSTARRS Telescope in Hawaii, US, they had spotted and taken an image of this asteroid. It doesn’t look like much, just a small dot in a sea of dots, but it was still important for Sekhar. Because this space rock, first observed about three decades ago, had just had a name given to it—33928 Aswinsekhar.

The organisation that decided on such nomenclatures for spatial bodies is the International Astronomical Union (IAU) and the naming of the asteroid was unexpected for Sekhar. There are two ways minor planets get named. One is ceremonial for public personalities. That’s how people like Mahatma Gandhi, Rabindranath Tagore, and Pandit Jasraj have asteroids named af­ter them. The other is the non-ceremonial route, on the basis of scientific merit. “Senior scientists in celestial mechanics and meteor science gave my name to the International Astronomical Union Nomenclature Committee. They have to justify why this person is befitting enough. The nomenclature committee also consists of very eminent scientists from different parts of the world who assess the body of work. They would look at my track record and then approve.” On June 21, Sekhar had been a speaker at the Asteroids, Comets, Meteors Conference in Arizona, US. Just before the banquet dinner, the organisers announced that his name had been given to the asteroid. “That was a very pleasant surprise. I didn’t really know my nomination was in the pipeline or approved or anything. I didn’t have any clue.” IAU’s citation on their decision says this about him: “Aswin Sekhar (b. 1985) is the first profes­sional meteor astronomer from India in modern times. He has made impor­tant contributions to the field of meteors in meteoroid stream dynamics, particularly in the effects of relativity and resonances in meteoroid streams.”

As it turns out, he might not just be the first professional meteor astronomer from India but also the only one even now. Sekhar can’t be certain about it but says over the decades he is yet to meet another Indian in all the conferences he has attended in the field. “In the last 20 years, for any meteor-related conference, there has been absolutely nobody [from India] in the professional meteor world. So, I actually cross-checked with some of the more senior people than me who have been in this game for much longer. Even they said that they have never met an Indian professional meteor scientist before.” The community of meteor astronomers is anyway very niche. Sekhar thinks there might not be more than 100 of them in the world. “We are probably the smallest, the most low-profile, and the least funded people in the astrophysics world,” he says. Making his own presence striking in this highly specialised world is that he comes from a small town in Kerala. “I was born in Ottapalam in Kerala. My schooling until 10th standard was in a small town called Cher­pulassery in Palakkad district. When I used to grow up, those days, in these small villages, we hardly had any pollution. So, I remember watching pristine night skies along the banks of Bharathapuzha. Some of my mentors encouraged me to look for celestial events like meteor storms, the arrival of comets, eclipses, and so on. I think these things triggered my interest in childhood. Traditionally, my family is mostly into Ayurveda. Most of my family members are either modern medicine doctors or Ayurvedic doctors. I am one of those non-useful doctors [PhD] in the family.”

He graduated in physics from Kerala University. After postgradu­ation from Vellore in Tamil Nadu, he did his M Phil inn uclear physics at Christ College Bengaluru. And then Sekhar decided that his inter­est lay elsewhere. “I always felt my inner calling is somewhere in as­trophysics and in the sky. So, luck­ily at that time, after my MPhil, I got a British scholarship in astro­physics from Queen’s University, Belfast, in Northern Ireland. I was there for a few years doing my Ph D under a Scottish astrophysicist who was supposed to be like an authority in the forecast of meteor storms. I learned a lot related to me­teor science from him.”

His PhD thesis was related to the comet Halley, which becomes visible to Earth every 75 to 79 years. Sekhar studied its orbital evolu­tion and two meteor showers that originate from it called Orionids and ETA Aquarids, and how the gravitational effects of Jupiter and Saturn would affect them. There are reasons to study this. “These periodic gravitational effects, called resonances, can actually en­hance the meteor activity in certain years. Because of these periodic kicks from Jupiter and Saturn, some of these particles could cluster up and it could come like a very intense meteor shower in certain years. Predicting them is challenging and exciting. Practically, it’s also important for the safety of our satellites and spacecraft.”

Meteor astronomy is a useful discipline for a number of rea­sons. It helps us understand the formation of the solar system, the evolution of planets, and how different bodies got into the places where they are at the moment. The field has however gained more significance in recent times because of the enormous number of satellites that humankind has launched. Studying the meteoroid environment around the earth can protect these satel­lites and spacecraft. “The number of these satellites is increasing. From Amazon to StarLink, all are sending loads of satellites. It’s important to understand how to navigate and protect them from dangerous dust particles that might come at very high speeds. That is the first priority of meteor astronomers these days. The second thing is essentially also trying to understand the past of our solar system.” Then there is the possibility of a large meteor, like the one that made dinosaurs extinct 66 million years ago, someday threatening Earth. Meteor astronomy can help in pre­ventive measures against it. “Events of that scale happen quite rarely but it’s still important for us to study, forecast and try to have mitigation strategies,” says Sekhar. For example, last year, there was an experimental mission by NASA called Dart, double asteroid redirection test. They sent a spacecraft and smashed it into an asteroid to change its trajectory.

Because the community of meteor astronomers is so small, Sekhar collaborates on many studies. He is affiliated with the Institute of Celestial Mechan­ics (IMCCE), Paris Observatory. But the work itself is mainly on a computer, doing complex cal­culations. Pre-Covid, he would mostly be in Europe but now spends a large part of his time in India. That however is no deterrent to research. “As long as you have a working internet connection, you could actually do all theoretical work wherev­er you are. Even observational astronomers in today’s world can do it. I’ll give you a small example. The Himalayan Chan­dra Telescope is in a place called Hanle in Ladakh. That telescope is entirely operated from the In­dian Institute of Astrophysics headquarters in Bengaluru. The scientists can give coordinates and the telescope would move in Ladakh, and they can actually point it to wherever they like and download images through the internet pipeline.”

Besides his work, Sekhar is also involved in science outreach with his writings in popular national and international media. “I find that a good way of connecting with the public. To write in simple language from a scientist’s perspective so that more people, maybe some students, get inspired to take up science.” In India, however, his own field meteor astronomy, has no av­enues for someone wanting to make a career of it but that he believes will eventually change. To young aspiring astronomers, his advice is to stay curious about nature. “That in itself will help you figure out things in the future. The other thing is to be pa­tient and persistent because, unlike a professional degree which lasts for three or four years and leads to a job and a comfortable lifestyle straightaway, a life in science takes a lot of time. Plus, a scientist’s life is an oscillation between fascination and frustra­tion, because some problems or techniques you employ give you positive results, and some don’t work. It’s important to not get disappointed and leave the field.” And then, maybe, eventually, a minor planet will be named after you too.

Aswin SekharHawaiiKeralaminor planetOttapalamOuter SpacePanstarrs Telescope