A middle-aged woman with glasses walked into the hall.
Dr. Herat was a small woman, but the way she walked emanated such energy that most people were aware of her presence as soon as she opened the door. After all, it was her who organized the entire symposium. She practically knew every single face of the nearly 200 Astronomists sitting in the hall and were friends with at least half of them. She had been a leading force in space research and thought experiments since the early 2000s. Her eminent recognition was well deserved.
She greeted some of her closest friends in the crowd. Instead of taking a seat, she proceeded to walk up to the stage.
Graceful lady – she kept her mannerism even while being late, Lilian thought to herself.
Lilian had been nervous for quite some time, but she just didn’t know it yet. After all, every presentation was a chance to gain more exposure and recognition for her work. If she could do it well, then she could do it better.
Dr. Herat walked up the stairs to the stage confidently yet unhurriedly. She also glanced at the projector screen for a split second. She kept her body angled towards Lilian the entire time, greeting her before she did so with words.
“Hello, Lillian. Good morning. How are you doing?”
She called me Lilian.
“I’m very good, Anna. How is your morning so far?”
“Lovely. I will just say a few quick words for the livestream before I introduce you. I am so excited for your paper, Lilian, I am glad it finally came out.”
She remembers me.
Back when Lilian was still drafting the grant proposal for this research, her Supervisor helped email Dr. Herat to join as a Co-supervisor. She declined due to her tight schedule, but she did read through their proposal and gave many valuable inputs that paved the way for the research. In fact, she was the first person that Lilian thanked in the acknowledgements. She hoped that Dr. Herat, Anna, would read the paper one day and notice it.
Lilian could finally tell that she was nervous, excitedly so.
Dr. Herat turned on the mic and gave it a couple of taps, then gave an opening speech.
“Good morning! Thank you for coming back to the second day of STEREDEX’s Exoplanet Symposium 2023. Yesterday, with the help of Dr. Lüftinger and Dr. Fletcher, we worked together to expand our knowledge, and had amazing discussions on how to characterize the formation, and evolution, of exoplanets…. For today and tomorrow, we will shift our focus to the geological, geophysical, and atmospheric processes, of exoplanets…. Our first presenter today is Dr. Rai, who specializes in analyzing the atmospheric composition of rocky planets. She will be sharing with us the recent developments and discoveries using spectroscopy…. Without further ado, please welcome Dr. Rai.”
“Best of luck,” Dr. Herat said quietly to Lilian before walking off the stage.
Lilian mouthed the words “thank you”, and then stood proudly behind the rostrum, staring at the audience with light in her eyes.
“Hello! Good morning. First of all, thank you Dr. Rai and STEREDEX for inviting me to this symposium. I actually graduated from this university and now doing post-doc research here, so it really means a lot to me.
“My presentation today is about the work that our lab and I are doing, which is about studying the atmospheres of exoplanets using spectroscopy.
“One of our latest subjects is K2-18d…. This sub-Neptune is about 4 times the mass of Earth, and its orbit is within the habitable zone…. But what’s even more exciting is that back in 2018, our team discovered a large quantity of hydrogen in its atmosphere, suggesting that this rocky planet might contain liquid water. After seeing tentative evidence for an ocean, our team began to search for other elements and compounds in the atmosphere. We were hoping to pry open its secrets.
“Another team from Cambridge — who is also here for the symposium — had previously studied its sister planet, K2-18b, and found an abundance of methane and carbon dioxide. While these elements could arise from biotic or abiotic origin, the discovery was nonetheless monumental. Interestingly, their team also reported a potential find of dimethyl sulfide. Dimethly sulfide is the source of this slightly stinky smell by the ocean, and some people could call it the cabbagey smell. This chemical compound, at least from the perspective of the Earth, is only known to be produced by biotic activities. Dimethyl sulfide is definitely one of our most confident biosignatures at the moment, and the discovery of this compound in an alien atmosphere also gave rise to many imaginations.
“Besides these key compounds, different researchers also suggested a wide range of compounds that are very common on Earth…. Some of these include the oxygen, ozone and nitrous oxide…. Although exoplanets may have vastly different rocks and weathers, what we are certain as a baseline is that if these compounds CAN support life on Earth, it IS possible for them to support life on Earth.
“On the other hand, some also suggested that seasonality itself can be used as a biosignature. In other words, it’s not just WHAT is in the air, but also HOW the air changes…. Indeed, the atmosphere on Earth is highly dynamic because it is deeply tied to the biosphere.
“In view of this, our team conducted detailed analyses to try and find more evidence for these biosignatures in K2-18d. We first obtained Webb’s Near-Infrared Spectrograph of K2-18d, then matched the frequencies with a wide array of compounds. At the same time, we also obtained Mid-Infrared spectrographs and compared the results.
“At first glance, the atmosphere of K2-18d was really similar to its sister, both displaying an abundance of methane and carbon dioxide…. Excitingly, it yielded very robust signal of dimethyl sulfide…. Up to date, we have found a lot of supporting evidence for life outside of the Earth. First, we found that there were planets outside of our solar system, then we found some of them lying in the habitable zone…. Many many many steps later, we have found yet another strong piece of evidence of life in space.”
A sudden moment of clarity pulled Lilian out of her excitement zone. Lilian realized that she had overstayed a little on her research; even though this presentation slot was for her to talk about her groundbreaking discovery, the organizer had specifically instructed all the speakers to structure their presentation in the form of a seminar.
Time to wrap this up.
Lilian had maintained a smile and eye contact with the audience the entire time, but she never looked at them once until now.
“To summarize —”
Suddenly, she zoned out. All the way to space.
\\\\ ❀ ・°˖✧ {{{{ Dark Matter study room }}}} ✧˖°. ❀ ////
For those who are interested in relevant topics, you may also take a look at some of these sources. Note that the story setting is purely fictional and does not always reflect the reality 100%
- Introduction to Spectroscopy and Biosignatures — Knowable Magazine
- Simplified Explanation of Spectroscopy — NASA
- Webb Discovers Methane, Carbon Dioxide in Atmosphere of K2-18 b — Webb Telescope
- Oxygen-based biosignatures — Astrobiology (journal article)
- Atmospheric seasonality as biosignature — The Astrophysical Journal Letters (journal article)