Kranti:
I will describe the planet to you, because you will never see it through Avi’s eyes. It is a violent place. Imagine: a world so close to its sun that they face each other like dancing partners. That’s how Annie first described it to me, when her group found it. The light curve signature was subtle but it was there. Shikasta 464’s only known planet, a not-so-hot Jupiter, had a tiny sibling. Two Earth masses, a rocky world too close to its sun to be in the habitable zone. But between its burning dayside and the frozen night, there was the terminator, the boundary.
Nobody actually believed we would get there. I say “we” but really I mean the spacecraft, the Rohith Vemula.
How hard were those early years! Now we have our reward: the signals, first from the spacecraft, and then from Avi! I can see through his eyes, as you should have been doing right now. I know what he knows, even though the knowledge is more than four years old. My grandfather is in Bhubaneswar, celebrating with palm beer. He says that because I am a kind of famous person now, all will work out for our people. But I know and he knows it is not that simple.
From faraway Arizona, Annie is looking at the pictures on her screen. The substellar side of the planet, always facing its dim red star, is all lava seas. But in the terminator, what you called the Twilight Zone, the temperatures are less extreme, and the terrain is solid rock. For this reason you and Chirag designed our proxy to be a small, flat climbing robot, with very short legs, There he is, up on the cliff face, like a crab.
I am used to boundaries. Ever since my exile from my people’s ancestral home, I have lived in in-between places. Living on a boundary, you know you don’t belong anywhere, but it is also a place of so much possibility.
Through Avi’s eyes, the planet’s terminator has become more and more familiar.
Annie:
For my people the number four is sacred—four directions, four holy mountains. It always felt right to me that this project began with the four of us on a rock, stargazing. We’re still figuring out what it means to be together again after all this time, without you.
Let me begin with the old question: How do you know when something is alive?
I grew up on the rez. Red dust and red rock, mesas and buttes against the widest sky you’ve ever seen. I grew up lying on boulders with my cousins, watching the constellations move across the sky, and the stars seemed close enough to touch. During the winter, when the snow still fell, we little ones would huddle inside the hogan, listening to our elders tell the stories of how Coyote placed the stars in the sky. My plump fingers would fumble as I tried to follow my grandmother’s hands deftly working the string patterns— with one flick of the wrist, one long pull, one constellation would turn into another. The cosmos was always a part of our lives; even in the hogan there was Mother Earth, Father Sky. Now we live in boxes like white people. My uncle is a retired professor and a medicine man. He says our rituals and ceremonies keep us reminded of these great truths, even in this terrible time for our people.
Growing up, I thought I’d follow his footsteps—my Uncle Joe, the professor of Futures Studies at Diné University. But I took freshman geology to fulfill a science requirement, and ended up hooked. I remember the first time I realized that I could read the history of the Earth in the shapes and striations of the rocks, the mesas, and the canyons. I ended up going to the State University as a geology major, hoping to do something for the Navajo economy, which relied at that time on mining operations. I was naïve then. Luckily I got distracted by exoplanet atmospheres—late-night homework session, too much coffee, my boyfriend at the time—so here I am, planet hunter, all these years later, looking for biosignatures in exoplanets.
I’ve been looking at the images and puzzling over a few things. After several thousand exoplanets, we still don’t really understand how planetary atmospheres originate. Earth is such a special case that it only tells us of one narrow band of possibilities. With the exception of the noble gases, nearly all the gases in our atmosphere are made by life. I’m thinking about my grandmother’s story of the holy wind—life is breath, breath is life, literally and in every other way.
Shikasta 464b is too close to its star to do more than graze its habitable zone. Which is why it is last on everybody’s list for habitability. But my argument is that (a) the thin atmosphere (only 0.6 atm) is nevertheless more than what we’d expect of a planet that ought to have lost much of its atmosphere long ago, so what’s causing it to persist? Could be geology, could be life. And (b) the terminator between the magma pools of the dayside and the frozen desert of the nightside is actually relatively temperate in places, with temperatures that might allow for liquid water. There are trace amounts of water vapor in the upper atmosphere, but—let’s not get excited—likely not enough to create oxygen by photolysis—nah, if you want an oxygen atmosphere you have to look elsewhere. There is hydrogen, methane, and carbon dioxide, but that is hardly surprising on a world with
