domingo, 14 de dezembro de 2014



Iuriy

It was a cold morning, that of October 9th, 2008 in Yevpatoria, Ukraine. Yuriy’s watch was showing 07:02 when he climbed the metal steps to the circular base of RT-70, and opened the locks. The 6º C and strong winds always got to him. He waved weakly to the television people setting up outside, and closed the door behind him.

One hour later the control room was clean, and there wasn’t a dust particle in the always-on computers. Technicians started coming in, and he retreated to his small room, with a window facing the back of the 70-meter radio-telescope, a few green trees on the plain outside.

He looked at his watch, his own special 1MWF Sturmanskie, given to him by his father, an astrophysicist and “failed cosmonaut”, as his mother always said. 08:27. He used it every day, but some days it felt heavier. It was just like the one Yuriy Alekseevich Gagarin had worn in the first Earth orbit in 1961, with a black bracelet and golden frame. Last time it felt this heavy was 5 years before, for Cosmic Call 2. Powerful signals were sent to deep space, to five different stars. The signal was due to reach the closest star only in 2036.

This time the target was closer. Gliese-581c, the third planet of star Gliese-581, smack in the middle of the habitable zone, believed to be a potential host for life because of the possible existence of liquid water, had been recently discovered. A super-earth, 5x the mass of our planet, its year lasts 13 days, and was found using the Radial Velocity method, where the wobble of a star is measured and used to deduce the presence, mass and size of planets around it. It’s a Red Dwarf, small and cold stars that can be comfortable for life because of their long lifetimes, and represent the majority of the stars in the Universe. Gliese-581 is one-third the size of our Sun, twice as old, and close to us at about 20 light-years away.

The popular press and social networks went wild when the planet was discovered, and the ensuing speculation led to that day: October 9, 2008. At 09:00, the A Message From Earth (AMFE) powerful radio signal was shot towards Gliese-581c, containing messages and photos selected from a global competition. The signal was expected to arrive in 2029.

After all the cameras and excitement of the television transmission, Yuriy was the last to go. A swipe of the floor, taking out the garbage, he turned off the lights and went home. He didn’t expect to be around for a return signal, 40 years in the future.

Shortly after the signal was sent, Gliese-581c was dismissed as a candidate for life. A likely runaway greenhouse effect, the scientific papers said, and temperatures exceeding 500º C. The search for life moved to other exoplanets.

But the signal went on.

 

It was the Spring of 2029 on Earth when the signal reached Gliese-581. Yuriy was in a hospital bed in Tiraspol, Moldova, exiled from home by the Russia-Ukraine war. It was long over, but he never went back. Aged 84, he slept most of the time, rotating the spring on the Sturmanskie every day.

The signal reached the 3 planets orbiting the star, closer to it than Mercury is to Sol.

Gliese-581c did not have a runaway greenhouse effect. Tidally locked, with the same side always facing the star, it has a permanent day affected only by huge sun spots, with the average temperature of about 12 degrees Celsius going down when they passed.

The center of the day-side, a roughly circular region that some would call Equator, received more light and was hotter. Mostly land, it was the home to two intelligent species: the Coldbloods inhabiting mostly in the center, and Hotbloods mostly on the coast. All of them short and strong, with wide 4 and 2 legs respectively. With the sunny side being about 450x the surface area of the Earth, there was no lack of space or need for conflicts. Plus, it was too tiring - time in 581c went by slowly. The ocean, which was circular and occupied the outer half of the planet, all around and near the dark side, was made of freshwater, and had been the source of life millions of years ago, when its metallic core was more active and volcanoes spewed lava and created solid land.

The dark side is only reachable by longboats, and only the Hotbloods go there, fascinated by the day turning into night, the water that turns into ice, the dancing lights in the sky that start halfway in the trip, and the shinning dots behind them. All around the planet, auroras that never sleep mark the separation between the day and dark side. Their cause is the same as on Earth: charged particles from the star’s winds hit the magnetic field, interact with it and cause currents of charged particles that travel to the circle that separates day from night. Reaching the atmosphere, they collide with the nitrogen and oxygen that compose it, excite them, and cause them to emit light. The Hotbloods see in the infrared, where the star emits most energy, so the color that they see in the sky is a dancing, fascinating, hot, blue.

100km into the dark side, the Hotbloods have built their first antenna facing the shiny star-dots. It took them almost 100 years to build, and 10000 years later, it had mapped the sky, the unreachable shinning dots, found thousands of planets, transmitted messages every day, waiting for a reply that never came. And even the long-lived Hotbloods grow tired. “Nothing out there”, they concluded. As it was powered off, the last Hotblood slowly entered the skidvehicle under the antenna, maybe sad of what was being left behind and would not resist the cold for long. “Nothing out there”, he thought, as the AMFE signal entered the atmosphere.

 

Back on Earth, Yuriy’s heart stopped beating.

 

 

[nota: escrito como exercício final para um curso Coursera, “Imagining Other Earths”. Poderia simplificá-lo para tirar alguma da ‘hard science’, mas fica assim]



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