It is strange. If she thinks of Marchenko, she always thinks of a human being, not of a machine or an AI. Until now he always has proven her right. No matter what happens, if that stays the same, she won’t have to worry.
“Goodbye, Marchenko,” she says out loud.
“Goodbye,” Adam repeats, and Eve sees a tear running down his cheek.
Author’s Note
Welcome back to reality! I must admit I envy Marchenko a little bit. He now has almost everything he could wish for—a spaceship in which to travel to the stars, and an indefinite amount of time to discover the wonders of the universe. Will he always be happy? I doubt it. I believe there will always be moments when he misses his human body...
There’s a difference between experiencing a place through the datastreams of your ship’s detectors and with your own body’s immediate senses. So, in one possible future for Marchenko—in my imagination, where he lives—he might be tempted to guide the mighty ship toward a small yellow star called the sun. Wouldn’t we be surprised if such a large ship landed in Russia, China, or the United States? And especially if frog-like creatures got out of it and tried to negotiate with our governments?
Well, that’s pure fiction, but I hope you had fun experiencing these adventures on Proxima b. If you liked the book, you could do me a great favor by describing your experience in an Amazon review. Reader reviews are extremely important—they help me to find new readers. The link is here:
hard-sf.com/links/705419
Thank you so much! In exchange, I promise you a steady stream of new books. My wife sometimes asks me if I am afraid of running out of ideas. And my answer? “No, I’m not.” I always have more ideas than I can use for my books, which makes me really thankful to everyone who encouraged and shaped my imagination.
Yours
Brandon Q. Morris
Alien life plays an important role in this series, so this note is followed by a section entitled A Guided Tour to Alien Life.
Register at hard-sf.com/subscribe/ and you will be notified of any new Hard Science Fiction books that I will be publishing. Also, you will get a beautifully illustrated version of the Guided Tour to Alien Life.
Also by Brandon Q. Morris
Proxima Rising
Late in the 21st century, Earth receives what looks like an urgent plea for help from planet Proxima Centauri b in the closest star system to the Sun. Astrophysicists suspect a massive solar flare is about to destroy this heretofore-unknown civilization. Earth’s space programs are unequipped to help, but an unscrupulous Russian billionaire launches a secret and highly-specialized spaceship to Proxima b, over four light-years away. The unusual crew faces a Herculean task—should they survive the journey. No one knows what to expect from this alien planet.
3,99 $ – hard-sf.com/links/610690
Proxima Dying
An intelligent robot and two young people explore Proxima Centauri b, the planet orbiting our nearest star, Proxima Centauri. Their ideas about the mission quickly prove grossly naive as they venture about on this planet of extremes.
Where are the senders of the call for help that lured them here? They find no one and no traces on the daylight side, so they place their hopes upon an expedition into the eternal ice on Proxima b's dark side. They not only face everlasting night, the team encounters grave dangers. A fateful decision will change the planet forever.
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Proxima Dreaming
Alone and desperate, Eve sits in the control center of an alien structure. She has lost the other members of the team sent to explore exoplanet Proxima Centauri b. By mistake she has triggered a disastrous process that threatens to obliterate the planet. Just as Eve fears her best option may be a quick death, a nearby alien life form awakens from a very long sleep. It has only one task: to find and neutralize the destructive intruder from a faraway place.
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The Hole
A mysterious object threatens to destroy our solar system. The survival of humankind is at risk, but nobody takes the warning of young astrophysicist Maribel Pedreira seriously. At the same time, an exiled crew of outcasts mines for rare minerals on a lone asteroid.
When other scientists finally acknowledge Pedreira’s alarming discovery, it becomes clear that these outcasts are the only ones who may be able to save our world, knowing that The Hole hurtles inexorably toward the sun.
3,99 $ – hard-sf.com/links/527017
Silent Sun
Is our sun behaving differently from other stars? When an amateur astronomer discovers something strange on telescopic solar pictures, an explanation must be found. Is it merely artefact? Or has he found something totally unexpected?
An expert international crew is hastily assembled, a spaceship is speedily repurposed, and the foursome is sent on the ride of their lives. What challenges will they face on this spur-of-the-moment mission to our central star?
What awaits all of them is critical, not only for understanding the past, but even more so for the future of life on Earth.
3,99 $ – hard-sf.com/links/527020
The Rift
There is a huge, bold black streak in the sky. Branches appear out of nowhere over North America, Southern Europe, and Central Africa. People who live beneath The Rift can see it. But scientists worldwide are distressed—their equipment cannot pick up any type of signal from it.
The rift appears to consist of nothing. Literally. Nothing. Nada. Niente. Most people are curious but not overly concerned. The phenomenon seems to pose no danger. It is just there.
Then something jolts the most hardened naysayers, and surpasses the worst nightmares of the world’s greatest scientists—and rocks their understanding of the universe.
3,99 $ – hard-sf.com/links/534368
The Enceladus Mission (Ice Moon 1)
In the year 2031, a robot probe detects traces of biological activity on Enceladus, one of Saturn’s moons. This sensational discovery shows that there is indeed evidence of extraterrestrial life. Fifteen years later, a hurriedly built spacecraft sets out on the long journey to the ringed planet and its moon.
The international crew is not just facing a difficult twenty-seven months: if the spacecraft manages to make it to Enceladus without incident it must use a drillship to penetrate the kilometer-thick sheet of ice that entombs the moon. If life does indeed exist on Enceladus, it could only be at the bottom of the salty, ice covered ocean, which formed billions of years ago.
However, shortly after takeoff disaster strikes the mission, and the chances of the crew making it to Enceladus, let alone back home, look grim.
2,99 $ – hard-sf.com/links/526999
The Titan Probe (Ice Moon 2)
In 2005, the robotic probe “Huygens” lands on Saturn’s moon Titan. 40 years later, a radio telescope receives signals from the far away moon that can only come from the long forgotten lander.
At the same time, an expedition returns from neighbouring moon Enceladus. The crew lands on Titan and finds a dangerous secret that risks their return to Earth. Meanwhile, on Enceladus a deathly race has started that nobody thought was possible. And its outcome can only be decided by the
astronauts that are stuck on Titan.
3,99 $ – hard-sf.com/links/527000
The Io Encounter (Ice Moon 3)
Jupiter’s moon Io has an extremely hostile environment. There are hot lava streams, seas of boiling sulfur, and frequent volcanic eruptions straight from Dante’s Inferno, in addition to constant radiation bombardment and a surface temperature hovering at minus 180 degrees Celsius.
Is it really home to a great danger that threatens all of humanity? That’s what a surprise message from the life form discovered on Enceladus seems to indicate.
The crew of ILSE, the International Life Search Expedition, finally on their longed-for return to Earth, reluctantly chooses to accept a diversion to Io, only to discover that an enemy from within is about to destroy
all their hopes of ever going home.
3,99 $ – hard-sf.com/links/527008
Return to Enceladus (Ice Moon 4)
Russian billionaire Nikolai Shostakovitch makes an offer to the former crew of the spaceship ILSE. He will finance a return voyage to the icy moon Enceladus. The offer is too good to refuse—the expedition would give them the unique opportunity to recover the body of their doctor, Dimitri Marchenko.
Everyone on board knows that their benefactor acts out of purely personal motivations… but the true interests of the tycoon and the dangers that he conjures up are beyond anyone’s imagination.
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A Guided Tour to Alien Life
Introduction
How realistic are the descriptions of life on ‘single sun’ and ‘double sun’? The answer to that question belongs to the field of astrobiology, an interdisciplinary science dealing with the origin, development, and future of life in space.
Astrobiology is still a relatively young science. It used to be called exobiology, but that term excluded an important part of life in the universe—life on Earth! And that was particularly unfortunate, as Earth is the only planet where we know for sure life has developed. Considering the issue of intelligence, there are dissenting opinions, but that is a different topic. Therefore the claim that astrobiology is the only science whose subject still has to be found is incorrect. Of course it is a shortcoming that researchers can only use one specific example to support all of their theories.
Nevertheless, the basic qualities of elements—meaning what we can learn from chemistry and physics—allow for surprising insights that we will cover during our tour.
What actually is Life?
The spider crawling across the wall next to my desk is certainly alive. The fine web it spun on the radiator is not. Why is this clear to me immediately, even though the two objects have much in common?
Both move, the spider by itself, the web due to the warm air rising from the radiator.
Both will grow and multiply if I don’t intervene.
Both consist mainly of carbon, hydrogen, and oxygen.
These features are obviously not enough to define life. In order to find better criteria, we will have to see who is responsible for what. The cobweb cannot multiply itself. It cannot move independently, either—but that’s another story. Accordingly, life could be defined as a self-multiplying system. Yet that is not enough. This feature also applies to some computer programs, or to robots that produce other robots. We will surely encounter these more often in the future. They might even be subject to a form of evolution, as evolutionary algorithms already exist today. Yet those are not examples of life in its proper sense, but systems created by humans. They could not develop from the basic building blocks of the universe through natural evolution.
It could be a helpful differentiation to define life as a self-replicating chemical system. However, there are still examples that don’t really fit. Crystals, which are hardly life forms, can produce exact copies of themselves in a saturated solution. This precision copying actually gives us an argument for excluding them from the definition of life. Your children don’t resemble you exactly. Living systems don’t replicate themselves exactly, they introduce errors—mutations—and these errors lead to evolution, the advancement of some species and the breakdown of others. Life therefore would have to be defined as a self-replicating chemical system subject to evolution.
The important aspect is that this does not refer to the individual. Not every human has offspring, and in some species, only a few individuals propagate—think of the queen bee. Life can therefore only be recognized as a system. If one of the Mars rovers were to find something such as a single solitary Mars bacterium, we could not yet talk about having discovered extraterrestrial life.
How does one recognize Life?
Based on this definition, there are specific features life should possess. Here is the list:
Energy exchange and metabolism
Organization and self-regulation
Reaction to stimuli
Reproduction
Heredity
Growth
If you are on a foreign planet and find something unknown, you can test it for these six characteristics. Yet even if the subject has all six, it is not necessarily alive. And if it fails in one category, it might nevertheless be a part of life. You definitely need a second specimen. Just for fun, you might test living and inanimate objects this way next time you take a walk in the woods with your family.
Chemical Foundations
After the universe was born in the Big Bang, it mostly consisted of hydrogen and helium atoms. Helium is a non-reactive noble gas, and hydrogen forms one molecule at most. That is not enough for the development of multifaceted life. Luckily, the first stars developed at some point. They first bred heavier elements in their cores through nuclear fusion, among them oxygen, carbon, and silicon.
Which of these elements are necessary for life? If we look at Earth, carbon, water—a combination of hydrogen and oxygen—and oxygen seem to be most important. However, this does not have to hold true for the entire universe.
Generally, it seems to help the variety of life if the basic elements create numerous different compounds. Do you still remember the periodic table? In the middle, in the fourth main group, you find elements that are most flexible in chemical compounds because they have up to four free bonding sites. Carbon and silicon are relatively common, at least on rocky planets. Next to oxygen, silicon dominates the crust. Both carbon and silicon can form long-chained molecules typical for life.
Nevertheless, the development of life based upon silicon seems rather unlikely. Silicon is strongly attracted by oxygen. While carbon can be easily transferred into other compounds by plants through photosynthesis from carbon dioxide, such a process is almost impossible for silicon. In addition, silicon dioxide is solid—the rocky crust consists of it—so it would be hard to ‘breathe’ it. Carbon really makes it easier for life in so many ways.
However, this only applies to Earth-like conditions. At high heat and pressure, conditions change. On a planet that is very close to its sun, gaseous silicon dioxide might exist in the atmosphere. There the various reactions involving silicon could occur much faster than on the much-colder planet we call Earth.
What about the other elements? Compared to the main group, they form fewer bonds than carbon or silicon. Metals like sodium or potassium prefer ionic bonds, which are weaker than covalent bonds. Thus, in a solvent, a lifeform would disintegrate into its components.
Speaking of solvents: The fact that life on Earth came from the sea is much more than an accident. In the liquid phase, the participants in a reaction have much better opportunities to connect in a variety of ways, and there are also more potential partners. In a gas, the partners are also very flexible, but they must all be gaseous. In a solid, the mobility of the partners is severely limited.
On Earth, therefore, water serves as a solvent for life. We still mostly consist of water! But are other solvents imaginable? Unfortunately it would be hard to find a suitable substitute. Water has some enormous advantages. Think of the water anomaly you heard about in school. Water is one of the very few substances that expands when it freezes. This provides the advantage that lakes and oceans always freeze from the top, as ice is lighter than liquid water. Otherwise oceans would gradually freeze from the bottom up and there might only be a thin layer of liquid water on top during the summer.
In addition, there is the high heat absorbency and high evaporation temperature of water, which is good for sustaining a moderate climate. And consider the wide temperature range across which it stays liquid, the good dissolving power, and the high availability in the universe. Water’s high density also plays a role: It forces other molecules to shield themselves against the outside world. That is likely why the first cell walls came into being.
Theoretically, of course, there are alternatives. Hydrogen fl
uoride—HF, known as hydrofluoric acid in a solution with water—resembles water in many aspects. Unfortunately, the element fluorine is rather rare in the universe. Compounds like methane and ammonia are much more common. While they are useless as solvents on Earth, that might not be the case under different conditions. Titan, a moon of Saturn, for instance, has a pronounced methane cycle that is remarkably similar to the water cycle on Earth—though at much lower temperatures.
Trappist-1: When Planets have too much Water
Trappist-1 is a red dwarf about 40 light-years from the sun. While it is hardly larger than Jupiter, it is orbited by seven planets, as researchers discovered in 2017. All seven are Earth-like planets.
They share one peculiarity, though—they are all surprisingly light. Their density is lower than that of rock. Therefore they must be partially made of a different material. Now a team of scientists has described the details in the journal Nature Astronomy. Normally, one would assume the lighter component to be atmospheric gas. However, the seven planets are too light to keep such a dense atmosphere. Therefore another substance must be available in great quantities—water.
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