Gold Rush, page 35
Terraforming Venus
Venus is the basket case of the solar system.
Physically, Venus could have been a candidate for a second Earth, but it’s the hottest planet in the solar system, far hotter than Mercury. A runaway greenhouse effect sent Venus to the extremes of what a rocky planet can endure. The carbon dioxide within its atmosphere is so hot and under so much pressure that it forms a supercritical fluid. At the surface, CO2 functions more like an ocean than an atmosphere, albeit one that is absurdly hot and capable of melting lead and tin.
The Venusian atmosphere is 96.5% carbon dioxide, with nitrogen making up only 3.5%. Compare that to Earth, where nitrogen makes up almost 80% of the atmosphere, and CO2 accounts for less than a percent. At a cursory glance, it seems as though Venus has much less nitrogen than Earth, but there is so much carbon dioxide there that the paltry 3.5% of nitrogen is still roughly four times as much nitrogen as found in Earth’s atmosphere!
When we think about terraforming a planet, we assume it’s the planet’s surface that needs to be habitable, but an astonishing 70% of Earth’s surface is uninhabitable by humans, as most of the planet is covered in water. In the same way that we sail across the seas here on Earth, the most viable option for Venus is for us to sail through the air. Forget about the hellish surface where temperatures reach 460 °C (860°F) and crushing pressures of 92 bar (which equates to about 3,000 ft beneath the ocean), Venus is still habitable—but at 55 km (34 miles) above the surface. At that height, the pressure drops to about 1 bar—Earth’s sea-level pressure—and the temperature falls to a range of roughly 20°C to 60°C (68°F to 140°F).
NASA has (admittedly rough) plans for HAVOC—the High Altitude Venus Operational Concept that would see blimps floating through the clouds. Beyond the challenge of getting there, the only other practical problem is sulfuric acid in the clouds.
The upper clouds of Venus are almost entirely made up of sulfuric acid droplets with a collective mass of 1.2 × 10¹⁶ kg, which is similar to that of a moderate-sized asteroid (like 65 Cybele). Although that’s huge by our standards, it’s trivial compared to the mass of the atmosphere and is considered a trace amount (less than 1%).
In Gold Rush, an alien species uses a comet to neutralize the sulfuric acid in the Venusian atmosphere. Since ammonia only makes up roughly 1% of regular comets, I’ve suggested that the comet in question came from somewhere akin to the Kuiper Belt, where the ammonia content can be as high as 5%. Given that the reaction to neutralize sulfuric acid with ammonia is…
H2 SO4 +2NH3 →(NH4 )2 SO4
The comet needs twice as much ammonia as sulfuric acid, plus a little extra to account for losses along the way, putting it in the region of four trillion tons. Although that sounds like a lot, it would result in a comet with a diameter of 10 km (6 miles). The comet Hale-Bopp is 60km (37 miles) in diameter, so this is well within the constraints of comets in our solar system and not far-fetched.
The byproducts of this reaction are NH4 amonium and SO4 sulfate. On Earth, both of these are considered particulates in the air rather than gases and contribute to global cooling rather than warming. Given the extremes on Venus, over time, the presence of these may help to cool the atmosphere slightly, but they’re expected to settle on the surface. While they’re in the atmosphere, they’ll contribute to light scattering, giving the sky a pink/brownish tinge.
Comet Yakov
Comet Yakov is fictional. It is described as being missed as it approached the Sun from the south, being obscured by the Sun when first observed, and then descending from the north. This illustration helps you imagine how this could unfold.
One question that came up during the beta read is what would realistically happen if a comet flew by Venus?
Any close encounter with a planet will cause an asteroid or comet to be deflected. How much depends on the object’s speed and its distance from the planet at its closest encounter. In 2029, the asteroid Apophis is going to race past Earth at a distance of 31,600 km (19,600 miles), which is 2.5 times the diameter of Earth. This particular encounter with Earth will alter the asteroid’s overall orbit of the Sun by an astonishing 13,850,000 miles as it is deflected by Earth’s gravity!
When it comes to the tail of a comet, it’s important to note that there are two tails. The brighter white tail is caused by dust coming off the comet’s surface, while the dull blue tail is caused by ionized gas boiling off. Both are influenced by the Sun, but they point in slightly different directions, forming a V-shape pointing away from the Sun.
When comets move away from the sun, their tails streak out in front of them. If a comet were to swing around a planet like Venus as described in this story, the dust thrown off by the comet would be drawn in toward the planet long before the comet got close. That dust would curl with the gravitational influence of the planet and be heavily perturbed. It would appear to fan out and scatter around like glitter. Once the comet moved away from the gravitational influence of the planet, its tail would settle and again face away from the Sun.
Although impacts with planets are rare, they do happen, and when they happen, they’re spectacular. Perhaps the best known is Comet Shoemaker-Levy 9, which struck Jupiter in the 1990s. However, even as I was writing this story, an announcement came that a comet from another star system was about to rush inside the orbit of Mars as it screamed past the Sun. In addition to that, while the book was going through its final edit, amateur astronomers spotted a massive impact on Saturn. It seems these occurrences aren’t as rare as we once thought.
Delta-V
Back in 1974, science fiction author Jerry Pournelle was chatting with Robert Heinlein and made the point that “If you can get a ship into orbit, you're halfway to the moon.” Heinlein replied, “If you can get your ship into orbit, you're halfway to anywhere.” And, broadly speaking, Heinlein was right.
The following table is in km/s and is a little simplistic and uses Hohmann transfer orbits, but it makes it easy to see Heinlein’s point: when it comes to exploring the solar system, most of the effort lies in getting off Earth in the first place.
Destination
Δv from Earth
From LEO
Low Earth Orbit (LEO) (~400 km)
10
-
Geostationary Orbit (GEO) (~35,786 km)
10.5 – 11
1
Moon (Lunar Orbit Insertion)
12 – 14
2 — 4
Venus (Aerobraking at Venus)
16 – 18
6 — 8
Mars (Aerobraking at Mars)
16 – 18
6 — 8
Jupiter (Arrival at orbit)
20 — 22
10 — 12
Saturn (Arrival at orbit)
22 — 25
12 — 15
When you recognize the average distance to Jupiter is 715 million km or 444 million miles, it is quite astonishing to realize that it takes roughly the same delta-v as getting into orbit in the first place, when orbit is only 400 km away!
Expanding Universe
One of the points discussed in passing within this novel is the impact of the expanding universe on our ability to interact with other intelligent species. By current estimates, there are a staggering two trillion galaxies in the visible universe—that’s two thousand billion, or two thousand thousand million galaxies. And that’s only relevant if you can get your head around what a million actually means in practice. The numbers are, somewhat unsurprisingly, astronomical.
Because the universe is expanding and light takes time to traverse the astonishing distances in the cosmos, over 95% of these galaxies are already unreachable. We can see them, but we could never travel to them as they’ve already moved beyond the cosmic event horizon. They’re effectively ghosts.
Imagine an old steam engine, the kind that once trundled across the vast open plains of the American West with clouds of white billowing from a smokestack, leaving a trail drifting above the railway tracks. The train is in the distance. It’s curling over the horizon, disappearing from sight, but as the air is still, you continue to see the smoke trail. The train has moved on, but the smoke is still visible. That’s, in essence, what’s happening with 95% of the galaxies we can see. We see what’s emitted—light instead of smoke—but the galaxy itself has moved so far away that it’s beyond what we consider the horizon.
If we were to detect an advanced intelligent alien species in any of those 95% of galaxies, we could never contact them, and they could never contact us. In fact, although we could see them, they’d never be able to see us—they’d only ever see Earth as it was billions of years ago. For that matter, a large majority of them would look where Earth is today and not even see the Sun as they’d be looking into the past, and our Sun only formed 4.5 billion years ago, so if they’re more than 4.5 billion years away from us, or roughly a third of the way across the universe, all they’d see is a cloudy nebula from which our solar system would eventually be born.
The Carbon Cycle
In the same way in which water cycles through the environment, falling as rain, running in rivers, gathering in the sea and evaporating to form clouds with more rain recycling the same water over and over again, carbon moves in a cycle through our environment, only carbon cycles over hundreds of millions of years.
As noted in this story, all of the carbon in our bodies has come from the air!
Plants convert CO2 into simple sugars, which become the building blocks of absolutely everything else. The carbon in our bodies is second, third, or fourth-hand, etc, but it all originated from plants (either directly or indirectly).
Although other forms of energy power some of the more obscure species of microbial life on Earth (like radiosynthesis and chemosynthesis in the depths of the ocean or miles beneath the ground), almost all surface life relies on the Sun and the astonishing ability of plants to convert a gas (carbon dioxide) into chemical energy (sugar). From there, the diversity of life on Earth arises from the biological recycling of that initial carbon store. If you’re interested in learning more about this, I recommend the non-fiction book Carbon: The Book of Life by Paul Hawken.
Although the prospect of terraforming Venus is a long way off, it will happen one day. In some regards, Venus is one of the crown jewels of the solar system. Venus has so much carbon dioxide and so much access to solar energy that it is a gold rush waiting to unfold. Although it might seem unlikely to us with our 21st-century technology, Venus has the potential to power growth throughout the solar system. But we’re like sailors in the 15th century hoisting canvas sheets, navigating by sextants and tugging on ropes, unable to see that one day, people will soar through the air in metal tubes with wings. As unlikely as it seems, one day, Venus will be an industrial powerhouse.
Venusian Atmosphere
We are a long way from transforming Venus into a habitable planet, but it is impractical rather than impossible. Neutralizing the sulfuric acid in the atmosphere with a large comet would be a great start. NASA’s HAVOC is essentially a series of blimps in which astronauts can live and work while soaring high above the surface of the planet in the temperate zone.
Although it sounds strange, atmospheres behave like fluids and can be thought of as a form of fluid distinct from the hydrosphere (seas, oceans, lakes). On Venus, the air is so dense that gases like oxygen and nitrogen can be used for buoyancy in the same way as hydrogen and helium are here on Earth. And as they’re breathable, we can fill airships with breathable air and live within them. Although they’d be challenging to establish, once in place, these airships would be no more technically difficult to operate than the Goodyear blimp or a cruise ship in the Caribbean.
On Earth, Rayleigh scattering causes the sky to appear blue. When sunlight strikes air molecules smaller than the wavelength of light itself, shorter wavelengths (like blue) scatter much more than longer wavelengths (such as red), so we see a brilliant blue sky above us.
On Venus (and places like Titan), the atmosphere is made up of much larger, more complex molecules like carbon dioxide. Sunlight striking these big molecules scatters more evenly across all frequencies (which is called Mie scattering). This is why clouds appear white.
During the descent of the Soviet Venera space probes, the sky on Venus appeared butterscotch (orange/yellow) at the altitude described in this novel.
Sled-Launched Rockets
A friend of mine is a fan of classic science fiction. While chatting one day, he told me about the forerunner to Thunderbirds, a show called Fireball XL5 that used a rocket-powered sled racing along the ground to launch larger rockets. He asked why we don’t use this today. It’s a good question that got me thinking and looking deeper into the concept, using it in the fictional RockX space company described in this novel.
There is absolutely no doubt that SpaceX has revolutionized spaceflight with its reusable rockets. Watching the first stage of a Falcon or Starship land on a barge at sea or back at the launch site is utterly spectacular and a triumph of engineering. It’s a great solution to a complex problem, but it’s not the only solution. In particular, the need to refuel Starship in orbit with ten additional flights screams of inefficiency. Some would argue that this can’t be avoided, and maybe they’re right, but are there other, more efficient ways to get payloads into space?
One alternative is the idea of a sled-launched rocket racing down a track until it has reached a speed that negates the need for a significant amount of the initial launch mass, reducing the need for so much fuel.
Radian Aerospace is developing a delta-wing rocket launched from a two-mile-long track that can reach space without the need for any stages at all. That is extremely ambitious! I wonder… would splitting the system into stages be even more efficient? The first stage would be the rocket sled rushing along the ground before turning up and launching the main vehicle. The second stage would be a delta-wing craft with scramjet engines to take the vehicle above the stratosphere, but this stage would never leave the atmosphere, returning to land as a drone. The delta stage would launch a rocket in a manner similar to Virgin Galactic’s mothership but with enough fuel to reach orbit. Perhaps this approach is too complex to be viable, but it is interesting to consider.
Supernova
I love how enigmatic reality is when you stop and look at the sheer size and scale of the universe. Stars explode as supernovae with astonishing frequency, several times a second. Some estimates suggest as often as 40-50 times a second! As a supernova can outshine the hundreds of billions of other stars in its host galaxy, that is a remarkable amount of power being unleashed in a hectic frequency. And yet, in our galaxy, we’ll only see one every fifty years. So supernovas are paradoxical, being common but rare.
Flyby of Pluto
In this book, the Vulcan is a crewed mission to provide local caching of data on the impact of Comet Yakov on Venus, with the satellite swarm sending pictures directly back to Earth and their detailed data to the Vulcan. Although this may seem a little convoluted, it is based on the historic flyby of Pluto by NASA’s New Horizons probe.
The New Horizons probe collected data for roughly four and a half hours as it soared past Pluto. It immediately sent back photographs to Earth, but it collected so much data in those four hours that it took 16 months for it to be fully downloaded. In this story, the hundreds of CubeSats and mini-satellites are deliberately set on decaying orbits, so they need to offload their data to the Vulcan before they burn up.
Thank You
Thank you for taking a chance on an obscure Australian science fiction author hailing from Auckland, New Zealand. Your support of my writing is deeply appreciated. By purchasing this book, you’re giving me the opportunity to write the next one, so I’m grateful for your enthusiastic support.
As noted in the dedication, I want to thank the following beta readers who helped me fine-tune this novel: Phil Bailey, CPL Gabe Ets-Hokin USMC, Chris Fox, Gerald Greenwood, Terry Grindstaff, Per Hansen, David Jaffe, Dr. Didi Kanjahn, LCDR Mike Morrissey USN RET, Jay Palermo, Dr. Randy Petersen, Melinda Robino and John Stephens. Their enthusiastic support and encouragement are very much appreciated.
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Peter Cawdron
Sunshine Coast, Australia
Peter Cawdron, Gold Rush
