My First Article for Popular Mechanics!

My First Article for Popular Mechanics!

There’s a potentially Earth-like planet around the closest star to Earth—that’s the space headline that captured the world’s imagination this summer. But here’s something that was easy to forget in all that furor over Proxima Centauri. Our neighboring star doesn’t look anything like the Sun.

We humans have known only one life-sustaining planet in the universe: a green-and-blue globe called Earth. So perhaps we can be forgiven for thinking the ideal ingredients for creating life must resemble what we se here: a bunch of planets around a medium-sized yellow star.

Mind-expanding missions like the Kepler Space Observatory, however, have scientists questioning whether a solar system like ours really is the perfect place to hunt for new Earths and the possibility of life beyond our planet. Lately, astronomers have been taking a closer look at red dwarfs—stars with low mass, low temperatures, and slow rates of fusion.These stars don’t look much like our life-giving Sun, but they make up almost 70 percent of the observable stars in the sky and could survive for trillions of years—far longer than our star.

If we’re going to find life beyond our solar system, many scientists believe it will be orbiting a red dwarf. Here’s why.

gliese_667_cc_sunset
Artist’s impression of a sunset seen from the super-Earth Gliese 667 Cc. Credit: ESO

The Alien Worlds of Red Dwarfs

In the past, planet-hunters thought the odds of finding potentially habitable worlds around red dwarfs were quite low. Because of their low mass and temperature, red dwarfs emit just 3 percent as much light as our sun. For an orbiting planet not to freeze into an uninhabitable iceball, it would need to be as close to the star as Mercury is to our Sun. Unfortunately, being so close to a star means the planets probably would be tidally locked, where one side is constantly facing the star and the other side always faces away. Not ideal conditions for creating life.

Red dwarfs are also far less stable compared to larger stars, undergoing sudden rises and drops in the amount of light and heat they emit. This creates big variations in temperature, adding yet another challenge for budding life.

If we’re going to find life beyond our solar system, it will likely be orbiting a red dwarf.

It’s not all bad news, though. Red dwarfs have a considerable advantage over other stars in their incredible lifespans. Our Sun has been around for 4.57 billion years, yet humanity has existed for just 200,000 years. Life takes a long time, and complex life even more so.

Time is one thing red dwarfs have plenty of—they can exist for trillions of years because of their low mass and slow rate of nuclear fusion. Since they’re also so common in our cosmos, the odds of finding planets within that habitable Golidlocks zone is statistically high. For astronomers, the pros are starting to outweigh the cons.

Artist's impression of the planet orbiting Proxima Centauri
Artist’s impression of what the surface of Proxima b could look like. Credit: ESO

The Case for Going Red

In 2005, astronomers from around the world converged on Mountain View, California, for a workshop sponsored by The Search for Extraterrestrial Intelligence (SETI) where scientists argued the case that red dwarf stars could be the best place to look for aliens. In the end, it comes down to sheer probability. Within 33 light years of Earth there were 240 known red dwarfs at the time, compared to just 21 stars like ours.

Although red dwarfs are hard to find because they’re dim, once they’re spotted it’s much easier to see how many chunks of rock are in orbit. The so-called transit method of finding exoplanets, which the Kepler telescope used to great effect, relies on looking for changes in brightness caused by a planet passing in front of its star. It looks something like this:

Because planets orbiting a red dwarf are likely to hug their stars so tightly, the orbital period is often just a few days long, which makes for pretty good odds of seeing such a transit.

New Worlds Emerge

Since that SETI conference more than a decade ago, oodles of new planets orbiting red dwarfs have been discovered. Between 2005 and 2010, astronomers found six exoplanets orbiting Gliese 581, a red dwarf located about 20 light years from Earth. Two of these planets, Gliese 581-c and -d, lie on the inner and outer edge the star’s habitable zone. Another exoplanet, Gliese 581-g, may also have an orbit fit for habitability (though its existence is still contested).

In 2012, the European Southern Observatory (ESO) published the results of a spectrographic survey that examined 102 red dwarf stars in the Milky Way over the course of six years. They found that red dwarf stars were more likely to have an Earth-like planet orbiting them than a gas giant. Two years later, another ESO study concluded that virtually all red dwarfs in the universe have at least one exoplanet orbiting them. At least a quarter of them have a super-Earth (a planet like ours but slightly bigger) orbiting within their habitable zones.

eso1629e.jpg
Artist’s impression of the planet orbiting Proxima Centauri. Credit: ESO/M. Kornmesser

The drumbeat goes on. This past July, researchers from the Harvard Smithsonian Center for Astrophysics (CfA) released a study in which the team calculated the likelihood of Earth-like planets forming within our universe over cosmic timescales, starting with the first stars to form, billions of years ago, and continuing into the distant future. They determined that low-mass red dwarf stars would be more likely than giant stars to maintain a system of planets long enough for life to emerge, and that likelihood only increased with time.

“We considered the likelihood of ‘life as we know it’ to form between the appearance of the first stars and the death of the last stars,” Professor Avi Loeb, a science professor at Harvard University and the lead author on the paper, told PM. ” We found that the likelihood peaks in the distant future around low-mass stars, simply because these stars live much longer than the Sun.”

Other discoveries made in the past five years have also bolstered the case for habitable planets around red dwarf stars with exoplanet candidates around Innes Star, Kepler 42, Gliese 832, Gliese 667, Gliese 3293, and most recently Proxima Centauri. All of these star systems are located relatively close to our own, though still impossibly out of reach with only today’s space-faring technology.

In the coming years, as more exoplanet hunters like the James Webb Telescope and the Transiting Exoplanet Survey Satellite look to the sky, it’s probable that scientists and astronomers will focus much of their efforts on nearby red dwarf stars.

“One of the great discoveries made in the past decade or so is that it seems like there are planets all over the place,” TESS project scientist Stephen Rinehart told PM, “even around these small stars so different from our own.”

See it here: Popular Mechanics

Terraforming Series Complete!

Terraforming Series Complete!

I’ve been busy over at Universe Today of late. In fact, as part of a promotional thing for my upcoming book – The Cronian Incident – I’ve been doing a series of articles about terraforming. And it’s actually kind of an interesting story, which I already touched on in a previous post. In any case, the series is now complete, with articles that cover everything from terraforming Mercury to terraforming the moons of the gas giants in the outer Solar System:

The Definitive Guide to Terraforming
How Do We Terraform Mercury?
How Do We Terraform Venus?
How Do We Terraform Mars?
How Do We Terraform the Moon?
How Do We Terraform Jupiter’s Moons?
How Do We Terraform Saturn’s Moons?

To give people the Cliff Notes version of this series, it is clear that at this point, humanity could colonize and terraform certain worlds in our Solar System. The only real questions are where could we? How could we? And why should we? To answer the first two, we could terraform Mars and Venus, since both planets are terrestrial (like Earth), both exist in our Sun’s habitable zone (like Earth), and have either abundant atmospheres or abundant sources of water we can work with. In any other case, the matter becomes impractical, except within certain contained environments (paraterraforming).

mars_greening
The “greening of Mars”. Credit: nationalgeographic.com

As for the third question – why should we? – that was one of the main reasons I tackled this subject. When it comes to terraforming, the questions concerning ethics and responsibility are unavoidable. And while I did my best to cover this in the course of writing the series, the real debate happened in the comments section. Again and again, people asked the following questions:

How can we live elsewhere when we can’t even take care of Earth?
Shouldn’t we take care of our problems here before we settle other worlds?
Wouldn’t those resources be better spent here?

All good (and predictable) questions. And rather than simply avoiding them or dismissing them as pedestrian, I wanted to seriously have an answer. And so I chose to reply whenever these questions, or some variation, popped up. Here’s the basics of why we should terraform other worlds in this century and the next:

1. Increased Odds of Survival:
As Elon Musk is rather fond of sharing, colonizing Mars was one of the main reasons he started SpaceX (which recently made their second successful landing of the reusable Falcon 9 rocket!) His reason for establishing this colony, he claims, is to create a “backup location” for humanity. And in this, he has the support of many policy analysts and space enthusiasts. Faced with the threat of possible extinction from multiple fronts – an asteroid, ecological collapse, nuclear war, etc. – humanity would have better odds of survival if it were a multi-planet species.

Artist's concept for a possible colony on Mars. Credit: Ville Ericsson
Artist’s concept for a possible colony on Mars. Credit: Ville Ericsson

What’s more, having other locations around the Solar System decreases the odds of us ruining Earth. So much of why Earth’s environment is threatened has to do with the impact human populations have on it. Currently, there are over 7 billion human beings living on planet Earth, with an additional 2 to 3 billion expected by mid-century, and between 10 and12 by the 2100. But it’s not just the number of people that matters. In addition to every human being constituting a mouth to feed, they are also a pair of hands that need to given something productive to do (lest they turn to something destructive).

Every human also requires an education, a place to live, and basic health and sanitation services to make sure they do not die prematurely. And providing for all of this requires space and a great deal of resources. As it stands, it is becoming more and more difficult to provide for those we have, and our ability to do so is dwindling (i.e. thanks to Climate Change). If we intend to survive as a species, we not only need new venues to expand to, we need other resource bases to ensure that our people can be fed, clothed, housed, and employed.

So simply put, creating permanent settlements on the Moon, Mars, and elsewhere in the Solar System could ensure that humanity survives, especially if (or when) our efforts to save Earth from ourselves fail.

Project Nomad, a concept for the 2013 Skyscraper Competition that involved mobile factory-skyscrapers terraforming Mars. Credit: evolo.com/A.A. Sainz/J.R. Nuñez/K.T. Rial
Project Nomad, a concept for the 2013 Skyscraper Competition that involved mobile factory-skyscrapers terraforming Mars. Credit: evolo.com/A.A. Sainz/J.R. Nuñez/K.T. Rial

2. Testing out Ecological and Geological Engineering Techniques:
Basically, there is no way humanity is going to be able to address Climate Change in this century if we do not get creative and start relying on techniques like carbon capture, carbon sequestration, solar shades, and artificially triggered global dimming and fungal blooms. The problem is, any or all of these techniques need to be tested in order to ensure that the results are just right. Altering our environment would not only threaten to disrupt systems human being depend upon for their livelihood, it could also threaten the lives of many people.

Such is the threat Climate Change poses, so we want to make sure the ways in which we address it helps the environment instead of screwing it up further. The best way to do that is to have testing grounds where we can try out these techniques, and where a misstep won’t result in the loss of innocent lives or billions in damages. Ergo, testing our methods on Mars and Venus will give us a chance to measure their effectiveness, while avoiding any of the political barriers and potential hazards using them on Earth would present.

3. Mars and Venus are Perfect Testing Grounds:
Astronomers have been aware for some time that Mars and Venus are similar to Earth in many ways. As previously mentioned, they are both terrestrial planets that are located in our Sun’s habitable zone. But of course, they are also different in several key respects. Whereas Mars’ atmosphere is very thin, it has no magnetosphere, and its surface is extremely cold and dry, Venus has an atmosphere that it extremely dense, hot enough to melt lead, and where sulfuric acid rains are common.

terraforming-mars2
Artist’s impression of a atmospheric generator on Mars. Credit: futurism.com

The reasons for this? Mars sits at the outer edge of the Sun’s habitable zone and receives less warmth. Combined with its eccentric orbit – and a lack of a protective magnetosphere that caused it to lose its atmosphere billions of years ago – this is what has led to it becoming the very cold and dry planet we are familiar with. Venus, sitting on the inner edge of the Sun’s habitable zone, suffered a runaway Greenhouse Effect early in its history, which caused it to become the extremely hot and hellish world it is today.

Terraforming Mars would therefore require that we thicken the atmosphere and warm it up. This means triggering a Greenhouse Effect by pumping lots of CO2 and nitrogen (probably in the form of ammonia) into its atmosphere and then converting them using cyanobacteria and other species of bacteria. So basically, to make Mars more Earth-like, we could build heavy industry there to pollute the hell out of the place – something we’ve been doing here on Earth for hundreds of years! – and then test out techniques designed to convert the atmosphere into something breathable. What we learn could then be applied here at home.

The same holds true for Venus. In order to terraform that world into something livable for humanity, the first challenge will be to arrest the runaway Greenhouse Effect there and convert the carbon dioxide/sulfur dioxide-rich atmosphere into one composed of nitrogen and oxygen gas. There are many ways to do this, and testing one or more of them out will yield crucial data for using similar techniques on Earth. In a nutshell, transforming Mars and Venus will help us save Earth.

Artist’s concept of a Venus cloud city – part of NASA’s High Altitude Venus Operational Concept (HAVOC) plan. Credit: Advanced Concepts Lab/NASA Langley Research Center
Artist’s concept of a Venus cloud city – part of NASA’s High Altitude Venus Operational Concept (HAVOC) plan. Credit: Advanced Concepts Lab/NASA Langley Research Center

4. Our Solar System has Abundant Resources:
Between the Moon, Mars, Venus, Mercury, the Asteroid Belt, and the systems of Jupiter, Saturn and beyond, there are literally enough resources to last humanity indefinitely. And while we can’t hope to possess them all at once, every step in colonizing the Solar System offers us the chance to expand our resource base, conduct scientific research and exploration, add more land which we can develop and use for human settlement, and ultimately grow as a species.

To break this process down piecemeal, we must start with the Moon. By establishing a colony in its southern polar region, we could leverage the local resources to create a permanent settlement and use it as a refueling base for mission deeper into the Solar System (a move which would save billions on all future missions). Solar operations could also be built on the surface to beam energy to Earth, the Moon’s rich minerals could be mined for Earth industries, and the mining of Helium-3 could power fusion reactors all over the world.

Already, NASA is eying the Shakelton Crater as a possible location, where there is an abundance of water ice and a dome could be built over it to create a contained atmosphere. The moon’s stable lava tunnels also present a good site, since they are large enough to fit entire cities within them and would hold an atmosphere nicely. And from there, humanity could mount missions to Venus and Mars, which would in turn add their abundant supplies of minerals to our economy.

The European Space Agency's concept for a Moon base. Credit: ESA
The European Space Agency’s concept for a Moon base. Credit: ESA

Mercury would also present a major opportunity for mining and solar operations.  And like the Moon, colonies could be built in the permanently shaded regions around the northern and southern polar regions (where there are abundant supplies of water ice) and in underground stable lava tubes. The Asteroid Belt literally has enough minerals and ices to keep humanity supplied indefinitely (hence the interest in asteroid prospecting of late), and the outer Solar System has enough ice, volatiles, and organic compounds to do the same.

In short, step by step, the colonization and/or terraforming of our Solar System offers humanity the opportunity to become a post-scarcity race. While many decry the idea of our species expanding because of the greed and abuse we have demonstrated in the past (and continue to demonstrate today), much of this greed and abuse comes from the fact that our current economic models are based on scarcity. By removing that from the equation, it would be that much more difficult for human beings to hoard resources for themselves while denying their neighbor.

Faced with all of this, the question no is longer one of “why should we”, but rather “why shouldn’t we?” Why shouldn’t we establish a human presence elsewhere in the Solar System, knowing that it could not only help us to save Earth, but ensure our survival as a species for the indefinite future? This of course does not address all the challenges that remain in doing so, but it does tackle one of the biggest arguments there is against space exploration and colonization.

Still pic from Wanderers, by Erik Wernquist
Still pic from Wanderers, by Erik Wernquist

As for the rest? Well, I’m sure we’ll tackle those questions, and then some, when the time comes. In the meantime, I encourage everyone to keep looking up at the stars and saying the question, “why not?”