Posts Tagged ‘Venus’

Rush Limbaugh: Evidence of Flowing Water on Mars Is Leftist NASA Plot

August 20, 2017

Here’s another right-wing gasbag, who should lose his radio show. In this clip from two years ago – 2015 – host Sam Seder of The Majority Report comments on Rush Limbaugh’s pronouncements about signs of flowing water on today’s Mars by NASA. NASA announced that they had found evidence that water still flows today on the Red Planet at the right season. The space agency states that this is a survivor from the period, 3 billion years ago, when the planet was much warmer and wetter than today, and a great ocean may have covered the entire northern hemisphere. The discovery is of immense importance in the search for possible life elsewhere in the solar system.

This is science, but it’s too much for Rush Limbaugh, who sees a conspiracy where there is none. NASA is part of the leftist plot to delude the world into believing in global warming, and this announcement, he goes on to suggest, may be part of it. He ridicules his producer, Sneedley, who was excited and enthusiastic about NASA’s announcement. Limbaugh then declares that he is a ‘big time science guy’ who gone past ‘science 101’. He then goes on to cast scorn and suspicion about the announcement. It’s part of some leftist plot being pursued by the agency, but he doesn’t quite know what yet. But it’s probably about global warming. Soon, he predicts, they’ll announce that they’ve found a graveyard.

Limbaugh’s a Republican broadcaster, who’s been a fixture of American right-wing radio since the 1980s, loudly applauding Ronald Reagan and ranting about how the ‘Leftists’ are trying to destroy his country. In the clip, Seder and his co-hosts and producers ridicule Limbaugh not only for his scientific ignorance – what, pray, is ‘Science 101?’, as well as the way he has openly sneered at and belittled his producer.

They then conclude the programme by further mocking him. They imitate Obama’s voice to declare that Islam is the one true religion. The Martians rejected this, which is why they were hit by a devastating drought. That’s why Obama is going to declare shariah law, and have a child from every White family in the mid-West sold into slavery in the Middle East.

This is to poke fun at Limbaugh, and the stupid, paranoid opinion amongst many American Republicans that Obama is a secret Muslim advancing the plans for an Islamic takeover of the US.

The clip shows much of what’s wrong with the American right’s attitude to science, their massive ignorance, which they think shows how perceptive they are, and their stupid paranoia about ‘leftists’. Which in this case, means anything and anyone, who isn’t as crazily right-wing as they are.

I’ve put up several pieces here about the possibility of life on Mars, and the use of certain genetically modified organisms to terraform the Red Planet. I know that several of the readers of this blog have science backgrounds and similar interests. I’ve put this up because I thought people might like to see just how stupid and ignorant Limbaugh, and by extension, his audience, is about this whole issue.

Firstly, as Seder points out, when NASA made the announcement they said it was about the state of Mars 3 billion years in the past. It’s nothing to do with global warming.

Absolutely correct. Planetary scientists now believe that there was a period during the early history of the solar system, when Mars was warm and wet. I think the National Geographical mentioned this when they did a piece on Mars in the 1980s or ’90s. It’s also discussed in Kim Stanley Robinson’s epic SF novel about the colonization of Mars, Red Mars.

What killed Mars was not global warming, but global cooling. Mars has no tectonic plates, and so it is theorized that the planet’s atmosphere was not renewed through releases of gases released from its rocks through geological forces. Over millions or billions of years, the atmosphere evaporated into space. The surface pressure is about 5 milibars – that of a laboratory vacuum. Without an atmospheric blanket to focus and increase the sun’s light, the planet cooled. Without atmospheric pressure to sustain it, water rapidly sublimates into vapour on the Martian surface. What water has survived is locked up in the ice caps, and may be as permafrost below the Martian surface.

Mars has never been cited as a warning of the dangers of global warming. That’s always been Venus. Venus lies closer to the Sun than Earth, and so has suffered runaway global warming as ever increasing amounts of carbon dioxide was released from its rocks. The result of this is that the planet is covered by a permanent cloud layer. Surface temperatures reach something like 400 degrees C, the rain is sulphuric acid, and its surface pressure is enough to squash a human flat. If you want an example of how different the histories of Mars and Venus are, go have a look, or read, the chapter ‘Blues for a Red Planet’ in Carl Sagan’s Cosmos. Sagan was a major believer in the threat of global warming, and in that episode of his epic science history blockbuster, explicitly drew a parallel between Mars’ fate and that of our own world, if we don’t cut carbon emissions.

As for finding a graveyard on Mars, some scientists have speculated on the possibility that we may find fossils of the creatures that may have lived on Mars, far back in ancient geologic time. There are also serious scientists, who have suggested that we should look for evidence of advanced extraterrestrial civilisations in the planets of our solar system. Our solar system lies in a part of the Galaxy, where the stars are an average of a single light year away from each other. That’s a short enough distance for an advanced civilization to make the difficult journey across interstellar space to another solar system. And the solar system is so old, about 4 billion years if not more, that it is statistically likely that intelligent life has arisen elsewhere in our Galaxy. And just as the Earth orbits the Sun, so the Sun orbits the centre of the Galaxy, taking 225 million years to complete one revolution. This is long enough for our Solar system to have come close to one of those other stars, harbouring alien life.

So signs of an extraterrestrial civilization may well exist on Mars. However, Mars has been dead for so long, that it’s unlikely that there exist any remains of an indigenous Martian civilization on the planet’s surface. In their entry ‘The Surface of Mars’, subtitled ‘Desert’, in their book Catalogue of the Universe, astronomers Paul Murdin and David A. Allen write

If once great cities stood here, they have crumbled to unrecognizable shapes. If trees bowed before moist zephyrs, they have returned to the dust whence they rose. If aircraft landed here, they too have vanished, or been buried beneath unknown depths of sand and rocks. (pp. 205-6).

Not all scientists are convinced that the features NASA suggested was evidence of flowing water were actually produced by it. Others believe that the marks on the surface may instead be produced by the release of other chemicals in liquid form from the underlying rock.

But if liquid water still flows on Mars, albeit it occasionally, not only does it augur well for the possible survival of some life, even if only primitive bacteria, but it also makes the planet more hospitable for possible colonization.

NASA’s claim to have found evidence of surface liquid water was therefore immensely exciting. And Limbaugh’s producer, Sneedley, was actually absolutely right to be excited about it. It’s his host, Limbaugh, who’s ignorant. And dangerously so.

No-one expects ordinary people to be experts on science. Science has advanced at such a rate that it’s too much for many ordinary people to keep update with scientific advances, some of which can be very arcane to laypeople.

But we do need people to be reasonable well-educated. And especially about threats to the planet, like global warming. It’s why there’s a need for good scientific writers and broadcasters to explain the issues clearly.

Limbaugh with his stupid denial of global warming, and his paranoid suspicion that NASA is part of some larger ‘left-wing’ plot, is actually doing the opposite. He’s disparaging real science and trying to keep people ignorant in order to promote his own, extreme right-wing views.

He’s also a danger on racial issues. A day or so ago I reported that Trump had cut funding for FBI and Department of Homeland Security initiatives against White racist terrorism. This included a charity, Life After Hate, that helps former Nazis leave these organisations without being attacked by their fellow stormtroopers. It’s a real danger. Matthew Collins, one of the founders and leaders of the anti-racist/ anti-religious extremism organization, Hope Not Hate, had to migrate to Australia in the 1990s after he appeared in a documentary exposing the violence of the NF and BNP. Obama had given $400,000 to the charity. He would have funded them sooner, but he was prevented from doing so by the ravings and possible denunciation by Limbaugh.

It’s debatable, however, how long Limbaugh will actually carry on. Far from being the influential Republican spokesman he thinks he is, his radio station in recent has been haemorrhaging sponsors and advertisers. His ratings have fallen to the point, where fewer people listen to him than to College radio stations with the range of only one or two miles. The only thing keeping him on air is money from Republican and similar extreme right-wing think tanks. If they pull out, he’s off the air.

Arthur C. Clarke Book on the Terraforming of Mars

March 18, 2017

Arthur C. Clarke – The Snows of Olympus: A Garden on Mars – The Illustrated History of Man’s Colonization of Mars (London: Victor Gollancz 1994).

A little while ago I put up a number of articles on the possible terraforming of various planets in our solar system. The prime candidate at the moment would be Mars, but people have also suggested ways to terraform Venus and the Moon. I’ve managed to dig out from my bookshelves a copy of Arthur C. Clarke’s book, The Snows of Olympus, which I bought way back in the 1990s. Clarke’s been called ‘The Space Prophet’ because of his article published in a radio hobbyists’ magazine shortly after the War predicting geostationary communications satellites. He has jokingly said in an article ‘How I Lost a Million Dollars in My Spare Time’ that he should have patented the concept, and so made himself a billionaire because of its immense value to the telecommunications industry. This book is no less prophetic in that it uses computer simulations to depict the gradual greening of the Red Planet over a thousand year period from the next few centuries to c. 3000.

The book has a prologue, in which Clarke gives the text of a speech he gave to future Martian colonists as part of the Planetary Society’s ‘Visions of Mars Project’. Launched by the late and much-missed astronomer and space visionary, Carl Sagan, this was a project to send the future colonists the gift of a collection of SF short stories about Mars aboard two probes due to land there. There’s then a short introduction in which Clarke lays out the aims of the book. The first chapter, ‘Prelude to Mars’, discusses the history of the exploration of the Red Planet by terrestrial astronomers and writers, such as Giovanni Schiaparelli, Percival Lowell, H.G. Wells and Edgar Rice Burroughs, C.S. Lewis in Out of the Silent Planet, and the controversy surrounding the supposed ‘face’ on Mars, made by Richard Hoagland and others.

Chapter 2 – ‘The Curtain Rises’ – is on the probes sent to explore Mars, such as the Mariner probes and discussion between himself, Sagan, Ray Bradbury and the JPL’s Bruce Murray at the Jet Propulsion Laboratory on the probes and their findings. He goes on to discuss Viking probes and the debate about American and Russian cooperative ventures in space research. This last ended for a time because of international tensions created by the Solidarity crisis in Poland.

Chapter 3 – ‘Going There’, describes the problems and suggested methods for reaching Mars, establishing crewed bases there, including various types of rocket from the conventional chemical to nuclear-thermal and atomic; solar sails and space elevators, George Bush seniors’ intention to launch a crewed mission to Mars by 2019, and the tasks that would immediately face the astronauts landing there.

Chapter 4- ‘Virtual Explorations’ is on the use of computers and VR to explore and map Mars, and particularly the Vistapro programme used in the generation of many of the images in the book.

Chapter 5 is on the artistic and computer depictions of Olympus Mons, the planet’s highest mountain and the gradual reclamation of its surface by vegetation, beginning with lichens, during the long centuries of terraforming. This culminates in the emergence of liquid water and creation of a sea surrounding the mountain.

Chapter 6 does the same for Eos Chasma, the ‘Chasm of the Dawn’, in the Valles Marineris.

Chapter 7 shows the same process as it would affect the Noctes Labyrinthes – the Labyrinth of Night. This forecasts the growth of forests in this part of Mars, beginning with pines but later including deciduous trees.

Chapter 8 – ‘The Longest Spring’ discusses the various methods that could be used to terraform Mars, such as coating the ice caps with carbon from Mars’ moon, Phobos, the use of orbiting mirrors to melt them, raising its temperature by turning Phobos into a miniature sun for about 40 days using ‘muon resonance’ – a form of nuclear reaction, and bombarding the planet with comets to cover it with water, and ‘Von Neumann’ machines that would gradually terraform the planet automatically.

‘Disneymars’ looks forward to a museum display and audiovisual presentation that would show the colonists what their planet would look like in the future as the terraforming progresses.

Chapter 9 – ‘Concerning Ends and Means’ discusses the moral dimension of terraforming, the immense historical importance of exploration and the need to continue this exploration to the Red Planet in order to preserve human civilisation and progress.

There are two appendices. The first is an extract from a speech, The Mars Project: Journeys beyond the Cold War, by US senator and WWII hero, Spark Matsunaga. The second, ‘So You’re Going to Mars’, is fictional advice given by the immigration authorities to people moving from Earth to Mars.

The quality of the computer graphics is mixed. Many of them, which were without doubt absolutely astonishing for the time, now look rather crude and dated as the technology has improved. Others, however, still stand up very well even today. The quality of the computer simulations of the terraforming process can be seen from this image below of what Eos Chasma might look like in 2500 AD.

There are also plenty of illustrations of Mars, rendered using more traditional artistic methods such as painting, including photos of Percival Lowell’s own drawings of what he believed was the planet’s network of canals.

Although the computer tools may have been superseded and improved in the decades since the book’s publication, I think the science, and the social issues Clarke discusses, are still solidly relevant and contemporary. Certainly there is now a popular movement to send humans to the Red Planet at some point in the coming decades, and prospective future colonists have even come forward to volunteer a few years ago. There is, however, a greater awareness of the medical dangers from radiation and microgravity that would affect – and possibly destroy – a mission to Mars. The dream, however, is still there, as shown by the success of the film The Martian a few years ago.

Two Views of a Partly Terraformed Mars

January 2, 2017

Over the past few days, I’ve been discussing on this blog the possible terraforming of Mars. Way back in the 1990s, the late Arthur C. Clarke published a book of pictures he’d generated on his computer of what Mars would look like during and after the centuries-long process. I’m afraid I cleaned that out years ago. I have, however, managed to find two pictures of a partly terraformed Mars by the artist Michael Carroll, in The Case for Mars: The Plan to Settle the Red Planet and Why We Must, by Robert Zubrin and Richard Wagner (London: Simon and Schuster 1996).

The first shows a group of explorers making their way along a defile or gully.

mars-terraform-1

The second shows a view of the planet from space.

mars-terraform-2

The caption for this reads

Liquid water once coursed over the face of Mars and, given the technological capability of the twenty-first century, it may once again. Several decades of terraforming could transform Mars into a relatively warm and slightly moist planet suitable some day for explorers without space-suits, although breathing gear would still be required. Returning oceans to Mars is actually a possibility for the distant future.

I think Kim Stanley Robinson explored a Mars, which after centuries of terraforming now possessed oceans, in two of his trilogy of books on the Red Planet, Blue Mars and Green Mars.

There are also a series of videos on YouTube by someone, who has used the astronomy programme Celesta, to simulate the terraformation of Venus, the Moon, Mars and Titan.

As for Titan, Stephen Baxter’s SF book of the same name concludes with two astronauts, sent on a mission to Jupiter’s moon, waking up billions of years in the future. The Sun has expanded into a Red giant, supplying this currently icy world with the heat necessary for an Earthlike environment. By this time, however, humanity is extinct and the moon’s current occupants are a race of alien explorers.

British Interplanetary Society Paper on Terraforming Mars with Microorganisms

January 1, 2017

Yesterday I put up a couple of articles on terraforming the various planets of the Solar system, including Mercury, Venus and Earth’s Moon, as well as Mars. There have been a couple of really interesting comments posted to them. Florence, one of the great people, who read this blog, stated that she was a microbiologist. She was very much looking forward to working on microorganisms for Mars, but unfortunately that, and much of the rest of the space programme, vanished.

As well as Carl Sagan’s suggestion in the 1960s that blue-green algae could be used to create a breathable atmosphere and Earthlike environment on Mars, a number of scientists have also suggested using microorganisms to terraform the Red Planet. Twenty years ago the American Astronautical Society published a series of papers, edited by Robert M. Zubrin, about the colonisation of Mars, From Imagination to Reality: Mars Exploration Studies of the Journal of the British Interplanetary Society: Part II: Base Building, Colonization and Terraformation (San Diego: Univelt 1997). This included a paper, ‘Genetic Modification and Selection of Microorganisms for Growth on Mars’ by Julian A. Hiscox and David J. Thomas.

bis-mars-terraforming

The abstract for this paper reads

Genetic engineering has often been suggested as a mechanism for improving the survival prospects of terrestrial microorganisms when seeded on Mars. The survival characteristics that these pioneer microorganisms could be endowed with and a variety of mechanisms by which this can be achieved are discussed, together with an overview of some of the potential hurdles that must be overcome. Also, a number of biologically useful properties for these microorganisms are presented that could facilitate the initial human colonisation and ultimately the planetary engineering of Mars.

After an Introduction, in which they state that the terraformation of Mars could be a two-stage process, with the construction of an Earthlike environment by microorganisms being the first, they then proceed to the following sections:

2. Selection of Bacteria for Mars The Search for a Marsbug, which discusses the suitability of terrestrial microbes for the process, such as the cyanobacterium Chroococcidiops and the extremophiles, which occupy of extreme environments here on Earth;

3. Genetic Engineering – A simple Matter of Cut and Paste;

4. Genetic Modification and Selection;

5. Gene Expression, with subsections on

1) Survival Properties – Tolerance to Peroxides; Osmotic Adaptation; UV Resistance; Tolerance to High Intracellular Acid Concentrations; Endospore Formation;

2) General Properties, with further subsections on photosynthesis, nitrogen fixation, and denitrification;

6. Uses of GEMOS and Some Speculations,

and then finally the conclusion and acknowledgments.

The conclusion reads

The introduction of microorganisms on Mars will greatly facilitate colonisation, both during initial attempts and in establishment of a stable ecosystem, either in enclosed habitats or at the end of ecopoiesis or terraformation. During the initial stages of ecopoiesis climatic conditions on Mars will be limiting for most terrestrial microorganism. By using genetic modification and directed selection under simulated Martian conditions, it may be possible to greatly enhance the survival capability of microorganisms during the alteration of the Martian climate to more clement conditions. Such microorganisms could be used to facilitate any planetary engineering effort. For example, they could be used to release Co2 and N2 from putative carbonate and nitrate deposits.

The genetic alteration of microorganisms will not be so much of a problem of introducing foreign genes into the organism but more a matter of understanding and controlling the regulatory pathways for the expression of such genes. However, such understandings will provide valuable insights into genetics, not only for increasing the productivity of microorganisms on Mars but possibly for Earth.

I’ve got very strong reservations about genetic engineering and modification, but here there is a strong case if it can be used to bring life to a sterile world. Assuming, that is, that Mars does not already possess life. In a way, the article’s ironic. Over a century ago, H.G. Wells had a germ, the common cold, destroy the invading Martians in his book, The War of the Worlds. Now terrestrial scientists are discussing using such organisms as ways to creating a living environment on the Red Planet.

Terraforming the Moon by Comet

December 31, 2016

In my last blog post, I discussed the passed in David A. Hardy’s book, Atlas of the Solar System, in which he described the possible methods which might be used in the future to transform Mercury, Venus, the Moon and Mars into worlds, where humans and other creatures could live in the open, instead of the enclosed environments they need now to protect them from the harsh conditions of space. In the case of Venus, comets would be used to increase the planet’s rotation from its current 224 Earth days to a terrestrial day, and give the planet water. Looking through YouTube, I found this video by Fraser Cain, in which he talks about using the same method to terraform the Moon, as suggested by the space scientist and SF writer, Gregory Benford. This is part of a series of videos on space and space colonisation. At the beginning of the video, he mentions a previous one about the terraforming of Venus.

The explanatory section on the YouTube page provides this transcript of his talk.

In our episode about terraforming Venus, we talked about cooling the planet with a giant sunshade, and then hand-wavingly bind up all that carbon dioxide.

We did the same with Mars, filling the atmosphere with greenhouse gasses to warm it up, and releasing the planet’s vast stores of C02 to thicken the atmosphere. Then just crash in a few comets worth of water and upgrade them to to a 3 star resort.

We’re pitching this as a new series on the Discovery Network, called “Flip My Planet – Canada”.

Now let’s turn our imagination towards another rockball that is really more of a fixer-upper: The Moon. I know, you never even thought of the Moon as a place that we could possibly terra-renovate. Go ahead and imagine with me all the possibilities of a verdant green and blue little world hanging in the night sky. Doesn’t that sound great?

So, what does it take? Do we tear it down and just use the orbital lot space? Should we raise it up and lay a new foundation? Or could we get away with a few coats of paint and adding an atrium on the backside?

Fortunately for me, scientist and sci-fi author Gregory “Planetary Makeover” Benford has already done the math.

Let’s take a look at what we’d need to get the Moon habitable. For starters, the fact that the Moon is so close to Earth is a huge advantage. This is like living on the same block as a Home Depot, and we won’t have to travel far to get supplies and equipment to and from our project.

We’re going to need an atmosphere thick enough to breathe and trap in the Sun’s heat. This takes wild comet capture and harvest, tear them apart and smash them into the Moon.

Benford notes that you probably want be careful not to let an entire comet collide with the Moon because it might spray your primary investment home with debris and do a little damage to the resale value, or potentially annoy your tenants.

This could get bad enough that we’d have to terraform Earth to get it livable again, and you’d need to bring in Mike Holmes to publicly shame us and put our primary residence back in order.

After you’d splattered a few comets on the Moon, it would have an atmosphere almost immediately. The transfer of momentum from the comet chunks would get the Moon rotating more rapidly.

If you invest a little more in your planning stage, you could get the Moon spinning once every 24 hours, and even tilt its axis to get seasons. Benford estimates that we’d need 100 Halley’s mass comets to get the job done. This might sound like a pretty tall order, but it’s tiny compared to number of comets we’d need for your Mars or Venus real estate scheme.

The maintenance and upkeep isn’t going to be without its challenges. Low gravity on the Moon means that it can’t hold onto its atmosphere for longer than a few thousand years.

Once you got the process going, you’d need to be constantly replenishing our your orbital cottage with fresh atmosphere. Fortunately, we’ve got a whole Solar System’s worth of ice to exploit.

The benefits of a terraformed summer home on the Moon are numerous. For example, if the Moon had an atmosphere as thick as the Earth’s, you could strap on a pair of wings and fly around in the 1/6th gravity.

The enormous gravity of the Earth would pull the Moon’s oceans around the planet with 20 meter tides. You could surf the tide for kilometers as it washes across the surface in a miniature version of the shallow water scene in Interstellar.

This might be the greatest sponsorship opportunity for GoPro of all time. Look out Kiteboarding, you’re about to get more extreme.

Everyone always wants to talk about terraforming Venus or Mars. Let them be, that’s too much work. The next time someone brings it up at D&D night, you can blow their minds with your well crafted argument on why we want to start with the Moon.

I can remember David A. Hardy illustrating a few articles on future human habitats on the Moon, showing people enjoying themselves flying around and swimming at just such a lunar resort. One of these was for an article in the sadly short-lived space and astronomy magazine, New Voyager. The resort was in an enclosed dome, rather than on the terraformed surface. The Scots space scientist, Duncan Lunan, in his book, Man and the Planets, also suggested that to prevent the Moon’s atmosphere from being lost to space, the whole planet should be contained with a kind of giant inflatable bubble. This is waaaay beyond modern technological capability, but not, perhaps, that of the future. So perhaps at some point in the far future, the Moon may also join Earth as a living, habitable world.

David A. Hardy on Terraforming the Solar System

December 31, 2016

As well as colonising the other planets in the solar system with self-contained, sealed environments to protect their future human inhabitants, it may also one day be possible to terraform them. This means transforming them from their currently hostile conditions to an Earthlike environment. At the moment, the planet considered most suitable for terraforming is Mars, because of all the planets it seems to present the least obstacles to this form of planetary engineering. I can remember reading a piece in the Sunday Express way back in the 1980s, which discussed James Lovelock’s suggestions for creating an earthlike atmosphere on the Red Planet. Lovelock is the creator of the Gaia hypothesis, the theory that Earth’s biosphere acts like a gigantic, self-regulating organism. This became a favourite of several of the New Age neo-pagan religions in the 1990s, where it was incorporated into worship of the Earth Mother. Lovelock believed that while nuclear weapons were a serious danger to all life on Earth, they could be used creatively on Mars to produce an environment that would support life. Mars has large amounts of carbon dioxide locked up at its polar regions in the form of dry ice. he believed that this could be melted using nuclear missiles. Specially targeted nuclear explosions would cover the polar regions with an insulating layer of soil. This would keep the heat in, which is currently radiated back into space, reflected by the white ice. The rise in temperature would cause the dry ice to sublimate into carbon dioxide gas. This would then start a greenhouse effect, which would see more carbon dioxide and other gases released into the Martian atmosphere. This would eventually create an environment, where the atmosphere was thick enough for humans to be able to move around without space suits. They would, however, still need oxygen masks and tanks to be able to breathe. Lovelock was extremely optimistic about how many weapons would be needed. He believed that you’d only need four, if I remember correctly.

Lovelock’s ideas are wrong, but other scientists and Science Fiction writers have also suggested ways of transforming the Red Planet into a place where life can thrive. Back in the 1990s, Kim Stanley Robinson wrote a trilogy of books set on a Mars that was being colonised and terraformed by humanity, beginning with Red Mars. The veteran SF writer, Arthur C. Clarke, also produced a book in which he used to a computer programme to show what Mars may look like as it’s being terraformed. Over hundreds, perhaps even a thousand years, rivers, seas and oceans develop and green spreads over its land surface as vegetation begins growing on its previously barren surface.

David A. Hardy, the space artist, who has illustrated a number of books on space, including several with the late Patrick Moore, also described the various ways in which the Moon, as well as Mercury, Venus and Mars, could be terraformed in his 1981 book, Atlas of the Solar System (Kingswood, Surrey: World’s Work). He writes

Taking the concept of manned bases on other planets still further, there is the staggering possibility of ‘planetary engineering’ or terraforming – a term coined in 1942 by science fiction writer Jack Williamson. The idea is simply to make other worlds habitable by humans. An early suggestion, in 1961, by Carl Sagan was to ‘seed’ the atmosphere of Venus with blue-green algae, converting the carbon dioxide into oxygen and at the same time reducing the pressure and temperature (by eliminating the greenhouse effect). The upper clouds would condense and rain would fall, forming oceans.

A more recent alternative, now that we know how hostile Venus really is, is to ferry in ice asteroids 15 km or so in diameter, put them into orbit around Venus and aim them, using rocket jets, at a specific spot on the surface. Each crashes at nearly 100 km/s, at such an angle that Venus’ rotation is increased until a 24-hour day is approached, while at the same time water is provided as the ice melts. Then the atmosphere is seeded with blue-green algae.

The same could even be done with the Moon: once given a breathable atmosphere by baking oxygen out of the rocks with giant parabolic mirrors, it would remain for thousands of years, even if not replenished. The time factor for the operation is remarkably short. Mercury would need to be shielded from the Sun by a ‘parasol’ of rocky particles put up by mass-driver, or by a man-made ring. Mars would need to be warmed up, perhaps by reflecting sunlight on to the poles with huge, thin metal-foil mirrors, increasing the energy-flow at the poles by 20 per cent. or we could spread dark material from its carbonaceous moons on them with a mass-driver. Rich not only in carbon but in oxygen, nitrogen and hydrogen, this is excellent raw material for fertiliser. One the atmosphere was thickened, the greenhouse effect and carefully chosen plant life should do the rest. (pp. 86-7).

The process of transforming these planets into habitable worlds would take quite a long time – decades, if not centuries, and at present it is the stuff of science fiction. But I hope that there will be a time when we can move out from Earth to create new homes for life and civilisation on these worlds.