Wet Workshop Technique

Wet Workshop Technique

The Jupiter module was a shuttle external propellant tank adapted for scientific use by a technique know as the “wet workshop”. Unlike the station’s lab and hab modules, which had been completely outfitted on the ground and transported to the station on heavy-lif boosters, only the major structural elements of the eventual Jupiter module – flooring, workstation wells, internal tunnel, bulkheads – were built into the tank’s internal sections.

The tank was then filled with liquid oxygen and liquid hydrogen; these powered the engines as the shuttle flew into orbit.

Since safety considerations required the shuttle engines to shot down before the fuel was completely expended, small amounts of these propellants remained floating weightlessly inside the tank after it achieved orbit. The liquid hydrogen was removed by a clever pumping device. The liquid oxygen was simply heated by sunlight until it turned into its gaseous, breathable state.

Illustration by Elena

Earth Is Near Moon

Earth Is Near Moon

All the evidence that the Crater Giordano Bruno was gouged out less than a thousand years ago, is inferential and indirect. The odds are against such an event happening in historical times. But the evidence is at least suggestive.

As the Tunguska Event and Meteor Crater in Arizona also remind us, not all impact catastrophes occurred in the early history of the solar system. But the fact that only a few of the lunar craters have extensive ray systems also reminds us that, even on the Moon, some erosion occurs (on Mars, however, where erosion is much more efficient, although there are many craters, there are virtually no ray craters, as we would expect). By noting which craters overlap which and other signs of lunar stratigraphy, we can reconstruct the sequence of impact and flooding events of which the production of crater Bruno is perhaps the most recent example.

Cosmic Rays. Attempt to visualize the events that made the surface of the lunar hemisphere we see from Earth. Image: © Elena

The Earth is very near the Moon. If the Moon is so severely cratered by impacts, how has the Earth avoided them? Why is Meteor Crater so rare? Do the comets and asteroids think it inadvisable to impact an inhabited planet? This is an unlikely forbearance. The only possible explanation is that impact craters are formed at very similar rates on both the Earth and the Moon, but that on the airless, waterless Moon they are preserved for immense periods of time, while on the Earth slow erosion wipes them out or fills them in. Running water, windblown sans and mountainbuilding are very slow processes. But over millions or billions of years, they are capable of utterly erasing even very large impact scars.

On the surface of any moon or planet, there will be external processes, such as impacts from space, and internal processes, such as earthquakes. There will be fast, catastrophic events, such as volcanic explosions, and processes of excruciating slowness, such as the pitting of a surface by tiny airborne sans grains. There is no general answer to the question of which processes dominate, the outside ones or the inside ones; the rare but violent events, or the common and inconspicuous occurrences. On the Moon, the outside, catastrophic events hold sway. On Earth, the inside, slow processes dominate. Mars is an intermediate case.

Seeking Messages from Aliens

Seeking Messages From Aliens

Today we are again seeking messages from an ancient and exotic civilization, this time hidden from us not only in time but also in space. If we should receive a radio message from an extraterrestrial civilization, how could it possibly be understood? Extraterrestrial intelligence will be elegant, complex, internally consistent and utterly alien. Extraterrestrials would, of course, wish to make a message sent to us as comprehensible as possible. But how could they?

Is there in any sense an interstellar Rosette stone? We believe there is. We believe there is a common language that all technical civilizations, no matter how different, must have. That common language is science and mathematics. The laws of Nature are same everywhere. The patterns in the spectra of distant stars and galaxies are the same as those for the Sun or for appropriate laboratory experiments: not only do the same chemical elements exist everywhere in the universe, but also the same laws of quantum mechanics that govern the absorption and emission of radiation by atoms apply everywhere as well. Distant galaxies revolving about one another follow the same laws of gravitational physics as govern the motion of an apple falling to Earth, or Voyager on its way to the stars. The patters of Nature are everywhere the same. An interstellar message, intended to be understood by an emerging civilizations, should be easy to decide.

The Magic. Illustration: Elena.

There may be effective methods of communication that have substantial merit: interstellar spacecraft; optical or infrared lasers; pulsed neutrinos; modulated gravity waves; or some other kind of transmission that we will not discover for a thousand years. Advanced civilizations may have graduated far beyond radio for their own communications. But radio is powerful, cheap, fast and simple. They will know that a backward civilization like ours, wishing to receive messages from the skies, is likely to turn first to radio technology. Perhaps they will have to wheel the radio telescopes out of the Museum of Ancient Technology. If we were to receive a radio message we would know that there would be at the very least one thing we could talk about; radio astronomy.

But is there anyone out there to talk to? With a third or half a trillion stars in our Milky Way Galaxy alone, could ours be the only one accompanied by an inhabited planet? How much likely it is that technical civilizations are a cosmic commonplace, that the Galaxy is pulsing and humming with advanced societies, and, therefore, that the nearest such culture is not so very far away – perhaps transmitting from antennas established on a planet of a naked-eye star just next door.

If They Exist

In ancient times already, globes were constructed portraying the Earth as viewed from space, and they were essentially correct in the well-explored Mediterranean but became more and more inaccurate the farther they strayed from home. Our present knowledge of the Cosmos shares this disagreeable but inevitable feature.

In the first century, the Alexandrian geographer Strabo wrote:

Those who have returned from an attempt to circumnavigate the Earth do not say they have been prevented by an opposing continent, for the sea remained perfectly open, but, rather, through want of resolution and scarcity of provision.

If this other part of the World is inhabited, it is not inhabited by people such as exist in our parts, and we should have to regard it as another inhabited world. Image: © Megan Jorgensen (Elena).

… If the extent of the Atlantic Ocean were not an obstacle, we might easily pass by sea from Iberia to India… It is quite possible that in the temperate zone there may be one or two habitable Earths.

If this other part of the World is inhabited, it is not inhabited by people such as exist in our parts, and we should have to regard it as another inhabited world.

These word were written in the 1st Century. As we can see, humans were beginning to venture, in almost every sense that matters, to other worlds.

Seeking Messages from Aliens - Part II

We are seeking messages from an ancient and exotic civilisation, hidden from us not only in time but also in space. But if we should receive a radio message from an extraterrestrial civilization, how could it possibly be understood? Extraterrestrial intelligence will be complex, internally consistent and utterly alien. Extraterrestrials would, of course, wish to make a message sent to us as comprehensible as possible. But how could they?

Is there in any sense an interstellar Rosette stone? We believe there is. We believe there is a common language that all technical civilizations, no matter how different, must have. That common language is science and mathematics. The laws of Nature are same everywhere. The patterns in the spectra of distant stars and galaxies are the same as those for the Sun or for appropriate laboratory experiments: not only do the same chemical elements exist everywhere in the universe, but also the same laws of quantum mechanics that govern the absorption and emission of radiation by atoms apply everywhere as well. Distant galaxies revolving about one another follow the same laws of gravitational physics as govern the motion of an apple falling to Earth, or Voyager on its way to the stars. The patters of Nature are everywhere the same. An interstellar message, intended to be understood by an emerging civilizations, should be easy to decide.

There may be effective methods of communication that have substantial merit: interstellar spacecraft; optical or infrared lasers; pulsed neutrinos; modulated gravity waves; or some other kind of transmission that we will not discover for a thousand years. Advanced civilizations may have graduated far beyond radio for their own communications. But radio is powerful, cheap, fast and simple.

They will know that a backward civilization like ours, wishing to receive messages from the skies, is likely to turn first to radio technology. Perhaps they will have to wheel the radio telescopes out of the Museum of Ancient Technology. If we were to receive a radio message we would know that there would be at the very least one thing we could talk about; radio astronomy.

But is there anyone out there to talk to? With a third or half a trillion stars in our Milky Way Galaxy alone, could ours be the only one accompanied by an inhabited planet? How much likely it is that technical civilizations are a cosmic commonplace, that the Galaxy is pulsing and humming with advanced societies, and, therefore, that the nearest such culture is not so very far away -  perhaps transmitting from antennas established on a planet of a naked-eye star just next door.

Is there anyone out there to talk to? Image : © Megan Jorgensen.

Calame and Mulholland

Calame and Mulholland

The astronomers Derral Mulholland and Odile Calame have calculated that a lunar impact would produce a dust cloud rising off the surface of the Moon with an appearance corresponding rather closely to the report of Canterbury monks.

If such an impact were made only 800 years ago, the crater should still be visible.. Erosion on the Moon is so inefficient, because of the absence of air and water, that even small craters a few billion years old are still comparatively well preserved. From the description recorded by Gervase, it is possible to pinpoint the sector of the Moon to which the observations refer. Impacts produce rays, linear trails of fine powder spewed out during the explosion. Such rays are associated with the very youngest craters on the Moon – for example, those named after Aristarchus and Copernicus and Kepler.

Dessin de l’enfant. There was a bright New Moon, and as usual in that phase its horns were tilted towards the east. Suddenly, the upper horn split in two. From the midpoint of the division, a flaming torch sprang up, spewing out fire, hot coals, and sparks. Image : © Elena

But while the craters may withstand erosion on the Moon, the rays, being exceptionally thin, do not. As time goes on, even the arrival of micrometeorites – fine dust from space – stirs up and covers over the rays, and they gradually disappear. Thus rays are a signature of a recent impact.

The meteoriticist Jack Hartung has pointed out that a very recent, very fresh-looking small crater with a prominent ray system lies in the region of the Moon referred to by the Canterbury monks.

This crater is called Giordano Bruno after the sixteenth-century Roman Catholic scholar who held that there are an infinity of worlds and that many are inhabited. For this and other crimes he was burned at the stake in the year 1600.

Another line of evidence consistent with this interpretation has been provided by Calame and Mulholland. When an object impacts the Moon at high speed, it sets the Moon slightly wobbling. Eventually the vibrations die down but not in so short a period as eight hundred years. Such a quivering can be studied by laser reflection techniques. The Apollo astronauts emplaced in several locales on the Moon special mirrors called laser retroreflectors. When a laser beam from Earth strikes the mirror and bounces back, the roundtrip travel time can be measured with remarkable precision. This time multiplied by the speed of light gives us the distance to the Moon at that moment to equally remarkable precision. Such measurements, performed over a period of years, reveal the Moon to be liberating, or quivering with a period (about three years) and amplitude (about three meters), consistent with the idea that the crater Giordano Bruno was gouged out less than a thousand years ago.

(Carl Sagan).

There was a bright New Moon, and as usual in that phase its horns were tilted towards the east. Suddenly, the upper horn split in two. From the midpoint of the division, a flaming torch sprang up, spewing out fire, hot coals, and sparks. Image : © Megan Jorgensen.

Greemhouse on Venus

Greenhouse on Venus

The surface temperatures on Venus, as deduced from radio astronomy and confirmed by direct spacecraft measurements, are around 480 C or 900 F, hotter than the hottest household oven.The corresponding surface pressure is 90 atmospheres, 90 times the pressure we feel from the Earth’s atmosphere, the equivalent of the weight of water 1 kilometer below the surface of the oceans. To survive for long on Venus, a space vehicle would have to be refrigerated as well as built like a deep submersible.

Something like a dozen space vehicles from the Soviet Union and United States have entered the dense Venus atmosphere, and penetrated the clouds; a few of them have actually survived for an hour or so on the surface (Pioneer Venus was a successful US mission inn1978-79, combining an orbiter and four atmospheric entry probes, two of which briefly survived the inclemencies of the Venus surface. 

A little greenhouse is a good thing. Image: Mosaic Moving © Elena

There are many unexpected developments in mustering spacecraft to explore the planets. This is one of them: Among the instruments aboard one of the Pioneer Venus entry probes was a net flux radiometer, designed to measure simultaneously the amount of infrared energy flowing upwards and downwards at each position in the Venus atmospheres. The instrument required a sturdy window that was also transparent to infrared radiation. A 13,5-karat diamond was imported and milled into the desired window. However, the contractor was required to pay a $12,000 import duty. Eventually, the U.S. Customs service decided that after the diamond was launched to Venus it was unavailable for trade on Earth and refunded the money to the manufacturer.

The global temperature on the Earth would be below the freezing point of water if not for the greenhouse effect. It keeps the ocean liquid and the life possible. A little greenhouse is a good thing. Like Venus, the Earth also has about 90 atmospheres of carbon dioxide; but it resides in the crust as limestone and other carbonates, not in the atmosphere.

If the Earth were moved only a little closer to the Sun, the temperature would increase slightly. This world drive some of the CO2 out of the surface rocks, generating a stronger greenhouse effect, which would in turn incrementally heat the surface further. A hotter surface would vaporize still more carbonates into CO2, and there would be the possibility of a runaway greenhouse effect to very high temperatures. This is just what we think happened in the early history of Venus, because of Venus’ proximity to the Sun. The surface environment of Venus is a warning: something disastrous can happen to a planet rather like our own.