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Month: November 2017
The Mars Society: A Short Video On Simulated Living On Mars
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Mars Society International Conference To Design A Mars Lander
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Are Aliens Out There On Other Planets?
If aliens are out there, they’re staying awfully quiet
The first tranche of a major search for ET concludes intelligent life doesn’t exist anywhere in 1500 trillion kilometre radius. Andrew Masterson reports.
The first comprehensive search for radio signals produced by extraterrestrial civilisations has drawn a blank. As far as signs of intelligent life go, it’s as quiet as the grave from here out to a distance of 50 parsecs – 1550 trillion kilometres – in every direction.
That’s the slightly dispiriting conclusion reached by a team of researchers led by astronomer Emilio Enriquez from the University of California, Berkeley, in the US, which has analysed data gathered by the Robert C. Byrd Green Bank Telescope (GBT) in Virginia as part of a privately funded project called the Breakthrough Listen Initiative.
The initiative – funded by Russian oligarch Yuri Milner and his wife Julia – works on an idea first formulated by astronomers Philp Morison and Guiseppe Cocconi in 1959 and embraced by the Search for Extraterrestrial Life Institute (SETI) ever since.
Morison and Cocconi reasoned that technologically advanced civilisations positioned light years apart from each other could communicate using microwaves – electromagnetic radiation with wavelengths between one and 10 gigahertz (GHz)
These wavelengths, like all on the electromagnetic spectrum, travel at the speed of light, but are especially attractive for interstellar communications. Galaxies naturally create enormous amounts of radio waves at lower frequencies, making it impossible for communication signals within that range to pass through without getting lost.
Higher frequencies – at least on Earth – tend to get absorbed within the atmosphere (which also emits some all by itself). The same effect would happen on inhabited alien worlds, assuming a broadly similar atmosphere.
The one-to-10 GHz range, thus, is called the Microwave Window. Signals coming from space with wavelengths within the window are automatically of interest to ET-hunters, and even more so if they display significant variation, indicating perhaps that they are encoding language or data streams rather than the uniform expression of microwave activity arising from some cosmic chemical interaction.
The Milners’ project aims to eventually monitor the microwaves emitted in the vicinity of one million stars, so the first tranche of results, covering just 692, is hardly conclusive. Neither, however, is it encouraging.
In addition to the GBT, an optical telescope, Enriquez and his colleagues also made use of the Parkes radio-telescope in Australia. The team made three five minute observations of each target, together with additional five minute observations at specific distances away.
The research focussed on the lower end of the Microwave Window, looking for signals at between 1.1 and 1.9 GHz. (The intention is cover the full window, but that is expected to take several years.)
At first, hopes of detecting an advanced alien civilisation may have been raised among the scientists. Eleven of the signals detected exceeded the thresholds established for identifying possible communications.
Sadly, however, detailed analysis showed all of them to be anthropogenic in origin. In effect, the telescopes were picking up our own species’ background babble.
In a paper posted on the preprint server arXiv, hosted by the Cornell University Library in the US, the researchers conclude that “none of the observed systems host high-duty-cycle radio transmitters emitting between 1.1 to 1.9 GHz”.
The chances of anywhere within 50 parsecs of Earth possessing such transmitters, they go on to estimate, is less than 0.1%.
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MIT’s Prize Winning Mars City Concept Topped By Domed Trees
MIT’s prize-winning Mars city concept topped by domed tree habitats
An MIT team won first place for urban design with the Redwood Forest, a series of woodsy habitats enclosed in open, public domes that would reside on the Martian surface
Most plans for Mars bases make becoming a colonist about as desirable as setting up house in an oil drum, but an MIT team has come up with a plan for a Mars city based on the architecture of a tree. Taking out first place in the Architecture section of the Mars City Design 2017 competition, the Redwood Forest concept is intended to provide settlers with not only protection against the harsh Martian environment, but open public spaces filled with plants and abundant water.
As Sir Elton John said, Mars ain’t the kind of place to raise your kids. Though the Red Planet is the most habitable of the planets, aside from our own, in the Solar System, it is still a terribly hostile place. The nighttime temperatures put the Antarctic to shame, the air is only a hundredth the pressure of Earth’s and is composed mostly of carbon dioxide, deadly UV radiation rains down during the day, and cosmic rays are present 24/7. It’s also dry to the point where the soil is composed of corrosive substances with very unpleasant properties.
Due to these drawbacks, it’s difficult to come up with designs for manned outposts that don’t look like a collection of tins that make the Amundsen-Scott South Pole Station look like a luxury resort. To break away from this stereotype, the MIT team of nine students led by MIT postdoc Valentina Sumini and Assistant Professor Caitlin Mueller took an interdisciplinary approach that uses location and system architecture, as well as water harvested from the Martian polar ice caps to supply tree-like habitats, for a design capable of housing 10,000 inhabitants in shirt-sleeve comfort.
At first glance, the MIT habitats don’t look very tree-like. They look more like giant glass balls sitting on the Martian plains, each housing 50 people. But, like real trees, much of the habitat is below the surface in the form of intricate tunnels that connect the spheres and provide protection from cold, radiation, micrometeorites, and other surface hazards.
“On Mars, our city will physically and functionally mimic a forest, using local Martian resources such as ice and water, regolith or soil, and sun to support life,” says Sumini. “Designing a forest also symbolizes the potential for outward growth as nature spreads across the Martian landscape. Each tree habitat incorporates a branching structural system and an inflated membrane enclosure, anchored by tunneling roots. The design of a habitat can be generated using a computational form-finding and structural optimization workflow developed by the team. The design workflow is parametric, which means that each habitat is unique and contributes to a diverse forest of urban spaces.”
The habitats rely heavily on water, but not just for drinking, agriculture, or public fountains. It’s a key ingredient in making the domes habitable.
“Every tree habitat in Redwood Forest will collect energy from the sun and use it to process and transport the water throughout the tree, and every tree is designed as a water-rich environment,” says Department of Aeronautics and Astronautics doctoral student George Lordos. “Water fills the soft cells inside the dome providing protection from radiation, helps manage heat loads, and supplies hydroponic farms for growing fish and greens. Solar panels produce energy to split the stored water for the production of rocket fuel, oxygen, and for charging hydrogen fuel cells, which are necessary to power long-range vehicles as well as provide backup energy storage in case of dust storms.”
The team believes that the Mars tree habitats could find a niche on Earth as well, at high latitudes, deserts and the sea floor, for example. In addition, the hydroponics technology could provide city dwellers with fresh food and the tunnels could be used to ease congestion in urban areas.
We Have Visitors
We Have Visitors
Astronomers were baffled last week when they noticed an interstellar object moving at high speeds through our solar system – the first time such an event has occurred.
Now they are racing to learn more about this strange visitor before it disappears.
Named A/2017 U1, it is likely an asteroid about a quarter of a mile long. It was first noticed by scientists Oct. 19 and was instantly flagged for its incredible speed – so fast that the Sun couldn’t catch it in its orbit, the New York Times reported.
That’s due to the asteroid’s very old hyperbolic orbit, which slings it past celestial bodies at speeds high enough to overpower their gravitational pull. That means that A/2017 U1 will eventually leave our solar system.
The asteroid came within about 15 million miles of Earth on Oct. 14, passing by at a speed of about 37 miles per second – more than three times the escape velocity of the New Horizons spacecraft.
But movie lovers should have no fear – neither aliens, nor an interstellar Armageddon is in the cards, NASA’s planetary defense officers say.
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