Will we find life — “not as we know it” — on Saturn’s moon Titan


Click to enlargeAzotosome, the theorized cell membrane on Titan

Liquid water is a requirement for life on Earth. But in other, much colder worlds, life might exist beyond the bounds of water-based chemistry.

Taking a simultaneously imaginative and rigidly scientific view, Cornell chemical engineers and astronomers offer a template for life that could thrive in a harsh, cold world – specifically Titan, the giant moon of Saturn. A planetary body awash with seas not of water, but of liquid methane, Titan could harbor methane-based, oxygen-free cells that metabolize, reproduce and do everything life on Earth does.

Their theorized cell membrane, composed of small organic nitrogen compounds and capable of functioning in liquid methane temperatures of 292 degrees below zero, is published in Science Advances…The work is led by chemical molecular dynamics expert Paulette Clancy…with first author James Stevenson, a graduate student in chemical engineering. The paper’s co-author is Jonathan Lunine…the College of Arts and Sciences’ Department of Astronomy…

On Earth, life is based on the phospholipid bilayer membrane, the strong, permeable, water-based vesicle that houses the organic matter of every cell. A vesicle made from such a membrane is called a liposome. Thus, many astronomers seek extraterrestrial life in what’s called the circumstellar habitable zone, the narrow band around the sun in which liquid water can exist. But what if cells weren’t based on water, but on methane, which has a much lower freezing point?

The engineers named their theorized cell membrane an “azotosome,” “azote” being the French word for nitrogen. “Liposome” comes from the Greek “lipos” and “soma” to mean “lipid body;” by analogy, “azotosome” means “nitrogen body.”

The azotosome is made from nitrogen, carbon and hydrogen molecules known to exist in the cryogenic seas of Titan, but shows the same stability and flexibility that Earth’s analogous liposome does. This came as a surprise to chemists like Clancy and Stevenson, who had never thought about the mechanics of cell stability before; they usually study semiconductors, not cells.

The engineers employed a molecular dynamics method that screened for candidate compounds from methane for self-assembly into membrane-like structures. The most promising compound they found is an acrylonitrile azotosome, which showed good stability, a strong barrier to decomposition, and a flexibility similar to that of phospholipid membranes on Earth. Acrylonitrile – a colorless, poisonous, liquid organic compound used in the manufacture of acrylic fibers, resins and thermoplastics – is present in Titan’s atmosphere.

Excited by the initial proof of concept, Clancy said the next step is to try and demonstrate how these cells would behave in the methane environment – what might be the analogue to reproduction and metabolism in oxygen-free, methane-based cells.

In part, Stevenson said he was inspired by science fiction writer Isaac Asimov, who wrote about the concept of non-water-based life in his 1962 essay, “Not as We Know It.” I think we can conclude as Asimov would – intelligence formed of life “not as we know it” – but with science grounded in material reality, will develop an understanding of science identical in premises as any of our own species’ physical scientists. Leading or trailing one another the results must be the same since material reality remains the same.

Perceptions can vary widely. An intelligent lifeform evolved through differing chemistry wouldn’t be likely to have the same senses or senses arrayed in the same hierarchy. The possibilities are intriguing.

Truly, a worthwhile adventure. I wish them well.

Biobattery plant turns a wide range of biomass into energy, consumables

Researchers at the Fraunhofer Institute for Environmental, Energy and Safety Technology have developed a “biobattery” in the form of a highly efficient biogas plant that can turn raw materials like straw, scrap wood and sludge into a variety of useful energy sources including electricity, purified gas and engine oil. The new plant design, currently being put to the test in a prototype plant in Germany, is said to be highly modular and economically viable even at the small scale.

The production of biogas  –  gas created by the breakdown of organic matter, by fermentation or through the action of anaerobic bacteria  –  is an interesting complement to other sources of renewable energy since it can not only generate electricity at little cost to the environment, but also create biofuel, fertilizer and engine oil. One issue, however, is that these plants only accept few organic substances as raw materials.

A new biogas plant developed at the Fraunhofer Institute could solve this problem by taking a number of materials that would normally have to be disposed of at great cost – like industrial biomass waste, sewage sludge, straw, scrap wood or manure – and process them with high efficiency into a more useful output, all through a highly modular, flexible design…

The end products can be used in various ways: the oil can be turned into fuel for ships or airplanes; the gases are used to produce electricity in a combined heat and power plant; and the biochar can be used as fertilizer.

Besides the flexibility that comes from accepting multiple raw materials and producing multiple outputs, another crucial advantage to the biobattery is that, according to the scientists’ financial analysis, even a small-scale plant requiring a small investment would be financially profitable. Because of the built-in modularity, the plant could then be gradually upgraded to process more materials with higher efficiency.

In their own way, the Fraunhoher Institute is as interesting a source for advancing life on this wee planet as the Max Planck Institute. Though not as dedicated to basic research as the latter, Fraunhofer turns out more practical science and engineering than most of their peers in the Western world.

This is one more example. RTFA for another few paragraphs of detail. Living as we do on a planet dominated by a species whose progress in economics and commerce is generally accompanied by an inordinate amount of waste – and wastefulness – Fraunhofer’s efforts are more than welcome.

The push for US colleges to divest Israel investments grows and flowers

The lecture hall had filled quickly. Several students wore keffiyehs, the traditional Palestinian headscarves, while another sat draped in the Israeli flag.

It was time for a ritual that has become increasingly commonplace on many American college campuses: A student government body, in this case at the University of California, Davis, would take up Israeli policy toward the Palestinians, and decide whether to demand their school divest from companies that work with the Jewish state.

In the United States, Israel’s closest ally, the decade-old boycott-divestment-sanctions movement, or BDS, is making its strongest inroads by far on college campuses. No U.S. school has sold off stock and none is expected to do so anytime soon. Still, the current academic year is seeing an increasing number of divestment drives on campus. Since January alone, student governments at four universities have taken divestment votes…

The boycott-divestment-sanctions movement grew from a 2005 international call from Palestinian groups as an alternative to armed struggle over control of the West Bank, Gaza and east Jerusalem, which Israel captured in 1967 and Palestinians seek for an independent state.

BDS advocates say the movement, based on the campaign against South African apartheid decades ago, is aimed at Israeli policy, not Jews, in response to two decades of failed peace talks and expanded Israeli settlement of the West Bank and east Jerusalem.

But supporters of Israel say that boycotting the country is no way to make peace, especially since many BDS supporters do not differentiate between protesting Jewish settlements on occupied lands or Israel as a whole.

The Jewish settlements are only part of the apartheid practices of Israel and I’m not quite certain why the AP rolls this out as a straw man. Apartheid is codified bigotry allowing only second-class citizenship to Palestinians – strictly enforced throughout every part of political life in Israel and the land that nation invaded and controls by force of arms.

In the U.S., activists have pressed for boycotts of Israeli products and cultural events, and divestment by churches and others. None of these efforts has gained as much momentum as the campus divestment movement.

Pension funds in the United States, like CALPERS, representing thousands of employees in California, ranging from teachers to police, is considering divesting all Israel-based investments. They are not alone.

The campaign will continue. In the American Jewish community, the percentage of young people who believe identity with and unconditional support for Israel is necessary – is a minority. Nor will they adopt the specious argument that opposition to Israel’s policies is somehow anti-Semitic. That canard is dead and gone except among reactionary True Believers.

Just as the campaign against apartheid in South Africa was long and difficult – this, too, shall succeed.