Tuesday, February 26, 2019
NASA-Funded Research Creates DNA-like Molecule to Aid Search for Alien Life
In a research breakthrough funded by NASA, scientists have synthesized a molecular system that, like DNA, can store and transmit information. This unprecedented feat suggests there could be an alternative to DNA-based life, as we know it on Earth – a genetic system for life that may be possible on other worlds.
This new molecular system, which is not a new life form, suggests scientists looking for life beyond Earth may need to rethink what they are looking for. The research appears in Thursday’s edition of Science Magazine.
DNA is a complex molecule that stores and transmits genetic information, is passed from parent to offspring in all living organisms on Earth, and its components include four key ingredients called nucleotides – all standard for life as we know it. But, what about life on other worlds?
“Life detection is an increasingly important goal of NASA’s planetary science missions, and this new work will help us to develop effective instruments and experiments that will expand the scope of what we look for,” said Lori Glaze, acting director of NASA’s Planetary Science Division.
One way to imagine the kinds of foreign structures found on other worlds is to try to create something foreign on Earth. A team of researchers, led by Steven Benner at the Foundation for Applied Molecular Evolution in Alachua, Florida, successfully achieved the fabrication of a new informational molecular system that is like DNA, except in one key area: The new molecule has eight informational ingredients instead of four.
The synthetic DNA includes the four nucleotides present in Earth life – adenine, cytosine, guanine, and thymine – but also four others that mimic the structures of the informational ingredients in regular DNA. The result is a double-helix structure that can store and transfer information.
Benner's team, which collaborated with laboratories at the University of Texas in Austin, Indiana University Medical School in Indianapolis, and DNA Software in Ann Arbor, Michigan, dubbed their creation "hachimoji" DNA (from the Japanese "hachi," meaning "eight," and "moji," meaning "letter"). Hachimoji DNA meets all the structural requirements that allow our DNA to store, transmit and evolve information in living systems.
“By carefully analyzing the roles of shape, size and structure in hachimoji DNA, this work expands our understanding of the types of molecules that might store information in extraterrestrial life on alien worlds,” said Benner.
Scientists have much more to do on the question of what other genetic systems could serve as the foundation for life, and where such exotic organisms could be found. However, this study opens the door to further research on ways life could structure itself in environments that we consider inhospitable, but which might be teeming with forms of life we haven’t yet imagined.
“Incorporating a broader understanding of what is possible in our instrument design and mission concepts will result in a more inclusive and, therefore, more effective search for life beyond Earth,” said Mary Voytek, senior scientist for Astrobiology at NASA Headquarters.
One of NASA’s goals is to search for life on other planets like Mars, where there was once flowing water and a thick atmosphere, or moons of the outer solar system like Europa and Enceladus, where vast water oceans churn under thick layers of ice. What if life on those worlds doesn’t use our DNA? How could we recognize it? This new DNA may be the key to answering these questions and many more.
This work also interests those interested in information as part of life.
“The discovery that DNA with eight nucleotide letters is suitable for storing and transmitting information is a breakthrough in our knowledge of the range of possibilities necessary for life," said Andrew Serazin, president of Templeton World Charity Foundation in Nassau, The Bahamas, which also supported this work. "This makes a major contribution to the quest supported by Templeton World Charity Foundation to understand the fundamental role that information plays in both physics and biology."
Climate Change Could Make These Super-Common Clouds Extinct, Which Would Scorch the Planet
If humanity pumps enough carbon dioxide into the atmosphere, one of Earth's most important types of cloud could go extinct. And if the stratocumulus clouds — those puffy, low rolls of vapor that blanket much of the planet at any given moment — disappear, Earth's temperature could climb sharply and radically, to heights not predicted in current climate models.
As Wolchover explained, clouds have long been one of the great uncertainties of climate models. Clouds are complicated, small and fast-changing. Computer models that easily capture the complexity and detail of most climate systems just aren't powerful enough to predict worldwide shifts in cloud behavior.
But clouds are important. They dye a wide swath of the atmosphere white, as seen from space, reflecting sunlight away from Earth's surface. And stratocumulus clouds are an important part of that picture; they're those white blankets you might have seen as you looked out the window of an airplane, rolling out below you and hiding the ground. Researchers suspect that certain sudden, past jumps in temperature may have been caused by changes to clouds like these.
For the new research, scientists modeled just a small patch of sky using a supercomputer. They found that if carbon dioxide (CO2) levels reach about 1,200 parts per million (ppm) in the atmosphere, stratocumulus clouds break up. That's a very high carbon dioxide concentration. Right now, levels have climbed past 410 ppm — already a dangerous shift from the 280 ppm that prevailed before the industrial revolution.
But humans put more and more CO2 into the atmosphere every year. If current trends continue, Earth could reach 1,200 ppm within 100 to 150 years. This could happen if our society doesn't follow through on any of its commitments to reduce emissions, Wolchover reported. And even if it does, the result would be another 14 degrees Fahrenheit (8 degrees Celsius) of heat added to the global average, on top of the dangerous changes already undrway due to greenhouse gases.
That's an enormous change, and it goes beyond predictions of worldwide ice melt and catastrophic sea-level rise. The last time our planet was that warm, crocodiles swam in the Arctic and the region around the equator was "scorched" and "mostly lifeless," according to Wolchover.
And once the stratocumulus clouds are gone, Wolchover reported, they likely wouldn't reappear until atmospheric carbon dioxide levels dropped below where they are currently.
There's still some uncertainty in the data, however; and it hasn't been replicated. The 1,200-ppm figure could shift up or down as scientists look into the issue further.
But whether or not humans kill off stratocumulus clouds or not, this study highlights the many factors in climate change we don't yet understand.
India's Air strike to Pakistan
Hi Guys,
There is a good news that-
There is a good news that-
This morning at 3:30 a.m. India had a Air strike on Pakistan to take his revenge of 40 CR PF soldiers who died in Pulwama Attack.According to the news almost 400 militants were killed in the air strike.
External:
India has confirmed the attack on the biggest training camp of Jaish-e-Mohammad, the terror group which was involved in the February 14 attack on a CRPF convoy. Twelve Mirage 2000 fighter jets struck joint training camps of Jaish and LeT inside Pakistan and completely destroyed them by shelling 1,000 kg bombs. It took 19 minutes to complete the operation.
SanDisk and Micron deliver world's first 1TB microSD cards
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