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Gizmorama - November 22, 2017

Good Morning,


An Earth-like planet has been discovered! Could this be the Earth 2 we've been looking for? I've got my bags packed!

Learn about this and more interesting stories from the scientific community in today's issue.

Until Next Time,
Erin


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*- Newly discovered Earth-sized planet looks to be life-friendly -*

Scientist have discovered a nearby Earth-like exoplanet with conditions favorable to life.

The planet orbits Ross 128, an inactive red dwarf star. The small, dim and quiet sun translates to moderate temperatures on Ross 128b. Scientists suspect the temperate planet may offer them their best chance yet at finding alien life.

"This is the closest Earth-mass planet potentially in the habitable zone that orbits a quiet star," Xavier Bonfils, an astrophysicist at the University of Grenoble Alpes in France, told Space.com.

Ross 128 and Ross 128b lie just 11 light-years from Earth, making the exoplanet the second closest temperate planet after Proxima b.

Ross 128b's transit was first revealed among the data gathered by the European Southern Observatory's HARPS instrument, located at the La Silla Observatory in Chile.

"This discovery is based on more than a decade of HARPS intensive monitoring together with state-of-the-art data reduction and analysis techniques," Nicola Astudillo-Defru, astronomer at the University of Geneva in Switzerland, said in a news release. "Only HARPS has demonstrated such a precision and it remains the best planet hunter of its kind, 15 years after it began operations."

Often, red dwarfs release periodic flares. The blasts of ultraviolet and X-ray radiation can rip away a nearby exoplanet's atmosphere and limit the possibility for alien life. But Ross 128 is rather quiet, suggesting conditions on Ross 128b are potentially peaceful enough for life to emerge.

Ross 128b orbits its host star once every 9.9 days and is 20 times closer to its host star than Earth is to the sun. Despite its close proximity, the alien world receives only 1.38 times more irradiation. Ross 128 emits just half the energy of the sun.

As of now, scientists aren't sure whether the alien world is in or out of the habitable zone -- the orbital range in which exoplanets can host water in liquid form. They hope to find out during follow up analysis using ESO's Extremely Large Telescope. Scientists also hope to learn more about the exoplanet's atmosphere.

"New facilities at ESO will first play a critical role in building the census of Earth-mass planets amenable to characterization," researcher Xavier Bonfils said. "In particular, NIRPS, the infrared arm of HARPS, will boost our efficiency in observing red dwarfs, which emit most of their radiation in the infrared. And then, the ELT will provide the opportunity to observe and characterize a large fraction of these planets."

Scientists described their discovery of Ross 128b in the journal Astronomy & Astrophysics.



*-- Scientists develop reliable kill switches -- in case bioengineered microbes go rogue --*

Scientists at Harvard have developed a pair of new kill switches that can be used to thwart bioengineered microbes that go rogue.

Researchers have been testing the use of bioengineered microbes for a variety of purposes, from the diagnosis of disease in the human body to the neutering of mosquitoes.

But there remain concerns about releasing manipulated microbes into nature. Could their augmented genes have unintended consequences? Could they morph and proliferate?

Kill-switches ensure the microbes effectively shutdown, or commit suicide, after they've executed their intended function. While kill switches have proven effective in the lab, researchers suggest kill-switch technologies needed to be improved to ensure safety in real-world environs.

"We needed to take our previous work further and develop kill switches that are stable in the long run and would also be useful in real-world applications," Pamela Silver, researcher at the Wyss Institute for Biologically Inspired Engineering at Harvard, said in a news release.

Silver and her colleagues developed two new types of kill switches for added security.

The first is known as the "essentializer," which piggybacks off another type of kill switch known as the "memory element." The memory element uses genes from a bacteria-infecting virus to build an alarm system into the genome of the microbe. The alarm is designed to remember the presence of a specific molecule, a signal that the microbe has ventured too far from its intended target.

When the target is sensed, the bacteriophage genes are triggered and toxins capable of killing the microbe are released. But as microbes evolve, they randomly tweak their genes. Over generations, these tweaks can yield useful adaptations. They can also disrupt the programmed kill-switch.

To account for the problem, researchers installed the essentializer. Scientists spliced the bacteriophage genes into another part of the microbe's genome. These genes are manipulated to ensure small amounts of toxins are produced, while the original memory element is designed to produce small amounts of an anti-toxin, keeping the microbe alive.

Should the original memory element kill-switch become lost, the essentializer would begin producing more toxins, thus killing the microbe.

"To create this sophisticated system of checks and balances, we also made sure that the kill switches themselves remained fully intact, which is an important prerequisite for future applications; we verified that they were still functional after about 140 cell divisions," said grad student Finn Stirling.

Scientists named their second new kill-switch "cryodeath." The switch uses similar toxin/anti-toxin DNA splices. But the switch is synched with temperature, instead of another kill-switch.

In lab tests, scientists showed when the temperature drops from 37 degrees to 22 degrees Celsius, the toxin genes are expressed and the anti-toxin genes are inhibited.

The researchers detailed their new kill switches in a new paper published this week in the journal Molecular Cell.

"This study shows how our teams are leveraging synthetic biology not only to reprogram microbes to create living cellular devices that can carry out useful functions for medicine and environmental remediation, but to do this in a way that is safe for all," said Donald Ingber, founding director of the Wyss Institute.

***

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