History made in space with gene-editing experiment
In a first, scientists carried out a gene-editing experiment aboard the International Space Station (ISS), which paves the way for extensive research into DNA repair in space.
The team developed and successfully demonstrated a novel method for studying how cells repair damaged DNA in space.
Damage to an organism’s DNA can occur during normal biological processes or as a result of environmental causes, such as UV light. In humans and other animals, damaged DNA can lead to cancer. However, cells have several different natural strategies by which damaged DNA can be repaired.
Astronauts traveling outside of Earth’s protective atmosphere face increased risk of DNA damage due to the radiation that permeates space. Understanding which DNA-repair strategies are employed by the body in space may be particularly important for protecting the health of space travellers.
Previous work suggests that microgravity conditions may influence this choice, raising concerns that repair might not be adequate. However, technological and safety obstacles have so far limited investigation into the issue.
Researchers have now used CRISPR/Cas9 genome editing technology to create precise damage to DNA strands so that DNA-repair mechanisms can then be observed in better detail. They successfully demonstrated the viability of the novel method in yeast cells aboard the ISS.
The study not only marks the first time that CRISPR/Cas9 genome editing has successfully been conducted in space, but also the first time that live cells have undergone successful transformation in space — incorporation of genetic material originating from outside the organism. More on Independent.
Ancient beetle discovered from dinosaur poop
By analysing fossilised dinosaur droppings, scientists have discovered a 230-million-year-old beetle species, representing a new family of beetles, previously unknown to science.
The fossilised faeces, also known as coprolites, can preserve ancient insect species offers a new alternative to amber fossils, which are fossilised tree resin that normally yield the best-preserved insect fossils.
The oldest insect fossils from amber, however, are approximately 140-million-years old, and thus from relatively recent geological times.
With coprolites, researchers can now look even further into the past, allowing them to learn more about insect evolution and food webs of yet unexplored time intervals.
The research team named the new beetle species Triamyxa coprolithica. The species belongs to the same group that represents modern day insect that are small and live on algae in wet environments.
Triamyxa likely lived in semiaquatic or humid environments and were likely consumed by Silesaurus opolensis — the probable producer of the coprolite — a beaked dinosaur ancestor about 2 m long and 15 kg heavy that lived in what is now Poland. More on CNN.
Why Mercury has a large iron core
Scientists have found that a planet’s distance from the sun influences the density, mass and iron content of a rocky planet’s core — this can explain why Mercury has a big core relative to its mantle.
For decades, scientists argued that hit-and-run collisions with other bodies during the formation of our solar system blew away much of Mercury’s rocky mantle and left the big, dense, metal core inside.
However, the new research reveals that it is the sun’s magnetism that is to blame.
The team from Tohoku University developed a model showing that the density, mass, and iron content of a rocky planet’s core are influenced by its distance from the sun’s magnetic field.
The four inner planets of our solar system — Mercury, Venus, Earth and Mars — are made up of different proportions of metal and rock. The metal content in the core drops off as the planets get farther from the sun.
The study shows that the distribution of raw materials in the early forming solar system was controlled by the sun’s magnetic field.
During the early formation of our solar system, when the young sun was surrounded by a swirling cloud of dust and gas, grains of iron were drawn toward the centre by the sun’s magnetic field. When the planets began to form from clumps of that dust and gas, planets closer to the sun incorporated more iron into their cores than those farther away.
The study suggests that magnetism should be factored into future attempts to describe the composition of rocky planets, including those outside our solar system. More on Tech Explorist.
Scientists closer to solving the mystery of methane on Mars
Reports of methane detection at Mars have captivated scientists, since a significant amount of methane on Earth is produced by microbes that help most livestock digest plants.
Finding methane on Mars is exciting because it may indicate the presence of microbes living on the Red Planet. Methane could also be produced by geological processes that involve the interaction of rocks, water, and heat can also produce it.
However, scientists were so far left baffled by why all Mars probes were not detecting the gas in the atmosphere. While NASA’s Curiosity rover has repeatedly detected methane above the surface of Gale Crater, the European Space Agency ExoMars Trace Gas Orbiter hasn’t detected any methane higher in the Martian atmosphere.
The Tunable Laser Spectrometer (TLS) instrument aboard Curiosity has measured less than one-half part per billion in volume of methane on average in Gale Crater. That’s equivalent to about a pinch of salt diluted in an Olympic-size swimming pool.
The European orbiter, designed to be the gold standard for measuring methane and other gases over the whole planet, however, did not find any traces of methane.
Researchers then hypothesised that the discrepancy between methane measurements comes down to the time of day they’re taken. Because it needs a lot of power, TLS operates mostly at night. The Martian atmosphere is calm at night, Moores noted, so the methane seeping from the ground builds up near the surface where Curiosity can detect it.
The Trace Gas Orbiter requires sunlight to pinpoint methane about 5 km above the surface.
While this study suggests that methane concentrations rise and fall through the day at the surface of Gale Crater, scientists are yet to solve the global methane puzzle at Mars.
Methane is a stable molecule that is expected to last on Mars for about 300 years before getting torn apart by solar radiation. If methane is constantly seeping from all similar craters, enough of it should have accumulated in the atmosphere for the Trace Gas Orbiter to detect.
Scientists suspect that something is destroying methane in less than 300 years. More on SciTechDaily.
Enormous lake disappears from Antarctica in three days
An enormous, ice-covered lake in Antarctica vanished suddenly in a span of three days, leaving scientists worried that such an event could happen again.
During the 2019 winter on the Amery Ice Shelf in East Antarctica, an estimated 600 million to 750 million cubic meters of water drained into the ocean.
The scientists captured the latest event using satellite images. The lake drained in roughly three days after the ice shelf beneath it gave way.
The team believes that the weight of water accumulated in this deep lake opened a fissure in the ice shelf beneath the lake, a process known as hydrofracture, causing the water to drain away to the ocean below.
Hydrofracturing leaves behind a fissure which compromises the structural integrity of the ice sheet, which could cause ice shelves to collapse. This could contribute to elevating sea levels. More on LiveScience.
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