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All 5 building blocks of DNA, RNA found in meteorites from Canada, U.S., Australia – CBC News

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A fresh examination of meteorites that landed in the United States, Canada and Australia is bolstering the notion that early in Earth’s history, such objects may have delivered chemical ingredients vital for the advent of life.

Scientists had previously detected on these meteorites three of the five chemical components needed to form DNA, the molecule that carries genetic instructions in living organisms, and RNA, the molecule crucial for controlling the actions of genes. Researchers said on Tuesday they have now identified the final two after fine-tuning the way they analyzed the meteorites.

Unlike in previous work, the methods used this time were more sensitive and did not use strong acids or hot liquid to extract the five components, known as nucleobases, according to astrochemist Yasuhiro Oba of Hokkaido University’s Institute of Low Temperature Science in Japan, lead author of the study published in the journal Nature Communications.

Nucleobases are nitrogen-containing compounds crucial in forming DNA’s characteristic double-helix structure.

Confirmation of an extraterrestrial origin of a complete set of nucleobases found in DNA and RNA buttresses the theory that meteorites could have been an important source of organic compounds necessary for the emergence of Earth’s first living organisms, according to astrobiologist and study co-author Danny Glavin of NASA’s Goddard Space Flight Center in Maryland.

The Tagish Lake meteorite fell in northern British Columbia on Jan. 18, 2000. It produced a remarkable fireball as it streaked across the dawn sky, which was witnessed as far away as Whitehorse, Yukon. (Royal Ontario Museum)

Scientists have been seeking to better understand the events that unfolded on Earth that enabled various chemical compounds to come together in a warm, watery setting to form a living microbe able to reproduce itself. The formation of DNA and RNA would be an important milestone, as these molecules essentially contain the instructions to build and operate living organisms.

“There is still much to learn about the chemical steps that led to the origin of life on Earth — the first self-replicating system,” Glavin said. “This research certainly adds to the list of chemical compounds that would have been present in the early Earth’s prebiotic [existing before the emergence of life] soup.”

Where the meteorites were found

The researchers examined material from three meteorites — one that fell in 1950 near the town of Murray in the U.S. state of Kentucky; one that fell in 1969 near the town of Murchison in Australia’s Victoria state; and one that fell in 2000 near Tagish Lake in B.C.

All three are classified as carbonaceous chondrites, made of rocky material thought to have formed early in the solar system’s history. They are carbon-rich, with the Murchison and Murray meteorites containing about two per cent organic carbon by weight and the Tagish Lake meteorite containing about four per cent organic carbon. Carbon is a primary constituent of organisms on Earth.

“All three meteorites contain a very complex mixture of organic molecules, most of which have not yet been identified,” Glavin said.

Earth formed roughly 4.5 billion years ago. In its infancy, it was pelted by meteorites, comets and other material from space. The planet’s first organisms were primitive microbes in the primordial seas, and the earliest known fossils are marine microbial specimens dating to roughly 3.5 billion years ago, though there are hints of life in older fossils.

The 5 key ingredients

The two nucleobases, called cytosine and thymine, newly identified in the meteorites may have eluded detection in previous examinations because they possess a more delicate structure than the other three, the researchers said.

The five nucleobases would not have been the only chemical compounds necessary for life. Among other things needed were: amino acids, which are components of proteins and enzymes; sugars, which are part of the DNA and RNA backbone; and fatty acids, which are structural components of cell membranes.

“The present results may not directly elucidate the origin of life on the Earth,” Oba said, “but I believe that they can improve our understanding of the inventory of organic molecules on the early Earth before the onset of life.”

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Joe Biden Wants to Put a Japanese Astronaut on the Moon – Gizmodo

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Gateway, illustrated here, will serve as a crucial part of the upcoming Artemis missions.
Illustration: NASA

President Joe Biden and Japanese Prime Minister Fumio Kishida further solidified their plans to send a Japanese astronaut to the upcoming lunar space station, while also affirming the possibility of having a Japanese astronaut walk on the Moon during future Artemis missions.

Biden and Kishida met in Tokyo on Monday to continue discussions around an Implementing Agreement that will potentially place a Japanese astronaut on the Gateway space station. The leaders also reaffirmed each country’s commitment to share data on climate change. The discussion around Gateway personnel is a part of ongoing conversations between the U.S. and Japan regarding NASA’s upcoming missions to the Moon.

Gateway is an integral component of NASA’s larger effort to return to the Moon, a series of upcoming missions known as the Artemis program. Once built, Gateway will serve as a Moon-orbiting outpost offering lunar-bound astronauts support for their visit. The lunar space station, in addition to serving as critical infrastructure for the Artemis missions, will also serve as a staging point for future crewed missions to Mars. The first pieces of the upcoming lunar station are set to launch no earlier than November 2024.

“In recent years, the alliance between Japan and the United States has grown stronger, deeper, and more capable as we work together to take on new challenges—just as important as the opportunities—of a rapidly changing world,” said President Biden in a NASA press release.

Japan and the U.S. are also interested in placing a Japanese astronaut on the surface of the Moon during a yet-to-be-determined Artemis mission, according to a White House fact sheet. NASA is looking to land astronauts on the lunar south pole by 2025, and Artemis will involve the first crewed Moon missions since Apollo 17 in 1972. NASA Administrator Bill Nelson said in the release: “Our shared ambition to see Japanese and American astronauts walk on the Moon together reflects our nations’ shared values to explore space responsibly and transparently for the benefit of humanity here on Earth.”

While the first pieces of Gateway are still a few years away from launch, having the U.S. and Japan team up is an opportunity to get more nations involved. The Artemis missions will be a global effort, and getting back to the Moon represents an exciting next step in space exploration and engineering.

More: This Tiny Moon-Bound Satellite Could Carve a Path For a Lunar Space Station.

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Crumbling comet could create meteor shower May 30 – Toronto Sun

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A crumbling comet could create a meteor shower on May 30.

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The ‘tau Herculids’ meteor display might be one of the most dramatic observed in over two decades, according to Space.com.

Meteor showers occur when dust or particles from asteroids or comets enter Earth’s atmosphere at a very high speed, the U.K. Sun explained.

This one is expected to be the product of a comet named 73P/Schwassmann-Wachmann, also known as SW3.

SW3 was first discovered in 1930 but did not reappear again until the 1970s, Republic World reported.

In 1995, astronomers noticed that the comet’s nucleus split into four smaller chunks, according to CNET.

It has continued to disintegrate more in the ensuing years.

The display is expected to be very visible in the Northern Hemisphere as it is occurring on a Moon-less night.

A consensus of experts predicts that the shower will be visible starting from 1 a.m. EST on May 31.

It is suggested viewers will want to be outside at least an hour before this so your eyes have a chance to adjust to the dark.

“The southwestern USA and Mexico are favored locations as the radiant, the area of the sky where these meteors come from, will be located highest in a dark sky,” Robert Lunsford wrote for AMS.

“The outburst may be seen from southeastern Canada and the remainder of the (eastern) USA, but at a lower altitude.”

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Boeing capsule returns from space station after test flight with no crew – CBC News

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Boeing’s crew taxi returned to Earth from the International Space Station on Wednesday, completing a repeat test flight before NASA astronauts climb aboard.

It was a quick trip back: the Starliner capsule parachuted into the New Mexico desert just four hours after leaving the orbiting lab, with airbags attached to cushion the landing. Only a mannequin was buckled in.

Aside from thruster failures and cooling system snags, Starliner appeared to clinch its high-stakes shakedown cruise, 2½ years after its botched first try. Flight controllers in Houston applauded and cheered the bull’s-eye touchdown.

NASA astronauts will strap in next for a trip to the space station. The space agency has long wanted two competing U.S. companies ferrying astronauts, giving it added insurance as it drastically reduced its reliance on Russia for rides to and from the space station.

Elon Musk’s SpaceX is already the established leader, launching astronauts since 2020 and even tourists. Its crew capsules splash down off the Florida coast; Boeing’s Starliner returns to the U.S. Army’s expansive White Sands Missile Range in New Mexico.

This image from NASA TV shows the Boeing Starliner approaching the International Space Station last Friday. (NASA/The Associated Press)

Boeing scrapped its first attempt to reach the space station in 2019, after software errors left the capsule in the wrong orbit and nearly doomed it. The company fixed the flaws and tried again last summer, but corroded valves halted the countdown. Following more repairs, Starliner finally lifted off from Cape Canaveral last Thursday and docked to the space station Friday.

Station astronauts tested Starliner’s communication and computer systems during its five days at the space station. They also unloaded hundreds of kilograms of groceries and other supplies that flew up in the Boeing capsule, then filled it with empty air tanks and other discarded gear.

A folded U.S. flag sent up by Boeing stayed behind, to be retrieved by the first Starliner crew.

“We’re a little sad to see her go,” station astronaut Bob Hines radioed as the capsule flew away.

Along for the ride was Starliner’s test dummy — Rosie the Rocketeer, a takeoff on the Second World War’s Rosie the Riveter.

The repairs and do-over cost Boeing nearly $600 million US.

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