Connect with us

Science

Some of the world’s oldest rubies linked to early life – Newswise

Published

 on


Newswise — While analyzing some of the world’s oldest coloured gemstones, researchers from the University of Waterloo discovered carbon residue that was once ancient life, encased in a 2.5 billion-year-old ruby.

The research team, led by Chris Yakymchuk, professor of Earth and Environmental Sciences at Waterloo, set out to study the geology of rubies to better understand the conditions necessary for ruby formation. During this research in Greenland, which contains the oldest known deposits of rubies in the world, the team found a ruby sample that contained graphite, a mineral made of pure carbon. Analysis of this carbon indicates that it is a remnant of early life.

“The graphite inside this ruby is really unique. It’s the first time we’ve seen evidence of ancient life in ruby-bearing rocks,” says Yakymchuk. “The presence of graphite also gives us more clues to determine how rubies formed at this location, something that is impossible to do directly based on a ruby’s colour and chemical composition.”

The presence of the graphite allowed the researchers to analyze a property called isotopic composition of the carbon atoms, which measures the relative amounts of different carbon atoms. More than 98 per cent of all carbon atoms have a mass of 12 atomic mass units, but a few carbon atoms are heavier, with a mass of 13 or 14 atomic mass units.

“Living matter preferentially consists of the lighter carbon atoms because they take less energy to incorporate into cells,” said Yakymchuk. “Based on the increased amount of carbon-12 in this graphite, we concluded that the carbon atoms were once ancient life, most likely dead microorganisms such as cyanobacteria.”

The graphite is found in rocks older than 2.5 billion years ago, a time on the planet when oxygen was not abundant in the atmosphere, and life existed only in microorganisms and algae films.

During this study, Yakymchuk’s team discovered that this graphite not only links the gemstone to ancient life but was also likely necessary for this ruby to exist at all. The graphite changed the chemistry of the surrounding rocks to create favourable conditions for ruby growth. Without it, the team’s models showed that it would not have been possible to form rubies in this location.

The study, Corundum (ruby) growth during the final assembly of the Archean North Atlantic Craton, southern West Greenland, was recently published in Ore Geology Reviews. A companion study, The corundum conundrum: Constraining the compositions of fluids involved in ruby formation in metamorphic melanges of ultramafic and aluminous rocks, was published in the journal Chemical Geology in June.

Adblock test (Why?)



Source link

Continue Reading

Science

BEYOND LOCAL: NASA launches spacecraft to test asteroid defense concept – BayToday

Published

 on


LOS ANGELES (AP) — NASA launched a spacecraft Tuesday night on a mission to smash into an asteroid and test whether it would be possible to knock a speeding space rock off course if one were to threaten Earth.

The DART spacecraft, short for Double Asteroid Redirection Test, lifted off from Vandenberg Space Force Base atop a SpaceX Falcon 9 rocket in a $330 million project with echoes of the Bruce Willis movie “Armageddon.”

If all goes well, the boxy, 1,200-pound (540-kilogram) craft will slam head-on into Dimorphos, an asteroid 525 feet (160 meters) across, at 15,000 mph (24,139 kph) next September.

“This isn’t going to destroy the asteroid. It’s just going to give it a small nudge,” said mission official Nancy Chabot of Johns Hopkins Applied Physics Laboratory, which is managing the project.

Dimorphos orbits a much larger asteroid called Didymos. The pair are no danger to Earth but offer scientists a better way to measure the effectiveness of a collision than a single asteroid flying through space.

Dimorphos completes one orbit of Didymos every 11 hours, 55 minutes. DART’s goal is a crash that will slow Dimorphos down and cause it to fall closer toward the bigger asteroid, shaving 10 minutes off its orbit.

The change in the orbital period will be measured by telescopes on Earth. The minimum change for the mission to be considered a success is 73 seconds.

The DART technique could prove useful for altering the course of an asteroid years or decades before it bears down on Earth with the potential for catastrophe.

A small nudge “would add up to a big change in its future position, and then the asteroid and the Earth wouldn’t be on a collision course,” Chabot said.

Scientists constantly search for asteroids and plot their courses to determine whether they could hit the planet.

“Although there isn’t a currently known asteroid that’s on an impact course with the Earth, we do know that there is a large population of near-Earth asteroids out there,” said Lindley Johnson, planetary defense officer at NASA. “The key to planetary defense is finding them well before they are an impact threat.”

DART will take 10 months to reach the asteroid pair. The collision will occur about 6.8 million miles (11 million kilometers) from Earth.

Ten days beforehand, DART will release a tiny observation spacecraft supplied by the Italian space agency that will follow it.

DART will stream video until it is destroyed on impact. Three minutes later, the trailing craft will make images of the impact site and material that is ejected.

John Antczak, The Associated Press

Adblock test (Why?)



Source link

Continue Reading

Science

Doing Photon Upconversion A Solid: Crystals That Convert Light To More Useful Wavelengths – Eurasia Review

Published

 on


Solid-solution organic crystals have been brought into the quest for superior photon upconversion materials, which transform presently wasted long-wavelength light into more useful shorter wavelength light. Scientists from Tokyo Institute of Technology revisited a materials approach previously deemed lackluster—using a molecule originally developed for organic LEDs—achieving outstanding performance and efficiency. Their findings pave the way for many novel photonic technologies, such as better solar cells and photocatalysts for hydrogen and hydrocarbon productions.

Light is a powerful source of energy that can, if leveraged correctly, be used to drive stubborn chemical reactions, generate electricity, and run optoelectronic devices. However, in most applications, not all the wavelengths of light can be used. This is because the energy that each photon carries is inversely proportional to its wavelength, and chemical and physical processes are triggered by light only when the energy provided by individual photons exceeds a certain threshold.

This means that devices like solar cells cannot benefit from all the color contained in sunlight, as it comprises a mixture of photons with both high and low energies. Scientists worldwide are actively exploring materials to realize photon upconversion (PUC), by which photons with lower energies (longer wavelengths) are captured and re-emitted as photons with higher energies (shorter wavelengths). One promising way to realize this is through triplet-triplet annihilation (TTA). This process requires the combination of a sensitizer material and an annihilator material. The sensitizer absorbs low energy photons (long-wavelength light) and transfers its excited energy to the annihilator, which emits higher energy photons (light of shorter wavelength) as a result of TTA (Figure 1).

Finding good solid materials for PUC has proven challenging for a long time. Although liquid samples can achieve relatively high PUC efficiency, working with liquids, especially those comprising organic solvents, is inherently risky and cumbersome in many applications. However, previous trials to create PUC solids generally suffered from poor crystal quality and small crystal domains, which lead to short travelling distances of triplet excited states and thus, low PUC efficiency. Additionally, in most previous solid PUC samples, stability under continuous photoirradiation was not tested and experimental data were often acquired in inert gas atmospheres. Hence, the low efficiency and insufficient materials stability had been of concern for a long time.

Now, in a recent study led by Associate Professor Yoichi Murakami from Tokyo Tech, Japan, a team of researchers found the answer to this challenge. Published in Materials Horizon, their paper (open access) describes how they focused on van der Waals crystals, a classical materials class that has not been considered for the quest of high-efficiency PUC solids. After discovering that 9-(2-naphthyl)-10-[4-(1-naphthyl)phenyl]anthracene (ANNP), a hydrocarbon molecule originally developed for blue organic LEDs, was an excellent annihilator for embodying their concept, they tried mixing it with platinum octaethylporphyrin (PtOEP), a staple sensitizer that absorbs green light.

The team found that aggregation of the sensitizer molecules could be completely avoided by utilizing the crystalline phase of a van der Waals solid solution with a sufficiently low proportion of PtOEP to ANNP (around 1:50000). They proceeded to thoroughly characterize the obtained crystals and found some insight into why using the ANNP annihilator prevented the aggregation of the sensitizer when other existing annihilators had failed to do so in previous studies. Moreover, the solid crystals the team produced were highly stable and exhibited outstanding performance, as Dr. Murakami remarks: “The results of our experiments using simulated sunlight indicate that solar concentration optics such as lenses are no longer needed to efficiently upconvert terrestrial sunlight.”

Overall, this study brings van der Waals crystals back into the game of PUC as an effective way of creating outstanding solid materials using versatile hydrocarbon annihilators. “The proof-of-concept we presented in our paper is a major technical leap forward in the quest for high-performance PUC solids, which will open up diverse photonics technologies in the future,” concludes Dr. Murakami. Let us hope further research in this topic allows us to efficiently transform light into its most useful forms.

Adblock test (Why?)



Source link

Continue Reading

Science

New Russian module docks with International Space Station – CGTN

Published

 on


A Soyuz rocket carrying the Progress cargo spacecraft and the Prichal node module lifts off from a launch pad at the Baikonur Cosmodrome, Kazakhstan, November 24, 2021. /CFP

A Soyuz rocket carrying the Progress cargo spacecraft and the Prichal node module lifts off from a launch pad at the Baikonur Cosmodrome, Kazakhstan, November 24, 2021. /CFP

A Russian cargo craft carrying a new docking module successfully hooked up with the International Space Station Friday after a two-day space journey.

The new spherical module, named Prichal (Pier), docked with the orbiting outpost at 6:19 p.m. Moscow time (1519 GMT). It has six docking ports and will allow potential future expansion of the Russian segment of the station.

The module has moored to the docking port of the new Russian Nauka (Science) laboratory module.

On Wednesday, a Soyuz rocket took off from the Russian launch facility in Baikonur, Kazakhstan, carrying the Progress cargo ship with Prichal attached to it. After entering space, the cargo ship with the module went into orbit.

Progress is also delivering 700 kilograms of various cargoes to the space station and is expected to undock from the station on December 22.

The first Soyuz spacecraft is expected to dock at the new module on March 18, 2022, with a crew of three cosmonauts: Oleg Artemyev, Denis Matveev and Sergei Korsakov.

Earlier this week, the Russian crew on the station started training for the module’s arrival, simulating the use of manual controls in case the automatic docking system failed.

The space outpost is currently operated by NASA astronauts Raja Chari, Thomas Marshburn, Kayla Barron, and Mark Vande Hei; Russian cosmonauts Anton Shkaplerov and Pyotr Dubrov; and Matthias Maurer of the European Space Agency.

Source(s): AP

Adblock test (Why?)



Source link

Continue Reading

Trending