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Researchers use 'superdeep' diamonds to shed light on Earth's inner workings – Folio – University of Alberta

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In a new study led by a University of Alberta PhD student, researchers used diamonds as breadcrumbs to provide insight into some of Earth’s deepest geologic mechanisms.

“Geologists have recently come to the realization that some of the largest, most valuable diamonds are from the deepest portions of our planet,” said Margo Regier, a PhD student in the Faculty of Science under the supervision of Graham Pearson and Thomas Stachel. “While we are not yet certain why diamonds can grow to larger sizes at these depths, we propose a model where these ‘superdeep’ diamonds crystallize from carbon-rich magmas, which may be critical for them to grow to their large sizes.”

Beyond their beauty and industrial applications, diamonds provide unique windows into the deep Earth, allowing scientists to examine the transport of carbon through the mantle.

“The vast majority of Earth’s carbon is actually stored in its silicate mantle, not in the atmosphere,” Regier explained. “If we are to fully understand Earth’s whole carbon cycle, we need to understand this vast reservoir of carbon deep underground.”

The study revealed that the carbon-rich oceanic crust that sinks into the deep mantle releases most of its carbon before it gets to the deepest portion of the mantle. That means most carbon is recycled back to the surface, and only small amounts are stored in the deep mantle—which has significant implications for how scientists understand the Earth’s carbon cycle.

The mechanism is important to understand for a number of reasons, Regier noted.

“The movement of carbon between the surface and mantle affects Earth’s climate, the composition of its atmosphere and the production of magma from volcanoes,” said Regier. 

“We do not yet understand if this carbon cycle has changed over time, nor do we know how much carbon is stored in the deepest parts of our planet. If we want to understand why our planet has evolved into its habitable state today and how the surfaces and atmospheres of other planets may be shaped by their interior processes, we need to better understand these variables.”

The study was made possible through a collaboration between researchers at the U of A and the University of Glasgow, including Jeff Harris, who collected the diamond samples. Support through federal funding from the Natural Sciences and Engineering Research Council of Canada, through the Diamond Exploration Research Training School at the U of A, was also integral in enabling the research.

The study, “The Lithospheric to Lower Mantle Carbon Cycle Recorded in Superdeep Diamonds,” was published in Nature.

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Asteroid On Track To Buzz Earth The Day Before The Presidential Election – HuffPost

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An asteroid hurtling close to Earth is on course to buzz the globe the day before the U.S. presidential election.

According to calculations by the National Aeronautics and Space Administration, the refrigerator-sized space boulder has only a minuscule chance (.41%) of entering Earth’s atmosphere and is likely to be a relatively comfortable — but very close in space terms — 4,776 kilometers (about 3,000 miles) from the center of the Earth when it makes its flyby.

“So if the world ends in 2020, it won’t be the fault of the universe,” astrophysicist Neil deGrasse Tyson said on Instagram Monday:

Asteroid 2018VP1 is hurtling through space at some 25,000 miles per hour. It was discovered two years ago when it was some 280,000 miles away.

If the asteroid entered the Earth’s atmosphere, it would quickly disintegrate because of its small size, per NASA Asteroid Watch. And if that happens, its fiery fall would provide a great light show potentially visible from Earth.

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Starlink's BITS licence approved, still needs spectrum to operate in Canada – Cartt.ca

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Service launch not coming soon… GATINEAU — The CRTC has approved an application by Elon Musk’s Space Exploration Technologies (SpaceX) for a Basic International Telecommunications Services (BITS) licence to provide telecom services via SpaceX’s Starlink low-Earth-orbit (LEO) satellite constellation. The Commission said in a letter dated October 15 and addressed to SpaceX’s chief financial officer, Bret Johnsen, it received 2,585 interventions regarding the licence application, and after considering the submitted comments, it is approving the application and issuing a BITS licence to SpaceX. Getting a BITS licence is not exactly the highest hurdle there is to clear (most are approved…

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NASA mission will touch down on asteroid Bennu today – CTV News

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After orbiting the near-Earth asteroid Bennu for nearly two years, NASA’s OSIRIS-REx spacecraft is ready to reach out its robotic arm and collect a sample from the asteroid’s surface on Tuesday. That sample will be returned to Earth in 2023.

A van-size spacecraft has to briefly touch down its arm in a landing site called Nightingale. The site is the width of a few parking spaces. The arm will collect a sample between 2 ounces and 2 kilograms before backing away to safety.

The site itself is nestled within a crater the size of a tennis court and ringed in building-size boulders.

Located more than 320 million kilometres from Earth, Bennu is a boulder-studded asteroid shaped like a spinning top and as tall as the Empire State Building. It’s a “rubble pile” asteroid, which is a grouping of rocks held together by gravity rather than a single object.

The mission — which stands for Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer — launched in September 2016.

Since arriving at Bennu, the spacecraft and its cameras have been collecting and sending back data and images to help the team learn more about the asteroid’s composition and map the best potential landing sites to collect samples.

The main event of the mission, called the Touch-and-Go sample collection event, or TAG, is scheduled for October 20 beginning at 5 p.m. ET.

Bennu has an orbit that brings it close to Earth, which is why it’s considered to be a near-Earth asteroid. One of its future approaches could bring it perilously close to Earth sometime in the next century; it has a one in 2,700 chance of impacting our planet.

The samples from Bennu could help scientists understand not only more about asteroids that could impact Earth but also about how planets formed and life began.

“It’s a historic first mission for NASA, returning an asteroid sample, and it’s hard,” said Thomas Zurbuchen, associate administrator of NASA’s Science Mission Directorate, during a Monday press conference.

“Bennu is almost a Rosetta Stone out there, and it tells the history of our Earth and solar system during the last billions of years. Bennu has presented a lot of challenges, but the ingenuity of the team has enabled us to get where we are.”

WHAT TO EXPECT

Rather than the so-called “seven minutes of terror” of trying to land the Perseverance rover on Mars next year, the OSIRIS-REx team is anticipating “4.5 hours of mild anxiousness,” according to Beth Buck, the mission’s operations program manager at Lockheed Martin Space in Littleton, Colorado.

During this time, the spacecraft will descend from its orbit around the asteroid and eventually come close enough to touch it.

The asteroid and spacecraft are currently about 207 million miles from Earth, which will cause a communication delay of about 18.5 minutes.

The team at NASA will livestream an animation depicting what is occurring based on the commands that have already been sent to OSIRIS-REx hours ahead for the sample collection sequence.

The spacecraft will perform the entire sequence of approaching the asteroid and collecting the sample autonomously since live commands from Earth won’t be possible.

TOUCHING DOWN ON AN ASTEROID

The event will take about 4.5 hours to unfold and the spacecraft will execute three maneuvers to collect the sample.

The spacecraft will first fire thrusters to leave its safe orbit around the asteroid, which is about 762 metres away from the surface, and travel for four hours before reaching just 125 metres away. Then, the spacecraft will adjust for position and speed to continue descending.

Next, OSIRIS-REx will slow its descent to target a path so it matches the asteroid’s rotation during contact. Its solar panels will fold into a Y-wing configuration above the spacecraft to protect them.

At last, OSIRIS-REx will touch down for less than 16 seconds. The spacecraft will fire a pressurized nitrogen bottle into the asteroid, using the gas as a way to lift material off Bennu’s surface.

The spacecraft’s collector head will capture the stirred up material. This head, located on the 3-metre-long robotic sampling arm, is the only part of the spacecraft that will touch Bennu. The team compares it to an air filter in an older model car, perfect for collecting fine material.

Small discs, which can collect dust like sticky pads, are also located on the head in case part of the sampling maneuver doesn’t go according to plan.

AfFTER THE EVENT

A camera on the spacecraft will take footage of the collection event.

The OSIRIS-REx spacecraft will have to detect hazards and delay its own mission if any obstacles get in the way of the sample collection. Based on its simulations, the team estimates there is less than a 6% chance the spacecraft will abort the mission.

By Tuesday night, the team should be able to confirm if the touchdown occurred successfully. Imagery will be returned by the spacecraft on Wednesday, which will provide more details of the sample collection and how the spacecraft is faring.

The team estimates that they will have a mass measurement of the sample on Saturday. By October 30, NASA will confirm if the spacecraft collected enough of a sample or if it needs to make another sample collection attempt in January at another landing site called Osprey.

But if everything runs smoothly, the spacecraft and its prized sample will begin the long journey back to Earth next year and land the sample on Earth in 2023.

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