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Astronomers find first exposed planetary core 730 light-years from Earth



July 1 (UPI) — For the first time, scientists have found an exposed planetary core. The discovery — published Wednesday in the journal Nature — could offer astronomers new insights into the interiors of planets.

Earth’s core remains a source of many scientific mysteries, and planetary scientists know even less about the cores of Earth’s neighbors. To understand planetary formation and evolution, researchers need to know more about the inside of planets.

For obvious reason, planetary cores are difficult to study. Now, scientists have found a planetary core that is entirely exposed, they said.

Researchers estimate the core, located 730 light-years from Earth, once formed the interior of a gas giant. It’s possible the gas giant’s growth was stunted during its infancy, but researchers suspect it’s more likely the gas giant had its outer layers stripped away over billions of years.

The planetary core, named TOI-849 b, is too big to be a rocky planet, researchers say.

David Armstrong, lead researcher on the study, told UPI that researchers concluded the planetary core was the remains of a gas giant based on its size and an expectation it underwent “runaway gas accretion,” a process of accumulating gas and growing even bigger.

“For such massive planets, gases like hydrogen and helium fall onto the forming planet very quickly, until the planet becomes something like Jupiter,” said Armstrong, an astrophysicist at the University of Warwick. “It’s very difficult to make a planet as massive and dense as TOI-849 b without it becoming a gas giant.”

But if TOI-849 b was once a gas giant, its gas layers are now nowhere to be found, researchers say.

Scientists suspect they were expelled during an unusually violent period of planetary evolution.

“This could be because it collided with another planet toward the end of its formation, or later ventured too close to its host star and was stripped of its atmosphere,” Armstrong said. “An alternative is that the planet got stuck while forming, building up a core but failing to collect the gas we would normally expect. That can happen if the core opens up a large gap in the disk of material it forms from, which is easier to do very close to the star.”

The planetary core enjoys an extremely intimate orbit, completing a lap around its sun once every 18 hours. Its surface is a scorching 1,800 degrees Kelvin.

The core is located in what’s called the “Neptunian desert,” as large planets are rarely found so close to their host stars.

“It suggests that the planet had a more unusual history, which supports a more aggressive past such as a planetary impact or tidal disruption by the host star,” Armstrong said.

Astronomers first spotted the planetary core using data collected by NASA’s TESS mission.

“We see small dips in the brightness of the star as the planet blocks some of the light reaching Earth,” Armstrong said. “We followed up the discovery using the HARPS spectrograph at the European Southern Observatory, trying to measure the mass of the planet using the ‘doppler technique,’ where we measure the movement of the host star as the planet orbits.”

To better understand how such a big, dense core ended up without gas layers and so close to its host stars, scientists need to acquire more detailed observations, Armstrong said.

“We are trying to measure the alignment of the planet’s orbit with the spin of its host star, which will help us work out what its past evolution was,” Armstrong said. “In the longer term, we would like to measure the constituents of the planet’s atmosphere, but that will require next-generation telescopes to do.”

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NASA’s OSIRIS-REx touches down on asteroid Bennu to nab sample



Oct. 20 (UPI) — NASA’s OSIRIS-REx touched down on asteroid Bennu on Tuesday evening in a mission to scoop a sample of rocks and dirt.

The spacecraft — the Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer — made soft contact with the asteroid at 6:12 p.m. EDT.

The historic “touch and go” event featured animation displaying OSIRIS-REx’s sample collection activities in real time. It takes time for real images of the touchdown to travel back to the Earth, so they won’t be released to the public until Wednesday.

The craft executed a series of maneuvers over the course of several hours before making soft contact with the surface of the asteroid to collect regolith, or rocks and dirt.

“It will be four and a half hours of anxiousness,” Beth Buck, OSIRIS-REx mission operations manager at Lockheed Martin Space, said in a news conference ahead of the event.

Buck made a comparison to the descent of a spacecraft on Mars, when there is typically “seven minutes of terror.”

The goal is to learn more about the solar system’s history and help “planetary defense” engineers with missions to protect earth from rogue asteroids. Bennu is believed to be a window into the solar system’s past since it’s a pristine, carbon-rich body carrying building blocks of both planets and life.

At around 1:50 p.m. EDT, the spacecraft left orbit around the asteroid before executing a series of burns to position itself over a sampling area nicknamed Nightingale.

Once in position, the craft began its approach to the asteroid at 5:50 p.m. EDT. It then spent about 15 seconds attempting to collect the regolith sample before backing away again.

The area, which is 52 feet in diameter, will make for a more demanding landing than expected, Kenneth Getzandanner, OSIRIS-REx flight dynamics manager at the NASA Goddard Space Flight Center in Maryland, said in the news conference.

The original mission called for a landing “zone” about 150% larger than Nightingale, at 82 feet, but that changed because Bennu was more rocky than expected.

The goal was to collect at least 1.7 ounces of fine-grained material, but the spacecraft can carry up to 4.4 pounds, Heather Enos, OSIRIS-REx deputy principal investigator at the University of Arizona said.

“I would love for that capsule to be completely full,” Enos said.

Though early images from the asteroid should hint at whether the mission succeeded, it will take engineers roughly 10 days to compare and analyze the mass before and after the maneuver to actually know how much dirt is inside the OSIRIS-REx.

If it failed, the spacecraft has enough fuel to attempt two more touch downs to collect material.

The spacecraft is expected to return to Earth, with the regolith sample from Bennu, in 2023.

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SpaceX scrubs Starlink launch until Thursday, if weather cooperates



Oct. 21 (UPI) — Just three days after sending 60 more Starlink satellites into orbit, SpaceX is aiming to launch another batch of broadband satellites into space from Florida.

If the weather cooperates, Thursday’s launch will be SpaceX’s 15th Starlink mission.

Liftoff had been scheduled for 12:29 p.m. EDT Wednesday aboard a Falcon 9 rocket at Launch Complex 40 at Cape Canaveral Air Force Station, but controllers scrubbed the launch due to weather and rescheduled for 12:14 p.m. on Thursday.

With a launch Sunday, SpaceX increased the size of their Starlink constellation to nearly 800 satellites. The 15th mission will see another 60-odd satellites join the network.

“The goal of Starlink is to create a network that will help provide Internet services to those who are not yet connected, and to provide reliable and affordable Internet across the globe,” according to the Kennedy Space Center.

Weather for Wednesday’s planned launch had looked so-so and the Space Force’s 45th Weather Squadron predicted a 60 percent chance of favorable conditions.

“A mid-level inverted trough and associated easterly wave currently across the Bahamas will meander into the state over the next few days, bringing enhanced moisture, cloud cover, and instability with a higher coverage of showers and storms,” Space Force forecasters wrote.

They said Thursday’s forecast looks quite similar to Wednesday’s.

Earlier this month, SpaceX founder and CEO Elon Musk tweeted that Starlink’s constellation was big enough to begin beta-testing the Internet service system in both the United States and southern Canada.

SpaceX has already offered Starlink Internet services to emergency responders in wildfire-stricken areas of Washington State.

Washington’s Hoh tribe is also using the Internet service to provide their members online education and telehealth services.

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Chernobyl-level radiation harms bumblebee reproduction



Oct. 21 (UPI) — Bees are more sensitive to radiation than scientists thought. Scientists found the reproduction rates of bumblebees declined significantly when exposed to Chernobyl-level radiation.

The research, published Wednesday in the journal Proceedings of the Royal Society B: Biological Sciences, suggests radiation in Ukraine’s Chernobyl Exclusion Zone could impair pollination services, triggering wider ecological consequences than previously estimated.

Humans are not allowed to live in the Chernobyl Exclusion Zone, the disaster area more directly impacted by the 1986 nuclear accident, the worst in history. However, the destroyed nuclear reactors are surrounded by forests that are populated by robust populations of birds, bears, bison, lynx, moose, wolves and more.

Efforts to gauge the effects of radiation contamination on insects have yielded mixed results in the past. While some studies have suggested insects are relatively radiation-resistant, others have demonstrated significant impairment.

When researchers exposed bumblebees in the lab to radiation dose of 100 µGyh-1, an amount approximating exposure inside the Chernobyl Exclusion Zone, reproduction rates among the bees dropped between 30 and 45 percent.

Researchers found a direct correlation between the size of the radiation dose and reproduction rate declines. Lower levels of radiation had a smaller effect, while larger doses yielded greater declines.

Scientists were surprised to find they were able to detect reproductive rate declines at very small levels of radiation exposure.

“Our research provides much needed understanding as to the effects of radiation in highly contaminated areas and this is the first research to underpin the international recommendation for the effects of radiation on bees,” lead study author Katherine Raines, environmental scientist at the University of Stirling in Scotland, said in a news release.

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