Article body copy
Hidden inside the Earth—within the first several hundred kilometers below the crust—there is another ocean. It is, most likely, the largest ocean in the world. This water is not sloshing around in a big pool. No fish plumb its depths. In fact, this ocean is only water in the loosest sense: broken into its composite hydrogen and oxygen atoms and chemically bound to the surrounding rock, this ocean is in storage. Or, most of it is.
Denis Andrault and Nathalie Bolfan-Casanova, geoscientists at the University of Clermont Auvergne in France, have developed a new model that shows more of this water is in transit than previously thought. When the solid rock in the mantle—the layer of the planet between the crust and the core—becomes saturated with chemically dissociated water, it can transform into a water-rich molten slurry. When it does, it seeps back up toward the crust. The researchers call this mantle rain.
Much as the cycling of water between the atmosphere, glaciers, lakes, rivers, aquifers, and the ocean affects the level of the sea, the abundance of rain, and the frequency of drought, the exchange of water between the mantle and the surface also dictates the habitability of the Earth. Scientists already know that water can be dragged down to the mantle by subducting tectonic plates and brought back to the surface by things like volcanic eruptions, hydrothermal vents, and the creation of new crust at oceanic spreading centers. If this deep water cycle between the mantle and the surface is in balance, Earth’s sea level remains stable. If not, our planet could exist as anything from a singular global ocean to a desiccated world.
Earth’s habitability has benefited greatly from the fact that Earth’s sea levels have remained relatively stable over billions of years. According to previous studies of the mantle, however, it could have been very different. Estimates based on previously understood mechanics of the deep water cycle suggest that nearly twice as much water is carried into the mantle as is released back to the surface.
“There is a layer about 410 kilometers below the surface that can hold a lot of water,” says Andrault. The prevailing understanding says that water should stay there forever, he says. If that were the case, the Earth’s surface water would have slowly decreased, locked away in the mantle.
But that’s where mantle rain comes in.
In their study, Andrault and Bolfan-Casanova show that mantle rain could be enough to keep the deep water cycle in balance.
To discover mantle rain, the researchers looked at what happens when a subducting slab of rock and rock-bound water sinks deeper into the mantle. They found that as it descends, increasing temperatures and pressures cause the rocks to melt, releasing the water.
“The melt is like a slurry,” says Andrault. “Imagine a mushy mix of sand grains glued to each other with mud in between—the mud is the mantle rain.”
As more rocks melt, and as more water is liberated from the rock, this melt eventually becomes light enough that it begins to rise. As it does, the water bonds to minerals in the upper mantle and lowers their melting points, causing more melting that releases more water—and the cycle continues.
Andrault and Bolfan-Casanova’s model of mantle rain, says Yoshinori Miyazaki, an earth and planetary scientist at the California Institute of Technology who was not involved in the study, “shows there could be another way to transport water towards the surface in addition to the global-scale convection of the mantle itself.”
“Water generally doesn’t like to be in the rock phase,” Miyazaki says. “It will happily escape to the melt phase and percolate upwards.” Andrault says more work is needed to understand the extent to which water is escaping in this way.
The mantle rain model also suggests that there is currently one ocean mass in the upper mantle. “Together with the ocean on the surface,” says Andrault, “this ensures that there will always be water on Earth’s surface.”
“We still have a lot to learn about the deep water cycle,” says Miyazaki. “But one certain fact is that it has worked in an amazing way to keep Earth’s average sea level relatively constant over the past 500 million years, and probably longer, to sustain a habitable environment for life to continue.”
Astronaut study reveals effects of space travel on human bones – Euronews
By Will Dunham
WASHINGTON – A study of bone loss in 17 astronauts who flew aboard the International Space Station is providing a fuller understanding of the effects of space travel on the human body and steps that can mitigate it, crucial knowledge ahead of potential ambitious future missions.
The research amassed new data on bone loss in astronauts caused by the microgravity conditions of space and the degree to which bone mineral density can be regained on Earth. It involved 14 male and three female astronauts, average age 47, whose missions ranged from four to seven months in space, with an average of about 5-1/2 months.
A year after returning to Earth, the astronauts on average exhibited 2.1% reduced bone mineral density at the tibia – one of the bones of the lower leg – and 1.3% reduced bone strength. Nine did not recover bone mineral density after the space flight, experiencing permanent loss.
“We know that astronauts lose bone on long-duration spaceflight. What’s novel about this study is that we followed astronauts for one year after their space travel to understand if and how bone recovers,” said University of Calgary professor Leigh Gabel, an exercise scientist who was the lead author of the research published this week in the journal Scientific Reports https://www.nature.com/articles/s41598-022-13461-1.
“Astronauts experienced significant bone loss during six-month spaceflights – loss that we would expect to see in older adults over two decades on Earth, and they only recovered about half of that loss after one year back on Earth,” Gabel said.
The bone loss occurs because bones that typically would be weight-bearing on Earth do not carry weight in space. Space agencies are going to need to improve countermeasures – exercise regimes and nutrition – to help prevent bone loss, Gabel said.
“During spaceflight, fine bone structures thin, and eventually some of the bone rods disconnect from one another. Once the astronaut comes back to Earth, the remaining bone connections can thicken and strengthen, but the ones that disconnected in space can’t be rebuilt, so the astronaut’s overall bone structure permanently changes,” Gabel said.
The study’s astronauts flew on the space station in the past seven years. The study did not give their nationalities but they were from the U.S. space agency NASA, Canadian Space Agency, European Space Agency and Japan Aerospace Exploration Agency.
Space travel poses various challenges to the human body – key concerns for space agencies as they plan new explorations. For instance, NASA is aiming to send astronauts back to the moon, a mission now planned for 2025 at the earliest. That could be a prelude to future astronaut missions to Mars or a longer-term presence on the lunar surface.
“Microgravity affects a lot of body systems, muscle and bone being among them,” Gabel said.
“The cardiovascular system also experiences many changes. Without gravity pulling blood towards our feet, astronauts experience a fluid shift that causes more blood to pool in the upper body. This can affect the cardiovascular system and vision.
“Radiation is also a large health concern for astronauts as the further they travel from Earth the greater exposure to the sun’s radiation and increased cancer risk,” Gabel said.
The study showed that longer space missions resulted both in more bone loss and a lower likelihood of recovering bone afterward. In-flight exercise – resistance training on the space station – proved important for preventing muscle and bone loss. Astronauts who performed more deadlifts compared to what they usually did on Earth were found to be more likely to recover bone after the mission.
“There is a lot we still do not know regarding how microgravity affects human health, particularly on space missions longer than six months, and on the long-term health consequences,” Gabel said. “We really hope that bone loss eventually plateaus on longer missions, that people will stop losing bone, but we don’t know.”
Understanding Plants Is Key to Finding a Cure for Cancer – SciTechDaily
If scientists can fully understand plant growth, they might be able to find a cancer cure
In order to increase agricultural yields, it is important to understand how plants process light. Plants use light to determine when to grow and bloom. Plants find light using proteins called photoreceptors. However, understanding plants have impacts in fields other than agriculture. Ullas Pedmale, an assistant professor at Cold Spring Harbor Laboratory (CSHL), and his colleagues have discovered how the proteins UBP12 and UBP13 regulate the activity of a CRY2 photoreceptor. Their finding could make new growth-control strategies apparent, with potential implications well beyond agriculture.
There are CRY photoreceptors in both plants and people. They are connected to a number of conditions including diabetes, cancer, and several brain disorders. CRY2 helps in regulating growth in both people and plants. Uncontrolled development in plants reduces their viability, whereas it causes cancer in humans. “If we understand growth,” Pedmale says, “we can cure cancer.”
Plants need the right amount of CRY2 to know when to grow and flower. Pedmale and former postdoctoral fellow Louise Lindbäck discovered that manipulating UBP12 and UBP13 can change the amount of CRY2 in plants. They found that increasing UBP12 and UBP13 reduces CRY2 levels. This made plants think there wasn’t enough light. In response, they grew longer, abnormal stems to reach more. Pedmale says:
“We have a way to understand growth here—and we could manipulate growth just by manipulating two proteins. We have found a way we can actually increase flower output. You need flowering for food. If there’s no flower, there is no grain, no rice, no wheat, no maize.”
Pedmale and Lindbäck didn’t know exactly how UBP12 and UBP13 regulated CRY2. When the researchers took a closer look, they made a surprising discovery. In humans and other organisms, versions of UBP12 and UBP13 protect CRY photoreceptors from degradation. But in plants, the team saw the opposite. UBP12 and UBP13 were actually helping degrade CRY2 instead. Lindbäck, who is currently a research and developmental engineer at Nordic Biomarker in Sweden, explains:
“From literature, it’s known that if you find an interaction like this, it will protect from degradation. Initially, we saw the opposite, and we thought, ‘okay, maybe I did something wrong,’ but then when I did it a few times, we realized, ‘okay, this is true.’ Instead of protecting CRY2, it causes CRY2 to degrade.”
Pedmale hopes their discovery will help plant researchers and plant breeders improve crop yields. He also hopes his work helps inform cancer research. “My colleagues at CSHL are working hard trying to understand cancer,” he says. “We are coming at it from a different angle with plants.”
The study was funded by the National Institutes of Health.
Reference: “UBP12 and UBP13 deubiquitinases destabilize the CRY2 blue light receptor to regulate Arabidopsis growth” by Louise N. Lindbäck, Yuzhao Hu, Amanda Ackermann, Oliver Artz and Ullas V. Pedmale, 13 June 2022, Current Biology.
Rocket Lab's Lunar Photon Completes Sixth Orbit Raise for NASA's CAPSTONE Mission to The Moon – Parabolic Arc – Parabolic Arc
LONG BEACH, Calif. (Rocket Lab PR) — Rocket Lab USA, Inc. (Nasdaq: RKLB) (“Rocket Lab” or “the Company”), a leading launch and space systems company, today confirmed its Photon Lunar spacecraft successfully completed a sixth on-orbit burn of the HyperCurie engine, bringing the CAPSTONE satellite closer to the Moon. Lunar Photon’s apogee – the point at which the spacecraft is farthest from Earth during its orbit – is now 43,297 miles (69,680 km).
This sixth burn was originally scheduled to be two burns, but Rocket Lab’s space systems team determined the HyperCurie engine would be capable of performing a single maneuver to accomplish the same delta-v, so combined the two.
The next and final burn is designed to set CAPSTONE on a ballistic lunar transfer trajectory to the Moon travelling at 24,500 mph (39,400 km/h) to break free of Earth’s orbit. This final maneuver is currently scheduled to take place as early as July 4th. After separating from Lunar Photon, CAPSTONE will use its own propulsion and the Sun’s gravity to navigate the rest of the way to the Moon, a four-month journey that will have CAPSTONE arriving to its lunar orbit on Nov. 13.
Designed and built Terran Orbital, and owned and operated by Advanced Space on behalf of NASA, the Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment (CAPSTONE) satellite will be the first spacecraft to test the Near Rectilinear Halo Orbit (NRHO) around the Moon. This is the same orbit intended for NASA’s Gateway, a multipurpose Moon-orbiting station that will provide essential support for long-term astronaut lunar missions as part of the Artemis program. CAPSTONE was successfully launched to space on Rocket Lab’s Electron launch vehicle on June 28.
Missing 13-year-old Edmonton girl found alive in Oregon, 41-year-old man arrested
People planning to attend AIDS conference in Montreal still struggling to get visas
‘Genshin Impact’ V2.8 Primogem Gift Codes, Plus New Banners And Diluc Skin – Forbes
Silver investment demand jumped 12% in 2019
Europe kicks off vaccination programs | All media content | DW | 27.12.2020 – Deutsche Welle
Global Media Markets, 2015-2020, 2020-2025F, 2030F – TV and Radio Broadcasting, Film and Music, Information Services, Web Content, Search Portals And Social Media, Print Media, & Cable – GlobeNewswire
Health23 hours ago
Mysterious staggering disease in cats down to previously unknown virus – New Scientist
Health24 hours ago
Monkeypox symptoms differ from previous outbreaks, U.K. study says – The Globe and Mail
News23 hours ago
Canada Day enforcement in Ottawa sees 284 parking tickets issued as protesters return – CBC.ca
News24 hours ago
How B.C. marked Canada Day 2022 — in pictures – CBC.ca
Tech3 hours ago
TCL 30 XE 5G Smartphone Review – CGMagazine
Sports22 hours ago
Raptors sign forward Otto Porter Jr. to 2-year deal: reports – CBC.ca
Science21 hours ago
2022-07-01 | NDAQ:RKLB | Press Release | Rocket Lab USA Inc. – Stockhouse
Economy12 hours ago
Quarterly Investment Guide 3Q 2022: US economy on shaky ground – CNBC