Chinese Meridian Project reveals: Storm-time ionosphere collapse disrupts HF radio propagation
Peer-Reviewed Publication
Updates every hour. Last Updated: 7-Sep-2025 04:11 ET (7-Sep-2025 08:11 GMT/UTC)
A recent study published in National Science Review has revealed an extreme ionospheric electron density depletion and the pronounced hemispheric asymmetry during the May 2024 geomagnetic storm. The near-total depletion of ionospheric electrons caused widespread failures in high-frequency radio wave propagation. This research provides critical observational evidence from CMP and modeling insights into the ionosphere's response to extreme space weather, advancing understanding of the physical processes of magnetosphere-ionosphere-thermosphere coupling.
Kyoto, Japan -- The size of our universe and the bodies within it is incomprehensible for us lowly humans. The sun has a mass that is more than 330,000 that of our Earth, and yet there are stars in the universe that completely dwarf our sun.
Stars with masses more than eight times that of the sun are considered high mass stars. These form rapidly in a process that gives off stellar wind and radiation, which could not result in stars of such high mass without somehow overcoming this loss of mass, or feedback. Something is feeding these stars, but how exactly they can accumulate so much mass so quickly has remained a mystery.
Observations of enormous disk-like structures that form around a star -- accretion disks -- had been proposed as the chief way of rapidly feeding young stars. However, a team of researchers from several institutions including Kyoto University and the University of Tokyo, has discovered another possibility.
A new national study led by researchers from Carleton University and the University of Toronto reveals that older adults living in greener neighborhoods were less likely to experience depression during the early months of the COVID-19 pandemic.
Astronomers from Chalmers University of Technology, Sweden, have discovered a vast and expanding bubble of gas and dust surrounding a red supergiant star – the largest structure of its kind ever seen in the Milky Way. The bubble, which contains as much mass as the Sun, was blown out in a mysterious stellar eruption around 4000 years ago. Why the star survived such a powerful event is a puzzle, the scientists say.
The new results are published in the scientific journal Astronomy and Astrophysics, and the team was led by Mark Siebert, Chalmers, Sweden. Using the ALMA radio telescope in Chile, the researchers observed the star DFK 52 – a red supergiant similar to the well-known star Betelgeuse.