When the first object ever known to have visited the Earth's Solar System from outer space zoomed past in 2017, it was so strange that at least one leading astronomer was convinced it was an alien vessel.
Planetary Sciences
Mar 26, 2023
6
90
In 2017, a mysterious comet dubbed 'Oumuamua fired the imaginations of scientists and the public alike. It was the first known visitor from outside our solar system, it had no bright coma or dust tail, like most comets, and ...
Astronomy
Mar 22, 2023
0
456
The number of exploding stars (supernovae) has significantly influenced marine life's biodiversity during the last 500 million years. This is the essence of a new study published in Ecology and Evolution by Henrik Svensmark, ...
Evolution
Mar 21, 2023
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135
Florence was a flourishing center for fundamental physics research throughout most of the twentieth century. Roberto Casalbuoni, Daniele Dominici and Massimo Mazzoni—all physicists currently working there—have reviewed ...
General Physics
Feb 13, 2023
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8
Astronomers have not yet been able to map large portions of the radio emissions from our universe because of interference from the Earth itself. A team of astronomers hopes to change that, beginning with the LuSEE Night mission ...
Astronomy
Jan 31, 2023
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15
Using the High Energy Stereoscopic System (HESS), German astronomers have investigated a very-high-energy (VHE) gamma-ray source known as HESS J1809−193. Results of the study, published January 18 on the arXiv preprint ...
Cosmic rays (CR) constitute high-energy particles that mainly originate outside our solar system. These primary CR interact with interstellar matter to produce secondary CR. The secondary nature of their origin is reflected ...
Astronomy
Jan 26, 2023
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29
Citizen science projects offer the general public, or segments of that public such as school students, an opportunity to take part in scientific research. The Extreme Energy Events (EEE) Project in Italy is a cooperation ...
Astronomy
Jan 20, 2023
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14
The chemistry of planet formation has fascinated researchers for decades because the chemical reservoir in protoplanetary disks—the dust and gas from which planets form—directly impacts planet composition and potential ...
Astronomy
Jan 10, 2023
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70
How are galaxies born, and what holds them together? Astronomers assume that dark matter plays an essential role. However, as yet it has not been possible to prove directly that dark matter exists. A research team including ...
General Physics
Dec 12, 2022
0
475
Cosmic rays are energetic particles originating from outer space that impinge on Earth's atmosphere. Almost 90% of all the incoming cosmic ray particles are protons, almost 10% are helium nuclei (alpha particles), and slightly under 1% are heavier elements and electrons (beta minus particles). The term ray is a misnomer, as cosmic particles arrive individually, not in the form of a ray or beam of particles.
The variety of particle energies reflects the wide variety of sources. The origins of these particles range from energetic processes on the Sun all the way to as yet unknown events in the farthest reaches of the visible universe. Cosmic rays can have energies of over 1020 eV, far higher than the 1012 to 1013 eV that man-made particle accelerators can produce. (See Ultra-high-energy cosmic rays for a description of the detection of a single particle with an energy of about 50 J, the same as a well-hit tennis ball at 42 m/s [about 94 mph].) There has been interest in investigating cosmic rays of even greater energies.
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