Voyager 1—one of two sibling NASA spacecraft launched 44 years ago and now the most distant human-made object in space—still works and zooms toward infinity.
Astronomy
May 10, 2021
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(Phys.org)—As if space travel was not already filled with enough dangers, a new study out today in the journal PLOS ONE shows that cosmic radiation – which would bombard astronauts on deep space missions to places like ...
Space Exploration
Dec 31, 2012
119
0
Scientists at Harvard University and the Black Hole Initiative (BHI) have developed a new method to find black holes in the outer solar system, and along with it, determine once-and-for-all the true nature of the hypothesized ...
Astronomy
Jul 10, 2020
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A mass of solar material that erupted from the sun on Oct. 9, 2021, reached Earth on Oct. 12. The Earth-directed coronal mass ejection, or CME, elevated the Kp index, a measure of disturbance to Earth's magnetic field, to ...
Planetary Sciences
Oct 14, 2021
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303
(Phys.org)—A nearby short duration gamma-ray burst may be the cause of an intense blast of high-energy radiation that hit the Earth in the 8th century, according to new research led by astronomers Valeri Hambaryan and Ralph ...
Astronomy
Jan 21, 2013
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A sunspot pointing toward Earth has the potential to cause solar flares, but experts told USA TODAY it's far from unusual and eased concerns over how flares would affect the Blue Planet.
Astronomy
Jun 22, 2022
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443
Powerful flares, breathtaking views across the solar poles, and a curious solar "hedgehog" are among the haul of spectacular images, movies and data returned by Solar Orbiter from its first close approach to the sun. Although ...
Astronomy
May 19, 2022
0
221
An international team of scientists has discovered a huge spike in radiocarbon levels 14,300 years ago by analyzing ancient tree-rings found in the French Alps.
Astronomy
Oct 9, 2023
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401
The sun emitted a significant solar flare peaking at 10:29 a.m. EDT on July 3, 2021. NASA's Solar Dynamics Observatory, which watches the sun constantly, captured an image of the event.
Space Exploration
Jul 6, 2021
3
463
Radioactive decay rates, thought to be unique physical constants and counted on in such fields as medicine and anthropology, may be more variable than once thought.
General Physics
Aug 31, 2010
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A solar flare is a big explosion in the Sun's atmosphere that can release as much as 6 × 1025 joules of energy. The term is also used to refer to similar phenomena in other stars, where the more accurate term stellar flare applies.
Solar flares affect all layers of the solar atmosphere (photosphere, corona, and chromosphere), heating plasma to tens of millions of kelvins and accelerating electrons, protons, and heavier ions to near the speed of light. They produce radiation across the electromagnetic spectrum at all wavelengths, from radio waves to gamma rays. Most flares occur in active regions around sunspots, where intense magnetic fields penetrate the photosphere to link the corona to the solar interior. Flares are powered by the sudden (timescales of minutes to tens of minutes) release of magnetic energy stored in the corona. If a solar flare is exceptionally powerful, it can cause coronal mass ejections.
X-rays and UV radiation emitted by solar flares can affect Earth's ionosphere and disrupt long-range radio communications. Direct radio emission at decimetric wavelengths may disturb operation of radars and other devices operating at these frequencies.
Solar flares were first observed on the Sun by Richard Christopher Carrington and independently by Richard Hodgson in 1859 as localized visible brightenings of small areas within a sunspot group. Stellar flares have also been observed on a variety of other stars.
The frequency of occurrence of solar flares varies, from several per day when the Sun is particularly "active" to less than one each week when the Sun is "quiet". Large flares are less frequent than smaller ones. Solar activity varies with an 11-year cycle (the solar cycle). At the peak of the cycle there are typically more sunspots on the Sun, and hence more solar flares.
This text uses material from Wikipedia, licensed under CC BY-SA
