In addition to being the largest and most powerful object in the solar system, the sun is one of the most mysterious entities in our cosmic neighborhood, making it difficult for researchers to determine exactly how it works. We're constantly learning new things about our home stars, and 2023 is no exception. From learning more about the upcoming solar maximum, to spotting ancient superflares and mysterious heartbeat signals, here are the top 10 things we learned about the Sun this year.
During the solar maximum (left), the Sun is more chaotic than the solar minimum (right). (*NASA Solar Dynamics Observatory).
The main news about the Sun this year is that we are rapidly approaching the Sun maximum, which will be more **** than we initially thought.
Back in 2019, at the beginning of the current solar cycle, space meteorological scientists** indicated that the solar maximum would begin in 2025, relatively weak compared to past solar cycles. However, many warning signs at the beginning of the year, including a rise in sunspot numbers, powerful X-magnitude solar flares and changes in Earth's upper atmosphere, suggest that the solar cycle is not developing as expected.
In June, Live Science published an exclusive in-depth feature on the upcoming solar maximum, which showed that the peak could arrive in 2024 and be more active than the initial one. In October, space weather scientists released an update on the current solar cycle, which is more in line with what experts are telling Live Science.
When the solar maximum arrives, we can expect to be bombarded by more solar storms, which will cause frequent aurora displays, radio blackouts, potential satellite issues, and disruption of some animal migration patterns.
The sun may not be as big as we think. (*EVE, HMI Science NASA SDO, and AIA team).
A study published in November showed that the outer edge of the sun's atmosphere, or corona, is not as far away as we previously thought.
Until recently, the best way to measure the Sun's corona was to observe it during a solar eclipse, when it became clearly visible around the Moon. But new technology allows scientists to measure oscillations or waves that pass through the corona. These waves do not travel as far as expected.
The difference between the new findings and previous estimates is relatively small: the Sun may be 003% to 007%。However, scientists say this could have a significant impact on the way we study stars.
Researchers have found that the sun can produce an aurora-like phenomenon above sunspots. (*Sijie Yu).
Within the solar system, aurora was previously thought to occur only on a few planets and moons. But a study in November showed that the sun also has aurora (although they are slightly different from the ones we see on Earth).
Astronomers, after pointing a radio telescope at sunspots, detected radio bursts crackling above sunspots. The frequency of radio waves is very similar to the wavelengths emitted by the aurora on Earth, which strongly suggests that a similar process is taking place on the Sun.
On Earth, auroras are created when solar storms and solar winds hit our planet and temporarily weaken our magnetic shield, which allows radiation from the sun to excite gas molecules in the upper atmosphere. However, researchers believe that the solar aurora is produced by electrons that accelerate along the Sun's magnetic field lines to incredible speeds.
14,000 years ago, a super-powerful solar flare slammed into our planet, and the rings of ancient trees show. （*getty images）
In October, researchers revealed that about 14,000 years ago, a super solar storm known as the Miyake Incident hit Earth. Experts say it could be the most powerful solar eruption ever to hit Earth.
Researchers have found evidence of a lurking cataclysmic event in the fossilized tree rings recently unearthed in the French Alps. The preserved plants all had extraordinary levels of radiation in the same ring, suggesting that they all absorbed radiation at the same time – and only the powerful Miyake event could explain the radiation levels found by the research team.
A solar storm like this today would be catastrophic for our modern technological society," the researchers wrote.
Researchers claim that ancient "superflares" may have sparked life on Earth. (*NASA Goddard Space Flight Center).
Continuing the age-old trend of solar storms, a May study showed that "superflares" from the early overactive sun may have provided the energy needed to spark life on Earth billions of years ago.
Researchers reconstructed the Earth's early atmosphere in the laboratory and emitted **charged particles in the original gases, like those found in the solar wind, and found that this created amino acids and carboxylic acids - proteins and the building blocks of all organic life.
Similar experiments to reproduce lightning have also created these compounds in the laboratory. But the team argues that lightning strikes won't provide as much power as superflares, making them less suitable for kick-starting life on Earth.
However, more work needs to be done before any specific conclusions can be drawn.
The neutrinos spewed out by the sun may lead us to a hidden treasure trove of dark matter. （*christopher dessert、nicholas l. rodd、benjamin r.Artistic rendering by Safdi and Zosia Rostomian (Berkeley Laboratory) based on data from the Fermi Large Area Telescope.
A preprint** published in August suggests that the sun, which may be hiding hidden particles of dark matter in its red-hot internal organs and neutrinos, or "ghost particles" spit out by the sun, may be the key to finding them.
Dark matter is an elusive substance, and its identity remains a mystery to scientists. Dark matter rarely interacts with conventional matter or light, but when it does, it theoretically emits neutrinos, which have little mass and no electric charge.
The researchers speculate that the Sun's core may contain high concentrations of dark matter, and if that's the case, they occasionally emit slightly more neutrinos than normal. However, so far, these extra neutrinos have not been detected.
Ancient texts from Korea indicate that the solar cycle of the sun used to be much shorter. （*yan et al. 2023）
Currently, it takes about 11 years for the Sun to complete a solar cycle, during which time it transitions from solar minima to solar maximum and back again. But a preprint** published in June suggests that past cycles may have been much shorter.
The researchers studied ancient documents unearthed in Korea that detailed the display of the aurora during the Mondstadt minimum, a period of reduced solar activity between 1645 and 1715. They found that the solar cycle during this period may have lasted only eight years.
However, scientists have not been able to properly explain why the solar cycle shortened during this period.
Scientists have finally figured out what caused the mysterious heartbeat signal from a solar flare. (*National Radio Astrophysics Center).
For more than a decade, scientists have pondered the origins of a mysterious heartbeat-like pattern in the stream of electromagnetic radiation emanating from the sun during solar flares.
The stream of radiation, known as a solar radio burst, usually flows out of the sun without stopping. But sometimes, there are fluctuations or gaps in the flow, called quasi-cyclic pulsations, and when viewed on a graph, they look similar to an electrocardiogram (ECG or EKG) of the human heart.
Earlier this year, scientists studied some mysterious patterns produced during a solar flare in 2017. They found that these patterns are generated by fluctuations within invisible current fields that pass through plasma loops on the surface of the sun.
Previously unknown spots of plasma are raining through the sun's corona. （*patrick antolin。Background**: ESA Solar Orbiter EUI HRI).
In July of this year, scientists announced the discovery of a new feature in the solar corona - meteors.
These "stars" are clumps of plasma that pass through the Sun's upper atmosphere, like meteors falling to Earth, because they are colder than the surrounding plasma and therefore denser.
These dense plasma spheres can reach up to 435 miles (700 km) and appear to fall along the magnetic field lines created on the surface of the Sun. Scientists refer to this phenomenon as coronal rain.
The solar wind is constantly flowing out of the sun. （*nasa/gsfc）
In August, scientists were one step closer to finally unraveling the origin of the massive amount of solar particles emanating from the sun's corona, known as the solar wind.
The European Space Agency's Solar Orbiter has discovered tiny plasma jets, called picojets, that shoot out from tiny black dots on the Sun, called coronal holes. Mini-jets are smaller than other solar-powered jets, but still punchy, and researchers believe they provide the necessary energy to trigger solar wind gusts.
Picojets could also explain why the outer corona is hotter than scientists expected.