An international team of scientists led by Cornell University in the United States monitored the universe through a radio telescope array and detected radio bursts from the constellation Boves. This signal may be the first radio pulse collected from a planet outside the solar system. The research results were published in the “Astronomy and Astrophysics” magazine on the 16th.
Using the low-frequency array of radio telescopes in the Netherlands, the researchers found that the exoplanet system, which is about 51 light-years away from the solar system, the Boeus τ system (containing a binary star and an exoplanet), shows an important radio signal. This is a unique and potential window into the planet’s magnetic field.
“This is one of the first clues we have proposed for the detection of exoplanets in the radio field,” said Jack D. Turner, one of the research team leaders and a postdoctoral researcher at Cornell University. “We think this is launched by the planet itself. Yes. Judging from the intensity and polarization of radio signals and planetary magnetic fields, this is consistent with theoretical predictions.”
Ray Jayawardhanna, one of the co-authors of the paper, said, “If confirmed by follow-up observations, the detection of this radio burst will open a new window for us to observe exoplanets, and also provide us with an exploration A new approach to the alien world decades away.”
Turner said that observing the magnetic fields of exoplanets helps astronomers decipher the planet’s interior and its atmospheric properties, as well as the physics of the interaction between stars and planets. “The magnetic field of terrestrial exoplanets protects the atmosphere from solar wind and The influence of cosmic rays makes them more habitable.”
Two years ago, researchers detected Jupiter’s radio radiation signals and scaled these radiations to simulate possible signals from distant Jupiter-like exoplanets. These results serve as templates for searching for radio radiation from exoplanets 40 to 100 light-years away. After carefully studying the results of nearly 100 hours of radio observations, the researchers found the out-of-system radio “Jupiter” in the τ system in Boves.
But on the other hand, scientists believe that the radio signal is very weak this time, and there is still great uncertainty in its source, so follow-up observations are still crucial.
Tianwen-1 completed the fourth midway correction of its orbit and returned the first image of Mars
At 20 o’clock on February 5, 2021, the engine of the first Mars exploration mission Tianwen-1 probe was ignited, and the fourth midway correction of the ground fire transfer section was successfully completed to ensure that Mars capture was carried out as planned.
Up to now, Tianwen-1 has been in orbit for about 197 days, about 184 million kilometers away from Earth, about 1.1 million kilometers away from Mars, and a flight mileage of about 465 million kilometers. The probe systems are in good condition.
Prior to this, Tianwen-1 acquired the first Martian image at a distance of about 2.2 million kilometers from Mars.
The potential mass range of dark matter is narrowed, helping to focus the search area
According to a report by the physicist organization network on the 27th, British scientists used the fact that gravity acts on dark matter to fundamentally calculate the mass range of dark matter for the first time. This range is much narrower than previously thought. The latest research has narrowed the range of potential masses of dark matter particles and also limited the search range for future dark matter “catchers”. It will also help scientists discover potential new forces in the future.
Dark matter does not emit light, emit electromagnetic waves, does not participate in electromagnetic interactions, and cannot be directly “seen” with any optical or electromagnetic wave observation equipment. Scientists have confirmed its existence through the effect of dark matter on galaxies. The result of the cosmic microwave background radiation observation experiment gives the proportion of dark matter in the total amount of cosmic matter. In the universe, ordinary matter accounts for only 4.9%, dark matter accounts for 26.8%, and dark energy accounts for 68.3%. Dark energy and dark matter are also considered to be two dark clouds in the physics sky at the beginning of the 21st century.
In the latest study, the research team led by Professor Xavier Kalmot of the School of Mathematics and Physical Sciences at the University of Sussex assumed that gravity is the only force acting on dark matter, and calculated that the mass of dark matter particles is between Between 10-3eV (electron volt) and 107eV, it is much narrower than the theoretically expected 10-24eV to 1028eV.
“This is the first time anyone has used quantum gravity to calculate the mass range of dark matter,” Carmott said. This study shows that unless there is a hitherto unknown force affecting it, dark matter cannot be like some theories. It is said to be “ultralight” or “overweight”.
The researchers believe that this research will benefit physicists in two ways: one is to focus on the search area of dark matter; the other is to help reveal whether there are mysterious unknown forces in the universe-if the mass of dark matter is found to exceed in the future The range predicted by the Sussex team indicates that dark matter is affected by other forces in addition to gravity.
The collapse of some marine species: sea surface temperatures continue to rise under multiple pressures
A zoology study published on the 28th in the British “Nature” magazine pointed out that some marine species are facing a crisis of “population collapse”-since 1970, the number of marine slatyfish in the world has decreased by 71%. Among these marine species, More than three-quarters of them are on the verge of extinction; and another study published at the same time pointed out the “climate crisis” of the ocean: global sea surface temperature has been rising for the past 12,000 years.
The ocean is facing multiple pressures. Issues such as climate change, rising sea temperature, pollution, overfishing, and ocean acidification have been affecting the health of the ocean. Scientists currently believe that the risk of marine species extinction should mainly come from overfishing. However, the reduction of individual species has always been difficult to measure. Although the reduction of marine and coastal plategill fish populations in different regions of the world has been recorded before, there has been no global development. analysis.
This time, the Simon Fraser University team in Canada estimated the relative abundance of 18 marine slaty fish species from 1970 to 2018 and assessed the extinction risk of all 31 marine slaty fish species. They found that from 1970 to 2018, the global abundance of marine slaty fish fell by 71.1%. Among these 31 species, 24 are on the verge of extinction; 3 shark species have declined especially, and are now classified as critically endangered—this is also the most threatened species in the World Conservation Union (IUCN) list The grade.
The researchers blamed the reduction of these species on fishing pressure, which increased 18 times during this period. The research team pointed out that immediate action should be taken to prevent “population collapse”, and specifically called on governments to implement fishing restrictions to help promote species recovery.
In the climate report published on the same day by the journal Nature, the Rutgers University of New Jersey team pointed out the “climate crisis” of the ocean. According to the report, the global average annual sea surface temperature has been rising for the past 12,000 years.
The researchers reinterpreted the two latest climate models this time and devised a method to assess the seasonal deviation of a single record, and then calculate the annual average sea surface temperature. They found that climate warming from 12,000 to 6,500 years ago was caused by the retreat of the ice sheet, while recent warming was caused by the increase in greenhouse gas emissions. The current temperature is the highest in the past 12,000 years. The temperature was similar during the last interglacial period about 125,000 years ago.
In addition to suggesting that emissions have caused the sea surface temperature to continue to rise, this study also fills a long-standing gap in the gap between climate models and data used to reconstruct historical climate changes in the Holocene.