facula with sunspot The relevant light spots are composed of bright fibers, 5000 to 10000 kilometers wide and 50000 kilometers long, which are roughly perpendicular to the equator; The spots unrelated to sunspots appear in the high latitude area of 70 °, with a small area, slightly circular, a diameter of about 2300km, and an average life of only half an hour. The spot appears several hours or days earlier than the sunspot, and then gathers into two parts, showing that Sunspot group allied dipole characteristic. sunlight Poor autorotation Gradually pull the initially circular spot into an ellipse, with its leading part slightly close to the equator. The light spot decomposes into many small pieces at the end of development, and then gradually collapses. Like sunspots, light spots have an activity cycle of 11 years, but their latitude activity range is about 15 ° wider than sunspots. The spectrum of the spot shows that its ion spectral line ratio photosphere Strong, and Neutral atomic spectral line It is weaker than the photosphere, so the temperature of the spot is higher than the photosphere. But the light spot and the light sphere Total radiation Strength ratio following separation center of the sun This indicates that the light spot is not in the radiation balance, and its bottom temperature is lower, while the upper temperature is higher. The upper layer of the light spot is seen near the edge of the solar surface. Its average temperature is about 100 degrees higher than the surrounding area, and its brightness is about 10% higher. The magnetic field of the light spot is mainly longitudinal, and the intensity reaches hundreds of gauss. Light spot, also refers to a light spot formed when light, moonlight, sunlight, etc. project on the water surface or ground. It is called light spot.
Solar flare In forestry, it refers to the round light surface projected to the ground through the gaps between the branches and leaves of the tree crown. The composition of the light spot in the forest is slightly different from the direct light in the open land, but the intensity is weakened. Due to the rotation of the earth and the swing of the branches and leaves, the light spot often moves on the ground, and the irradiation time is also short, and sometimes appears. The light spot in the forest has certain influence on the growth of understory plants, young trees and rugby soil. [4]
Uncover the source of mysterious light spot on the surface of Ceres: or it was once the "eruption point" of ice volcano [5]
Ceres has a mysterious impact crater, which contains some extremely bright materials. Scientists believe that this may have been the "eruption point" of ice volcanoes. In a recent study, scientists found that these bright spots on Ceres were only four million years old, 30 million years later than their impact craters.
The diameter of Kereis crater is 92 kilometers. There is a huge hemispherical structure in the crater, which "contains Ceres The brightest substance on the. Thomas Platz, a scientist at Max Planck Solar System Research Institute, pointed out that. The visible/infrared spectrometer data of Cerealia Facula area shows that the area is rich in carbonate. The researchers said that there is a rugged uplift structure in the hole in the center of the impact crater, which may be the traces left by the ancient mountains. Scientists believe that the mountain range formed at the same time as the Kereis impact crater about 34 million years ago, and finally gradually collapsed. However, the researchers pointed out that the formation of hemispherical structures containing bright materials was 30 million years later.
Sina Science and Technology News On March 20, Beijing time, according to foreign media reports, there is a mysterious impact crater on Ceres, which contains some extremely bright substances. Scientists believe that this may have been the "eruption point" of ice volcanoes. [5]
In a recent study, scientists found that these bright spots on Ceres were only four million years old, 30 million years later than their impact craters. The distribution and properties of this rare bright material indicate that they are caused by repeated astronomical activities. It can be seen that Ceres is the nearest celestial body to the sun with iceberg activity.
NASA's Dawn probe Ceres has been studied for nearly two years. During this period, scientists found some strange bright spots in the Crater, which are mainly composed of mineral salts. In order to better understand the geological activities of this asteroid, scientists from the Max Planck Institute for Solar System Research recently carried out an investigation of the geological structure in the impact crater, including cracks, collapsed rocks, and even smaller impact craters.
Kereis crater is 92 kilometers in diameter. There is a huge hemispherical structure in the crater, which "contains the brightest material on Ceres". Thomas Platz, a scientist at Max Planck Solar System Research Institute, pointed out that.
The visible/infrared spectrometer data of Cerealia Facula area shows that the area is rich in carbonate. In addition, bright spots elsewhere in the crater also contain carbonate and a black substance. [5]
The researchers said that there is a rugged uplift structure in the hole in the center of the impact crater, which may be the traces left by the ancient mountains. Scientists believe that the mountain range formed at the same time as the Kereis impact crater about 34 million years ago, and finally gradually collapsed.
However, the researchers pointed out that the formation of hemispherical structures containing bright materials was 30 million years later.
Scientists judge the formation time of geological structure by the degree of "perforation" on its surface. The later the crater is formed, the less surface perforation occurs. [5]
"The age and appearance of the materials around the hemispherical structure all indicate that the Cerealia Facula area was formed through repeated ice volcano eruptions, which also ejected these materials to the peripheral area of the central hole." Andreas Nathues of Planck Research Institute pointed out that "a single eruption of an iceberg is unlikely to cause this result."
Some celestial bodies have similar hemispherical structures, such as Ganymede and Callisto. Scientists believe that these are the traces left by volcanic eruptions, indicating that there are icebergs on these celestial bodies. They also pointed out that Ceres may have experienced a similar process.
"The huge collision that formed the Kereis impact crater must be the beginning of all events, and it also gave birth to the subsequent ice volcanism."
Scientists pointed out that after the impact, the underground water level of Ceres rose.
In addition, water and dissolved methane carbon dioxide Such gases can escape from the forming vent, and finally eject from the cracks on the surface of Ceres. [5] The researchers said that the mineral salts deposited in this process may be the source of the bright spots we see today.
The pictures of the Kereis impact crater taken from 14000 kilometers away show that the brightness of these bright spots has a diurnal rhythm, which provides evidence for a new theory.
"The light scattering mode at the bottom of the Ceres impact crater is obviously different from other areas on the surface of Ceres," pointed out Guneshwar Singh Thangjam of the Max Planck Solar System Research Institute, "the most likely explanation is that there is a thin, translucent water mist near the bottom of the impact crater." [5]
The researchers said that this water mist may be formed by the sublimated water vapor escaping from the surface fissure in the impact crater under the sunlight. [5]
