One of this year's largest mass ejections from the Sun's atmosphere was recorded last Sunday by TESIS telescopes aboard the CORONAS-PHOTON satellite (video - wmv 4.3 MB). The source of the ejection was the active area currently located on the far side of the Sun, which is, as yet, invisible from Earth. In total, approximately 103-106 million tons of ionized gas was released into interplanetary space.
The last time events of this size were observed on the Sun was approximately two months ago in mid-April of this year. Over the course of a week, two gigantic solar prominences were simultaneously ejected from the surface of the Sun. At least one of these succeeded in breaking away from the Sun's gravitational field and entered interplanetary space. The Sun then sent its "warmest regards" to the planets of Mercury and Mars, which found themselves in the path of the ionized matter stream.
Although it is not always possible to predict the motion trajectory of solar ejections, on this occasion we can be confident that the stream will pass by at a great distance from our closest neighbouring planets. The fact is that all of Earth's neighbours (Mercury, Venus and Mars) are now located to the west of the Sun and are visible in the sky has morning planets, while the burning hot plasmoid was ejected on a path in the opposite direction (from the eastern surface of the Sun). Earth will not feel the Sun's influence either. Although the angular domain, from which the solar prominences came, is located not far from us, the lines of the interplanetary magnetic field are not directed at Earth, but are rather pointing away from us. The solar prominence will veer and decline in this same direction as it moves away from our planet.
Solar prominences are one of the most beautiful formations observable within the Sun's atmosphere and capture the imagination both with their size and variety of forms. Ionized matter in the solar corona always produces recurring forms of magnetic field configurations: plasma appears to spread along the hidden lines of the magnetic field, illuminating them and making them visible to us for observation. Thus, solar prominences are of interest not only as displays of solar activity, but also provide a visual means of investigating the structure and dynamics of the Sun's magnetic fields. This time the telescopes were able to photograph a gigantic magnetic arch within the Sun's corona, which reached a height of over 600,000 km - twice that of the distance from Earth to the Moon.
The problem of the interaction between solar prominences and the Sun's magnetic field is one of the most interesting in modern solar physics. As yet it is not fully understood whether the upwards movement of solar prominences is caused by processes in the Sun's magnetic fields (the fields holding the plasma in place change shape and open up a path for the prominence to enter interplanetary space) or whether matter rises to the surface "independently", breaking its way through the magnetic structures constraining it - disrupting and stretching them.
It will only become possible to observe the active area responsible for the formation of one of this year's largest mass ejections in 2-3 days time when it comes into the Earth's line of sight due to solar rotation.
