A new theory claims that it is Raining on our Sun
Sun experiences plasma precipitation in form of mist as well as vicious showers.
The sun of our solar system is quite consistent in comparison to some other stars of the Milky Way. The size and brightness of some of these stars vary so abruptly that it ends up in a vicious explosion. Our sun is very stable as the amount of its light varies only by 0.1% in a relatively longer solar cycle which spreads over a period of 11 years. Greg Kopp, a Solar Physicist at the University of Colorado, told the world that such a small quantity of sun’s light exceeds all other natural sources of energy in the following words:
“The light reaching the top of the Earth’s atmosphere provides about 2,500 times as much energy as the total of all other sources combined.”
Despite the stability, events of eruption are common on the surface of our star but they are extremely different in terms of their intensity. Some of them are simply accompanied by a solar flare while others may result in a ‘Coronal Rain’, where an additional ejection of solar material called Coronal Mass Ejection (CME) is observed. In extreme cases, movement of complex structures and the changes in the magnetic field loop them into the sun’s atmosphere. This phenomenon is referred to as the ‘Corona’.
An eruption led to all three of them simultaneously on 19th July 2012. The explosion of a moderately powerful solar flare on the right lower limb of the sun-generated substantial amounts of light and radiation. The explosion was followed by a CME which rocketed into space. This offered a magnificent display of a Coronal Rain to the viewers. The Atmospheric Imaging Assembly Instrument of Solar Dynamics Observatory of NASA was used to record these amazing scenes. The footage showed that the hot plasma cooled and condensed along strong magnetic fields in the region. This plasma was visible quite clearly in strong ultraviolet radiations which have the ability to highlight materials that are at a temperature of about 50,000 Kelvin.
Interface Region Imaging Spectrograph (IRIS) of NASA observed another instance of rain on Sun on 24th July 2016. A continuous bombardment of flares releases a fairly large amount of magnetic energy which heats up the atmosphere of the sun. As a result, energized particles are thrown away into space. IRIS also recorded beautiful scenes of Coronal Rain as plasma settled down on the solar surface. Scientists lack any logical explanation for this. Having said that, missions like IRIS helps humanity to figure out the movement patterns of solar materials in the lower atmosphere of our star.
According to the latest data gathered in this regard, a Coronal Rain can fall in form of a mist as well as showers because it turns up in the most unexpected places. Researchers believe that the movement patterns of plasma might solve the mystery of why Corona is so hot. The rain on the sun is very much similar to what we experience on Earth except for the fact that plasma replaces water in case of our star. Hot plasma condenses and falls back to the solar surface once it reaches a cooler part of the Corona. This relates to Earth as hot air condenses into clouds to form water droplets that fall down on Earth in form of rain. Emily Mason, a Solar Physicist at the Catholic University of America, presented these new observations of Coronal rain by saying,
“The physics is literally the same.”
One of her colleagues, Spiro Antiochos, suggested that ‘Tall Streamers’, which can go as high as 6 solar radii above the surface of the sun, could be cooler at their tip than their base so they should be full of rain. Mason analyzed the recordings of the Solar Dynamics Observatory of NASA in order to search bright blobs of plasma falling within the Tall Streamers but all her efforts went in vain as she found nothing. However, she found rain showers in ‘Null-point Topologies’ which create much smaller loops. Coronal rain fell for 30 hours in one of these loops which stretch only 0.1 solar radii above the solar surface. Mason summed it up beautifully as she said,
“These things rain like crazy.”