![sun corona hotter sun corona hotter](https://www.esa.int/var/esa/storage/images/esa_multimedia/images/2015/03/solar_corona_viewed_by_proba-2/15310257-1-eng-GB/Solar_corona_viewed_by_Proba-2_pillars.png)
“It’s sort of like if you’re sampling the atmosphere here on Earth – you don’t need to point at a particular direction,” Dantzler said. Hotter inner layer will be brighter than the cooler outer layer. The whole spacecraft is optimally designed to dissipate heat,” Dantzler told New Scientist.Īnd because the spacecraft will be embedded inside the corona, instruments don’t ever have to point directly at the Sun. The corona extends outwards for more than a solar radius. “It’s not your run-of-the-mill spacecraft. The side of the shield facing the Sun will heat up to 1400 ☌elsius (2600 ☏), while the instrument-carrying payload behind the shield will remain at room temperature, said Solar Probe project manager Andrew Dantzler. The heat shield technology is based on that used in Messenger, a NASA spacecraft that completed its first flyby of Mercury in January and that was also designed by engineers at APL. The mini-bus sized Solar Probe will be protected from the Sun’s fierce radiation by a disc-shaped, carbon-composite heat shield that will be 2.7 metres in diameter and about 15 centimetres thick. But scientists have only recently been able to design heat shields for such a spacecraft within NASA’s tight budgetary guidelines. On the other hand, with a suitably complex non-LTE computational model, it should only be a matter of properly implementing the relevant physical processes, as indicated above, with the the required fine detail such as to reproduce the main features of the solar corona, that is without need for any exotic physical processes.The idea of studying the Sun at close range was first proposed by the US National Academy of Science in 1958. Why the corona is up to 300 times hotter than the. As the gases cool, they become the solar wind.
![sun corona hotter sun corona hotter](https://cdn.mos.cms.futurecdn.net/Pa42K2fYULDTzNmdi9z7c9-1200-80.jpg)
So, as this is very much a non-LTE problem (given the huge energy range of about a factor 1000 involved), the attempt to address this with methods of thermodynamics (as is usually done), are destined to yield wrong answers and/or result in just more questions. Temperatures in the sun's corona can get as high as 3.5 million degrees F (2 million degrees C). The hot coronal plasma is just likely due to the few plasma particles that make it through the photosphere without being slowed down by inelastic collisions. This defines the 'surface' of the Sun with its low temperature (which corresponds actually almost exactly to a cooling factor (electron mass/proton mass). The photosphere is the region where the density (which decreases outwards) has become low enough for atoms to exist, which then in turn cool the plasma due to inelastic collision. Edln and Grotrian’s finding that the Sun’s corona is so much hotter than the photosphere despite being further from the Sun’s core, its ultimate source of energy has led to much head-scratching in the scientific community. CHINA is on course to finish building an 'artificial sun' before the end of the year, local media reports. Below the photosphere the density is too high for atoms to exist (the interior of the sun is just a plasma of bare nuclei and electrons). Over many decades of study, the photosphere’s temperature has been consistently estimated at around 6,000C. So the question should rather be: why is the temperature in the photosphere so low? There are no complicated theories needed to answer this, as cooling of a gas is always due to inelastic collisions, in this case the inelastic collisions of high energy ions and electrons with neutral atoms, which turn the high kinetic energy of the plasma into radiation.
![sun corona hotter sun corona hotter](https://3c1703fe8d.site.internapcdn.net/newman/csz/news/120/2017/59dcc1a035075.jpg)
The problem is actually more likely the other way around: the temperature of the corona is pretty much the natural temperature of the Sun, reflecting its gravitational potential energy (corresponding to about $10^7 K$).