It's not perfect some heat transfer occurs between sunshield and the body of the probe via thermal conductivity. The body would cool to a bit above 2.7 kelvins if the probe's sunshield was perfect. The temperature of the Sun's corona has almost nothing to do with how hot the body of the Parker Space Probe will get. What is relevant is that the Parker Space Probe will get much, much closer to the Sun than the roughly one astronomical unit distance between the ISS and the Sun. That the temperature of the Sun's atmosphere at that altitude is in the millions of degrees is as irrelevant to Parker Space Probe heating as is the temperature of the thermosphere with respect to ISS heating. The Sun's corona at an altitude of six million kilometers above the photosphere is orders of magnitude less dense than is the thermosphere through which the ISS orbits. The heat transfer between the thermosphere and the ISS is numerical noise. (The drag on the vehicle is a concern.) The Space Station's temperature instead represents a balance between the heat it gains in the form of sunlight versus the heat it loses in the form of thermal radiation into empty space.
Those high temperatures are not a concern because of the low density. It orbits in a low density medium whose temperature can reach as high as three thousand kelvins. It instead depends on how much electromagnetic radiation the object is absorbing / emitting, and on thermal conduction amongst parts of the macroscopic object.Ĭonsider the International Space Station. The temperature of a macroscopic object in space (e.g., a thermometer) has almost nothing to do with the temperature of the extremely thin medium that occupies that space. To the contrary, it would cool off, eventually reaching a temperature a tiny bit about 2.7 kelvin. However, a macroscopic thermometer in this hot medium would not get anywhere close to those high temperatures. The temperature of the extremely sparse intergalactic medium can be in the hundreds of millions of kelvins. To take matters to an even greater extreme, consider the intergalactic medium. You are missing something basic here, which is that the Sun's corona is rather sparse. So what it really means when we say the temperature of corona is at 2 million degrees Fahrenheit - say, if we place a thermometer in the corona (that can measure extreme levels), will that read 2 million degrees or 2,500 degrees?Ĭan someone help me understand in layman terms? or am I missing something very basic here? I can understand the oven vs boiling water comparison in the above link, but then does that mean there will not be any high temperature contact at all during the corona fly-through or those few high temperature particles will not damage the probe? Or even if it is very few particles that contact the probe, won't they still damage the probe because of the high temperature at 2 Million degrees? I am not quite not getting the science that explains the Heat Vs Temperature, which is how the Parker probe is going to survive the corona of Sun.
Although the short mission duration still leaves many unanswered questions about coronal heating, the new results are a key breakthrough in understanding the solar corona and its behavior.This is not about about heat shields, materials, coolant, etc. Writing in the last issue of the journal Nature, the astronomers report that the sizes and activity of the braids they observe are in agreement with the properties needed for the magnetic heating theory to be correct. The rocket flight lasted only 10 minutes, but the high resolution images it obtained in that time enabled the scientists to directly observe the hypothetical magnetic braid activity. The CfA scientists, in collaboration with colleagues at NASA's Marshall Space Flight Center, produced the finest mirrors for extreme ultraviolet light ever made for a space mission and launched them in a telescope on a sub-orbital rocket, the Hi-C mission, last July. Because proof of this mechanism relies in part on images capable of seeing these braids at work, this explanation has been difficult to verify.ĬfA astronomers Leon Golub, Kelly Korreck, Mark Weber, and Patrick McCauley were key members of the team that has resolved this long-standing puzzle. This second stage of heating has been attributed to the energetic unraveling of braids of powerful magnetic fields generated by the movement of charged particles in the corona. The active Sun, however, has sunspots and regions that can reach temperatures up to four million kelvin. It is thought that this "wave heating" can raise the temperature of the corona to about 1.5 million kelvin, its temperature in its quiescent phase.
The first mechanism is heating from the solar interior carried to the surface by waves in the hot gas. The mechanisms that heat the corona are poorly understood, but are thought to be of two kinds.
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