Temperature of planet mercury
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Temperature of Planet Mercury
Mean Disk Temperature of Mercury
Observations of Mercury's radio emissions have provided valuable insights into its temperature. Measurements taken at wavelengths near 3 cm indicate that the mean disk temperature of Mercury is approximately 400 K 16. This value is derived from microwave radiation data and is consistent across various studies.
Sub-Solar Point Temperature
The temperature at Mercury's sub-solar point, where the Sun is directly overhead, is significantly higher. Estimates suggest that this temperature can reach around 1100 K 16. This high temperature is due to the intense solar radiation that Mercury receives, given its proximity to the Sun. However, this value is highly dependent on the temperature of Mercury's dark hemisphere, which has been assumed to be close to zero in some models .
Dark-Side Temperature
Contrary to earlier assumptions, recent observations have measured the dark-side temperature of Mercury to be around 111 K . This finding indicates that Mercury's surface retains some heat even on the side perpetually facing away from the Sun. The thermal inertia of Mercury's surface, which is similar to that of the Moon, plays a crucial role in this heat retention .
Day-Night Temperature Variation
Mercury experiences extreme temperature variations between day and night. During the day, temperatures can soar above 325°C (approximately 598 K), while at night, they can plummet to -123°C (approximately 150 K) . This drastic change is due to Mercury's lack of a significant atmosphere, which means there is no medium to retain heat when the Sun is not shining on the surface.
Internal Temperature Distribution
The internal temperature of Mercury also varies significantly. The highest temperature within Mercury's interior, at the core-mantle boundary on the sunward side, can reach up to 1380 K . This temperature distribution is influenced by the planet's internal structure, which includes a core and a mantle similar to Earth's .
Equatorial Midnight Temperature
At the equator, the temperature at midnight is observed to be around 100 K . This value is derived from microwave data and aligns with thermophysical models that predict Mercury's thermal behavior based on its unique diurnal cycle .
Polar Temperatures and Water Ice Stability
Interestingly, despite Mercury's overall high temperatures, the poles can be much colder. In permanently shadowed regions of large craters at the poles, temperatures can be as low as 60 K . These cold temperatures are conducive to the stability of water ice, which has been detected in these regions .
Conclusion
Mercury's temperature varies widely across its surface and interior. The mean disk temperature is around 400 K, while the sub-solar point can reach up to 1100 K. The dark side of Mercury is much cooler, with temperatures around 111 K. The planet experiences extreme day-night temperature variations, and its poles can harbor water ice due to significantly lower temperatures. These findings highlight the complex thermal dynamics of Mercury, influenced by its proximity to the Sun and lack of a substantial atmosphere.
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