TC_209 [he/him, comrade/them]

  • 3 Posts
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Joined 4 years ago
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Cake day: August 14th, 2020

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  • https://earthobservatory.nasa.gov/images/153325/the-korean-peninsula-at-night

    An astronaut aboard the International Space Station took this photo of the Korean Peninsula showing the distribution of nighttime light. North Korea (extending beyond the top of this image) lies on the upper part of the peninsula and is almost devoid of nighttime lights. In contrast, South Korea lies on the lower part of the peninsula and exhibits night lights from many cities of different sizes.
    […]
    Astronaut photograph ISS070-E-80670 was acquired on January 24, 2024, with a Nikon D5 digital camera using a focal length of 24 millimeters. It is provided by the ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit, Johnson Space Center. The image was taken by a member of the Expedition 70 crew. The image has been cropped and enhanced to improve contrast, and lens artifacts have been removed.

    While it’s true the DPRK has much less urban development than SK (and half the population), you can see how this NASA photograph compares to the one in the OP; most “lol north korea no electricity” photographs greatly enhance the amount of light emitted by SK while dimming or even erasing light from the DPRK.




  • The primary source of the linked article: https://arxiv.org/abs/2409.20432

    Observed magnitudes of Qianfan spacecraft range from 4 when they are near zenith to 8 when low in the sky.

    Since this is the first run of the Qianfan satellite constellation, the most appropriate comparison would be to Starlink’s original satellites. As you can see below, the notion that China’s satellites are “significantly brighter than those of Western systems” is a inaccurate.

    A 2022 paper on Starlink Original, VisorSat and Post-VisorSat models: https://arxiv.org/pdf/2210.17268

    The Original spacecrafts have a relatively flat phase function, so they are comparatively bright over a wide range of phase angle. […] the characteristic magnitudes are: 4.7 (Original) […]

    A 2024 paper on Starlink newer Direct-to-Cell satellites: https://arxiv.org/abs/2407.03092

    The mean apparent magnitude of Starlink Mini Direct-To-Cell (DTC) satellites is 4.62 while the mean of magnitudes adjusted to a uniform distance of 1000 km is 5.50.

    Clearly, even the newest Starlink satellites are well above the magnitude 7 limit astronomers recommend for satellite brightness.