Aug 28, 2020 04:10 AM
https://www.salon.com/2020/08/27/the-sky...ervations/
EXCERPT: . . . an in-depth new report from a working group of astronomers released by the American Astronomical Society shows how these satellites could drastically change the scope of astronomy work conducted on Earth. Specifically, astronomers state that existing satellites, including the 538 satellites from SpaceX as well as future ones, will "fundamentally change the way astronomers can plan and execute observations." In other words, the field of astronomy is facing an existential threat.
[...] The authors warn that, even in this last year, "the sky has changed," as a "growing numbers of satellite trails contaminating astronomical images." The risk of contaminated data, they write, can be hard to predict and mitigate: "A bright satellite crossing near a long spectrograph slit . . . could ruin the entire exposure, as it is not known a priori which observations are contaminated, forcing a repeat exposure or possible loss of science opportunity."
[...] at what price for science? As the report explains, the success of astronomical investigations depends on the ability to observe any part of the sky with the same quality of view. Specifically, investigations such as observing stellar populations in the Milky Way and neighboring galaxies, and looking for potentially hazardous near-Earth objects, could be undermined with more LEO satellites, especially given how time-sensitive these observations can be.
"For example, if a near-Earth object is not recovered, its orbital parameters are lost," the authors of the report state. "If the transit of a promising super-Earth exoplanet candidate is missed, the orbital timing may not be recovered."
Authors of the report called out OneWeb as a particularly problematic constellation due to its high altitude at 1200 kilometers above Earth. "Constellations at high altitudes, such as the OneWeb constellation at 1200 km, present particularly serious challenges; they will be visible all night during summer and significant fractions of the night during winter, fall, and spring, and will have negative impacts on nearly all observational programs," the report said, referring to "twilight observations," which are often important when it comes to searching for Earth-threatening asteroids and comets.
The report includes ten recommendations to mitigate the influence of satellites on astronomical investigations, including launching "fewer" or no LEO satellites. "However impractical or unlikely, this is the only option identified that can achieve zero astronomical impact," a press release about the report stated. Other ways include deploying satellites to orbital altitudes, darkening the satellites, and finding a way to minimize satellite trails. The authors of the report also note that these commercial satellites could spoil starry nights for amateur astronomers... (MORE - details)
EXCERPT: . . . an in-depth new report from a working group of astronomers released by the American Astronomical Society shows how these satellites could drastically change the scope of astronomy work conducted on Earth. Specifically, astronomers state that existing satellites, including the 538 satellites from SpaceX as well as future ones, will "fundamentally change the way astronomers can plan and execute observations." In other words, the field of astronomy is facing an existential threat.
[...] The authors warn that, even in this last year, "the sky has changed," as a "growing numbers of satellite trails contaminating astronomical images." The risk of contaminated data, they write, can be hard to predict and mitigate: "A bright satellite crossing near a long spectrograph slit . . . could ruin the entire exposure, as it is not known a priori which observations are contaminated, forcing a repeat exposure or possible loss of science opportunity."
[...] at what price for science? As the report explains, the success of astronomical investigations depends on the ability to observe any part of the sky with the same quality of view. Specifically, investigations such as observing stellar populations in the Milky Way and neighboring galaxies, and looking for potentially hazardous near-Earth objects, could be undermined with more LEO satellites, especially given how time-sensitive these observations can be.
"For example, if a near-Earth object is not recovered, its orbital parameters are lost," the authors of the report state. "If the transit of a promising super-Earth exoplanet candidate is missed, the orbital timing may not be recovered."
Authors of the report called out OneWeb as a particularly problematic constellation due to its high altitude at 1200 kilometers above Earth. "Constellations at high altitudes, such as the OneWeb constellation at 1200 km, present particularly serious challenges; they will be visible all night during summer and significant fractions of the night during winter, fall, and spring, and will have negative impacts on nearly all observational programs," the report said, referring to "twilight observations," which are often important when it comes to searching for Earth-threatening asteroids and comets.
The report includes ten recommendations to mitigate the influence of satellites on astronomical investigations, including launching "fewer" or no LEO satellites. "However impractical or unlikely, this is the only option identified that can achieve zero astronomical impact," a press release about the report stated. Other ways include deploying satellites to orbital altitudes, darkening the satellites, and finding a way to minimize satellite trails. The authors of the report also note that these commercial satellites could spoil starry nights for amateur astronomers... (MORE - details)