This is the first step toward our vision of a future, massive "Greater #Yellowstone Ecosystem International Dark Sky Reserve" that would encompass well over 10 million acres (>40000 km2) of territory in the U.S. states of #Wyoming, #Idaho and #Montana.
As we learn more about #light (especially at night) and human #health, it's becoming apparent that we need more direct #dosimetry of the light exposures people actually get.
The Windred et al. paper is one of the first I have seen that tries to measure light exposures directly instead of guessing what they are, and does so with a very large sample size. Their conclusion seems stronger to me, for that reason.
Note: this is still mostly seen in people receiving light indoors. The next frontier is to put wearable devices on people when they’re in outdoor spaces. We would also like to know the color of the light to which they’re exposed, which requires more sophisticated wearable tech.
(I forgot to mention like a week ago that it was) #PaperDay!
Here our group shows the 1st successful theoretical model that predicts the degree & angle of linear #polarization of scattered night-sky #light accounting for ground light sources. A 🧵 (1/14)
Thanks to Nocturne Podcast for having me on the show recently along with my co-author, Aparna Venkatesan, to talk about our word "noctalgia" in the context of ongoing efforts to preserve dark skies in West Marin, #California.
"As the numbers of rocket launches and commercial aircraft flights increase, the probability of a catastrophic collision between an aircraft and reentering space debris is also growing. ... From a broad economic perspective, space companies are externalizing some of their risks and costs and imposing them on the aviation industry."
"This Article examines the growing number of soon-to-be-ubiquitous constellations of small satellites and the special problems they pose. It also suggests some legal reforms to combat the dilemmas and temper an otherwise dangerous renewal of an unconstrained and unproductive international race to space."
It's #MilkyWay season again here in the northern hemisphere.
I took this image using my phone last night around 2am looking south from my moderately light-polluted site in east Tucson. 5×90s subs captured in Astroshader were combined in Siril. A final stretch was applied in GIMP.
Further experiments last night. Here, I doubled the total exposure time (so, a total of 900 s). Same processing steps.
Having started in astrophotography about a million years ago using film, it blows my mind that my phone can collect the data used to make an image like this now.
Had a nice visit here in Tucson today with Jhong-Fu Huang from the Taiwan Dark Sky Association. He is visiting the U.S. on a National Committee on U.S.-China Relations fellowship. We talked about dark-skies efforts in our respective countries and how we can work together more closely.
The #FCC Chair has requested that future satellite applications include results of analyses showing that the risk of collision/debris generation from a given satellite due to spontaneous explosion is less than 0.1% over its expected lifetime.
"'The light pollution from the [Tesla] Gigafactory is freaking nutty.'"
"'I live in a neighborhood very close to it and had to get blackout curtains for my bedroom. On cloudy nights it basically lights up the night sky brighter than a full moon.'"
@JohnBarentine The light emissions seen by the VIIRS DNB satellite for the factory in Texas are about 3x larger than the emissions from the factory in Brandenburg, Germany.
Depending on whether the lights are shielded in Germany, the difference could be much larger than 3x...
This ensures that more big, bright #satellites are coming: "A Block 1 satellite would have 10 times the capacity of the company’s 1,500-kilogram BlueWalker-3 prototype; [Block2] would be twice as big and have 10 times the capacity of a Block 1 BlueBird." (via @spacenews_inc)
(Also, a reminder that this comms mode is potentially very harmful to ground-based radio astronomy.)
Call for abstracts: "The impact of large satellite constellations on astronomy: five years on" at this year's @royalastrosoc U.K. National Astronomy Meeting. The session will be held from 3-5pm on Tuesday, 16th July, at the E.A. Milne Centre for Astrophysics at the University of Hull.