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skyglowberlin.fediscience.org.ap.brid.gy
Christopher Kyba 🇨🇦🇪🇺
@skyglowberlin.fediscience.org.ap.brid.gy
46 followers 10 following 100 posts
Heisenberg Professor for Nighttime Light Remote Sensing at the Institute of Geography of the Ruhr University Bochum

Guest scientist @GFZ (until November 2025) […]

🌉 bridged from ⁂ https://fediscience.org/@skyglowberlin, follow @ap.brid.gy to interact
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skyglowberlin.fediscience.org.ap.brid.gy
The season might be coming to an end, but our farm share is still going VERY strong. #kohlrabi
Bearded dude holding a Kohlrabi that's larger and rounded than his head.
November 13, 2025 at 9:22 PM
skyglowberlin.fediscience.org.ap.brid.gy
I'm very pleased with this observation of the light curve of the asteroid Eros that I took a few nights ago. It rotates with a period of about 5 hours, so it gets (slightly) brighter and darker over time if you observe it long enough.

Lots of things about […]

[Original post on fediscience.org]
Image that shows the result of observations of the asteroid Eros. At right is a circle showing the field of view with a dashed line showing where the asteroid traveled, and at the bottom is a light curve that looks vaguely like a sine wave with two gaps where I looked at some other object.
November 9, 2025 at 9:24 PM
skyglowberlin.fediscience.org.ap.brid.gy
@sundogplanets Just to clarify one point - streetlights are usually found to be responsible for *less* than half of light emissions or skyglow. Here is a table from a paper we published: https://doi.org/10.26607/ijsl.v25i1.133

I also misremembered that there […]

[Original post on fediscience.org]
Table showing the fraction of light that comes from different sources in different scientific studies.
November 9, 2025 at 9:00 AM
skyglowberlin.fediscience.org.ap.brid.gy
There are now 250 Dark Sky Places around the world certified by DarkSky International (formerly IDA)! https://darksky.org/news/250-international-dark-sky-places-2/

To be certified, a place doesn't only need to have a certain level of sky quality - much more […]

[Original post on fediscience.org]
Text: DarkSky International celebrates the certification of the 250th International Dark Sky Place View of the sign "Starlight Highway" with mountains, fields, the Milky Way and Magellanic clouds in the background. Credit: “Starlight Highway” by Tom Rae, Aoraki / Mount Cook National Park, Canterbury, New Zealand
November 6, 2025 at 9:04 AM
skyglowberlin.fediscience.org.ap.brid.gy
The @ruhr-uni-bochum.de has a news piece (in German) about my professorship and the research I will be doing in the coming years: https://news.rub.de/leute/2025-10-14-neu-ernannt-christopher-kyba-traeumt-von-einem-satelliten
Photo of a man in a suit jacket. The series name "Neu ernannt" is at the top, and the text below says "Christopher Kyba comes with a Heisenberg Professorship to the Ruhr University"
October 14, 2025 at 7:20 AM
skyglowberlin.fediscience.org.ap.brid.gy
I'm very pleased to officially announce that l have been appointed Heisenberg Professor for Nighttime Light Remote Sensing at the Institute of Geography at the Ruhr University Bochum 🎉

#RemoteSensing #rub #bochum
Three smiling people stand in front of a RUB banner. The man in the middle is holding a certificate. Photo credit: RUB, Kramer.
October 1, 2025 at 9:14 AM
skyglowberlin.fediscience.org.ap.brid.gy
I'm soon starting up a Nighttime Lights Remote Sensing webinar. Speakers will come from all over the world, and the talks will take place alternately in the (European) morning or late afternoon/evening, to allow international participation.

The first talk in […]

[Original post on fediscience.org]
Title: A geospatial perspective on electrification strategy in urbanizing Africa Co-presented by: Jessica Kersey (UC Berkeley Energy and Resources Group) Sam Miles (Johns Hopkins University) Vivek Sakhrani (AtlasAl) Date: Monday, October 6 Time: 00:00 Brisbane (AEST - next day!) 22:00 Beijing (CST) 16:00 Berlin (CEST) 14:00 UTC 10:00 Toronto (EDT) 7:00 Los Angeles (PDT)
September 30, 2025 at 4:43 PM
skyglowberlin.fediscience.org.ap.brid.gy
How sure are you that it wasn't 1580.49?

I wonder how many digits there need to be before the journal editor or reviewers point out that your numbers are ridiculous?

1580.5128576392749274?

1580.51285763927492744795003625123?
screenshot with text "exhibited values between 1580.51 and 2090.20, suggesting"
September 28, 2025 at 12:00 PM
skyglowberlin.fediscience.org.ap.brid.gy
Unless you take action, #linkedin is going to use your account for generative "AI". You can turn this off in settings.
Screenshot. The text reads: Data for Generative Al Improvement Can LinkedIn use your personal data and content you create on LinkedIn to train generative Al models that create content? Use my data for training content creation Al models off @ When this setting is on, LinkedIn can use your data and content to train content-generating Al models that are used in product features. The data we use for this purpose does not include your private messages. Learn more
September 23, 2025 at 9:04 AM
skyglowberlin.fediscience.org.ap.brid.gy
Is it too early to suggest possible Christmas presents for the nature lovers in your life? Here's a new book that just came out: https://theexperimentpublishing.com/catalogs/summer-2025/living-night/
Image of an owl at twilight with the title "Living Night: On the wonders of wildlife after dark".
September 23, 2025 at 6:06 AM
skyglowberlin.fediscience.org.ap.brid.gy
Oh this is cool, our paper about the global growth in light emissions was just cited for the 1000th time (according to Google Scholar): https://www.science.org/doi/full/10.1126/sciadv.1701528

Thanks to everyone who was interested in the paper and read and […]

[Original post on fediscience.org]
Image from the journal Science Advances when the paper was published. The background image is a picture of a city from space.
September 16, 2025 at 7:57 AM
skyglowberlin.fediscience.org.ap.brid.gy
Photogrammetry and #RemoteSensing job at TU Graz: https://jobs.tugraz.at/en/jobs/5eb41c80-4df1-3acf-4c38-688b183ca4a8?preview=true

#academicjobs
Image showing screenshot that says "Professorship in Photogrammetry"
September 12, 2025 at 7:24 AM
skyglowberlin.fediscience.org.ap.brid.gy
A really interesting paper just came out in Science a few weeks ago: https://www.science.org/doi/10.1126/science.adv9472

The authors compared satellite measurements of #lightpollution from #viirs_dnb to 2.6 million bird calls recorded at 7,824 locations […]

[Original post on fediscience.org]
Cover image from Science with the title "Light pollution prolongs avian activity"
September 8, 2025 at 4:12 PM
skyglowberlin.fediscience.org.ap.brid.gy
Animated map showing the spread of municipalities turning their streetlights off late at night in France (typically midnight or 1 am), from this report: https://www.cerema.fr/fr/actualites/extinction-eclairage-public-etude-pratiques-collectivites

Over 15,000 […]

[Original post on fediscience.org]
Animated of France with lots of dots showing where communities turn their lights off, which fills in with dots as the animation progresses.
August 8, 2025 at 1:05 PM
skyglowberlin.fediscience.org.ap.brid.gy
Here's an example: the primary beam of light from this floodlight doesn't even hit the church.

But even with proper aiming, the optics are such that much or most of the light would still miss the church.

This should not be acceptable in 2025.

#lightpollution #energy #climatecrisis
Photo showing a light beam from a misdirected floodlight that isn't aimed correctly at the church. The trail of an insect passing through the light beam is visible as a small streak
August 7, 2025 at 9:10 AM
skyglowberlin.fediscience.org.ap.brid.gy
Check out this piece in The Conversation by Georgia MacMillan and collaborators: https://theconversation.com/street-lamps-arent-the-only-form-of-artificial-light-pollution-heres-how-to-create-darker-nights-260514

I love the example of the church. There are […]

[Original post on fediscience.org]
August 7, 2025 at 9:05 AM
skyglowberlin.fediscience.org.ap.brid.gy
Search result summary vs actual webpage...

#duckduckgo #aislop
Screenshot: Chef's Resource https://www.chefsresource.com > does-food-weigh-more-frozen-2 Does food weigh more frozen? - Chef's Resource Yes, frozen vegetables weigh more than fresh vegetables. This is due to the water content in the vegetables turning into ice when frozen, which increases the weight. Once the vegetables thaw, they will return to their original weight. What happens to the weight of liquids when they are frozen? When... Screenshot: Does Food Weigh More Frozen? The Definitive Answer The short answer is no, food does not weigh more when frozen. While the density of some foods increases due to the formation of ice crystals and the slight contraction of water upon freezing, the mass remains constant, and therefore, the weight stays the same. Freezing only changes the state of the water within the food, not the fundamental amount of matter.
August 2, 2025 at 2:45 PM
skyglowberlin.fediscience.org.ap.brid.gy
The Leeds City Council estimated back in 2004 that their street light replacement program which was estimated to cost £181 million would reduce crime by 20%, providing an estimated benefit to the city of £109 million.

But since humans can't actually tell how […]

[Original post on fediscience.org]
Excerpt from the Leeds City Council business case for street lighting PFI Credits. Highlighted text says "The research suggests reduction in crime rates attributable to improved lighting of over 25%. We believe that a reduction of 20% in nighttime crime only is a reasonable assumption in the context of Leeds." Conclusion The conclusion of the study is that changes to the level of crime, positive or negative, could not be detected following relighting down at the level of just a few percent. This null result was despite the large dataset, 471,374 crimes and 78,189 replacement white lamp installations, that essentially comprised the complete relighting of the whole city of Leeds. The null result is consistent with that from another large longitudinal study, funded by the UK’s NIHR, National Institute of Health and Care Research. One can say that the Leeds study suggests the following range of impacts for comprehensive relighting. 1) The daylight adjusted darkness crime rate, that is the ratio of the darkness to daylight crime rate, going from before the relighting to after, showed a 2% increase in crime for its point estimate within a 95% confidence interval of (-3% to +7%).
July 16, 2025 at 4:30 PM
skyglowberlin.fediscience.org.ap.brid.gy
Early career researchers, this is for you: https://erc.europa.eu/news-events/events/webinar-erc-work-programme-2026
Screenshot with text: Webinar on ERC Work Programme 2026 10 July 2025 15.00 - 16.00 CEST Online ERCEA
July 8, 2025 at 7:46 PM
skyglowberlin.fediscience.org.ap.brid.gy
Cool news: https://www.space.com/astronomy/exoplanets/nasa-exoplanet-hunting-spacecraft-and-citizen-scientists-discover-a-cool-new-alien-world

Link to paper: https://iopscience.iop.org/article/10.3847/1538-3881/add88b

#citizenscience #astronomy
Screenshot of title: NASA exoplanet-hunting spacecraft and citizen scientists discover a cool new alien world By Robert Lea published 8 hours ago
June 30, 2025 at 8:51 PM
skyglowberlin.fediscience.org.ap.brid.gy
I'm in a hotel with no air conditioning, and just got off a zoom call with a journalist. It's HOT in Europe at the moment, so I've got the window open and the lights off because I don't want to get bugs in.

But it makes it look like I'm in witness protection or something 😂
Image of an entirely black silhouette of a person in front of a lit fence with stars in the background.
June 30, 2025 at 8:35 PM
skyglowberlin.fediscience.org.ap.brid.gy
This also suggests that artificial skyglow (a form of light pollution) is almost certainly a source of evolutionary pressure.

If you care about #biodiversity, if you care about #globalchange, or if you care about #sustainability, you should care about […]

[Original post on fediscience.org]
Two fisheye images of the night sky by Andreas Jechow. On the left is a location several tens of kilometers from Berlin. The sky is relatively dark overhead and you can see the Milky Way, but the horizon is still quite bright. On the right is an image taken in front of Berlin Cathedral (Berliner Dom). The sky is a bright blue-white color, and far fewer stars are visible. Image of a staircase with terribly bright glaring lights. Image of a staircase that is very well lit with an amount of light that fits well with the surroundings.
June 28, 2025 at 9:23 AM
skyglowberlin.fediscience.org.ap.brid.gy
Remember the big results I posted about last week? We've made short videos to explain what #Nachtlichter was about, and what we measured.

Check it out in English: https://youtu.be/OhNa-d3HcKc
or in German: https://youtu.be/hZo17_V_klg

Here's the original […]

[Original post on fediscience.org]
Screenshot from Youtube with the title slide of the presentation. A person is holding an app and looking at a light. There is a title text that says "Nachtlichter project", logos from the BMBF, Helmholtz Association, RUB, GFZ, and the Nachtlichter logo, and a small cutout showing me giving the talk.
June 27, 2025 at 9:04 AM
skyglowberlin.fediscience.org.ap.brid.gy
Reminder: my #lps25 talk is tomorrow - literally the last talk of the conference.

But I promise it's going to be entertaining and you'll leave on a high note! Here's a sneak peak...

#RemoteSensing #lightpollution #aotearoa #newzealand #viirs_dnb #suominpp #night
Text says Aotearoa (New Zealand) by starlight and airglow. 7 years cloud-free, moon-free data from VIIRS DNB. Equivalent exposure ~1s. Processing by Helga Kuechly. Image shows a satellite view of Aotearoa at night with no clouds. The cities are shining brightly, and you can clearly make out the albedo differences at the land-water boundary, as well as the bright reflection from glaciers.
June 26, 2025 at 7:15 PM
skyglowberlin.fediscience.org.ap.brid.gy
It's a bit surreal to be in this #lps25 panel discussion about the future of small sats and constellations, and no one talks at all about the fact that LEO is already on the way to runaway debris at the present number of space objects […]

[Original post on fediscience.org]
June 26, 2025 at 9:17 AM