Members Can Post Anonymously On This Site
Light Fantastic: Laser at Inner Harbor Beams Hubble's Heartbeat
-
Similar Topics
-
-
By NASA
5 min read
February’s Night Sky Notes: How Can You Help Curb Light Pollution?
Light pollution has long troubled astronomers, who generally shy away from deep sky observing under full Moon skies. The natural light from a bright Moon floods the sky and hides views of the Milky Way, dim galaxies and nebula, and shooting stars. In recent years, human-made light pollution has dramatically surpassed the interference of even a bright full Moon, and its effects are now noticeable to a great many people outside of the astronomical community. Harsh, bright white LED streetlights, while often more efficient and long-lasting, often create unexpected problems for communities replacing their old street lamps. Some notable concerns are increased glare and light trespass, less restful sleep, and disturbed nocturnal wildlife patterns. There is increasing awareness of just how much light is too much light at night. You don’t need to give in to despair over encroaching light pollution; you can join efforts to measure it, educate others, and even help stop or reduce the effects of light pollution in your community.
Before and after pictures of replacement lighting at the 6th Street Bridge over the Los Angeles River. The second picture shows improvements in some aspects of light pollution, as light is not directed to the sides and upwards from the upgraded fixtures, reducing skyglow. However, it also shows the use of brighter, whiter LEDs, which is not generally ideal, along with increased light bounce back from the road. City of Los Angeles Amateur astronomers and potential citizen scientists around the globe are invited to participate in the Globe at Night (GaN) program to measure light pollution. Measurements are taken by volunteers on a few scheduled days every month and submitted to their database to help create a comprehensive map of light pollution and its change over time. GaN volunteers can take and submit measurements using multiple methods ranging from low-tech naked-eye observations to high-tech sensors and smartphone apps.
Globe at Night citizen scientists can use the following methods to measure light pollution and submit their results:
Their own smartphone camera and dedicated app Manually measure light pollution using their own eyes and detailed charts of the constellations A dedicated light pollution measurement device called a Sky Quality Meter (SQM). The free GaN web app from any internet-connected device (which can also be used to submit their measurements from an SQM or printed-out star charts) Night Sky Network members joined a telecon with Connie Walker of Globe at Night in 2014 and had a lively discussion about the program’s history and how they can participate. The audio of the telecon, transcript, and links to additional resources can be found on their dedicated resource page.
Light pollution has been visible from space for a long time, but new LED lights are bright enough that they stand out from older street lights, even from orbit. The above photo was taken by astronaut Samantha Cristoforetti from the ISS cupola in 2015. The newly installed white LED lights in the center of the city of Milan are noticeably brighter than the lights in the surrounding neighborhoods. NASA/ESA DarkSky International has long been a champion in the fight against light pollution and a proponent of smart lighting design and policy. Their website (at darksky.org) provides many resources for amateur astronomers and other like-minded people to help communities understand the negative impacts of light pollution and how smart lighting policies can not only help bring the stars back to their night skies but make their streets safer by using smarter lighting with less glare. Communities and individuals find that their nighttime lighting choices can help save considerable sums of money when they decide to light their streets and homes “smarter, not brighter” with shielded, directional lighting, motion detectors, timers, and even choosing the proper “temperature” of new LED light replacements to avoid the harsh “pure white” glare that many new streetlamps possess. Their pages on community advocacy and on how to choose dark-sky-friendly lighting are extremely helpful and full of great information. There are even local chapters of the IDA in many communities made up of passionate advocates of dark skies.
DarkSky International has notably helped usher in “Dark Sky Places“, areas around the world that are protected from light pollution. “Dark Sky Parks“, in particular, provide visitors with incredible views of the Milky Way and are perfect places to spot the wonders of a meteor shower. These parks also perform a very important function, showing the public the wonders of a truly dark sky to many people who may have never before even seen a handful of stars in the sky, let alone the full, glorious spread of the Milky Way.
More research into the negative effects of light pollution on the health of humans and the environment is being conducted than ever before. Watching the nighttime light slowly increase in your neighborhood, combined with reading so much bad news, can indeed be disheartening! However, as awareness of light pollution and its negative effects increases, more people are becoming aware of the problem and want to be part of the solution. There is even an episode of PBS Kid’s SciGirls where the main characters help mitigate light pollution in their neighborhood!
Astronomy clubs are uniquely situated to help spread awareness of good lighting practices in their local communities in order to help mitigate light pollution. Take inspiration from Tucson, Arizona, and other dark sky-friendly communities that have adopted good lighting practices. Tucson even reduced its skyglow by 7% after its own citywide lighting conversion, proof that communities can bring the stars back with smart lighting choices.
Originally posted by Dave Prosper: November 2018
Last Updated by Kat Troche: January 2025
View the full article
-
By NASA
NASA, ESA, and M. Wong (University of California – Berkeley); Processing: Gladys Kober (NASA/Catholic University of America) This NASA Hubble Space Telescope image shows the planet Jupiter in a color composite of ultraviolet wavelengths. Released on Nov. 3, 2023, in honor of Jupiter reaching opposition, which occurs when the planet and the Sun are in opposite sides of the sky, this view of the gas giant planet includes the iconic, massive storm called the “Great Red Spot.” Though the storm appears red to the human eye, in this ultraviolet image it appears darker because high altitude haze particles absorb light at these wavelengths. The reddish, wavy polar hazes are absorbing slightly less of this light due to differences in either particle size, composition, or altitude.
Learn more about Hubble and how this type of data can help us learn more about our universe.
Image credit: NASA, ESA, and M. Wong (University of California – Berkeley); Processing: Gladys Kober (NASA/Catholic University of America)
View the full article
-
By USH
A rare and intriguing phenomenon has been observed in China. On the night of October 27th, Chinese astrophotographer Shengyu Li set up his camera to capture star trails over Mount Xiannairi in Sichuan Province. To his surprise, he recorded mysterious blue flashes accompanying an avalanche.
The exact cause of these "blue lights" remains unclear, sparking various theories. Some speculate they could stem from geomagnetic activity, interactions of cosmic rays in the upper atmosphere, or rare atmospheric phenomena like blue jets or elves. However, Li offers another explanation: the flashes might result from triboluminescence—light produced by friction during ice fragmentation.
Triboluminescence occurs when certain materials emit light as they are fractured, scratched, or rubbed. This phenomenon happens due to the breaking of chemical bonds or the sudden separation of surfaces, which generates electrical charges. These charges can ionize the surrounding air or excite the material itself, creating visible light.
The hypothesis suggests that this event could be an example of triboluminescence. However, it also raises the intriguing possibility of a connection to UFO phenomena, such as orbs or other unexplained lights that have been observed around the world over the years.
Hypothesis: The sighting depicts what appears to be a blue light descending onto a snowbank, following the avalanche as it moves downward, and then vanishing before seemingly ascending again.
Did the avalanche trigger the blue light, or did the blue light crash into the snow, causing the avalanche?
Whether this phenomenon is a rare case of triboluminescence, potentially the first instance of it being captured on camera or something linked to unexplained UFO activity, the recording of this light remains a unique and fascinating occurrence. View the full article
-
-
-
Check out these Videos
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.