Members Can Post Anonymously On This Site
-
Similar Topics
-
By NASA
NASA/JPL-Caltech/MSSS NASA’s Curiosity Mars rover captured this feather-shaped iridescent cloud just after sunset on Jan. 27, 2023. Studying the colors in iridescent clouds tells scientists something about particle size within the clouds and how they grow over time. These clouds were captured as part of a seasonal imaging campaign to study noctilucent, or “night-shining” clouds. A new campaign in January 2025 led to Curiosity capturing this video of red- and green-tinged clouds drifting through the Martian sky.
Learn more about iridescent twilight clouds on Mars.
Image credit: NASA/JPL-Caltech/MSSS
View the full article
-
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’s SPHEREx space observatory was photographed at BAE Systems in Boulder, Colorado, in November 2024 after completing environmental testing. The spacecraft’s three concentric cones help direct heat and light away from the telescope and other components, keeping them cool. Credit: BAE Systems NASA will host a news conference at 12 p.m. EST Friday, Jan. 31, to discuss a new telescope that will improve our understanding of how the universe evolved and search for key ingredients for life in our galaxy.
Agency experts will preview NASA’s SPHEREx (Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer) mission, which will help scientists better understand the structure of the universe, how galaxies form and evolve, and the origins and abundance of water. Launch is targeted for no earlier than Thursday, Feb. 27.
The news conference will be hosted at the agency’s Jet Propulsion Laboratory in Southern California. Watch live on NASA+, as well as JPL’s X and YouTube channels. Learn how to watch NASA content through a variety of platforms, including social media.
Laurie Leshin, director, NASA JPL, will provide opening remarks. Additional briefing participants include:
Shawn Domagal-Goldman, acting director, Astrophysics Division, NASA Headquarters James Fanson, project manager, SPHEREx, NASA JPL Beth Fabinsky, deputy project manager, SPHEREx, NASA JPL Jamie Bock, principal investigator, SPHEREx, Caltech Cesar Marin, SPHEREx integration engineer, Launch Services Program, NASA’s Kennedy Space Center in Florida To ask questions by phone, members of the media must RSVP no later than two hours before the start of the event to: rexana.v.vizza@jpl.nasa.gov. NASA’s media accreditation policy is available online. Questions also can be asked on social media during the briefing using #AskNASA.
The SPHEREx observatory will survey the entire celestial sky in near-infrared light to help answer cosmic questions involving the birth of the universe, and the subsequent development of galaxies. It also will search for ices of water and organic molecules — essentials for life as we know it — in regions where stars are born from gas and dust, as well as disks around stars where new planets could be forming. Astronomers will use the mission to gather data on more than 450 million galaxies, as well as more than 100 million stars in our own Milky Way galaxy.
The space observatory will share its ride on a SpaceX Falcon 9 rocket with NASA’s PUNCH (Polarimeter to Unify the Corona and Heliosphere) mission, which will lift off from Launch Complex 4E at Vandenberg Space Force Base in Central California.
The SPHEREx mission is managed by NASA JPL for the agency’s Astrophysics Division within the Science Mission Directorate at NASA Headquarters in Washington. The principal investigator is based at Caltech in Pasadena, California, which manages NASA JPL for the agency.
The spacecraft is supplied by BAE Systems. The Korea Astronomy and Space Science Institute contributed the non-flight cryogenic test chamber. Mission data will be publicly available through IPAC at Caltech.
For more information about the mission, visit:
https://nasa.gov/spherex
-end-
Alise Fisher
Headquarters, Washington
202-358-2546
alise.m.fisher@nasa.gov
Val Gratias / Calla Cofield
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-6215 / 626-808-2469
valerie.m.gratias@jpl.nasa.gov / calla.e.cofield@jpl.nasa.gov
Share
Details
Last Updated Jan 27, 2025 EditorJessica TaveauLocationNASA Headquarters Related Terms
SPHEREx (Spectro-Photometer for the History of the Universe and Ices Explorer) Astrophysics Division Jet Propulsion Laboratory Polarimeter to Unify the Corona and Heliosphere (PUNCH) Science Mission Directorate View the full article
-
By USH
The American Meteor Society website shared a video on their channel showing a fireball streaking across the skies of Michigan and Ohio on Sunday, January 19, 2025, around 01:31 UT.
Though, Meteor Society noted that the video might not actually depict a fireball event, leaving some viewers curious about the meaning behind this statement.
At the moment the fireball appears on camera, a strange object seems to materialize above it, expanding in size and partially obscuring the fireball before gradually fading out as the fireball continues its path through the sky.
This phenomenon has sparked varied interpretations. Some suggest it might indicate alien intervention, while others offer a more plausible explanation: the "object" is likely a water droplet on the camera lens, creating the illusion of interaction with the fireball.
However, since the Meteor Society suggested that it might not actually depict a fireball event, we might question whether it was truly a fireball, a meteor, including a water droplet, or something entirely different.
View the full article
-
By NASA
On Jan. 7, 1610, Italian astronomer Galileo Galilei peered through his newly improved 20-power homemade telescope at the planet Jupiter. He noticed three other points of light near the planet, at first believing them to be distant stars. Observing them over several nights, he noted that they appeared to move in the wrong direction with regard to the background stars and they remained in Jupiter’s proximity but changed their positions relative to one another. Four days later, he observed a fourth point of light near the planet with the same unusual behavior. By Jan. 15, Galileo correctly concluded that he had discovered four moons orbiting around Jupiter, providing strong evidence for the Copernican theory that most celestial objects did not revolve around the Earth.
Two of Galileo’s telescopes.National Geographic. Painting by Giuseppe Bertini (1858) of Galileo demonstrating his telescope to the Doge of Venice.gabrielevanin.it Page from Galileo’s notebook about his observations of Jupiter’s satellites.University of Michigan Special Collections Library. In March 1610, Galileo published his discoveries of Jupiter’s satellites and other celestial observations in a book titled Siderius Nuncius (The Starry Messenger). As their discoverer, Galileo had naming rights to Jupiter’s satellites. He proposed to name them after his patrons the Medicis and astronomers called them the Medicean Stars through much of the seventeenth century, although in his own notes Galileo referred to them by the Roman numerals I, II, III, and IV, in order of their distance from Jupiter. Astronomers still refer to the four moons as the Galilean satellites in honor of their discoverer.
In 1614, the German astronomer Johannes Kepler suggested naming the satellites after mythological figures associated with Jupiter, namely Io, Europa, Ganymede, and Callisto, but his idea didn’t catch on for more than 200 years. Scientists didn’t discover any more satellites around Jupiter until 1892 when American astronomer E.E. Barnard found Jupiter’s fifth moon Amalthea, much smaller than the Galilean moons and orbiting closer to the planet than Io. It was the last satellite in the solar system found by visual observation – all subsequent discoveries occurred via photography or digital imaging. As of today, astronomers have identified 95 moons orbiting Jupiter.
Image of Jupiter and three of its four Galilean satellites through an amateur telescope, similar to what Galileo might have seen. Hubble Space Telescope image of Jupiter and three of its four Galilean satellites during a rare triple transit. Although each of the Galilean satellites has unique features, such as the volcanoes of Io, the heavily cratered surface of Callisto, and the magnetic field of Ganymede, scientists have focused more attention on Europa due to the tantalizing possibility that it might be hospitable to life. In the 1970s, NASA’s Pioneer 10 and 11 and Voyager 1 and 2 spacecraft took ever increasingly detailed images of the large satellites including Europa during their flybys of Jupiter. The photographs revealed Europa to have the smoothest surface of any object in the solar system, indicating a relatively young crust, and also one of the brightest of any satellite indicating a highly reflective surface. These features led scientists to hypothesize that Europa is covered by an icy crust floating on a subsurface salty ocean. They further postulated that tidal heating caused by Jupiter’s gravity reforms the surface ice layer in cycles of melting and freezing.
Image of Europa taken by Pioneer 10 during its flyby of Jupiter in 1973. Image of Europa taken by Voyager 1 during its 1979 flyby of Jupiter. Image of Europa taken by Voyager 2 during its 1979 flyby of Jupiter. More detailed observations from NASA’s Galileo spacecraft that orbited Jupiter between 1995 and 2003 and completed 11 close encounters with Europa revealed that long linear features on its surface may indicate tidal or tectonic activity. Reddish-brown material along the fissures and in splotches elsewhere on the surface may contain salts and sulfur compounds transported from below the crust and modified by radiation. Observations from the Hubble Space Telescope and re-analysis of images from Galileo revealed possible plumes emanating from beneath Europa’s crust, lending credence to that hypothesis. While the exact composition of this material is not known, it likely holds clues to whether Europa may be hospitable to life.
Global view of Europa from the Galileo spacecraft. More detailed views of varied terrain on Europa from Galileo. Cutaway illustration of Europa’s icy crust, subsurface ocean and possible vents that transport material to the surface. Future robotic explorers of Europa may answer some of the outstanding questions about this unique satellite of Jupiter. NASA’s Europa Clipper set off in October 2024 on a 5.5-year journey to Jupiter. After its arrival in 2030, the spacecraft will enter orbit around the giant planet and conduct 49 flybys of Europa during its four-year mission. Managed by the Jet Propulsion Laboratory in Pasadena, California, and the Applied Physics Laboratory at Johns Hopkins University in Baltimore, Maryland, Europa Clipper will carry nine instruments including imaging systems and a radar to better understand the structure of the icy crust. Data from Europa Clipper will complement information returned by the European Space Agency’s JUICE (Jupiter Icy Moon Explorer) spacecraft. Launched in April 2023, JUICE will first enter orbit around Jupiter in 2031 and then enter orbit around Ganymede in 2034. The spacecraft also plans to conduct studies of Europa complementary with Europa Clipper’s. The two spacecraft should greatly increase our understanding of Europa and perhaps uncover new mysteries.
Illustration of the Europa Clipper spacecraft investigating Europa. Illustration of the JUICE spacecraft exploring Europa.European Space Agency. 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.