Contributor Posts

Sue Tucker on Unsplash

NASA Astronomy Picture of the Day:

Although they look like cotton candy, you cannot eat these clouds! Taken in Cádiz, Spain, today's image features the Rho Ophiuchi complex, a rich tapestry of young and old astronomical phenomena. This colorful cloud complex is a nearby star-forming region containing hundreds of young stellar objects, including protostars and T Tauri stars. Light from the triple star system at its center reflects off of small dust grains to create the blue reflection nebula. Ultraviolet light from hot stars ionizes the surrounding hydrogen gas, creating the red emission nebula. Antares, a red supergiant big enough to engulf the Solar System’s asteroid belt, lights up the yellow region. Dark interstellar dust blocks some of the complex’s color. Recent JWST observations exhibit shadows cast by hidden circumstellar disks, the beginning stages of planet formation. Messier 4, a globular cluster almost as old as the universe, sits in the bottom right and witnesses yet another chaotic burst of youth in the Milky Way.

Photo by Ángel Molina Text: Keighley Rockcliffe (NASA GSFC, UMBC CSST, CRESST II)

Willan's chromodoris (Chromodoris willani), Anilao, Philippines. This 5 centimetres (2.0 in)-long nudibranch can be found in the Western Pacific Ocean and feeds, like many other nudibranchs, on sponges.

Diego Delso, CC BY-SA 4.0, via Wikimedia Commons. View source.

Looking through these three windows on history reminds us that while the tools of civilization evolve, the human story continues to be driven by many of the same hopes, challenges, and ambitions that have shaped every generation. Continue reading 

By Markus Spiske on Unsplash

NASA Astronomy Picture of the Day:

Why are parts of this asteroid's surface so smooth? The answer seems likely to do with the dynamics of an asteroid that is a loose pile of rubble rather than a solid rock. The unusual asteroid Itokawa was visited by the Japanese spacecraft Hayabusa in 2005 which imaged and documented its unusual structure and mysterious lack of craters. Analyses of the border regions between smooth and rugged sections indicate that jostling of the asteroid might be creating segregation between large and small rocks near the surface, like the Brazil nut effect. The robotic Hayabusa actually touched down on one of the smooth patches, dubbed the MUSES Sea, and collected soil samples. These samples were returned to Earth and are not only giving clues to the ancient history of this unusual asteroid, but also about the early years of our entire Solar System. Computer simulations show that 500-meter asteroid Itokawa may impact the Earth within the next few million years. Rocking Space: Today is Asteroid Day

Little street musicians, Paris. Image captured between 1910 and 1929.

Jules Séeberger, Louis Séeberger and Henri Séeberger, Licence Ouverte, via Wikimedia Commons. View source.

"Girona’s old town overflows with colourful displays during the “Temps de Flors” event each spring. The streets of Girona fill with colour and scent as the city hosts its annual flower festival in the medieval quarter".

By Biel Morro on Unsplash

NASA Astronomy Picture of the Day:

Why is the Cigar Galaxy billowing red smoke? M82, as this starburst galaxy is also known, was stirred up by a recent pass near large spiral galaxy M81. This doesn't fully explain the source of the red-glowing outwardly expanding gas and dust, however. Evidence indicates that this gas and dust is being driven out by the combined emerging particle winds of many stars, together creating a galactic superwind. The dust particles are thought to originate in M82's interstellar medium and are actually similar in size to particles in cigar smoke. The featured photographic mosaic combines images taken in visible light from the Hubble Space Telescope and images taken in infrared light from James Webb Space Telescope. It shows the light-colored central galaxy nearly edge on across the image center with tremendous orange and red colored filaments of gas and dust extending both up and down. The filaments extend for over 10,000 light years. The 12-million light-year distant Cigar Galaxy is the brightest galaxy in the sky in infrared light and can be seen in visible light with a small telescope towards the constellation of the Great Bear (Ursa Major).