Contributor Posts

NASA Astronomy Picture of the Day:

You'd think the Pacman Nebula would be eating stars, but actually it is forming them. Within the nebula, a cluster's young, massive stars are powering the pervasive nebular glow. The eye-catching shapes looming in the featured portrait of NGC 281 are sculpted dusty columns and dense Bok globules seen in silhouette, eroded by intense, energetic winds and radiation from the hot cluster stars. If they survive long enough, the dusty structures could also be sites of future star formation. Playfully called the Pacman Nebula because of its overall shape, NGC 281 is about 10,000 light-years away in the constellation Cassiopeia. This sharp composite image was made through narrow-band filters in Spain in mid 2024. It combines emissions from the nebula's hydrogen and oxygen atoms to synthesize red, green, and blue colors. The scene spans well over 80 light-years at the estimated distance of NGC 281.

Photo by Juan Montilla (AAE)

NGC 281 is a bright emission nebula in the northern constellation of Cassiopeia, at a distance of 9200 ly from the Solar System. The partial superimposition of a dark nebula makes it resemble Pac-Man.

Chuck Ayoub, CC BY-SA 4.0, via Wikimedia Commons. View source.

NASA Astronomy Picture of the Day:

What causes a blue band to cross the Moon during a lunar eclipse? The blue band is real but usually quite hard to see. The featured HDR image of last week's lunar eclipse, however -- taken from Norman, Oklahoma (USA) -- has been digitally processed to exaggerate the colors. The gray color on the upper right of the top lunar image is the Moon's natural color, directly illuminated by sunlight. The lower parts of the Moon on all three images are not directly lit by the Sun since it is being eclipsed -- it is in the Earth's shadow. It is faintly lit, though, by sunlight that has passed deep through Earth's atmosphere. This part of the Moon is red -- and called a blood Moon -- for the same reason that Earth's sunsets are red: because air scatters away more blue light than red. The unusual purple-blue band visible on the upper right of the top and middle images is different -- its color is augmented by sunlight that has passed high through Earth's atmosphere, where red light is better absorbed by ozone than blue. Celestial Surprise: What picture did APOD feature on your birthday? (post 1995)

Photo by Zixiong Jin

Annunciation (c. 1472–1475), is thought to be Leonardo da Vinci's earliest complete work. Today is the Feast of the Annunciation.

Leonardo da Vinci, CC BY-SA 4.0, via Wikimedia Commons. View source.

Portrait of French novelist Jules Verne taken in 1884 by Étienne Carjat. Known for his adventure novels taking into account the technological progress of his time, he's the second most-translated author in the world. He died on this day 120 years ago.

Étienne Carjat / Adam Cuerden, Public domain, via Wikimedia Commons. View source.

Albert Einstein (1879 – April 1955) - German-born theoretical physicist best known for developing the theory of relativity and his important contributions to quantum mechanics. His mass–energy equivalence formula E = mc2, which arises from special relativity, has been called "the world's most famous equation". He received the Nobel Prize in Physics in 1921, "for his services to Theoretical Physics and especially for his discovery of the law of the photoelectric effect" More 

NASA Astronomy Picture of the Day:

This was once a beach -- on ancient Mars. The featured 360-degree panorama, horizontally compressed, was taken in 2017 by the robotic Curiosity rover that explored the red planet. Named Ogunquit Beach after its terrestrial counterpart, evidence shows that at times long ago the area was underwater, while at other times it was at the edge of an ancient lake. The light peak in the central background is the top of Mount Sharp, the central feature in Gale Crater where Curiosity explored. Portions of the dark sands in the foreground were scooped up for analysis. The light colored bedrock is composed of sediment that likely settled at the bottom of the now-dried lakebed. The featured panorama (interactive version here) was created from over 100 images and seemingly signed by the rover on the lower left.

Singer "Shakey Sue" at a concert by the band "The Hellfreaks" in Erfurt.

Steffen Prößdorf, CC BY-SA 4.0, via Wikimedia Commons. View source.