Public Posts

NASA Astronomy Picture of the Day:

Comet Lemmon is brightening and moving into morning northern skies. Besides Comet SWAN25B and Comet ATLAS, Comet C/2025 A6 (Lemmon) is now the third comet currently visible with binoculars and on long camera exposures. Comet Lemmon was discovered early this year and is still headed into the inner Solar System. The comet will round the Sun on November 8, but first it will pass its nearest to the Earth -- at about half the Earth-Sun distance -- on October 21. Although the brightnesses of comets are notoriously hard to predict, optimistic estimates have Comet Lemmon then becoming visible to the unaided eye. The comet should be best seen in predawn skies until mid-October, when it also becomes visible in evening skies. The featured image showing the comet's split and rapidly changing ion tail was taken in Texas, USA late last week. Growing Gallery: Comet Lemmon in 2025

Photo by Victor Sabet & Julien De Winter

Loggerhead sea turtle (Caretta caretta) with diver in the background, Fernando de Noronha Marine National Park, Pernambuco, Brazil.

João D'Andretta, CC BY-SA 4.0, via Wikimedia Commons. View source.

NASA Astronomy Picture of the Day:

It may look like these comets are racing, but they are not. Comets C/2025 K1 ATLAS (left) and C/2025 R2 SWAN (right) appeared near each other by chance last week in the featured image taken from France's Reunion Island in the southern Indian Ocean. Fainter Comet ATLAS is approaching our Sun and will reach its closest approach in early October when it is also expected to be its brightest -- although still only likely visible with long exposures on a camera. The brighter comet, nicknamed SWAN25B, is now headed away from our Sun, although its closest approach to Earth is expected in mid-October, when optimistic estimates have it becoming bright enough to see with the unaided eye. Each comet has a greenish coma of expelled gas and an ion tail pointing away from the Sun. Growing Gallery: Comet SWAN25B

Photo by Luc Perrot (TWAN)

Fall of the Rebel Angels is a fresco by Giacinto Brandi adorning the central vault of Sant'Ambrogio e Carlo al Corso basilica in Rome. It depicts Michael the Archangel's victory in battle over fallen angels. Today is Michaelmas.

Giacinto Brandi, CC BY-SA 4.0, via Wikimedia Commons. View source.

William Edward Burghardt (W.E.B.) Du Bois - (1868  - 1963) was an American sociologist, socialist, historian, and Pan-Africanist civil rights activist. Born in Great Barrington, Mass. , Du Bois completed his graduate work at Belin's Friedrich Wilhelm University and Harvard University, where he was its first African American to earn a doctorate. Du Bois rose to national prominence as a leader of the Niagara Movement, a group of black civil rights activists seeking equal rights who opposed the the Atlanta Compromise, insisting on full civil rights and increased political representation. He was one of the founders of the National Association for the Advancement of Colored People (NAACP) in 1909

Du Bois argued that the true measure of a nation's prosperity lies not in wealth accumulation by a select few, but in the well-being and opportunities available to all citizens. He emphasized the importance of addressing poverty, ensuring access to healthcare, providing quality education, and fostering a culture of literacy as key indicators of a truly prosperous nation.

NASA Astronomy Picture of the Day:

What is creating these unusual spots? Light-colored spots on Martian rocks, each surrounded by a dark border, were discovered last year by NASA's Perseverance Rover currently exploring Mars. Dubbed leopard spots because of their seemingly similarity to markings on famous Earth-bound predators, these curious patterns are being studied with the possibility they were created by ancient Martian life. The pictured spots measure only millimeters across and were discovered on a larger rock named Cheyava Falls. The exciting but unproven speculation is that long ago, microbes generated energy with chemical reactions that turned rock from red to white while leaving a dark biosignature ring, like some similarly appearing spots on Earth rocks. Although other non-biological explanations have not been ruled out, speculation focusing on this potential biological origin is causing much intrigue.

French chemist and microbiologist Louis Pasteur photographed by Nadar. Renowned for his scientific discoveries, he saved millions by developing vaccines for rabies and anthrax, as well as the process of pasteurization. He died on this day 130 years ago.

Paul Nadar, Public domain, via Wikimedia Commons. View source.

NASA Astronomy Picture of the Day:

On the morning of September 24 a rocket crosses the bright solar disk in this long range telescopic snapshot captured from Orlando, Florida. That's about 50 miles north of its Kennedy Space Center launch site. This rocket carried three new space weather missions to space. Signals have now been successfully acquired from all three - NASA's Interstellar Mapping and Acceleration Probe, NASA’s Carruthers Geocorona Observatory, and the National Oceanic and Atmospheric Administration (NOAA) Space Weather Follow-On Lagrange 1 (SWFO-L1) - as they begin their journey to L1, an Earth-Sun lagrange point. L1 is about 1.5 million kilometers in the sunward direction from planet Earth. Appropriately, major space weather influencers, aka dark sunspots in active regions across the Sun, are posing with the transiting rocket. In fact, large active region AR4225 is just right of the rocket's nose.

Photo by Pascal Fouquet

Panoramic view of the west bank of Nigeen Lake in Srinagar, India, with the distant Middle Himalayan Pir Panjal mountain range in the background. The city, situated on the banks of the Jhelum river and several lakes in the Himalayan Kashmir Valley, is the summer capital of Jammu and Kashmir and the northernmost million-plus city of India.

Original: KennyOMG Derivative work: UnpetitproleX, CC BY-SA 4.0, via Wikimedia Commons. View source.