Contributor Posts

NASA Astronomy Picture of the Day:

What's happening in the center of nearby spiral galaxy M77? The face-on galaxy lies a mere 47 million light-years away toward the constellation of the Sea Monster (Cetus). At that estimated distance, this gorgeous island universe is about 100 thousand light-years across. Also known as NGC 1068, its compact and very bright core is well studied by astronomers exploring the mysteries of supermassive black holes in active Seyfert galaxies. M77's active core glows bright at x-ray, ultraviolet, visible, infrared, and radio wavelengths. The featured sharp image of M77 was taken by the Hubble Space Telescope. The image shows details of the spiral's winding spiral arms as traced by obscuring red dust clouds and blue star clusters, all circling the galaxy's bright white luminous center. Free APOD Lecture in Phoenix: Wednesday, December 10 at 7 pm

Fortified city of Carcassonne during the blue hour, France. Founded during the Gallo-Roman period, the citadel derives its reputation from its 3 kilometres (1.9 mi) long double surrounding walls interspersed by 52 towers. The medieval citadel, situated on a hill on the right bank of the river Aude, was restored at the end of the 19th century by the theorist and architect Eugène Viollet-le-Duc. In 1997, it was added to the UNESCO list of World Heritage Sites because of its exceptional testimony to the architecture and planning of a medieval fortress town.

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

NASA Astronomy Picture of the Day:

How typical is our Solar System? Studying 3I/ATLAS, a comet just passing through, is providing clues. Confirmed previous interstellar visitors include an asteroid, a comet, a meteor, and a gas wind dominated by hydrogen and helium. Comet 3I/ATLAS appears relatively normal when compared to Solar System comets, therefore providing more evidence that our Solar System is a somewhat typical star system. For example, Comet 3I/ATLAS has a broadly similar chemical composition and ejected dust. The featured image was captured last week from Texas and shows a green coma, a wandering blue-tinted ion tail likely deflected by our Sun's wind, and a slight anti-tail, all typical cometary attributes. The comet, visible with a telescope, passed its closest to the Sun in late October and will pass its closest to the Earth in mid-December, after which it will return to interstellar space and never return. Explore the Universe: Random APOD Generator

Photo by Victor Sabet & Julien De Winter

Narrow-banded dartwhite (Catasticta flisa postaurea) on Mimosa pudica, Villa Gerar, Silvania, Cundinamarca, Colombia.

Charles J. Sharp, CC BY-SA 4.0, via Wikimedia Commons. View source.

NASA Astronomy Picture of the Day:

If you could stand on Titan -- what would you see? The featured color view from Titan gazes across an unfamiliar and distant landscape on Saturn's largest moon. The scene was recorded by ESA's Huygens probe in 2005 after a 2.5-hour descent through a thick atmosphere of nitrogen laced with methane. Bathed in an eerie orange light at ground level, rocks strewn about the scene could well be composed of water and hydrocarbons frozen solid at an inhospitable temperature of negative 179 degrees C. The large light-toned rock below and left of center is only about 15 centimeters across and lies 85 centimeters away. The saucer-shaped spacecraft is believed to have penetrated about 15 centimeters into a place on Titan's surface that had the consistency of wet sand or clay. Huygen's batteries enabled the probe to take and transmit data for more than 90 minutes after landing. Titan's bizarre chemical environment may bear similarities to planet Earth's before life evolved.

Vineyard worker at Guadalupe Valley, Baja California, Mexico, where 95% of Mexican wines are produced.

Tomas Castelazo, CC BY 3.0, via Wikimedia Commons. View source.

NASA Astronomy Picture of the Day:

This is not a screen from a video game. Nestled below the tree-line, the small mountain church does look like it might be hiding from Moon though. In the well-composed telephoto snapshot, taken on November 23, the church walls are partly reflecting light from terrestrial flood lights. Of course, the Moon is reflecting light from the Sun. At any given time the Sun illuminates fully half of the Moon's surface, also known as the lunar dayside, but on that night only a sliver of its sunlit surface was visible. About three days after New Moon, the Moon was in a waxing crescent phase. The single exposure was captured shortly after sunset in skies near Danta di Cadore, northern Italy, planet Earth.

Photo by Giorgia Hofer