Contributor Posts

Westrup Heide in the early morning during the heather blossom season, Haltern am See, North Rhine-Westphalia, Germany.

Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons. View source.

NASA Astronomy Picture of the Day:

This sparkling, colorful gemstone is a spiral galaxy, NGC 300. It is one of the closest spiral galaxies to Earth, only about 6 million light-years away. But does it really look like this? Here is a more standard portrait of it. This unusual image combines the light from the stars and dust within the galaxy with the light from ionized clouds of interstellar gas shown in red (Sulphur), green (Hydrogen) and blue (Oxygen). Combining red and green light in different proportions makes yellow or orange light, most visible in the image. Light from other ionized gases is also at work in neon signs, fluorescent tubes and street lights. These massive clouds of ionized gas are typically created by young, massive stars that produce high-energy ultraviolet radiation capable of ionizing the gas. Massive stars are short-lived, compared with lighter stars like our sun, and explode as supernovas at the end of their lives. Some of the colorful clouds in the image could be hiding supernova remnants.

Photo by Team Ciel Austral Text: Cecilia Chirenti (NASA GSFC, UMCP, CRESST II)

Emerald swift (Sceloporus malachiticus) Finca El Pilar, Antigua Guatemala. Also known as the green spiny lizard.

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

NASA Astronomy Picture of the Day:

Is there an angry Sith using force lightning in the Tatacoa Desert? This is not science fiction, but a red sprite with multiple streamers! Ordinary lightning occurs when thundercloud particles collide, lose their electrons, and build up negative charge at the cloud bottom. The cloud’s negative charge repels negative charge deeper into the Earth, leaving Earth’s surface positively charged. The opposite charges attract, reaching towards each other and superheating the air into a white strike of plasma. Red sprites are millisecond events triggered by positive cloud-to-ground lightning. They extend up into the mesosphere where the air is too thin for thunder. Their red glow comes from heated molecular nitrogen. There are several potential causes for red sprites, including that the preceding positive lightning exposes the negatively charged cloud core to the positively charged upper atmosphere, allowing those charges to connect. NASA’s Juno has observed sprites on Jupiter, indicating that sprites occur on other planets!

Photo by Mario Vargas Text: Keighley Rockcliffe (NASA GSFC, UMBC CSST, CRESST II)

Adult woman of the Laarim Tribe smoking in a pipe, Kimotong, South Sudan.

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

John Constable (1776 – 1837). English landscape painter, born in Suffolk. His work is classified as being in the Romantic tradition. He is known principally for revolutionizing the genre of landscape painting with his paintings of Dedham Vale where his home was located. The area is now known "Constable Country" Some of his most well known paintings include Wivenhoe Park (1816), Dedham Vale (1821) and The Hay Wain (1821). His paintings are now among the most popular and valuable in British art. 

NASA Astronomy Picture of the Day:

Why is this asteroid a double? Earlier this month the Japanese robotic spacecraft Hayabusa2 shot past asteroid 98943 Torifune and captured pictures. Although previous observations from distant Earth indicated that Torifune was oblong, Hayabusa2 found that Torifune actually has two joined lobes. With a length of about four soccer fields, this space rock frequently comes near the Earth as it orbits the Sun, although it is not a threat. Besides the two lobes, Torifune shows many large boulders, but, surprisingly, no obvious craters, likely because its surface is a pile of rubble. Like asteroid Arrokoth, it appears that each lobe formed separately before colliding and becoming stuck together. Hayabusa2 famously encountered asteroid Ryugu in 2018, and now heads for an encounter in 2031 with 1998 KY26, a smaller asteroid that rotates unusually fast and might have reservoirs of ice.

Photo by JAXA, U. of Tokyo, Chiba Tech, Tokyo U. of Science, AIST, Paris Obs., IAC

The Medieval town of Belcastel in Aveyron, France, named one of "the most beautiful villages of France". Today is Bastille Day, the French National Day.

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