Magazine Posts

NASA Astronomy Picture of the Day:

At sunset, an alignment of rainbow and mountain shadow was captured in this remarkable snapshot. The stunning view was recorded from a fire lookout on Smith Peak in the Plumas National Forest near Portola, California on July 13. Still, near sunset it's no accident that the majestic mountain shadow seems to point to the center of the graceful rainbow arc. Due to perspective and the long line of sight the mountain shadow naturally forms a tapering triangular shape, its apex positioned at the point opposite the Sun on the horizon. Following thunderstorms across the region, the rainbow arcs across the early evening sky, with its colorful and characteristic 42 degree arc formed as sunlight is refracted and reflected by the atmospheric water droplets. The geometric center of a rainbow arc lies at the antisolar point. And in this scene from the golden hour on planet Earth, that's also oposite the setting Sun along the distant horizon.

Sur En/Sent, municipality of Scuol, kanton Graubünden. Sculpture Negativ - Positive. Artwork by Peter Gredig.

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

Welcome to Kudos365 Weekly History Challenge. Test your history  knowledge and see how many of the history questions you can answer correctly. A new updated History Challenge is released every Saturday.

NASA Astronomy Picture of the Day:

Comet 10P/Tempel 2 orbits the Sun once every 5.4 years. Currently visible in binoculars or small telescopes toward the constellation Capricornus, the periodic comet is captured in this sharp telescopic image from July 11 sporting a bright nuclear region and pretty greenish coma. Remarkably, a thin dust trail, not a typical dust tail, is also seen extending both east and west of the Tempel 2 nucleus. Unlike a comet dust tail, which tends to temporarily fan out in a direction away from the Sun, this dust trail is due to the residual dust shed during many past orbits along this ancient periodic comet's orbital plane. In fact, Tempel 2's dust trail may get a little narrower and brighter from our perspective as Earth crosses through the comet's orbital plane on July 20. Comet 10P/Tempel 2 will reach a perihelion on August 2, and make its closest approach to Earth on August 3.

Photo by Dan Bartlett

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.