Enceladus

image

Caption: On 9 Oct. 2008, just after coming within 25 kilometers (15.6 miles) of the surface of Enceladus, NASA's Cassini probe captured this stunning mosaic of Saturn's 500 km large ice-moon. Craters and cratered terrains are rare in this view of the southern region of the moon's Saturn-facing hemisphere. Instead, the surface is replete with fractures, folds, and ridges — all hallmarks of remarkable tectonic activity for a relatively small world. In this enhanced-color view, regions that appear blue-green are thought to be coated with larger grains than those that appear white or gray. Similar to Europa, Enceladus has a subsurface ocean of liquid water spanning the entire moon. A false colour image of a partially illuminated Enceladus. The white surface is covered by numerous straight and curved crevices at random orientations
Credit: NASA/JPL/Space Science Institute
Credit Link

Glossary Terms: Moons
Categories: Solar System

License: Public Domain Public Domain icons

File ( image 588.31 kB)

Titan in natural colours

image

Caption: This image taken by NASA's Cassini spacecraft in January 2012 shows Saturn's moon Titan in near natural colours. The orange-yellowsh colour stems from a layer of partially charged hyodrocarbon compounds. In the visible light, Titan's surface remains largely hidden below the opaque atmosphere.
Credit: NASA/JPL-Caltech/Space Science Institute
Credit Link

Glossary Terms: Moons , Titan
Categories: Solar System

License: Public Domain Public Domain icons

File ( image 24.07 kB)

Chilean Nights

video
Created for the OAE

Caption: Honourable mention in the 2022 IAU OAE Astrophotography Contest, category Time lapses of celestial patterns.   Shot in December 2020, this time-lapse shows the sky from San Pedro de Atacama, Chile, in the southern hemisphere. Right in the first frame we can see our home galaxy, the Milky Way, as well as both the Large and Small Magellanic clouds, two satellite galaxies orbiting the Milky Way. In the bottom of the image the bright stars Rigil Kentaurus and Hadar (also known as Alpha and Beta Centauri) are visible, both in the constellation Centaurus. Just above, we can also see the small constellation Crux, visible from the northern tropical circles southwards. It is important for navigation purposes because its longer axis indicates the direction of the celestial south pole. The bright whitish star in the top of the image and to the right of the Galaxy is Canopus, one of the brightest stars in the night sky, located in the constellation Carina. Canopus is the second brightest star in the sky, while Rigil Kentaurus is the third brightest. In some of the next frames, Orion, the great hunter, appears clearly with its bright stars and its characteristic asterism, the belt, composed of three aligned bright stars. Since this video was taken from the southern hemisphere, the Greek hero from the northern hemisphere seems to be performing a headstand. We can also see the planets Jupiter and Saturn in a close conjunction, even finding themselves in the significant beam of Zodiacal light setting down below the horizon. There are also a few meteors blinking in some of the frames, one of them with a long-lasting and developing trail. The very bright object rising from behind the volcanoes of the Andes, creating spectacular shadows and crepuscular rays, is the Moon. In the last frame we see the Moon next to Saturn and Jupiter.
Credit: Robert Barsa/IAU OAE

Glossary Terms: Astronomical Observatory , Constellation , Milky Way , Orion , Large Magellanic Cloud (LMC) , Small Magellanic Cloud (SMC) , Alpha Centauri
Categories: Galaxies , Milky Way and Interstellar Medium , Stars , Telescopes, Instruments and Observatories

License: Creative Commons Attribution 4.0 International (CC BY 4.0) Creative Commons Attribution 4.0 International (CC BY 4.0) icons

This file on Zenodo ( video 114.03 MB)

Flowing Night Sky

video
Created for the OAE

Caption: Honourable mention in the 2022 IAU OAE Astrophotography Contest, category Time lapses of celestial patterns.   This time-lapse was shot from Slovakia in August 2020. By fixing the relative movement of the sky to Earth's rotation in some of the frames, we can experience a different perspective as a viewer. The Milky Way, our home galaxy, is visible throughout the whole video. The bright objects near the Milky Way are Jupiter and Saturn, close together, Jupiter being the brighter one. This video also shows the interaction of amateur astronomers observing the Perseids meteor shower with their telescopes pointed towards the sky. An unfortunate aspect of the art of astronomical observing, clouds can suddenly cover the whole sky. The fog occurs mostly because of the higher humidity after the rain. Most of the light trails in the sky are made by satellites, but some of them, appearing just very briefly and not very noticeably, are meteors, as the video was shot around the peak of Perseids meteor shower.
Credit: Robert Barsa/IAU OAE

Glossary Terms: Jupiter , Milky Way , Saturn , Shooting Star
Categories: Milky Way and Interstellar Medium , Naked Eye Astronomy , Stars

License: Creative Commons Attribution 4.0 International (CC BY 4.0) Creative Commons Attribution 4.0 International (CC BY 4.0) icons

This file on Zenodo ( video 254.11 MB)

Equatorial Milky Way

image
Created for the OAE

Caption: Honourable mention in the 2022 IAU OAE Astrophotography Contest, category Still images of celestial patterns: Equatorial Milky Way   Taken in Bromo-Tengger-Semeru National Park, Java Island, Indonesia, in March 2016, this image captures regions of the southern Milky Way and, at its left edge, the two planets Mars and Saturn. Mars appears orange and is similar in colour to the star Antares, whose Greek name — anti Ares — references this. Saturn is a little bit fainter than Mars, but clearly visible among the stars of Ophiuchus, above the Pipe Nebula and forming an isosceles triangle with Mars and Antares. Mars is on the top and Saturn is vertically below. Visible to the naked eye, both planets have significance in many cultures around the world. In Roman mythology Mars is the god of war and fertility, and Saturn the god of sowing and agriculture. Its Greek equivalent, the god Kronos, is also considered the regent of completion. Indigenous Australians, including the Kamilaroi and Wailan people, associate Saturn with “wunygal”, a small bird. Mars is called Iherm-penh (something burnt in flames) by the Anmatyerre people of the Central Desert, while the Kokatha people of the Western Desert associate Mars and the star Anatres with the red-tailed black cockatoo (Kogolongo). In the middle of this photograph, the most famous southern constellations are clearly recognisable: the Southern Cross (Crux), the pointer stars, Alpha and Beta Centauri, the dark Coalsack Nebula and the red Eta Carina Nebula, which is not visible to the unaided eye but is prominent in modern photographs. In the 19th century, the star eta Carinae had been the second-brightest star in the sky for some time, but since it varies irregularly, it has hardly been recognisable in recent decades, and its future visibility is unpredictable. Triangulum Australe is visible between the pointer stars and the Scorpion, and in the constellation of Centaurus, the bright globular star cluster Omega Centauri is clearly displayed. It was considered a “nebulous star” since antiquity and, thus, was listed in star catalogues for at least 2000 years. Only within the last century did astronomers discover that globular star clusters are in the halo of our galaxy and that this one consists of roughly 10 million stars. The dark regions in the Milky Way, which are cool, dense clouds of dust and gas, form the head and body of the Celestial Emu Tchingal. Together with the Southern Cross and the pointer stars, they appear in the Dreamtime stories of many Indigenous Australians. One story associated with the Djab Wurrung and the Jardwadjali people is part of a Dreamtime Story involving Tchingal, the Bram-bram-bult brothers (the pointer stars), their mother Druk (Delta Crux), and Bunya the hunter, who gets transformed into a possum (Gacrux, the red star at the top of the Southern Cross).
Credit: Giorgia Hofer/IAU OAE

Glossary Terms: Dust , Mars , Milky Way , Saturn , Scorpius , Southern Cross , Dust Cloud , Interstellar Extinction , Alpha Centauri
Categories: Milky Way and Interstellar Medium , Naked Eye Astronomy

License: Creative Commons Attribution 4.0 International (CC BY 4.0) Creative Commons Attribution 4.0 International (CC BY 4.0) icons

This file on Zenodo ( image 1.61 MB)