Io: The Volcanic Moon

Dunkleosteus

Dunkleosteus, a placoderm, or armoured, fish. It lived around 370 million years ago, during the Devonian period and is arguably the biggest predator of its time. This was a truly impressive fish, literally hard as nails, its head was encased in a solid armour plating and like a shark, it had a streamlike body to swiftly move through the water. Its heavy armour means it would’ve been a relatively slow swimmer, yet capable of short spurts of speed, sort of like some sharks today.

This formidable beast had a major evolutionary strength, a moveable jaw. Fish began to dominate the oceans when they evolved the ability to move their jaw, yet Dunkleosteus had no teeth, what it had was much more menacing. It had  razor like blades to slice its prey apart, like a pair of scissors to paper, with a bite more powerful than a great white. It would’ve been able to slice its prey in half so it was able to consume huge animals, yet on the downside the Dunkleosteus was unable to chew and on occasion its stomach found the huge chunks of meat hard to handle, evidence of this is in fossilised sick of the Dunkleosteus that has been found…

(Dunkleosteus armour means its head is often very well preserved. You can see how its teeth would’ve been more than capable of shearing through flesh.)

Relatives of the dunkleosteus, other armoured fish, were mostly dog sized, but Dunkleosteus was an exception. At 6 metres long on average, twice the length of human, this was a seriously big fish, yet it could reach up to 10 metres long, the length of a bus. 

Dunkleosteus seems like the perfect predator. However, in its bony plates, indents of other animal teeth have been found suggesting that despite its strength, it was itself hunted. Dunkloesteus teeth marks have been found in its own fossils, they would eat whatever they could get their teeth into, including each other. The success of this gigantic beast was short lived, it was outcompeted by the more nimble sharks. Placoderm fish themselves would be extinct by the end of the devonian, taking the Dunkleosteus with it.

Great Basin National Park in Nevada is one of the darkest spots in the United States. What better time to appreciate this park’s clear night sky, then on International Day of Clean Air? Good air quality coupled with a lack of light pollution give visitors majestic starry views of Wheeler Peak. On clear, moonless nights at Great Basin, thousands of stars, numerous planets, star clusters, meteors, man-made satellites, the Andromeda Galaxy, and the Milky Way can be seen with the naked eye. The area boasts some of the darkest night skies left in the country. Low humidity, good air quality, and minimal light pollution, combined with high elevation, create a unique window to the universe. Photo by John Vermette (sharetheexperience.org). Photo description: A bright Milky Way and night sky filled with stars light up the mountains below.

Saturn’s atmosphere exhibits a banded pattern similar to Jupiter’s, but Saturn’s bands are much fainter and are much wider near the equator. The nomenclature used to describe these bands is the same as on Jupiter. Saturn’s finer cloud patterns were not observed until the flybys of the Voyager spacecraft during the 1980s. Since then, Earth-based telescopy has improved to the point where regular observations can be made. The composition of the clouds varies with depth and increasing pressure.

The winds on Saturn are the second fastest among the Solar System’s planets, after Neptune’s. Voyager data indicate peak easterly winds of 500 m/s (1,800 km/h).

Thermography has shown that Saturn’s south pole has a warm polar vortex, the only known example of such a phenomenon in the Solar System. Whereas temperatures on Saturn are normally −185 °C, temperatures on the vortex often reach as high as −122 °C, suspected to be the warmest spot on Saturn.

Credit: NASA/JPL-Caltech/Space Science Institute and Kevin M. Gill

QUETZALCOATLUS

Quetzalcoatlus goes down in history as the largest flying organism of all time, with a wingspan of 12 metres, which is larger than some planes. Quetzalcoatlus was the undisputed king of the Late cretaceous skies, so it seems fitting that its name is derived from an Aztec god, Quetzalcoatl. Although its wingspan is impressive, Quetzalcoatlus also had a huge 2.5 metre long skull, that is the average height of an Asian elephant! To get such a huge animal in the air, a complex system of air sacs was needed inside the bones, this meant that Quetzalcoatlus probably weighed no more than 250kg. Quetzalcoatlus, along with many pterosaurs, was originally thought to spend most of its time gliding over the oceans, skimming fish out from the surface of the water with their elongated beaks. However, due to the skull and beak morphology and the presence of fossils far inland it has become more widely accepted that Quetzalcoatlus stalked prey far below on the land. The fore and hind limb morphology of Quetzalcoatlus also suggests that they were competent walkers on the land, they would have stood up to 3 metres tall. 

The feeding habits of Quetzalcoatlus still remain something of a mystery. It was originally thought to be more of a scavenger, but the blunt beak was unsuited to stripping and picking flesh of a bony creature. It is more likely that Quetzalcoatlus hunted like modern-day storks, stalking the land from the skies above for smaller animals and then swooping down to eat them whole.

The Secret Life of Crows

Walking the edge of Bromo Crater. Would you hike this route ? East Java, Indonesia 🇮🇩 🎥 @backpackertampan

planetearthtv

Hubble Anniversary Image Captures Roiling Heart of Vast Stellar Nursery by NASA Hubble

Jupiter is perpetually covered with clouds composed of ammonia crystals and possibly ammonium hydrosulfide. The clouds are located in the tropopause and are arranged into bands of different latitudes, known as tropical regions. These are sub-divided into lighter-hued zones and darker belts. The interactions of these conflicting circulation patterns cause storms and turbulence. Wind speeds of 100 m/s (360 km/h) are common in zonal jets. The zones have been observed to vary in width, color and intensity from year to year, but they have remained sufficiently stable for scientists to give them identifying designations.

The cloud layer is only about 50 km (31 mi) deep, and consists of at least two decks of clouds: a thick lower deck and a thin clearer region. There may also be a thin layer of water clouds underlying the ammonia layer. Supporting the idea of water clouds are the flashes of lightning detected in the atmosphere of Jupiter. These electrical discharges can be up to a thousand times as powerful as lightning on Earth. The water clouds are assumed to generate thunderstorms in the same way as terrestrial thunderstorms, driven by the heat rising from the interior.

source

Created using still images taken by the Cassini spacecraft during it’s flyby of Jupiter and while at Saturn. Shown is Io and Europa over Jupiter’s Great Red Spot.

NASA/JPL-Caltech/SSI/CICLOPS/Kevin M. Gill

I am so grateful that this thing is fucking extinct.

I would never have been able to tolerate having the job of creating this 3D model.

THIS IS WHAT MY WORST NIGHTMARE LOOKS LIKE.