Saturn And Dione - October 2 2011

“To go into solitude, a man needs to retire as much from his chamber as from society. I am not solitary whilst I read and write, though nobody is with me. But if a man would be alone, let him look at the stars. The rays that come from those heavenly worlds will separate between him and what he touches. One might think the atmosphere was made transparent with this design, to give man, in the heavenly bodies, the perpetual presence of the sublime. Seen in the streets of cities, how great they are! If the stars should appear one night in a thousand years, how would men believe and adore; and preserve for many generations the remembrance of the city of God which had been shown! But every night comes out these envoys of beauty, and light the universe with their admonishing smile.”

— Ralph Waldo Emerson, Nature (1836) | I. Isaac Asimov, in Nightfall, had a very different take.

Farewell to Cassini

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

Celebrating Five Years at Jupiter!

We just released new eye-catching posters and backgrounds to celebrate the five-year anniversary of Juno’s orbit insertion at Jupiter in psychedelic style.

On July 4, 2016, our Juno spacecraft arrived at Jupiter on a mission to peer through the gas giant planet’s dense clouds and answer questions about the origins of our solar system. Since its arrival, Juno has provided scientists a treasure trove of data about the planet’s origins, interior structures, atmosphere, and magnetosphere.

Juno is the first mission to observe Jupiter’s deep atmosphere and interior, and will continue to delight with dazzling views of the planet’s colorful clouds and Galilean moons. As it circles Jupiter, Juno provides critical knowledge for understanding the formation of our own solar system, the Jovian system, and the role giant planets play in putting together planetary systems elsewhere.

Get the posters and backgrounds here!

For more on our Juno mission at Jupiter, follow NASA Solar System on Twitter and Facebook.

Make sure to follow us on Tumblr for your regular dose of space!

“Cassini's own discoveries were its demise.”

– Earl Maize, its project engineer @ JPL

current mood: emotional about a space probe

Cassini is the first spacecraft that was destroyed not from malfunction, or as a necessary end result of its mission… but out of love.

The probe was running out of propulsion fuel, but there’s no reason it couldn’t have been pushed into a stable orbit from where it could collect data and send back pictures for a long while yet.

Except it had detected that one of Saturn’s moons held liquid water and organic compounds: a world that might support life. A world that is, at the least, dreaming of life.

There is no orbit stable enough to be certain that the probe, carrying radioactive batteries and Earth’s bacteria, would never have come into contact with Enceladus. A delicate island of alien life could have been snuffed out or overrun. The sheep could have eaten the rose.

So instead - for the love of this fragile possibility, this potential that might yet never be realized - Cassini was brought into a final, intimate tango with Saturn.

But of course, all space probes are built for the sake of awe, which is nearly love. Science is rational, but scientists are driven to understand the universe just as the religious strive to know the face of God.

The Cassini probe was a 4 billion dollar machine for understanding Saturn. And yesterday, two decades after it launched from our planet, it was destroyed while sending us information about Saturn it never could have gathered from a distant, stable orbit: advancing its purpose, even though it would be consumed.

sometimes i think about the golden record and i want to cry

(by lorenz.weisse)

50 Foot Long Congo Snake

In 1959 Remy Van Lierden was flying over the Katanga region in the Democratic Republic of the Congo. He was flying a helicopter and returning to the base that he commanded in Kamina. As he passed over a clearing in the jungle he noticed a large animal laying out in the sun. What he saw was a 50 foot long snake, with green and brown scales. He couldn’t believe his eyes and neither could his passengers. He circled around and made several passes off the monstrous snake, however he flew away when it got into the striking position and thought it was too dangerous to contour to fly over the animal. During one of the passes he made a passenger on his aircraft snapped this picture to prove what they saw. The snake in question is clearly large and it’s easy to see how it could have been a threat to a low flying helicopter. It’s believed that the snake is a Titanoboa which is thought to be extinct, and has been for millions of years. But it’s possible that the species may have survived. The natives claim that the snake pictured here is a small one and that they can get up to twice and three times the size.

Decoding Nebulae

We can agree that nebulae are some of the most majestic-looking objects in the universe. But what are they exactly? Nebulae are giant clouds of gas and dust in space. They’re commonly associated with two parts of the life cycle of stars: First, they can be nurseries forming new baby stars. Second, expanding clouds of gas and dust can mark where stars have died.

Not all nebulae are alike, and their different appearances tell us what's happening around them. Since not all nebulae emit light of their own, there are different ways that the clouds of gas and dust reveal themselves. Some nebulae scatter the light of stars hiding in or near them. These are called reflection nebulae and are a bit like seeing a street lamp illuminate the fog around it.

In another type, called emission nebulae, stars heat up the clouds of gas, whose chemicals respond by glowing in different colors. Think of it like a neon sign hanging in a shop window!

Finally there are nebulae with dust so thick that we’re unable to see the visible light from young stars shine through it. These are called dark nebulae.

Our missions help us see nebulae and identify the different elements that oftentimes light them up.

The Hubble Space Telescope is able to observe the cosmos in multiple wavelengths of light, ranging from ultraviolet, visible, and near-infrared. Hubble peered at the iconic Eagle Nebula in visible and infrared light, revealing these grand spires of dust and countless stars within and around them.

The Chandra X-ray Observatory studies the universe in X-ray light! The spacecraft is helping scientists see features within nebulae that might otherwise be hidden by gas and dust when viewed in longer wavelengths like visible and infrared light. In the Crab Nebula, Chandra sees high-energy X-rays from a pulsar (a type of rapidly spinning neutron star, which is the crushed, city-sized core of a star that exploded as a supernova).

The James Webb Space Telescope will primarily observe the infrared universe. With Webb, scientists will peer deep into clouds of dust and gas to study how stars and planetary systems form.

The Spitzer Space Telescope studied the cosmos for over 16 years before retiring in 2020. With the help of its detectors, Spitzer revealed unknown materials hiding in nebulae — like oddly-shaped molecules and soot-like materials, which were found in the California Nebula.

Studying nebulae helps scientists understand the life cycle of stars. Did you know our Sun got its start in a stellar nursery? Over 4.5 billion years ago, some gas and dust in a nebula clumped together due to gravity, and a baby Sun was born. The process to form a baby star itself can take a million years or more!

After billions more years, our Sun will eventually puff into a huge red giant star before leaving behind a beautiful planetary nebula (so-called because astronomers looking through early telescopes thought they resembled planets), along with a small, dense object called a white dwarf that will cool down very slowly. In fact, we don’t think the universe is old enough yet for any white dwarfs to have cooled down completely.

Since the Sun will live so much longer than us, scientists can't observe its whole life cycle directly ... but they can study tons of other stars and nebulae at different phases of their lives and draw conclusions about where our Sun came from and where it's headed. While studying nebulae, we’re seeing the past, present, and future of our Sun and trillions of others like it in the cosmos.

To keep up with the most recent cosmic news, follow NASA Universe on Twitter and Facebook.

Make sure to follow us on Tumblr for your regular dose of space.

The Most Hardcore Period in Earth’s History, or the Permian, was preceded by a complete ecosystem collapse, and featured three different major mass extinction events - including the largest in earth’s history, the Great Dying, which lead to nearly all life on earth dying out. 

During the Permian, all the land on Earth was in one supercontinent, called Pangea; and all the water was in one ocean, called Panthalassa. This meant that life intermingled and expanded all over the world, more so than it was able to in other periods (besides the Triassic, which also featured a single continent and a single ocean). 

Pangea, and the Permian, was characterized by extremes. The beginning of the Period featured the end of the Karoo Ice Age - the poles were filled with ice caps, the center of the continent was dry, and temperature extremes were found throughout the land and ocean. The end featured multiple mass extinctions and a rapid warming of the continent, reaching the extreme heat of the Triassic period. 

By @franzanth​ 

The Carboniferous Rainforest Collapse was primarily caused by an intensification of that ice age - leading to the start of the Permian featuring dry, harsh, extreme climates. This time period featured the rapid diversification and specialization of some of the earliest animals adapted for a dry existence - prior to now, life almost entirely existed in the oceans, or in the forested and swampy world of the Carboniferous. This was the first truly dry time for (at least some) life.  

By @alphynix​

Olson’s Extinction marked a change from that initial habitat in the Cisuralian epoch to the next, the Guadalupian. As the world began to rapidly warm after the Karoo Ice Age ended, this lead to a major extinction of plants and vertebrates especially. The vertebrates would not fully recover before the Triassic; however, it did lead to many new forms, especially among synapsids, appearing in the new vacant environmental roles. 

(By @paleoart​) 

The Capitanian Extinction was caused by the explosion of a moderately sized laval flow system, the Emeishan Traps, which lead to immediate global cooling followed by rapid global warming. This greatly affected ocean chemistry, making it far more acidic than previously. Many reef animals were killed by this extinction, in addition to brachiopods; many vertebrates were also affected. 

(By @paleoart​) 

So the Permian was a hard, broken world when the Siberian Traps - one of the largest lava flows in Earth’s History, and one of the largest volcanic events known - exploded, leading to even more dramatic climate change and extremely rapid global warming. This lead to acidification of the ocean’s and a dramatic drop in ocean oxygen. Almost every group of organisms was dramatically affected, and this extinction was the largest known in Earth’s History, with between 85-96% of life on Earth dying out (and some researchers thinking it may have even been higher), leading to this extinction being dubbed The Great Dying. Many groups utterly disappeared, despite having been features of the entire Paleozoic Eon (the eon that the Permian was at the end of) - trilobites, eurypterids, “spiny sharks”, tabulate and rugose corals, and blastoids complete disappeared, as did many other groups. Brachiopods, Gastropods, Ammonites, Radiolarians, Foraminiferans, Crinoids, and most Parareptiles also went extinct, as did many synapsids and amphibians. It was an utter catastrophe. 

(By @paleoart​) 

The Permian was a time of extensive hardship, dramatic changes, and extinction event after extinction event. Life was truly on the brink - just as it was beginning to settle into terrestrial existence. So new animals, from insects to amniotes to conifers, spent their school years in a prehistoric hunger games - and only a few species managed to reach the weirdness kiln of the Triassic. 

Welcome to the Permian. 

The Most Hardcore Period of Earth’s History.