Category: saturn

Spectacular Planetary And Lunar Alignment To Grace The Post-Sunset Thanksgiving Skies

“As 2019 has progressed, Saturn has followed Jupiter in its sky-crossing migration from east to west. Meanwhile, for about the past month, Venus has emerged as an evening star after sunset, drifting from west to east. On Sunday, November 24, Venus and Jupiter nearly met — achieving a conjunction — coming within 1.4° of each other.”

Normally, astronomical conjunctions are a big and spectacular deal, especially when they’re close, and particularly when they’re between the two brightest planets of all: Venus and Jupiter. But on American Thanksgiving, November 28, an extraordinary and unusual event will occur: the young crescent Moon will align with Venus and Jupiter as well, fresh off a conjunction. While skywatchers worldwide will get a spectacular show, the best views come for people in European and African longitudes, as they’ll see the Moon appear between closely spaced Venus and Jupiter.

This rare sight will only last for that one night, so make sure you know where to look and what to look for, because it’s your last chance to experience it for years!

Happy 230th Birthday, Enceladus, Our Solar System’s Greatest Hope For Life Beyond Earth

“It is still a complete unknown whether Earth is the only world in the Solar System to house any form of life: past or present. Venus and Mars may have been Earth-like for a billion years or more, and life could have arisen there early on. Frozen worlds with subsurface oceans, like Enceladus, Europa, Triton or Pluto, are completely different from Earth’s present environment, but have the same raw ingredients that could potentially lead to life as well.

Are water, energy, and the right molecules all we need for life to arise? Finding even the most basic organisms (or even the precursor components of organisms) anyplace else in the Universe would lead to a scientific revolution. A single discovered cell in the geysers of Enceladus would be the most momentous discovery of the 21st century. With the recent demise of Cassini, on the 230th anniversary of Enceladus’ discovery, the possibility of finding the incredible compels us to go back. May we be bold enough to make it so.”

On this date in 1789, William Herschel, armed with the most powerful telescope known to humanity at the time (you can get a lot of grant money when you discover the planet Uranus and name it after the King), discovered a relatively small moon of Saturn just 500 kilometers across: Enceladus. For some 200 years, Enceladus was never seen as more than a single pixel across, until the Voyager probes flew by it. What they revealed was a remarkable, unique world in all the Solar System. Now that the Cassini mission is complete, we can look back at all we know about this world, and all the signs point to a remarkable story: there’s a subsurface ocean, possibly suitable as a home for undersea life.

Is Enceladus truly our Solar System’s best hope for life beyond Earth? That’s debatable, but there’s every reason to be hopeful. Come get the story here.

Saturn, Not Earth Or Jupiter, Has The Largest Storms In Our Solar System

“But from December of 2010 to August of 2011, the largest storm of all occurred: on Saturn. For 200+ days, this Saturnian hurricane raged, maintaining its leading “head” until May. It came to encircle the entire planet, as methane-poor tail end stands out against the relatively methane-rich remainder. Viewed 11 hours (1 Saturn-day) apart, we determined the hurricane migrated across Saturn at 60 miles-per-hour (100 kph). These storms have occurred every 20-30 years since first observed in 1876, as hot air rises, cools and falls.”

Many worlds in our Solar System have enormous storms that occur in their atmospheres. Earth routinely experiences hurricanes, with wind speeds frequently in excess of 225 kph. But what happens on the giant worlds in our Solar System dwarf anything that happens on Earth. Saturn’s hurricane at its north pole is bigger and faster than any hurricane we’ve ever seen here. Jupiter’s great red spot is bigger than the entire Earth itself. But the largest storm of all? 

Believe it or not, it’s a periodic weather event that appears to occur on Saturn every 20-30 years or so. Keep your eyes peeled in the 2030s, because it’s going to return!

The Moon Will Swallow Saturn This Friday Morning, And You Can See The Event Yourself

“Almost all occultations that are visible from Earth occur between the Moon and another planet, but there’s something special about occultations of Saturn, owing to the extended, easily-visible nature of its ring system. The events themselves last longer as the planet disappears and reappears behind the Moon, as Saturn with its rings is a more extended sight than any other world as viewed from Earth.

There’s an entire astronomy enthusiast community devoted to observing occultations, and they’ve developed some very extensive resources that are freely available to the public. If you miss the occultation of Saturn on March 29, don’t fret; there’s another coming up on April 25, visible from Australia, New Zealand, and the western portion of South America.

When you see that pinprick of light approach the Moon, remember what it is you’re really looking at: the great ringed giant of our Solar System, preparing for its spectacular moment in the shade.”

On Friday morning, March 29, the Moon will appear to pass in front of Saturn, creating the spectacular and rare phenomenon of an occultation. For skywatchers across most of the world, it will simply appear as a close approach, as though the Moon had a satellite of its own for a brief time. But if you’re located in eastern South America or southern Africa, you might want to take a closer look for a chance at seeing the disappearance or reapparance of Saturn behind the Moon!

The Moon will swallow Saturn this coming Friday morning, and if you’re careful and prepared, you can see the event for yourself.

Don’t forget to follow on instagram! -> funophysics

Saturn’s rotational axis is tilted, just like Earth. While Earth’s
axis is tilted at an angle of 23.4°, Saturn’s tilt is 26.7°, which is
pretty close. 

In these pictures [1-2] you can witness the
dramatic shadows on Saturn that are cast by its rings. And in [3-4] the
shadows that are cast by Saturn on its rings. Truly epic!


Image Credit: NASA/JPL-Caltech/Space Science Institute
     

        

Top 6 Discoveries Of Cassini As Its 20-Year Mission Comes To An End

2.) The largest storm ever known in the Solar System. Like all the planets with atmospheres, Saturn contains its own weather, complete with storms both large and small. While the Cassini mission was able to discover a number of interesting ones on the ringed-world, such as the long-lived polar hexagon and the Southern hemisphere’s Dragon Storm, the most spectacular occurred in 2011, emerging in the northern hemisphere, encircling the entire planet, lapping itself and lasting over 200 days. Images taken as close together as one rotation apart showed that the storm migrated across the Saturnian surface at 60 miles per hour (100 km/hr).

While a handful of storms of this magnitude have been observed every 20–30 years or so dating back to 1876, this was the largest, longest-lived one. In April, we found these storms are suppressed by water vapor in the lower layers of Saturn’s atmosphere. Being heavier than not only hydrogen and helium but also methane, the wet water vapor forms a layer underneath Saturn’s outer exosphere, insulating the inner part of the world. Eventually, the outer layers cool so much that they sink, allowing the inner, wet layers — and storms — to re-emerge. Having developed this picture from Cassini’s true and false-color images, the next major Saturnian storm, predicted for the 2030s, could finally teach us how much water our ringed neighbor contains.”

Launched back in October of 1997, Cassini will take its final plunge into the ringed world it’s been orbiting for over a decade on Friday, September 15th. Before it does, however, it’s worth a look back at the tremendous science that’s come about from the first dedicated mission to venture out to Saturn, including a series of surprises that we had no idea we’d find when we were planning and preparing this mission. Sure, our radioisotope-powered spacecraft was equipped with a lander to investigate the giant moon Titan, and many instruments to analyze the various molecules it would find on Saturn, in its rings, and in its many moons. But the polar hexagon and the central vortex, the largest storm ever seen in the Solar System’s history, a myriad of features in the rings (and their gaps), the cause of the two-toned nature of Iapetus and much, much more all came about not because we were seeking to solve these mysteries, but because we had built a spacecraft capable of looking for more than what we were anticipating.

Take a look back at the top six discoveries of Cassini, with more than 20 images to take your breath away!

Enceladus – Life in our solar system?

Enceladus is Saturns icy moon that measures approximately 504km in diameter, about a tenth of the size of Saturn’s largest moon Titan. Almost completely covered in ice, this moon could potentially harbour the same type of life-sustaining chemical reactions found in deep sea hydrothermal vents here on Earth.

In 2005, NASA’s Saturn orbiting Cassini spacecraft spotted geysers of water and ice erupting fro fissures near Enceladus’ South Pole. Scientists believe they originate from a great ocean beneath the shell of ice. This ocean manages to stay liquid because the gravitational force exerted by Saturn is so intense that it twists and stretches the moon generating internal heat.

In October 2015, Cassini went on a dive through one of the plumes passing within just 39km of Enceladus’ surface. A team of scientists led by Hunter Waite analysed the observations made by the spacecraft. They discovered that the geysers contain between 0.4%-1.4% molecular hydrogen (H2) and 0.3%-0.8% carbon dioxide (CO2). These are being produced continuously by reactions between hot water and rock near the core of the moon. Some of the most primitive metabolic pathways found in microbes at deep ocean hydrothermal vents involve the reduction of CO2 with H2 to form methane (CH4) by a process known as methanogenesis.