Category: enceladus

Happy 230th Birthday, Enceladus, Our Solar S…

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.

No, NASA Did Not Find Even ‘Hints Of Lif…

No, NASA Did Not Find Even ‘Hints Of Life’ On Enceladus

“So if it happened here on Earth, why couldn’t it happen on another world as well? The answer, of course, is that it could happen there, and it could have happened there billions of years ago. Life could very easily be surviving and thriving beneath the icy crust of this distant, Saturnian moon.

But that’s not what we found. We didn’t find molecules that indicate they’re the products of life processes; the molecules we found are the raw ingredients for life. There’s a tremendous difference between the two, and finding raw ingredients on Enceladus no more means there’s life on that world than finding sugar, flour, eggs, milk, and butter in your house means there’s a successfully baked cake there.”

Did you hear about the news on Enceladus? For the first time, on a world beyond Earth, we’ve detected the trifecta of combinations:

-a liquid water ocean,
-an undersea source of heat and energy,
-in combination with the presence of the raw ingredients necessary for life.

Many are speculating that this makes Enceladus a surefire winner in the search for the first life that has an origin beyond Earth. But that’s speculation, not science.

The truth of the matter is that finding the ingredients for life, which are everywhere, is a very different prospect than finding the products of life, which are nowhere to be found in these plumes. These are not the hints of life we were hoping for.

Ask Ethan: How Can Worlds That Never Get Above Freezing Have…

Ask Ethan: How Can Worlds That Never Get Above Freezing Have Liquid Water?

“I was reading about Saturn’s moon Enceladus, and how scientists believe it has liquid water oceans beneath its water-ice crust. And yet I also read that the warmest surface temperatures are -90 celsius. How can this moon have liquid water? […] At such cold temperatures and low pressures it seems Enceladus can have water ice and water gas but not liquid. What am I missing?”

Here on Earth, water can easily exist in all three phases of matter: solid, liquid, and gas. The reason for this is simple: Earth has the right range of temperatures and pressures to experience not just the common solid and gas phases, but the liquid water phase, too. In the outer Solar System, worlds like Europa, Enceladus, and Pluto are too far from the Sun to ever reach surface temperatures high enough to create a liquid phase; it seems that water is a no-go. But there must be subsurface oceans on these worlds! Not only is there geological evidence of an ocean beneath a thick layer of ice, but on some worlds, like Enceladus, we can actually see large plumes of liquid water ejected hundreds of kilometers above the surface, like some sort of planet-scale geyser. While the increased pressure from the ice plays a role, it isn’t enough on its own; there must be other factors, too.

How do worlds that never get above freezing actually come to have liquid water on their surfaces? Find out on this week’s Ask Ethan!

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

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!

Eight Other Worlds In Our Solar System Might Have Life Beyond…

Eight Other Worlds In Our Solar System Might Have Life Beyond Earth

5.) Venus. Venus is hell, literally. At a constant surface temperature of some 900 degrees Fahrenheit, no human-made lander has ever survived more than a couple of hours while touched down on our nearest neighboring planet. But the reason Venus is so hot is because of it’s thick, carbon-dioxide rich atmosphere laden with heat-trapping clouds of sulphuric acid. This renders the surface of Venus thoroughly inhospitable, but the surface isn’t the only place to look for life. In fact, speculation is rampant that perhaps something interesting is happening some 60 miles up! Above the cloud-tops of Venus, the environment is surprisingly Earth-like: similar temperatures, pressures, and less corrosive material. It’s conceivable that with its own unique chemical history, that environment is filled with carbon-based airborne life, something that a mission to Venus’ upper atmosphere could easily sniff out.”

The Earth, to the best of our knowledge, is the only inhabited world we have. The ingredients for life may be everywhere, from asteroids to nebulae to exoplanets and more, but so far, only Earth is confirmed to have life. While Earth-like planets around Sun-like stars at the right distance for liquid water on their surface might seem like the best place to look for life, we don’t necessarily need to go that far. Right here in our own cosmic backyard, our own solar system boasts eight potential candidates for worlds with life on them today. Some of them are planets, like Mars and Venus; others are moons, like Europa and Titan; even asteroids like Ceres or Kuiper belt objects like Pluto get in on the action. The life that might be present might not look like most of life on Earth, but unless we look at the likely locations of biological activity in situ, we simply won’t know for certain.

Come find out all eight possible locations, and see if you can come up with a better possibility than any of these!

Enceladus – Life in our solar system? Enceladus is Saturns icy…

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.