The Big Space Exploration Topic [21-08-2017: Total Solar Eclipse in the USA!]

Thunderfinger

On this day in 1981 space shuttle Columbia had its first flight. I remember it well, a very exciting day. It felt like the future was finally here.

Gustav_Graves

Hold the presses! NASA revealed some major discoveries about our lovely Ocean Worlds; Saturn's moon Enceladus and Jupiter's moon Europa. First things first, I want you guys to dig a bit deeper into a biological process on Earth (Terra) that we call 'Methanogenesis' ;-). Here you can read everything about it: https://en.wikipedia.org/wiki/Methanogenesis

And now, here's the full press release of major discoveries on Enceladus and Europa:

NASA Missions Provide New Insights into 'Ocean Worlds' in Our Solar System

Two veteran NASA missions are providing new details about icy, ocean-bearing moons of Jupiter and Saturn, further heightening the scientific interest of these and other "ocean worlds" in our solar system and beyond. The findings are presented in papers published Thursday by researchers with NASA’s Cassini mission to Saturn and Hubble Space Telescope.

In the papers, Cassini scientists announce that a form of chemical energy that life can feed on appears to exist on Saturn's moon Enceladus, and Hubble researchers report additional evidence of plumes erupting from Jupiter's moon Europa.

“This is the closest we've come, so far, to identifying a place with some of the ingredients needed for a habitable environment,” said Thomas Zurbuchen, associate administrator for NASA's Science Mission Directorate at Headquarters in Washington. ”These results demonstrate the interconnected nature of NASA's science missions that are getting us closer to answering whether we are indeed alone or not.”

The paper from researchers with the Cassini mission, published in the journal Science, indicates hydrogen gas, which could potentially provide a chemical energy source for life, is pouring into the subsurface ocean of Enceladus from hydrothermal activity on the seafloor.

The presence of ample hydrogen in the moon's ocean means that microbes – if any exist there – could use it to obtain energy by combining the hydrogen with carbon dioxide dissolved in the water. This chemical reaction, known as "methanogenesis" because it produces methane as a byproduct, is at the root of the tree of life on Earth, and could even have been critical to the origin of life on our planet.

Life as we know it requires three primary ingredients: liquid water; a source of energy for metabolism; and the right chemical ingredients, primarily carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur. With this finding, Cassini has shown that Enceladus – a small, icy moon a billion miles farther from the sun than Earth – has nearly all of these ingredients for habitability. Cassini has not yet shown phosphorus and sulfur are present in the ocean, but scientists suspect them to be, since the rocky core of Enceladus is thought to be chemically similar to meteorites that contain the two elements.

"Confirmation that the chemical energy for life exists within the ocean of a small moon of Saturn is an important milestone in our search for habitable worlds beyond Earth," said Linda Spilker, Cassini project scientist at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California.

The Cassini spacecraft detected the hydrogen in the plume of gas and icy material spraying from Enceladus during its last, and deepest, dive through the plume on Oct. 28, 2015. Cassini also sampled the plume's composition during flybys earlier in the mission. From these observations scientists have determined that nearly 98 percent of the gas in the plume is water, about 1 percent is hydrogen and the rest is a mixture of other molecules including carbon dioxide, methane and ammonia.

The measurement was made using Cassini's Ion and Neutral Mass Spectrometer (INMS) instrument, which sniffs gases to determine their composition. INMS was designed to sample the upper atmosphere of Saturn's moon Titan. After Cassini's surprising discovery of a towering plume of icy spray in 2005, emanating from hot cracks near the south pole, scientists turned its detectors toward the small moon.

Cassini wasn't designed to detect signs of life in the Enceladus plume – indeed, scientists didn't know the plume existed until after the spacecraft arrived at Saturn.

"Although we can't detect life, we've found that there's a food source there for it. It would be like a candy store for microbes," said Hunter Waite, lead author of the Cassini study.

The new findings are an independent line of evidence that hydrothermal activity is taking place in the Enceladus ocean. Previous results, published in March 2015, suggested hot water is interacting with rock beneath the sea; the new findings support that conclusion and add that the rock appears to be reacting chemically to produce the hydrogen.

The paper detailing new Hubble Space Telescope findings, published in The Astrophysical Journal Letters, reports on observations of Europa from 2016 in which a probable plume of material was seen erupting from the moon’s surface at the same location where Hubble saw evidence of a plume in 2014. These images bolster evidence that the Europa plumes could be a real phenomenon, flaring up intermittently in the same region on the moon's surface.

The newly imaged plume rises about 62 miles (100 kilometers) above Europa’s surface, while the one observed in 2014 was estimated to be about 30 miles (50 kilometers) high. Both correspond to the location of an unusually warm region that contains features that appear to be cracks in the moon’s icy crust, seen in the late 1990s by NASA's Galileo spacecraft. Researchers speculate that, like Enceladus, this could be evidence of water erupting from the moon’s interior.

“The plumes on Enceladus are associated with hotter regions, so after Hubble imaged this new plume-like feature on Europa, we looked at that location on the Galileo thermal map. We discovered that Europa’s plume candidate is sitting right on the thermal anomaly," said William Sparks of the Space Telescope Science Institute in Baltimore, Maryland. Sparks led the Hubble plume studies in both 2014 and 2016.

The researchers say if the plumes and the warm spot are linked, it could mean water being vented from beneath the moon's icy crust is warming the surrounding surface. Another idea is that water ejected by the plume falls onto the surface as a fine mist, changing the structure of the surface grains and allowing them to retain heat longer than the surrounding landscape.

For both the 2014 and 2016 observations, the team used Hubble's Space Telescope Imaging Spectrograph (STIS) to spot the plumes in ultraviolet light. As Europa passes in front of Jupiter, any atmospheric features around the edge of the moon block some of Jupiter’s light, allowing STIS to see the features in silhouette. Sparks and his team are continuing to use Hubble to monitor Europa for additional examples of plume candidates and hope to determine the frequency with which they appear.

NASA's future exploration of ocean worlds is enabled by Hubble's monitoring of Europa's putative plume activity and Cassini's long-term investigation of the Enceladus plume. In particular, both investigations are laying the groundwork for NASA's Europa Clipper mission, which is planned for launch in the 2020s.

“If there are plumes on Europa, as we now strongly suspect, with the Europa Clipper we will be ready for them,” said Jim Green, Director of Planetary Science, at NASA Headquarters.

Hubble's identification of a site which appears to have persistent, intermittent plume activity provides a tempting target for the Europa mission to investigate with its powerful suite of science instruments. In addition, some of Sparks' co-authors on the Hubble Europa studies are preparing a powerful ultraviolet camera to fly on Europa Clipper that will make similar measurements to Hubble's, but from thousands of times closer. And several members of the Cassini INMS team are developing an exquisitely sensitive, next-generation version of their instrument for flight on Europa Clipper.

Gustav_Graves

no one? :open_mouth:

DarthDimi

I marvel at these images, Gustav, but I wouldn't know what comments to type. I'm sure many of us are in that same boat. Don't worry, your posts are being very much appreciated. ;-)

CommanderRoss

check. Fantastic news indeed!!!! (and please keep us posted @Gustav!)

Gustav_Graves

Cassini will end its 13-year mission soon :-(. It will plunge into Saturn in the end, but before that will happen it'll plunge right into the rings:

Murdock

It may be the end for Cassini but the mission will always continue, boldly going where no one has gone before. :)

DarthDimi

Yes, indeed. I'm not sad. Because when Cassini makes its final drop, it will once again startle us with beautiful images.

Thunderfinger

Thunderfinger

http://www.bibliotecapleyades.net/archivos_pdf/image-analysis-unusual-structures-far-side-moon.pdf

Gustav_Graves

New pictures!

The beautiful dark-coloured sand dunes on Mars:

DarthDimi

Beautiful!

zebrafish

There could be sandworms hiding beneath that sand...

Gustav_Graves

zebrafish wrote: »

There could be sandworms hiding beneath that sand...

I wanna strap myself up in a spacesuit, start running there like a madman and explore the shit out of that Mars-globe. Also, it's so sad to see Mars so empty :-(. Gonna colonize ya soon Mars!

CommanderRoss

beautiful!

Thunderfinger

NASA have discovered whistling sounds from Saturn. People whistle everywhere, at least in this solar system.

CommanderRoss

The question is, what is Saturn whistling?

Some_Kind_Of_Hero

CommanderRoss wrote: »

The question is, what is Saturn whistling?

Sounds a little like Goldfinger.

Gustav_Graves

Now that everyone is eagerly waiting for the new "Star Trek" TV Series, I decided to post the best resolution images of the most wonderous moons and planets in our solar system:

Enceladus (moon of Saturn):




Europa (moon of Jupiter):

CommanderRoss

very, very beautiful!

Gustav_Graves

Okay, trivia question. What are these two .GIF images?

Thunderfinger

As I have posted that before, I will let someone else have a guess.

CommanderRoss

Can't see, so can't tell....

Gustav_Graves

Great video made by NASA:

Thunderfinger

Here is more.

The South Pole:


Southern lights (auroras)

Infrared emission:

zebrafish

Gustav_Graves wrote: »

Okay, trivia question. What are these two .GIF images?

I think those are cloud formations over Saturn's poles, no? Phil Plait had an explanation of the hexagonal shape in his blog a while ago. Each side of the hexagon is about the size of Earth.

Thunderfinger

http://www.messagetoeagle.com/growing-risk-that-earth-will-be-hit-by-asteroid-from-the-taurids/

DarthDimi

Wonderful images!

Asteroids on their way? Good, Earth needs some cleaning, fast.

CommanderRoss

So, depending on the hit of the asteroid, we know which religion god loves most, right? ;-)

Gustav_Graves

Something else now. Next year the James Webb Giant Space Telescope will be launched into outer space. And giant it is. 'Star Trek'-y giant. It will be much bigger than the current Hubble Space Telescope. Here you'll find some information about the most massive deep space object ever build by humanity. Down below a model in real size:




This is a short overview how the James Webb Space Telescope will be 'spreading its wings' once it finds it final orbit:


And down below a short documentary about this fan-ff-ing-tastic bit of human engineering:


And then, you'll gasp for air, if you see how the James Webb Space Telescope will be deployed. It's jawdropping awesome: