Διάστημα, μια ιστορία εξερεύνησης

[dust 4,051]

πανεμορφο βιντεο.ειδικα εκει που περνα απο το βορειο σελας

[panchristo 6,255]

<Παρένθεση>: Αν και σε κάπως μεγάλη ηλικία, συνήθιζα να βλέπω μια παιδική εκπομπή (γαλλικής παραγωγής με 2 τύπους σε μια νταλίκα) που εξηγούσε διάφορα φαινόμενα με πολύ ωραίο τρόπο για παιδιά.

Εκεί λοιπόν θυμάμαι που εξηγούσε ότι το ίδιο φαινόμενο με τις αστραπες μπορούμε να το παρατηρήσουμε - σε πολύ μικρότερη κλίμακα βεβαίως - όταν βγάζουμε μάλλινα ρούχα στο σκοτάδι που δημιουργούν σπινθήρες με τα μαλλιά μας. </Παρένθεση>

 

Από τότε, αυτή η παρομοίωση μου έχει αποτυπωθεί πολύ έντονα. Τώρα βλέποντάς το σε αυτή τη κλίμακα, στα σημεία που δείχνει σύννεφα και αστραπές, κατά κάποιον τρόπο έκλεισε το big picture για μένα.

[wraith 6,406]

Πολύ μεγάλο άρθρο για να το παραθέσω όλο. Ένα αναλυτικό what if σενάριο διάσωσης του Columbia με βάση το πόρισμα της επιτροπής διερεύνησης του ατυχήματος

 

The audacious rescue plan that might have saved space shuttle Columbia

[Χρήστος Λάππας 25,085]

Όταν λέμε "διάστημα", λίγοι συνειδητοποιούμε πραγματικά τι σημαίνει λέξη.

 

Ο παρακάτω χάρτης με σωστή κλίμακα (αν η σελήνη μας ήταν ένα pixel) θα βοηθήσει να κατανοήσετε τις αποστάσεις και κυρίως τα... κενά.

(αν έχετε την υπομονή να τον φτάσετε μέχρι το τέλος διαβάζοντας όσα λέει ενδιάμεσα, θα καταλάβετε το κύριο πρόβλημα των διαστημικών ταξιδιών και γιατί δεν έχουμε καταφέρει να πάμε σε κανένα άλλο πλανήτη εκτός από τον δικό μας)

 

http://joshworth.com...olarsystem.html

[wraith 6,406]

αν έχετε την υπομονή να τον φτάσετε μέχρι το τέλος διαβάζοντας όσα λέει ενδιάμεσα, θα καταλάβετε το κύριο πρόβλημα των διαστημικών ταξιδιών και γιατί κανένας άνθρωπος δεν έχει καταφέρει να πάει έστω και σε ένα άλλο πλανήτη εκτός από την Γη

 

Δηλαδή το Star Trek δεν είναι ντοκιμαντέρ;!;!;! :shock:

[dust 4,051]

28 χρονια time lapse της γης απο το διαστημα.αξιζει να δωσετε εμφαση στο 1,28 πως αλαλζει με τα χρονια η λιμνη στον καναδα.επισης κατα ποσο αληθευει οτι οι παγοι λιωνουν.

και να σκεφτεις οτι οταν ξεκινουσε αυτο το time lapse παιζει και να μην ζουσα ακομα.

http://www.youtube.com/watch?v=JDUOQjNZEp4

[Χρήστος Λάππας 25,085]

Όμορφα πλάνα από τις δοκιμές του καινούργιου επαναχρησιμοποιήσιμου πυραύλου Falcon 9 Reusable, της Space X

 

http://youtube.com/watch?v=0UjWqQPWmsY

[Χρήστος Λάππας 25,085]

Live streaming του πλανήτη μας από τον Διεθνή Διαστημικό Σταθμό:

 

http://www.ustream.tv/channel/17074538

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[Χρήστος Λάππας 25,085]

Black Holes May Collapse Into Their Exact Opposites: White Holes

 

July 22, 2014 | by Janet Fang

 

photo credit: Artist’s drawing of a black hole named Cygnus X-1, which formed when a large star caved in. This black hole pulls matter from the blue star beside it / NASA/CXC/M.Weiss

 

Despite its name, a black hole is not an empty void. Most black holes form when stars die in a supernova explosion, collapsing under their own gravity. When a star 10 times more massive than the sun dies in a supernova, for example, its mass can be squeezed into a ball with the diameter of New York City. The resulting gravitational field is so strong not even light can escape.

 

For decades, astrophysicists have wondered whether black holes destroy information -- meaning what falls into them is lost forever. A new model suggests that at the end of their lives, black holes turn into “white holes,” explosively pouring all the material they have ever swallowed into space, Nature reports.

 

According to the new model, developed by Carlo Rovelli and Hal Haggard from Aix-Marseille University in France, the transformation from a black hole to a white hole would occur right after the initial formation of the black hole. Their model is based on a theory called “loop quantum gravity” -- where gravity and space-time are quantized, woven from tiny-individual loops that can’t be subdivided any further.

 

As a dying star collapses under its own gravity, it’s surrounded by a boundary called the event horizon: the point of no return, past which nothing can escape the black hole’s gravity. The star will continue to shrink, but eventually it will reach a stage where it can’t get any smaller because the loops cannot compress anymore.

 

At this point, the loops exert an outward pressure called “quantum bounce,” which transforms the black hole into a white hole. According to the team’s rough estimates, it takes just a few thousandths of a second for a black hole to transform into a white hole. Yet even though the transformation is nearly instantaneous, the researchers say, black holes can still appear to us as lasting billions or trillions of years because their gravity stretches light waves and dilates time.

 

If that’s the case, then rather than being shrouded by a true, eternal event horizon, black holes would be concealed by a temporary “apparent horizon,” Rovelli says. That’s important, because a true event horizon might violate the laws of physics.

 

In the 1970s, Stephen Hawking of the University of Cambridge calculated that a black hole should emit radiation out of its event horizon, slowly losing energy and shrinking in the process until it completely disappears. But that means information carried by matter falling into black holes would vanish forever. “There is no escape from a black hole in classical theory," the famed physicist told Nature earlier this year, "but quantum theory enables energy and information to escape.”

 

Having black holes turn into white holes could solve one of fundamental physics’ most troublesome questions. Their work is available at arXiv.

 

Via Nature]

 

Πηγή: http://www.iflscience.com/space/black-holes-may-collapse-their-exact-opposites-white-holes

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The Fermi Paradox

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DISTANT OASIS

 

Europa's frozen, fissured surface, seen here in a colorized mosaic image from the Galileo spacecraft, hides a liquid ocean that may hold all the ingredients needed for life.: http://www.nationalg.../distant-oasis/

 

 

Εξαιρετικά ενδιαφέρον, διαδραστικό αρθράκι

[Χρήστος Λάππας 25,085]

These stunning images of Comet 67P/CG are like a dark science fiction dreamscape

 

posted by DeadState November 14, 2014 Current Events, Featured, Science

 

 

 

In the weeks before the Philae landing on Comet 67P/CG, the Rosetta spacecraft maintained an orbit around the giant rock at about six miles out. Now, the European Space Agency (ESA) has just released a collection of previously unseen images taken by Rosetta’s navigation camera, revealing the towering, dark and dreamlike terrain of the comet.

 

 

The photo below shows the boulder known as Cheops, which is the largest boulder towards the center of the frame, measuring 147 feet across and 82 feet high. Apparently, Cheops and the surrounding boulders reminded scientists of the pyramids at Giza in Egypt, prompting them to name it for the largest of those pyramids, the Great Pyramid, which was built as a tomb for the pharaoh Cheops.

 

 

The next image below shows the boulder-strewn “neck” region of the comet.

From io9:

The scene also shows the contrast between the rugged material in the cliff walls rising up to the smaller lobe and the soft, more ‘textured’ material that characterizes the neck and that is also coating the larger lobe in this region.

 

 

This dramatic view along the horizon highlights several relatively smooth, flat-topped plateaus that stand above the rugged surface on the larger lobe of the comet. But their flat tops betray the scars of the walls just below, extensively crisscrossed with fracture-like features. At their bases lies plentiful rubble, perhaps once originating from the cliff faces, having crumbled away under the erosive forces at work on the comet.

 

 

Mark Strauss of io9 was struck as to how the images look kind of like the artwork of famed science fiction illustrator Chesley Bonestell, and his imagining of how the moon’s surface might look long before humans ever got there. We have to agree.

 

 

Oh, and just in case you didn’t know, this is the comet’s size relative to Los Angeles:

 

 

 

Πηγή: http://deadstate.org...ion-dreamscape/

[Δεν Ξενερώνω! 4,748]

[ChristosZ 2,649]

https://www.youtube.com/watch?t=141&v=Dr_IsCQkd0s

[Χρήστος Λάππας 25,085]

Το παράδοξο του Fermi με απλά λόγια:

 

[OliaTax 2,868]

Όταν λέμε "διάστημα", λίγοι συνειδητοποιούμε πραγματικά τι σημαίνει λέξη.

 

Ο παρακάτω χάρτης με σωστή κλίμακα (αν η σελήνη μας ήταν ένα pixel) θα βοηθήσει να κατανοήσετε τις αποστάσεις και κυρίως τα... κενά.

(αν έχετε την υπομονή να τον φτάσετε μέχρι το τέλος διαβάζοντας όσα λέει ενδιάμεσα, θα καταλάβετε το κύριο πρόβλημα των διαστημικών ταξιδιών και γιατί δεν έχουμε καταφέρει να πάμε σε κανένα άλλο πλανήτη εκτός από τον δικό μας)

 

http://joshworth.com...olarsystem.html

Πολύ έξυπνο , αλλά μέχρι να φτάσεις στο τέλος θέλεις ένα 20' σχεδόν .

[Χρήστος Λάππας 25,085]

Και αυτό μέχρι να φτάσουμε στον πιο μακρινό πλανήτη του δικού μας ηλιακού μας συστήματος, έτσι; Πρακτικά μέχρι το επόμενο στενό στο οικοδομικό τετράγωνο της γειτονιάς μας.

Για να βγούμε από την γειτονιά μας, και να πάμε στον επόμενο πλησιέστερο άστρο...

Proxima Centauri claims the honor of being our true nearest neighbor at only 4.24 light years away.
It’s difficult to conceptualize such vast distances, but a popular analogy sets the Sun at the size of a grapefruit. If you wanted to get from your grapefruit-sized Sun to a grapefruit-sized Alpha Centauri system, you would have to travel about 2,500 miles, which is about the distance from coast to coast on the continental United States. And that’s just to the Sun’s closest neighbor!

Πηγή: http://www.skyandtelescope.com/astronomy-resources/far-closest-star/

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Ladies and gentlemen, we have history in the making!

Πηγή: https://instagram.com/p/5HTXKMoaFL/

[Kyriakoschar 6,029]

Χρήστο, 16 ώρες έκανε να έρθει η φωτογραφία λέει?

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Όχι, λέει ότι η φωτογραφία τραβήχτηκε 16 ώρες πριν το διαστημόπλοιο φτάσει στο κοντινότερο προγραμματισμένο σημείο από τον νανοπλανήτη.

 

Αν οι πλανήτες ήταν όλοι σε μια ευθεία γραμμή και λαμβάνοντας υπόψη ότι το φως παίρνει περίπου 324,3 λεπτά (γύρω στις 5,4 ώρες) για να φτάσει απ' την Γη στον Πλούτωνα (καθώς και ότι τα ηλεκτρομαγνητικά κύματα μέσω των οποίων μεταδίδουμε τις εικόνες και πληροφορίες ταξιδεύουν με την ταχύτητα του φωτός) θα έπρεπε να μας έχει έρθει σε 5,4 ώρες. Όμως οι πλανήτες δεν είναι σε ευθεία γραμμή και δεν ξέρω πως οι τροχιές τους επηρεάζουν την ταχύτητα με την οποία φτάνει το φως και οι πληροφορίες σε εμάς.

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Follow NASA's historic mission to Pluto with the New Horizons app on your iPhone, iPad, or Apple Watch

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This is the first high resolution image of Pluto's surface

By Sean O'Kane

on July 15, 2015 03:23 pm


NASA just released the first frame of the high resolution scans of Pluto. The new image is zoomed into less than one percent of Pluto's surface. It was published less than 24 hours after NASA received confirmation that the New Horizons spacecraft successfully completed its flyby of Pluto. More of these scans will be released on Friday.

The high-resolution image of Pluto's surface shows us a fraction of the lower left portion of yesterday's image. John Spencer, a New Horizons science team member, said that the team has yet to find an impact crater in any of the scans, which means Pluto is very young relative to the rest of the solar system. Spencer also said that the mountains seen in the image stretch to over 11,000 feet (about 3,350 meters) high, and are likely made of a type of water-ice bedrock.



See Pluto in high-resolution

The mountains probably formed less than 100 million years ago, according to NASA. They might also still be growing. That's counterintuitive to the way we've previously viewed icy worlds, which are typically only geologically active if they're orbiting much larger bodies. (Take Saturn's moon Titan, for example, which has visibly active cryovolcanoes that are aided by Saturn's massive gravitational pull.)

Spencer said that this one image is already making the team rethink how the activity on these worlds is powered. Alan Stern, New Horizons' principal investigator, agreed. "The one thing we can say for sure is that tidal energy is not at play here," he said. "[Now] we have to get a little more clever."

The team also announced that the "heart" feature of Pluto will now be known as the Tombaugh Regio, after Clyde Tombaugh, the discoverer of Pluto.

Zoom into Pluto & discover mountains, seen during yesterday's @NASANewHorizons #PlutoFlyby: http://t.co/6QLXLxiW0ohttps://t.co/toJQ0j7wB6
— NASA (@NASA) July 15, 2015

The images that NASA released over the last few weeks were interesting because it was the first time we had seen Pluto in any real detail. But now, New Horizons has made its observations and is safely beyond Pluto. NASA will spend the next 16 months analyzing that data, releasing both images and scientific observations along the way. This image — and the images of the moons Charon and Hydra — is just the beginning.
Developing...

Πηγή: http://www.theverge.com/2015/7/15/8972271/nasa-new-horizons-new-pluto-image

[Χρήστος Λάππας 25,085]

Curiosity Finds a 'Floating Spoon' on Mars

SEP 1, 2015 05:32 PM ET // BY IAN O'NEILL

 

A small rocky overhang on the Martian surface as seen by NASA's Mars rover Curiosity's Mastcam on sol 1089 (Aug. 30).

NASA/JPL-CALTECH

 

Update (Sept. 3): Agreeing with the analysis below, NASA's Curiosity Twitter feed confirmed that the "spoon" is a feature shaped by the wind. "There is no spoon. This weird Mars feature is likely a ventifact -- a rock shaped by wind," NASA tweeted on Wednesday.

 

We’ve seen “rats,” “yetis,” “faces,” even “elephants” on Mars, but this new image captured by NASA’s Mars rover Curiosity is one of the most fascinating views of a rock formation on the Martian surface yet.

 

Sure, like these other examples I’ve included in “quotes,” this “spoon” is yet another wonderful example of Mars pareidolia, but with a twist.

 

This latest Mars oddity was spotted by members of the UnmannedSpaceflight.com forum in an image captured by Curiosity’s Mastcam on sol 1089 of the mission (Aug. 30). Once you spot it, it becomes obvious; it really does look like a spoon hanging in the air, just above the surface of some layered rock. But as Mars is devoid of any civilization, advanced or otherwise, that is capable of manufacturing said spoon, there’s probably a more logical answer.

 

The logical answer, however, is still pretty awesome.

 

Pareidolia is a psychological phenomenon that makes our brains interpret some kind of random visual stimulus as a familiar pattern or object. A famous example of space pareidolia is the “Face of Mars”, where a mesa (a hill) in the Cydonia region of Mars had the pattern of a human face in early Viking spacecraft observations. Now we have high-resolution cameras in orbit about Mars, we have since proven that the face was nothing more than a product of some fortuitous shadows and psychological trickery.

 

Down on the Martian surface, recent images beamed back by Curiosity have been awash with rocks of all shapes and sizes — needless to say, the high-resolution imagery from the mission has been a hotbed of pareidolia, leading to numerous conspiracy theories — the most recent being a rock shaped like an iguana, which has taken social media by storm.

 

But now we have (what appears to be) a spoon (and it REALLY looks like a spoon, just sayin’) jutting out from rocks on Mars. Undoubtedly a great example of pareidolia, but also an insight to the wonderfully calm Martian environment and fascinating geological processes.

 

Windy Erosion

 

On Earth, if the conditions are right, rocks, shaped by hundreds of thousands or even millions of years of wind erosion, can appear unnaturally balanced or shaped (such as Colorado’s Garden of the Gods or Utah’s Balanced Rock). But on Mars, where the atmosphere is thin, gravity is weak and other erosion processes are few, wind action can create even more elegant structures than on Earth. Aeolean processes (wind action) dominates Mars, producing everything from small dust devils to planet-wide dust storms. This windy activity creates vast dune fields and snaking valleys — it can also create tiny arches and overhangs, like this “spoon.”

 

Wider view of Curiosity's observation including the "spoon."

NASA/JPL-CALTECH

 

In addition, we already know from Curiosity’s analysis of various rocky outcrops at the base of Mount Sharp, mineral veins are commonplace. Often, these veins jut high above the surrounding, soft sedimentary rock. These veins have been found to be rich in calcium sulfate and other examples have shown evidence of episodic flows of water in Mars’ ancient past. Interestingly, in this Curiosity observation, a bright vein of material can be seen snaking from top to bottom, to the right of the image.

 

And these veins could contribute to reinforcing small structures like this floating “spoon.”

 

Of course, it could be a trick of the light, creating what appears to be a shadow beneath the “spoon,” but looking at the direction of sunlight on the surface in this Curiosity observation, it appears as if it has been carved out of the sedimentary rock and aligned with rocky layers that can be seen tracing lines across the dusty surface.

 

So, once again, this little nugget of Mars pareidolia is a rock that happens to be shaped like a spoon. But it’s a fascinating rock, and an awesome find, providing some geological hints as to the erosion processes that can etch out such delicate formations on the surface of the Red Planet.

 

Πηγή: http://news.discovery.com/space/curiosity-finds-a-floating-spoon-on-mars-150901.htm

 

Bonus το σχόλιο της ημέρας από τον Paul Fidalgo:

Martians have apparently developed floating spoon technology. Their domination will be swift and ruthless.

[Χρήστος Λάππας 25,085]

New Pluto pics show weird terrain shaped by alien ‘water’ cycle

nh-apluto-wide-9-17-15-finalNASA/JHUAPL/SwRI

Pluto has again stunned researchers in the latest pictures downloaded from NASA’s New Horizons probe. The images, taken just 15 minutes after the spacecraft’s closest approach to the dwarf planet on July 14, reveal incredible mountain ranges and glaciers that look surprisingly like Earth.

In the first picture, above, New Horizons is looking back at Pluto, towards the sun, allowing the probe’s camera to spy the layered haze of the tiny world’s tenuous nitrogen atmosphere. The image was taken from a distance of 18000 kilometres and stretches 1250 kilometres across, around half the width of the entire dwarf planet.

nh-apluto-mountains-plains-9-17-15NASA/JHUAPL/SwRI

This second image zooms in on the central region of the first and you can really see these 3.5 kilometre high mountains popping out. They lie just to the left of Pluto’s now famous heart-shaped ice plain, informally known as Sputnik Planum.

“This image really makes you feel you are there, at Pluto, surveying the landscape for yourself,” said New Horizons lead scientist Alan Stern. “But this image is also a scientific bonanza, revealing new details about Pluto’s atmosphere, mountains, glaciers and plains.”

nh-apluto-low-haze-9-17-15-updatedNASA/JHUAPL/SwRI

Zooming further reveals a low-lying fog illuminated by the setting sun. That suggests Pluto’s weather changes daily, just like on Earth. The team now believe that Pluto has a “water” cycle similar to Earth’s, but with exotic ices like frozen nitrogen, rather than water.

“We did not expect to find hints of a nitrogen-based glacial cycle on Pluto operating in the frigid conditions of the outer solar system,” said team member Alan Howard. “Driven by dim sunlight, this would be directly comparable to the hydrological cycle that feeds ice caps on Earth, where water is evaporated from the oceans, falls as snow, and returns to the seas through glacial flow.”

https://www.newscientist.com/article/new-pluto-pics-show-weird-terrain-shaped-by-alien-water-cycle/?utm_source=NSNS&utm_medium=SOC&utm_campaign=hoot&cmpid=SOC%257CNSNS%257C2015-GLOBAL-hoot