Why?
Astronomy & Space Exploration
- Thread starter MrMarcello
- Start date
Why?
Why what ?
But without the Sun our planet wouldn't had any life, only one think the astronauts tested in the ISS and would survive in the cold space was seeds, seeds survive the space (vacuum) but not bacteria.
That has to do with the atmosphere, not the sun. Atmosphere protects life from radiation, so if you put something outside of it, it will die.
On moons like Europa the sunlight that reaches doesn't really have the required energy to support life, but tidal forces from Jupiter are thought to be strong enough that there'll be enough heat down at the foot of the ocean.
Every year they find our planet suffered an incredible journey to be what is today, from Jupiter and Saturn triggering all the events like Mars been smaller than it should, to cause the ice around the asteroid belt to bombard our planet, looks like a set of big gears aligned perfectly for life to exist. Since no aliens show up yet we need to go to a comet and try to study the core to see if has elements that could be the building blocks of life, then we are 100% sure life exists in our vast universe.
Sorry I should have been more clear, why should we take into account that life as we know it may not exist (I'm assuming you mean exist elsewhere, rather than doesn't exist at all which is a whole other philosophical debate)?
ISS has some protection from radiation but not that much and would be interesting if they take seeds to our moon and then bring back after a few years to see if they still good.
Basically the numbers make those things pretty much irrelevant. Things we perceive as so unlikely as to be almost impossible to replicate become almost commonplace when you consider the number of possible locations AND the vast timescales involved. It's the same reason some people struggle so much with the concept of evolution, its just very difficult to mentally process numbers that big.
My personal thought is that life is going to be little more than a particular chemical reaction. Given that the number of basic elements that could form those building blocks is so small, the idea that it couldn't have happened a vast number of times elsewhere seems insanely unlikely to me. Once you have the very earliest form of life come into being, the rest just becomes a matter of whether it survives long enough to evolve further, and thats where the numbers come in again.
Anthropic Bias - we are using information and knowledge that our brains have invented over time to make a probabilistic extrapolation that we are not alone. I'm not arguing against the idea that we may not be alone, I'm simply stating that we have to give equal weighting to the idea that we may be alone based on the rules our own brains have invented in terms of numbers, odds, and the definition of life.
In a nutshell - when we talk of life elsewhere, we are not just passively observing whether or not life exists - we are actively affecting our perceived probability of the outcome based on rules that we have created. Or as they say in the Quantum world, "there is no reality independent of choice of measurement. What we perceive as reality now depends on our earlier decision on what to measure"
Mystery object in weird orbit beyond Neptune cannot be explained
By Shannon Hall
“I hope everyone has buckled their seatbelts because the outer solar system just got a lot weirder.” That’s what Michele Bannister, an astronomer at Queens University, Belfast tweeted on Monday.
She was referring to the discovery of a TNO or trans-Neptunian object, something which sits beyond Neptune in the outer solar system. This one is 160,000 times fainter than Neptune, which means the icy world could be less than 200 kilometres in diameter. It’s currently above the plane of the solar system and with every passing day, it’s moving upwards – a fact that makes it an oddity.
The TNO orbits in a plane that’s tilted 110 degrees to the plane of the solar system. What’s more, it swings around the sun backwards unlike most of the other objects in the solar system. With this in mind, the team that discovered the TNO nicknamed it “Niku” after the Chinese adjective for rebellious.
To grasp how truly rebellious it is, remember that a flat plane is the signature of a planetary system, as a star-forming gas cloud creates a flat disk of dust and gas around it. “Angular momentum forces everything to have that one spin direction all the same way,” says Bannister. “It’s the same thing with a spinning top, every particle is spinning the same direction.”
Planet Nine
He should know – Batygin was one of two astronomers who earlier this year announced that the presence of another highly inclined group of objects could be pointing toward a large undiscovered world, perhaps 10 times as massive as Earth, lurking even further away – the so-called Planet Nine.
Upon further analysis, the new TNO appears to be part of another group orbiting in a highly inclined plane, so Holman’s team tested to see if their objects could also be attributed to the gravitational pull of Planet Nine.
It turns out Niku is too close to the solar system to be within the suggested world’s sphere of influence, so there must be another explanation. The team also tried to see if an undiscovered dwarf planet, perhaps similar to Pluto, could supply an explanation, but didn’t have any luck. “We don’t know the answer,” says Holman.
Read more: We are closing in on possible whereabouts of Planet Nine
Bannister couldn’t be more thrilled. “It’s wonderful that it’s so confusing,” she says. “I’m looking forward to seeing what the theoretical analysists do once they get their hands on this one.”
But Batygin isn’t jumping up and down just yet. “As they say in the paper, what they have right now is a hint,” he says. “If this hint develops into a complete story that would be fantastic.”
Journal reference: arxiv.org/abs/1608.01808
https://www.newscientist.com/articl...ird-orbit-beyond-neptune-cannot-be-explained/
We may have another big planet in our solar system but too far away to reflect light from the sun for us to detect and maybe changed the path of a very small planet.
http://www.universetoday.com/130419/eso-announcement-address-reports-proxima-centauri-exoplanet/
Rocky Earth like Planet found in orbit of Proxima Centauri
Rocky Earth like Planet found in orbit of Proxima Centauri
Bring on the press conference! Wonder when it will happen, anyone got a link?
Edit: We might get a video here:
http://www.eso.org/public/events/press-evt/
https://twitter.com/eso
The way these fecks are building it up they better announce a second earth like planet with some real live aliens who currently are on their way to visit us.
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Stumbled upon this really interesting table mapping chances of habitability using an Earth Similarity Index (ESI). Mars sits on 0.797, Mercury 0.596, Venus 0.444, Moon 0.56. Wonder what the designated ESI of Proxima Centauri's tidal locked exoplanet is.
Last time around, they got really excited about Alpha Centauri B b, and it was an inhospitable 0.27:
Solar System Planets and Moons
Extrasolar planets
Planets discovered by Kepler
Even Mars and Venus are right at the edge of the Sun's habitable zone:
Last time around, they got really excited about Alpha Centauri B b, and it was an inhospitable 0.27:
Considering that Mercury at 0.596 has almost 8 times the orbital velocity of Earth, negligible g, with a surface temperature variance of 600 °C - you have to wonder about the ESI of Proxima's exoplanet - especially since we don't know its atmospheric chemistry, and whether they will redefine the ESI model with a new reference point/index, instead of Earth at a universal ideal of 1.0.
Solar System Planets and Moons
Extrasolar planets
Planets discovered by Kepler
Even Mars and Venus are right at the edge of the Sun's habitable zone:
And the latter has some of the most hostile environs - 224 mph winds, surface temperature of 462 °C, Sulfuric Acid in abundance with the lower atmosphere consisting of 96% Carbon Dioxide.
Don't be a spoilsport invictusStumbled upon this really interesting table mapping chances of habitability using an Earth Similarity Index (ESI). Mars sits on 0.797, Mercury 0.596, Venus 0.444, Moon 0.56. Wonder what the designated ESI of Proxima Centauri's tidal locked exoplanet is.
Last time around, they got really excited about Alpha Centauri B b, and it was an inhospitable 0.27:
Considering that Mercury at 0.596 has almost 8 times the orbital velocity of Earth, negligible g, with a surface temperature variance of 600 °C - you have to wonder about the ESI of Proxima's exoplanet - especially since we don't know its atmospheric chemistry, and whether they will redefine the ESI model with a new reference point/index, instead of Earth at a universal ideal of 1.0.
Solar System Planets and Moons
Extrasolar planets
Planets discovered by Kepler
Even Mars and Venus are right at the edge of the Sun's habitable zone:
And the latter has some of the most hostile environs - 224 mph winds, surface temperature of 462 °C, Sulfuric Acid in abundance with the lower atmosphere consisting of 96% Carbon Dioxide.
Stumbled upon this really interesting table mapping chances of habitability using an Earth Similarity Index (ESI). Mars sits on 0.797, Mercury 0.596, Venus 0.444, Moon 0.56. Wonder what the designated ESI of Proxima Centauri's tidal locked exoplanet is.
Last time around, they got really excited about Alpha Centauri B b, and it was an inhospitable 0.27:
Considering that Mercury at 0.596 has almost 8 times the orbital velocity of Earth, negligible g, with a surface temperature variance of 600 °C - you have to wonder about the ESI of Proxima's exoplanet - especially since we don't know its atmospheric chemistry, and whether they will redefine the ESI model with a new reference point/index, instead of Earth at a universal ideal of 1.0.
Solar System Planets and Moons
Extrasolar planets
Planets discovered by Kepler
Even Mars and Venus are right at the edge of the Sun's habitable zone:
And the latter has some of the most hostile environs - 224 mph winds, surface temperature of 462 °C, Sulfuric Acid in abundance with the lower atmosphere consisting of 96% Carbon Dioxide.
Yeah. Unlike houses, 'location, location, location' doesn't always apply. Whether a world is habitable depends not only on its present position in respect to its sun, but also its past history, and the time in its evolution the determination is made.
Mars and Venus may have had conditions much more favourable to life in the past. Mars was too small to hold on to its atmosphere, had no protection against the solar wind when its core solidified and it lost its magnetic field, and eventually turned into the cold, dry, almost atmosphere-less world it is today. Venus fell victim to runaway greenhouse warming.
On the other hand, if ETs visited Earth 600 million years ago, they'd have found a world covered in ice from poles to equator, and life barely hanging on.
If we can observe this world directly, and it turns out to be promising, it'll be very exciting though. A probe at 20% light speed can be there in 20 years. Pictures back in 24.
The NY Times just reported on this as well.....
http://www.nytimes.com/2016/08/25/science/earth-planet-proxima-centauri.html
http://www.nytimes.com/2016/08/25/science/earth-planet-proxima-centauri.html
Yep, it's quite exciting in theory.Yeah. Unlike houses, 'location, location, location' doesn't always apply. Whether a world is habitable depends not only on its present position in respect to its sun, but also its past history, and the time in its evolution the determination is made.
Mars and Venus may have had conditions much more favourable to life in the past. Mars was too small to hold on to its atmosphere, had no protection against the solar wind when its core solidified and it lost its magnetic field, and eventually turned into the cold, dry, almost atmosphere-less world it is today. Venus fell victim to runaway greenhouse warming.
On the other hand, if ETs visited Earth 600 million years ago, they'd have found a world covered in ice from poles to equator, and life barely hanging on.
If we can observe this world directly, and it turns out to be promising, it'll be very exciting though. A probe at 20% light speed can be there in 20 years. Pictures back in 24.
But something approaching 20% speed of light is incredibly, incredibly, incredibly fast ~ 216 million kmph. The fastest speed a man-made object has reached is a paltry 60,000 kmph - so we're speaking of a magnitude of 4000 times faster than that. And since the propulsion-energy-speed curve gets out of hand way before that, we'd need an impractical amount of propellant to reach that on a macro level - something like several trillion times the mass of the payload if you take normal oxidizer based propellant (that's before taking into account the effects of relativity - which will spike up the mass of the object). So for even a a probe weighing 1 gram (rest mass), that's greater than 10x billion kgs of fuel (rough calculation) + 10x billion kgs of liquid oxygen (and hope it doesn't blow up). We might be several centuries away from even getting close to that on a macro level.
Our best bet might be to shoot a swarm of carbon based nanobots at specific targets - and the level of nanotech we've reached so far is still at a rather primitive stage, given that you'll need incredible processor embedding on that scale, interstellar radiation proofing (for plasma clouds) and a relay system to transmit the signal back to earth without a crazy amount of attenuation, and another million different oddities. And that's even without considering the amount of energy we'd need to send it at 20% the speed of light - several hundred gigawatts, which is only 10 or so magnitudes lower than the entire energy consumption on earth (so you'll need international treaties to redirect that, at a time when there's a severe energy crisis in most countries).
The technology required to concentrate that much raw energy, and build a laser array to sustain that ticking atomic bomb for several seconds while you fire the bots is just mindboggling (for reference, we had to build a collider with a circumference of 27km just to send fundamental particles at sub-light speed - and, the LHC consumes only ~100 megwatts). Plus, any laser array we build will just melt rightaway, even if it absorbs a tiny, tiny, tiny fraction of the energy it's reflecting.
The Breakthrough Starshot idea is 100 gigawatts (pronounced, as we all well know, as jiggawatts) for a couple of minutes I believe. Intense! Great that there's now a tangible target to focus minds and ideas, though.
Aye, the Breakthrough Starshot fairly intriguing, though I'm a bit of a skeptical hippo given their small current funding capacity, and the ever-present conundrum of energy harnessing for that amount of time (for reference, the National Ignition Facility does produce a few thousand times the energy required for the laser, but only for a few billionths of a second).
* For anyone interested in the concept, they did a Live Conference not too long ago:
Have people watched the Niel Degrasse Tyson series - Cosmos: A space time journey?
My ladyfriend and I are 8 episodes in, and it is so damn interesting.
My ladyfriend and I are 8 episodes in, and it is so damn interesting.
Thought you had split up with Nasri after he forced a move to City?
We reconciled, though he's got to get rid of that stupid bleached hair. That was my ultimatum.
http://www.nasa.gov/feature/jpl/nasas-juno-successfully-completes-jupiter-flybyNASA's Juno Successfully Completes Jupiter Flyby
NASA's Juno mission successfully executed its first of 36 orbital flybys of Jupiter today. The time of closest approach with the gas-giant world was 6:44 a.m. PDT (9:44 a.m. EDT, 13:44 UTC) when Juno passed about 2,600 miles (4,200 kilometers) above Jupiter's swirling clouds. At the time, Juno was traveling at 130,000 mph (208,000 kilometers per hour) with respect to the planet. This flyby was the closest Juno will get to Jupiter during its prime mission.
"Early post-flyby telemetry indicates that everything worked as planned and Juno is firing on all cylinders," said Rick Nybakken, Juno project manager at NASA's Jet Propulsion Laboratory in Pasadena, California. There are 35 more close flybys of Jupiter planned during Juno's mission (scheduled to end in February 2018). The August 27 flyby was the first time Juno had its entire suite of science instruments activated and looking at the giant planet as the spacecraft zoomed past.
"We are getting some intriguing early data returns as we speak," said Scott Bolton, principal investigator of Juno from the Southwest Research Institute in San Antonio. "It will take days for all the science data collected during the flyby to be downlinked and even more to begin to comprehend what Juno and Jupiter are trying to tell us." While results from the spacecraft's suite of instruments will be released down the road, a handful of images from Juno's visible light imager -- JunoCam -- are expected to be released the next couple of weeks. Those images will include the highest-resolution views of the Jovian atmosphere and the first glimpse of Jupiter's north and south poles.
"We are in an orbit nobody has ever been in before, and these images give us a whole new perspective on this gas-giant world," said Bolton.
Transit of Europa across the 'Great Red Spot'
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Simply amazing and quite bizarre how a storm could last that long. Wonder what the size and length (in time) would be to scale on Earth?
Where have I been? I love stuff like this.
On a related note, Saturn's Hexagon storm is even more intriguing:
Saturn's hexagon is a persisting hexagonal cloud pattern around the north pole of Saturn, located at about 78°N. The sides of the hexagon are about 13,800 km (8,600 mi) long, which is more than the diameter of Earth (about 12,700 km (7,900 mi)).
Infrared image:
New theory could explain why the EmDrive generates thrust.
The Curious Link Between the Fly-By Anomaly and the “Impossible” EmDrive Thruster
The same theory that explains the puzzling fly-by anomalies could also explain how the controversial EmDrive produces thrust.
About 10 years ago, a little-known aerospace engineer called Roger Shawyer made an extraordinary claim. Take a truncated cone, he said, bounce microwaves back and forth inside it and the result will be a thrust toward the narrow end of the cone. Voila … a revolutionary thruster capable of sending spacecraft to the planets and beyond. Shawyer called it the EmDrive.
Shawyer’s announcement was hugely controversial. The system converts one type of energy into kinetic energy, and there are plenty of other systems that do something similar. In that respect it is unremarkable.
The conceptual problems arise with momentum. The system’s total momentum increases as it begins to move. But where does this momentum come from? Shawyer had no convincing explanation, and critics said this was an obvious violation of the law of conservation of momentum.
Shawyer countered with experimental results showing the device worked as he claimed. But his critics were unimpressed. The EmDrive, they said, was equivalent to generating a thrust by standing inside a box and pushing on the sides. In other words, it was snake oil.
Since then, something interesting has happened. Various teams around the world have begun to build their own versions of the EmDrive and put them through their paces. And to everyone’s surprise, they’ve begun to reproduce Shawyer’s results. The EmDrive, it seems, really does produce thrust.
In 2012, a Chinese team said it had measured a thrust produced by its own version of the EmDrive. In 2014, an American scientist built an EmDrive and persuaded NASA to test it with positive results.
And last year, NASA conducted its own tests in a vacuum to rule out movement of air as the origin of the force. NASA, too, confirmed that the EmDrive produces a thrust. In total, six independent experiments have backed Shawyer’s original claims.
That leaves an important puzzle—how to explain the seeming violation of conservation of momentum.
Today we get an answer of sorts thanks to the work of Mike McCulloch at Plymouth University in the U.K. McCulloch’s explanation is based on a new theory of inertia that makes startling predictions about the way objects move under very small accelerations.
First some background. Inertia is the resistance of all massive objects to changes in motion or accelerations. In modern physics, inertia is treated as a fundamental property of massive objects subjected to an acceleration. Indeed, mass can be thought of as a measure of inertia. But why inertia exists at all has puzzled scientists for centuries.
McCulloch’s idea is that inertia arises from an effect predicted by general relativity called Unruh radiation. This is the notion that an accelerating object experiences black body radiation. In other words, the universe warms up when you accelerate.
According to McCulloch, inertia is simply the pressure the Unruh radiation exerts on an accelerating body.
That’s hard to test at the accelerations we normally observe on Earth. But things get interesting when the accelerations involved are smaller and the wavelength of Unruh radiation gets larger.
At very small accelerations, the wavelengths become so large they can no longer fit in the observable universe. When this happens, inertia can take only certain whole-wavelength values and so jumps from one value to the next. In other words, inertia must quantized at small accelerations.
McCulloch says there is observational evidence for this in the form of the famous fly by anomalies. These are the strange jumps in momentum observed in some spacecraft as they fly past Earth toward other planets. That’s exactly what his theory predicts.
Testing this effect more carefully on Earth is hard because the accelerations involved are so small. But one way to make it easier would be to reduce the size of allowed wavelengths of Unruh radiation. “This is what the EmDrive may be doing,” says McCulloch.
The idea is that if photons have an inertial mass, they must experience inertia when they reflect. But the Unruh radiation in this case is tiny. So small in fact that it can interact with its immediate environment. In the case of the EmDrive, this is the truncated cone.
The cone allows Unruh radiation of a certain size at the large end but only a smaller wavelength at the other end. So the inertia of photons inside the cavity must change as they bounce back and forth. And to conserve momentum, this must generate a thrust.
McCulloch puts this theory to the test by using it to predict the forces it must generate. The precise calculations are complex because of the three-dimensional nature of the problem, but his approximate results match the order of magnitude of thrust in all the experiments done so far.
Crucially, McCulloch’s theory makes two testable predictions. The first is that placing a dielectric inside the cavity should enhance the effectiveness of the thruster.
The second is that changing the dimensions of the cavity can reverse the direction of the thrust. That would happen when the Unruh radiation better matches the size of the narrow end than the large end. Changing the frequency of the photons inside the cavity could achieve a similar effect.
McCulloch says there is some evidence that exactly this happens. “This thrust reversal may have been seen in recent NASA experiments,” he says.
That’s an interesting idea. Shawyer’s EmDrive has the potential to revolutionize spaceflight because it requires no propellant, the biggest limiting factor in today’s propulsion systems. But in the absence of any convincing explanation for how it works, scientists and engineers are understandably wary.
McCulloch’s theory could help to change that, although it is hardly a mainstream idea. It makes two challenging assumptions. The first is that photons have inertial mass. The second is that the speed of light must change within the cavity. That won’t be easy for many theorists to stomach.
But as more experimental confirmations of Shawyer’s EmDrive emerge, theorists are being forced into a difficult position. If not McCulloch’s explanation, then what?
Ref: arxiv.org/abs/1604.03449 : Testing Quantized Inertia on the EmDrive
https://www.technologyreview.com/s/...-anomaly-and-the-impossible-emdrive-thruster/
Crap I will be dead by then....Yeah. Unlike houses, 'location, location, location' doesn't always apply. Whether a world is habitable depends not only on its present position in respect to its sun, but also its past history, and the time in its evolution the determination is made.
Mars and Venus may have had conditions much more favourable to life in the past. Mars was too small to hold on to its atmosphere, had no protection against the solar wind when its core solidified and it lost its magnetic field, and eventually turned into the cold, dry, almost atmosphere-less world it is today. Venus fell victim to runaway greenhouse warming.
On the other hand, if ETs visited Earth 600 million years ago, they'd have found a world covered in ice from poles to equator, and life barely hanging on.
If we can observe this world directly, and it turns out to be promising, it'll be very exciting though. A probe at 20% light speed can be there in 20 years. Pictures back in 24.
Scientists Looking For Alien Life Investigate 'Interesting' Signal From Space
http://www.npr.org/sections/thetwo-...ife-investigate-interesting-signal-from-space
http://www.seti.org/seti-institute/a-seti-signal
http://www.npr.org/sections/thetwo-...ife-investigate-interesting-signal-from-space
http://www.seti.org/seti-institute/a-seti-signal
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The EmDrive not so ridiculed now.
http://www.ibtimes.co.uk/emdrive-na...assed-peer-review-says-scientist-know-1578716
http://www.ibtimes.co.uk/emdrive-na...assed-peer-review-says-scientist-know-1578716
Apparently, the SETI signal was (most likely) terrestrial disturbance:
https://www.engadget.com/2016/08/31/seti-unusual-signal-likely-came-from-earth/
Is it just me or is there loads of stuff about potential alien life lately? If I were Kingminger I'd suggest they're building us up to something *X Files music*
One of my mates just got an internship with the ESA.
Dang, that can't be good. Hoping for no injuries, but if anyone was working there and the rocket's fuel went off, not good.
This is pretty cool. The Juno probe has reached Jupiter and sent back a recording of the radio signals emanating from its magnetic field. Or something like that. Cool pics too.
http://www.telegraph.co.uk/news/201...ictures-of-jupiters-poles-its-like-nothing-w/
http://www.telegraph.co.uk/news/201...ictures-of-jupiters-poles-its-like-nothing-w/
NASA's streaming from the ISS, we've got a pretty good looking planet