Astronomy

Could we fly/drive through Jupiter?

Could we fly/drive through Jupiter?


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If Jupiter is made of gas, could we fly or drive through it or would its center be too dense?


http://spaceplace.nasa.gov/review/dr-marc-solar-system/gas-giants.html

We think of a gas as something very… well, airy. After all, air is the gas we all know and love. We breathe it and fly planes right through it with no trouble. So it makes sense to think that a gas planet must be like a big, airy cloud floating out in space. Saturn in true color.

The bigger a planet becomes, the heavier is the material weighing down on its center. Think of how it feels to dive under water. If you are wearing a face mask, you notice that as you dive deeper, the mask presses harder and harder on your face. Also, your ears start feeling the pressure even at 2 or 3 meters (5 or 10 feet) below the surface. The pressure you feel on your body is due to the weight of the water above you. The deeper you go, the heavier the water above you and so the greater the pressure on your body. Even on Earth's surface, each square inch of your body experiences 14.7 pounds of pressure due to the weight of the atmosphere above you. If you could dive down to the center of Earth, the pressure on your body would be about 3.5 million times as great! The center of Jupiter is more than 11 times deeper than Earth's center and the pressure may be 50 million to 100 million times that on Earth's surface!

The tremendous pressure at the center of planets causes the temperatures there to be surprisingly high. At their cores, Jupiter and Saturn are much hotter than the surface of the Sun!

Strange things happen to matter under these extraordinary temperatures and pressures. Hydrogen, along with helium, is the main ingredient of Jupiter's and Saturn's atmospheres. Deep in their atmospheres, the hydrogen turns into a liquid. Deeper still, the liquid hydrogen turns into a metal!

But what's at the very center of these planets? The material becomes stranger and stranger the deeper you go. Scientists do not understand the properties of matter under the extreme environments inside Jupiter and Saturn. Many different forces and laws of nature are at work, and the conditions inside these planets are very difficult to create in a laboratory here on Earth. But you can be sure that you wouldn't be able to fly through these bizarre materials! As we now know, the gas giants are much more than just gas.


Could we fly/drive through Jupiter? - Astronomy

I recall reading an Arthur Clarke novel titled "2061". The novel revolved around a manned mission to interface with Halley's Comet. How feasible is such a mission?

We have actually already sent a spacecraft to Halley's comet. During the mid 1980s Halley made one of its visits to the inner solar system and five spacecraft were sent to intercept it. The most famous was called Giotto.

Since then, we have sent several missions to comets. In 1999, NASA launched Stardust, which traveled through the coma (part of the tail) of comet Wild 2 and returned samples to Earth in 2006.

NASA's Deep Impact spacecraft was launched in January 2005 and reached the comet Tempel 1 on July 4, 2005. Deep Impact was the first mission to blast a crater in a comet and observe the results! The mission revealed that the comet was much dustier and less icy than expected. The Stardust mission will fly-by Tempel 1 in 2014 to photograph the crater, while Deep Impact travels on to observe comet Boethin sometime in the next decade.

Finally, the European Space Agency's Rosetta mission, launched in 2004, will orbit and land on a comet sometime in 2014.


17th Century: Discovery

The incomparable Italian astronomer Galileo Galilei discovered Ganymede — along with Io, Europa, and Callisto — in 1610. A series of winter evenings found Galileo aiming one of the world’s first telescopes at Jupiter, discovering three, and later four small dots near the planet. Galileo was initially intrigued because these “stars,” as he originally called them in his notes, were in a straight line near Jupiter’s equator. Within a few weeks, punctuated by the occasional cloudy nights (some things never change!), the truth became obvious: These celestial bodies were orbiting the larger planet.


Chris asks Caroline Crawford from the University of Cambridge to answer this listener's giant question.

Caroline - This is a very good question because Jupiter really is giant. It’s got a volume of which is equivalent to 1,300 earths. But the fact that it only weighs just over 300 times the mass of the Earth immediately tells you it’s mainly made of gas. So it’s hydrogen, helium things like that - that’s the predominant component. But we do think there's a rocky core, and maybe a rocky core that could be 10, maybe even up to 30 times the mass of the Earth all compressed down into something slightly less than the size of the Earth, right down into all that atmosphere. We can’t fly through and find out, this isn’t experiment you can do because the trouble is, if you throw a spacecraft into Jupiter, which we have done by the way, in the Galileo mission. A spacecraft goes into Jupiter - a good way to dispose of the spacecraft at the end of it’s mission.

Chris - And a comet because Shoemaker-Levy 9 plunged into Jupiter as well, didn’t it?

Carolin - What happens is when you look at the disc of Jupiter all you see is the cloud tops just in the few hundred kilometres. The gas is molecular for about 1,000 kilometres in but after that it has to carry the weight of all the overlying layers of gas and it starts to get high temperature, high pressure and becomes as incompressible as a liquid. So if you throw any spacecraft in, it’s just going to get crushed, it’s going to get destroyed really quickly, so we can’t fly in and find the rocky core or see it. We think it’s there from everything we understand about how planets form. We think you have to have a rocky core that grows quickly that can then sweep up the gas and accumulate this huge atmosphere.

But the question is how do we measure it’s size? How do we measure its mass? And this is, in fact, what we’re doing now with the Juno spacecraft that’s in orbit around Jupiter, and it’s got this 53 day orbit. On one end of the orbit it skirts to within about 4,000 kilometres of the cloud tops of Jupiter and, as it does that, it’s tracking the form of Jupiter’s gravitational field which, of course, depends on the distribution of mass within the planet. So that’s our way of tracking it and that’s one of the main things of this spacecraft - it’s got a lot of other science - one of the main things it’s trying to determine.

Dani was saying if you Google on thing tonight - go and do “tongue parasites”. Well that doesn’t quite appeal to me, especially when I’m having my dinner, but I would say go and Google “NASA Juno mission”. They put up, just in the last week, some fantastic images of some of these fly pasts of Jupiter and they are just beautiful, as well as being really interesting science, but just mesmerising.

Duncan - If there is a rocky core, is there any way of knowing what the rocky core is made of?

Carolin - It’s the same as all the rocky planets. So it’s going to be carbon, nitrogen, oxygen, magnesium, silicon, iron. All the normal things that make up all the rocky planets. It’s just that when Jupiter forms, it forms further out from the Sun and you’ve got all these volatile ices and molecules. That rocky core can then sweep up those and accumulate in an atmosphere in a way that the planets like Earth and Mars can’t because they haven’t got all those lightweight gases around.


Juno Scientists Solve Mysteries of Jupiter’s Lightning

Ever since NASA’s Voyager 1 flew past Jupiter in 1979, planetary researchers have wondered about the origin of Jovian lightning. That encounter confirmed the existence of the lightning, which had been theorized for years. But when the venerable explorer hurtled by, the data showed that the lightning-associated radio signals didn’t match the details of the radio signals produced by Earth’s lightning. In two papers published in the journals Nature and Nature Astronomy, researchers from NASA’s Juno mission describe the ways in which Jupiter’s lightning is actually analogous to Earth’s lightning.

This artist’s concept of lightning distribution in Jupiter’s northern hemisphere incorporates a JunoCam image with artistic embellishments. Data from NASA’s Juno mission indicates that most of the lightning activity on Jupiter is near its poles. Image credit: NASA / JPL-Caltech / SwRI / JunoCam.

“No matter what planet you’re on, lightning bolts act like radio transmitters — sending out radio waves when they flash across a sky,” said Shannon Brown, Juno scientist at NASA’s Jet Propulsion Laboratory and lead author of the Nature paper.

“But until Juno, all the lightning signals recorded by several NASA spacecraft were limited to either visual detections or from the kilohertz range of the radio spectrum, despite a search for signals in the megahertz range. Many theories were offered up to explain it, but no one theory could ever get traction as the answer.”

Enter NASA’s Juno orbiter. Among its suite of instruments is the Microwave Radiometer Instrument (MWR), which records emissions from Jupiter across a wide spectrum of frequencies.

“In the data from our first eight flybys, Juno’s MWR detected 377 lightning discharges,” Brown said.

“They were recorded in the megahertz as well as gigahertz range, which is what you can find with terrestrial lightning emissions. We think the reason we are the only ones who can see it is because Juno is flying closer to the lighting than ever before, and we are searching at a radio frequency that passes easily through Jupiter’s ionosphere.”

“While the revelation showed how Jupiter lightning is similar to Earth’s, the paper also notes that where these lightning bolts flash on each planet is actually quite different.

“Jupiter lightning distribution is inside out relative to Earth. There is a lot of activity near Jupiter’s poles but none near the equator. You can ask anybody who lives in the tropics — this doesn’t hold true for our planet.”

Why do lightning bolts congregate near the equator on Earth and near the poles on Jupiter? Follow the heat.

Earth’s derives the vast majority of its heat externally from solar radiation. Because our equator bears the brunt of this sunshine, warm moist air rises (through convection) more freely there, which fuels towering thunderstorms that produce lightning.

Jupiter’s orbit is five times farther from the Sun than Earth’s orbit, which means that the giant planet receives 25 times less sunlight than Earth. But even though the gas giant’s atmosphere derives the majority of its heat from within the planet itself, this doesn’t render the Sun’s rays irrelevant.

They do provide some warmth, heating up Jupiter’s equator more than the poles — just as they heat up Earth.

Scientists believe that this heating at Jupiter’s equator is just enough to create stability in the upper atmosphere, inhibiting the rise of warm air from within. The poles, which do not have this upper-level warmth and therefore no atmospheric stability, allow warm gases from Jupiter’s interior to rise, driving convection and therefore creating the ingredients for lightning.

“These findings could help to improve our understanding of the composition, circulation and energy flows on Jupiter. But another question looms. Even though we see lightning near both poles, why is it mostly recorded at Jupiter’s north pole?” Brown said.

In the Nature Astronomy paper, a research team led by Dr. Ivana Kolmašová of the Czech Academy of Sciences presents the largest database of lightning-generated ‘whistlers’ (low-frequency radio emissions) around Jupiter to date.

The data set of more than 1,600 signals, collected by Juno’s Waves instrument, is almost 10 times the number recorded by Voyager 1.

Juno detected peak rates of four lightning strikes per second (similar to the rates observed in thunderstorms on Earth) which is six times higher than the peak values detected by Voyager 1.

“These discoveries could only happen with Juno,” said Juno principal investigator Dr. Scott Bolton, a researcher at the Southwest Research Institute and co-author of both papers.

“Our unique orbit allows our spacecraft to fly closer to Jupiter than any other spacecraft in history, so the signal strength of what the planet is radiating out is a thousand times stronger.”

“Also, our microwave and plasma wave instruments are state-of-the-art, allowing us to pick out even weak lightning signals from the cacophony of radio emissions from Jupiter.”

Shannon Brown et al. 2018. Prevalent lightning sferics at 600 megahertz near Jupiter’s poles. Nature 558: 87-90 doi: 10.1038/s41586-018-0156-5

Ivana Kolmašová et al. Discovery of rapid whistlers close to Jupiter implying lightning rates similar to those on Earth. Nature Astronomy, published online June 6, 2018 doi: 10.1038/s41550-018-0442-z

This article is based on text provided by the National Aeronautics and Space Administration.


Fly over Jupiter in this stunning video from NASA's Juno spacecraft

What if you could hitch a ride on NASA's Juno spacecraft at Jupiter? We may be stuck on Earth, but the space agency has given us the next best option: a new video flyover of Jupiter based on photos from Juno's recent flyby in June.

The stunning video, which is made up of 41 images captured on June 2, gives us a glimpse of what we'd see if we were able to fly around Jupiter ourselves, combining pictures taken from different angles as the spacecraft sped by the solar system's largest planet.

Throughout the video, we see zoomed-in views of Jupiter's upper atmosphere at Juno's closest approach, when the spacecraft was about 2,100 miles (3,400 kilometers) above the planet's cloud tops, as well as zoomed-out views. At the spacecraft's closest point to Jupiter, the gas giant's powerful gravity sped the spacecraft up to an impressive 130,000 mph (209,000 kph) relative to the planet, according to a NASA statement.

Citizen scientist Kevin Gill created the video with data from Juno's JunoCam, which digitally projects images onto a sphere with a virtual "camera," giving us these beautiful views of Jupiter. These pictures were taken between 5:47 a.m. and 7:25 a.m. EDT (0947 and 1125 GMT) on June 2 as the spacecraft made its 27th close flyby of the planet.

Juno launched in 2011 and, after a five-year trek through space, reached Jupiter in July 2016. The spacecraft circles the solar system's largest planet taking data so we can understand the origin and evolution of Jupiter. Since its first flyby, Juno has provided incredible information about the planet, including an up-close look at Jupiter's Great Red Spot, a giant storm swirling through the planet's atmosphere.

Though the spacecraft was meant to take a dive into Jupiter's atmosphere in 2018, NASA has extended its mission through 2021.

Follow Kasandra Brabaw on Twitter @KassieBrabaw. Follow us on Twitter @Spacedotcom and on Facebook.


Jun 28th: Would We See the Aliens Coming?

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Classic sci fi trope time. The air force detects a fleet of alien spacecraft out past Jupiter, leaving enough time to panic and demonstrate what awful monsters we truly are before they come ring our bell.

Is that how this would work?

Imagine a pivotal scene in your favorite alien mega disaster movie. Like the one where the gigantic alien ships appear over London, Washington, Tokyo, and Paris and shoots its light-explody ray, obliterating a montage of iconic buildings. Demonstrating how our landmark construction technology is nothing against their superior firepower.

What could we do? We’re merely meat muppets with pitiful silicon based technology. How could we ever hope to detect these aliens with their stealth spacecraft and 3rd stage guild navigators? If we’re going to do this, I’m going to make up some rules. If you don’t like my rules, go get your own show and then you can have your own rules.

Alternately, as some of you are clearly aware, you can rail against the Guide To Space in the comments below. Dune reference notwithstanding, I’m going to assume that aliens live in our Universe and obey the laws of physics as we understand them. And I know you’re going to say, what if they use physics we haven’t discovered yet?

Then just pause this video and get that out of your system. You can make that your first decree against the state right in the comments below.

As I was saying, physical aliens, physical universe. We’ll discuss the metaphysical aliens in a magic universe in a future video. The ones that have crystals and can heal your liver through the power of song.

A basic rule of the Universe is that you can’t go faster than the speed of light. So I’m going to have any aliens trying to attack us traveling at sublight speeds.

So, we’ll say they’ve got access to a giant mountain of power. They can afford to travel at 10% the speed of light, which means before they get to us, they have to slow down.

At this speed, deceleration is expensive. We’d see the energy signature from their brakes long before they even reached Earth.

Let’s say they’re passing the orbit of the dwarf planet Pluto, which is 4 light-hours away. Since they’re travelling at 10% the speed of light, we’d have about 40 hours to scramble jet fighters, get those tanks out onto the streets and round up Will Smith, Jeff Goldblum and Bruce Willis to hide behind.

Would we even notice? Maybe, or maybe not. A growing trend in astronomy is scanning the sky on a regular basis, looking for changes. Changes like supernova explosions, asteroids and comets zipping past, and pulsating variable stars.

One of the most exciting new observatories under construction is the Large Synoptic Survey Telescope in Chile. Once it begins regular operations in 2022, this array of telescopes will photograph the entire sky in fairly high resolution every few nights.

Computers will process the torrent of data coming from the observatory and search for anything that changes. What if they engage their cloak?

Actually (push glasses up your nose) the laws of physics say that the aliens can’t hide the waste heat from whatever space drive they’re using. We’re actually pretty good at detecting heat with our infrared telescopes.

A space drive decelerating a city-sized alien spacecraft from a significant portion of the speed of light would shed a mountain of heat, and that’s all heat we might detect.

Astronomers have been searching for alien civilizations by looking for waste heat generated by Dyson spheres encapsulating entire stars or even all the stars in a galaxy. Nothing’s turned up yet. Which I for one, find a little suspicious.

If you’re from an alien race who’s planning to invade. Cover your ears. If aliens wanted to catch us off guard, they can use one of the oldest tricks in the aerial combat book, known as the Dicta Boelcke. They can fly at us using the Sun as camouflage. A rather large portion of the sky is completely obscured by that glowing ball of fiery plasma. It worked in WW1, and it’ll still work now.


New Space Telescope, 40 Times The Power Of Hubble, To Unlock Astronomy's Future

The concept design of the LUVOIR space telescope would place it at the L2 Lagrange point, where a . [+] 15.1-meter primary mirror would unfold and begin observing the Universe, bringing us untold scientific and astronomical riches.

NASA / LUVOIR concept team Serge Brunier (background)

Since humanity first turned our gaze skyward, we've realized that the cosmic story of our existence — our origins, all that exists today, and what our ultimate fate is — is literally written across the Universe. Our understanding of what our Universe truly is, what it's made up of, and how it came to be this way has improved dramatically every time we've built better instruments to probe the stars, galaxies, and the depths of space in new ways. The Hubble Space Telescope gave us a huge leap forward, showing us what our Universe looked like next year, James Webb will give us an equally big leap, showing us how our Universe came to be this way. To take that next giant leap means dreaming big, and seeking to answer the biggest questions astronomy has today. Only LUVOIR, a proposed 15.1-meter space telescope with 40 times the light-gathering power of Hubble, dares humanity to solve those puzzles.

Is 'Planet Nine' real? If so, most ground-based telescopes or even current/future space-based . [+] telescopes will be barely able to image a single pixel's worth of it. But LUVOIR will be able, even at its great distance, to reveal intricate structure on the surface of the world.

NASA / LUVOIR concept team

LUVOIR, a concept for a Large UltraViolet, Optical, and InfraRed observatory, would basically be a scaled-up version of Hubble in space, capable of doing the science that was unfathomable a generation ago. That's not to belittle Hubble's accomplishments at all! Consider what Hubble has given us: a revolution in cosmology, a revolution in our understanding of galaxies and their building blocks, a keen eye on our dynamic Solar System, and our first steps into the study of exoplanetary atmospheres. At 15.1 meters, with a segmented design, instrumental capabilities far outstripping what we have today, superior resolution, and so much more, LUVOIR would represent not an incremental improvement, but a transformative one, over anything not only in existence, but over any observatory ever proposed.

If the Sun were located 10 parsecs (33 light years) away, not only would LUVOIR be able to directly . [+] image Jupiter and Earth, including taking their spectra, but even the planet Venus would yield to observations.

NASA / LUVOIR concept team

I spoke with John O'Meara, the lead of Cosmic Origins Science for LUVOIR, about a wide variety of topics related to this proposed telescope. In every astronomical arena you can imagine — from the Solar System to exoplanets, stars, galaxies, intergalactic gas, dark matter and more — a telescope this advanced would push our scientific knowledge forward in a way nothing else ever has. Going so much larger, combined with the other advanced technology that will be aboard LUVOIR, makes this truly the astronomer's dream observatory. Compared with what we can do today, here's a look at six things a giant space telescope like this would allow us to learn.

An outer world in the Solar System's Kuiper belt would appear with many rich features from a 10-15 . [+] meter class telescope (L), while Hubble, even at its maximum operational limits, would only see a handful of pixels with any information at all (R).

Solar System — Imagine what it would be like to directly image geysers on Europa and Enceladus, eruptions on Io, or to map out the magnetic fields of the gas giants from right here, near our own world? Imagine looking out at a distant world in the Kuiper belt, and not just getting a single pixel of light to extrapolate from, but to take an image of the world itself and be able to discern surface features? That's the promise of a 10-or-more-meter space telescope, which should not only be able to take incredible images of these worlds, but to obtain spectra of a huge variety of features on them.

The strongest driver on the size of the LUVOIR telescope is the desire to have a large sample of . [+] exoEarth candidates to study. This figure shows the real stars in the sky for which a planet in the habitable zone can be observed. The color coding shows the probability of observing an exoEarth candidate if it’s present around that star (green is a high probability, red is a low one).

C. Stark and J. Tumlinson, STScI

Exoplanets — Instead of inferring the existence of planets from their transits or the wobbles they cause in the orbits of their parent stars, LUVOIR will have the capability to image a great many of them directly. With a coronagraph of unprecedented quality, coupled with its one-of-a-kind size and location in space, it should be able to find and image hundreds of star systems for candidate exoplanets with the potential for life on them: all the stars within about 100 light years. With the spectra it will obtain, LUVOIR can do what no other current or planned observatory will be able to: search for molecular biosignatures around hundreds of Earth-sized, potentially habitable worlds. For the first time, it could give us evidence of life beyond our own solar system.

A simulated image of what Hubble would see for a distant, star-forming galaxy (L), versus what a . [+] 10-15 meter class telescope would see for the same galaxy (R). The resolution is many times better for the image at right, but what isn't encoded in this image is the fact that the image at left needs to be exposed for up to 40 times as long to capture the same amount of light.

NASA / Greg Snyder / LUVOIR-HDST concept team

Stars — When the Hubble Space Telescope was launched, it opened up a fascinating possibility to observational astronomers: the capability of measuring the properties of individual stars in the Andromeda galaxy, more than 2 million light years away. With LUVOIR, we'll be able to make those same measurements for every galaxy within about 300 million light years! For the first time, we'll be able to measure stars in every type of galaxy in the Universe, from dwarfs to spirals to giant ellipticals to the rare ring galaxy to galaxies in the active process of merging. This cosmic census would be impossible without a large, optical space telescope like this.

Although there are magnified, ultra-distant, very red and even infrared galaxies in the eXtreme Deep . [+] Field, there are galaxies that are even more distant out there, which LUVOIR will be able to reveal without the assistance of gravitational lenses.

Credit: NASA, ESA, R. Bouwens and G. Illingworth (UC, Santa Cruz)

Galaxies — Hubble, quite remarkably, has been able to find galaxies from when the Universe was only 400 million years old: just 3% of its current age. But galaxies this distant are rare, since Hubble can only see the brightest ones among them, and even at that, the ones that are aided by having gravitational lenses in the foreground. By contrast, LUVOIR will be able to see every galaxy, including the faint ones, the dwarf ones, the tiny building blocks of modern galaxies, and the ones that don't have gravitational lenses or serendipitous alignments at all. We will finally be able to learn about the full population of galaxies in the Universe, and to measure them to resolutions of just 300-400 light years per pixel, no matter how distant they are in the Universe.

The unmistakable pink color along the spiral arms traces out regions of ionized hydrogen, caused by . [+] the formation of hot, young stars in this galaxy, many of which will eventually go supernova. While measuring the gas that feeds a galaxy like this is barely possible today, LUVOIR will allow us to not only measure it, but to map it and identify its molecular and atomic components.

Intergalactic gas — Today, we can take a "pencil beam" of a galaxy, measuring the halo of gas surrounding a galaxy and serving as its fuel tank and recycling center. We can measure the absorption features of this gas, and compare it with the best 3D simulations our theory and technology can offer. But with LUVOIR, we can directly image dozens or even hundreds of "pencil beams" per galaxy, measuring and mapping out the circumgalactic medium for any galaxy at all. We can even, in some cases, directly image the emission properties of the excited gas, allowing us to directly compare our observations with the simulations, without having to do the interpolation necessary in absorption alone.

Do smaller and/or younger galaxies obey a different gravitational or acceleration law than large, . [+] old ones? That would go a long way towards discerning between dark matter and modified gravity, and LUVOIR, by taking measurements of galaxies billions of light years away, will enable us to find out.

Adam Block/Mount Lemmon SkyCenter/University of Arizona

Dark matter — This invisible, transparent mass is responsible for the majority of gravitation in the Universe, yet we can only map it out from its effects on visible matter. In the past, this has meant looking at bulk properties of large areas of distant galaxies, with the Milky Way, from our vantage point within it, being one of the most difficult galaxies to map. LUVOIR will change all of that, allowing us to measure the rotation properties of galaxies more distant than ever before, testing whether and how the dark matter profile of galaxies has evolved over billions of years. We'll be able to test models of dark matter explicitly, by measuring the proper motions of Milky Way stars to never-before-achieved precision, and by analyzing the smallest building blocks of galaxies that are currently beyond even the world's most powerful telescopes.

A simulated view of the same part of the sky, with the same observing time, with both Hubble (L) and . [+] LUVOIR (R). The difference is breathtaking.

G. Snyder, STScI /M. Postman, STScI

There's no substitute for being in space no matter how good adaptive optics get, you'll never be able to overcome 100% of the atmosphere's effects. This is particularly true in the ultraviolet, and at many infrared wavelengths, which can really be only imaged accurately from space, due to atmospheric absorption at those wavelengths. There's also no substitute for size, which determines both the maximum resolution you can achieve and the amount of light-gathering power you have. Across the board, LUVOIR will be capable of better than six times the resolution of Hubble and of taking images to the same depth approximately 40 times faster. What LUVOIR could see with nine days of continuous observations would take Hubble an entire year, and still Hubble would only have 16% as good resolution.

The great red spot in all its beauty seen by the JunoCam, image processed to intensify the beauty of . [+] the bands and zones of Jupiter. LUVOIR will be able to get images of this same quality from our own planet's backyard.

NASA / JPL-Caltech / SwRI / MSSS processing by Carlos Galeano - Cosmonautika

As good as JUNO's images are of Jupiter, LUVOIR will be able to get those images from its vantage point in orbit near Earth, rather than having to fly a spacecraft to a distant planet. When it comes to measuring the ultraviolet light from a source, LUVOIR will use a microshutter array on its spectroscopic instrument, allowing it to image many objects simultaneously, rather than just a single object at a time like today's telescopes. And just like Hubble works with today's largest ground-based observatories, LUVOIR will work with the current generation of under-construction 30-meter-class observatories, like GMT and ELT, to discover and follow-up on the faintest, most distant objects that humanity will ever know. While James Webb will be NASA's flagship astrophysics mission of the 2010s and WFIRST will fly in the 2020s, LUVOIR could come to be as early as the 2030s, depending on how the upcoming decadal survey goes.

But these potential discoveries are what we know we're going to be looking for. With every new major technological leap forward we've ever taken in astronomy and astrophysics, the greatest achievements of all have been the ones we could not have anticipated in advance. The great unknowns of the Universe, including what it looks like in the faintest regimes, how the most distant stars, galaxies, gas clouds, and the intergalactic medium behaved at early times, and what it looks like beyond anything we've ever seen will all be exposed for the first time. It's possible that we'll learn we were quite arrogant and wrongheaded in a great multitude of arenas, but we'll need this new, high-quality data to show us the way.

This concept art of a completed SLS launch vehicle will be capable of housing up to a 15.1-meter . [+] space telescope, if it's segmented and folded properly. It is the ideal vehicle to carry LUVOIR to the L2 Lagrange point.

In order for LUVOIR to work, we'll need to use the largest, heaviest-design launch vehicle capable: NASA's Space Launch System. We'll need the segmented mirrors to achieve picometer-level stability more than 10 times better than the stability we achieve today. To perform the exoplanet imaging, we'll need a coronagraph that can pick out 1-part-in-10,000,000,000, a huge improvement over today's best systems. The mirror and mirror-coating systems will demand improved technology over today's best. And most ambitiously, we'll need the capability to service this telescope at the L2 Lagrange point: 1.5 million kilometers away from Earth, which is four times as far as the most distant human has ever flown from our world. And as far as why we need this, I think John said it best in his own words:

I believe very strongly that LUVOIR is a critical part of our next great era in science when we definitively advance not just the search for life, but the telling of its story over cosmological time. LUVOIR can give us the tools to answer many of our most fundamental questions as human beings trying to understand their place in the universe. If that isn’t worth it, what is?


NASA’s Juno spacecraft to remain in current orbit around Jupiter

Concerns about the health of the Juno spacecraft’s main engine have compelled NASA managers to keep the research probe in its current arcing, high-altitude orbit around Jupiter, a decision that will delay the full science return from the $1.1 billion mission but should still allow it to meet all predetermined objectives.

Juno fired its main engine to brake into orbit around Jupiter on July 4, 2016, maneuvering into an egg-shaped 53-day orbit that takes the spacecraft several million miles from the giant planet on each circuit.

At the low end of the orbit, the spacecraft passes within 3,000 miles (5,000 kilometres) from Jupiter’s cloud tops, permitting Juno’s instruments to peer deep into the atmosphere, measure the planet’s extreme magnetic field and radiation belts, observe its auroras, and take the first detailed images of its poles.

But engineers called off another engine burn planned for Oct. 19 to put Juno in a tighter 14-day orbit, the science perch envisioned by mission managers since the project’s inception. Most of Juno’s scientific observations occur when the probe is closer to the planet, and the 14-day orbit was designed to give researchers rapid-fire data returns during close approaches every two weeks.

Ground controllers noticed two helium check valves inside the spacecraft’s main propulsion system did not behave as expected during pressurization of Juno’s propellant tanks about a week before the planned Oct. 19 engine firing. The valves opened in several seconds before previous engine burns, but took several minutes to open in October.

Rick Nybakken, Juno’s project manager at NASA’s Jet Propulsion Laboratory, told Spaceflight Now that engineers recommended canceling the maneuver and keeping the craft in its current 53-day orbit after a multi-month investigation.

“The project recommended not doing the burn,” Nybakken said in a Feb. 17 interview. “We’re in a great science orbit, the spacecraft is healthy, the instruments are healthy. We’re getting incredible science, and it’s teaching us more about Jupiter, and there are a lot of very interesting surprises about Jupiter, so we recommended not to take any additional risk that might jeopardize that — not to do this burn — and ultimately NASA Headquarters agreed with that recommendation.”

This diagram shows Juno’s original flight plan, in which the spacecraft would have completed two 53-day orbits, then transitioned into a lower 14-day science orbit around Jupiter. NASA has decided to keep the spacecraft in the 53-day orbit for the rest of the mission. Credit: NASA/JPL-Caltech

According to Nybakken, experts considered an option in which Juno’s Leros 1b main engine, designed and built by Moog-ISP in the United Kingdom, could have fired in a backup “blow-down” mode using residual tank pressure, bypassing the suspect check valves. In a normal burn, the check valves would actuate to regulate pressure in the propellant system feeding the thruster.

Officials decided the risk of doing a “blow-down” burn was too great, Nybakken said. Any problem during such an engine firing could have stranded Juno midway between the 53-day and 14-day orbits in a less optimal perch for science observations.

In the 53-day orbit, Juno will avoid flying through Jupiter’s shadow, keeping the craft’s power-generating solar panels in sunlight. If Juno ended up in an unplanned lower orbit because of a sub-optimal engine burn, the probe would have flown through a series of eclipses in 2019, starving it of sunlight and likely ending the mission.

The choice not to execute the orbit-lowering burn preserves the option to use Juno’s smaller maneuvering thrusters to steer clear of Jupiter’s shadow and keep the mission going beyond 2019.

“It wasn’t so much that the risk was unacceptable, it’s just that if anything off-nominal were to happen, you bring in these mission-ending eclipses in 2019,” Nybakken said. “In our current orbit, the size of the orbit is large enough, and the time of the orbit helps give us the operational latitude to avoid those eclipses.”

Nybakken said the inquiry into Juno’s propulsion woes did not determine a root cause for the sticky valves. Officials quickly decided against using the valves for a “regulated” burn, and instead studied the backup “blow-down” option before eventually concluding Juno’s orbit should not be lowered at all.

“At a high level, one of the leading theories is that we can have a very low level of interaction at the vapor level between fuel and oxidizer, and it can create products that can interfere with proper valve operation,” Nybakken said. “Beyond that, it is kind of to be determined. We didn’t require root cause to realize the valves are not working as intended.”

NASA’s Juno spacecraft soared directly over Jupiter’s south pole when JunoCam acquired this image on February 2, 2017 at 6:06 a.m. PT (9:06 a.m. ET), from an altitude of about 62,800 miles (101,000 kilometres) above the cloud tops. This image from Juno’s JunoCam camera was processed by citizen scientist John Landino. Credit: NASA/JPL-Caltech/SwRI/MSSS/John Landino

Engineers ruled out any link between Juno’s propulsion problem and engine failures on two geostationary communications satellites last year, Nybakken said.

The commercial Intelsat 33e and the U.S. Navy’s MUOS 5 communications satellites were to use on-board engines to raise their orbits to geostationary altitude 22,300 miles (35,800 kilometres) above Earth’s equator after launching in June and August 2016. Both satellites had to use backup thrusters to finish the job.

Nybakken said those engine failures were unrelated to the issue aboard Juno, and engineers with JPL and Lockheed Martin — Juno’s prime contractor — cleared the Leros 1b engine on the Jupiter orbiter in October, before encountering the sticky check valves.

“There were a couple of failures last fall that we looked into, and we were able to determine that those failures did not represent any sort of increased risk to Juno,” Nybakken said. “And after we completed that investigation, we were, in fact, planning to go ahead with this maneuver.”

One benefit of Juno’s predicament is the higher 53-day orbit will keep the spacecraft away from the worst of Jupiter’s intense radiation belts, which harbour hazards that mission designers believed would limit the mission’s duration to some time in 2018.

“It turns out in the 53-day orbits, we cross the equator, where the radiation belts are, much farther out, so we have much less radiation dose,” Nybakken said. “Of course, with the orbits being larger, the dose as a function of time is much slower as well.”

Juno’s next close pass by Jupiter is set for March 27, completing its fifth orbit of the planet since last year’s arrival.

“Juno is healthy, its science instruments are fully operational, and the data and images we’ve received are nothing short of amazing,” said Thomas Zurbuchen, associate administrator for NASA’s science mission directorate in Washington, in a statement. “The decision to forego the burn is the right thing to do — preserving a valuable asset so that Juno can continue its exciting journey of discovery.”

The Juno mission is funded through July 2018, for a total of 12 science orbits, down from the 32 science orbits originally planned, NASA said in a statement.

Juno’s science team can then propose to continue the mission for another two years as part of NASA’s senior review process, in which a panel of independent researchers recommend to the agency which of its planetary science missions should continue to receive federal funding.

“Juno is providing spectacular results, and we are rewriting our ideas of how giant planets work,” said Scott Bolton, the mission’s principal investigator from the Southwest Research Institute in San Antonio. “The science will be just as spectacular as with our original plan.”

“We’re very excited about what we’ve seen so far, and every time we fly by the planet it’s like Christmas time,” Nybakken said. “The data is stunning.”

Follow Stephen Clark on Twitter: @StephenClark1.


For 'flying around'

When they are actually in space, they use the Deutronium Annihilation Drive:

Deep space propulsion is accomplished with two deutronium-annihilation atomic motors. Theoretically, these engines are capable of producing unlimited thrust and speed. Photons are created through deutronium annihilation in the hafnium carbide reactor chamber located in the center of the lower region of the spacecraft. The photons radiate through the urns projecting from the Thompson field projector. These engines cannot be activated except in deep space. Operation within the atmosphere of a planet would result in life-threatening contamination due to dangerous radioactive exhaust.

This is from the Lost in Space wikia, concerning the liftoff and flight procedure for the Jupiter 2:

The anti-gravity drive system was designed for use in vehicle liftoff and touch down. The anti-gravity drive consumes 250 megawatts at full power and is capable of delivering up to 10 g’s of acceleration. In terms of the Earth’s gravitational field at sea level, this translates to 55,000 pounds of thrust. The engine is relatively compact with the major space requirement being for the circular track in the lower region of the spacecraft which houses the Thompson unitectic gravity field projector. Visible light is given off as a by-product of each revolution of the generated field. The anti-gravity drive is throttled back when the pull of gravity on the spacecraft is less than 1/20th of Earth’s gravity at sea level. At that field strength, the anti-gravity drive becomes ineffective, producing less than 200 pounds of thrust.

Check out "Jupiter Two Propulsion Specifications" by Earl Hooks. Pretty good explantion of the ISD (Ion Singularity Drive).

In addition to the Thompson Field Projector the Jupiter 2 also utilized Gyro Stability systems which were un caged during lift off. The wobble dampers were used to enforce ship stability by electronic servo mechanistic control. Artificial gravity was regulated proportional to relative external graviton measurements influenced incident to relative proximity to a given gravitational field external influence associated with a planetary body. Servos compensated coordination to maintain attitude, yaw and pitch control rockets that produced a harmless mist of plum exhaust served to trim the angular position orientation as an auxiliary control agency when needed. Forward motion was achieved by magnetic and anti graviton persuasion, resulting in accelerating the space craft by way of seeking out a strong magnetic field in lieu of exerting a relatively stronger magnetic field induced toward the frontal axis of the space craft. Reverse thrust by way of conventional rockets with solid fuel propellants provide braking action via retro rocket propulsion for slowing for atmosphere reentry. The Space Theodalite, encapsulated in the bubble shield atop the Jupiter 2 serves as a navigational relay system. It provides reference data fixed star to fix star bearings determination for the inertial guidance control system. Vector records were telecommunicated and down linked to the data tape recorder for navigation tracking and Telemonitoring control. The R.G.S. Scanner is the Remote Guidance System that serves as a cognitive cybernetic positronic matrix brain which perceives and correlate all navigational data to direct the master central Astrogator. The Robot is Environmental control Cybernetic Servo Mechanism. Master computer systems located in the robot storage magnetic lock room area direct and augment the robots functions by way of full duplex telecasters download and upload link over microwave transmission frequencies. Redundant guidance control and maneuver overriding controls are accessed by pilots via the central view port instrument cluster panel. Internal atmosphere is regenerated by hydroponics plants which emit oxygen in exchange for carbon dioxide, oxygen accumulator compresses captured air and exchange system maintains internal dynamic air pressure. Trace artificial atmospheric gas elements are also synthetically produced by way of a replicate that approximates the molecular structure of trace elements, and manufactures them to the demands required by relative needs. Fuel cells produce drinking and potable water from an osmotic micro pump system. Food stuffs are produced by replication of molecular structure patterns copping of data script from food galley computer software directed scripting control of Nan no-replicates. The food storage purifier sustains potency for prolonged storage. Raw materials of indiscriminate nature are transformed to eatables form virtually any available material substance introduced into its admittance aperture.

Professor: Howard Daniel Rollins III


Watch the video: Αυτοκινητόδρομος. Τρόπος Οδήγησης. Οδική Ασφάλεια (January 2023).