Monday, November 11, 2024

SPACE/COSMOS


THE ORIGINAL SKYNET
UK's oldest satellite veers miles off track on its own leaving scientists confused

UK satellite launched in 1969 moves dep into outer space but nobody knows who moved it or how

By Web Desk|
November 11, 2024
An undated image shows Skynet-1A satellite. — X/@Horashi0

In a shocking turn of events for the space industry in the United Kingdom, scientists recently discovered that the country's oldest satellite has veered deep into space, thousands of miles off track.

Skynet-1A, a satellite that was launched into space in 1969 soon after man's first lunar landing, and was originally positioned over East Africa to facilitate British military communications.

However, recently, it was found by scientists to have relocated and hovering above the Americas, far from its expected trajectory over the Indian Ocean, the Daily Express reported.

What scientists found baffling about this was that they had no clear explanation of who moved it or how.

According to the scientists, orbital mechanics suggest that a half-tonne satellite shouldn't drift that far on its own which leads to the conclusion that it was intentionally moved.

Nobody can say who would want or be able to do such a thing. But is the satellite's relocation a good thing or a bad thing?

Space consultant Dr Stuart Eves told the BBC: "It's still relevant because whoever did move Skynet-1A did us few favours.

“It's now in what we call a 'gravity well' at 105° West longitude, wandering backwards and forwards like a marble at the bottom of a bowl. And unfortunately this brings it close to other satellite traffic on a regular basis.

"Because it's dead, the risk is it might bump into something, and because it's 'our' satellite, we're still responsible for it.

The satellite was made in the United States and put in space by a US Air Force (USAF) Delta rocket.

Thanks to veterans of the programme that put it in space, the satellite revolutionised UK telecommunications capacity and allowed London to communicate securely with British forces, such as Singapore.

Rachel Hill, a PhD student from University College London, has reviewed documents and believes that plausible explanations exist for how the satellite has arrived at its present location.

She said: "A Skynet team from Oakhanger would go to the USAF satellite facility in Sunnyvale (colloquially known as the Blue Cube) and operate Skynet during 'Oakout'. This was when control was temporarily transferred to the US while Oakhanger was down for essential maintenance. Perhaps the move could have happened then?”

Mining old data from NASA's Voyager 2 solves several Uranus mysteries


Mining old data from NASA's Voyager 2 solves several Uranus mysteries
The first panel of this artist’s concept depicts how Uranus’s magnetosphere — its protective
 bubble — was behaving before the flyby of NASA’s Voyager 2. The second panel shows 
an unusual kind of solar weather was happening during the 1986 flyby, giving scientists a 
skewed view of the magnetosphere. Credit: NASA/JPL-Caltech

When NASA's Voyager 2 spacecraft flew by Uranus in 1986, it provided scientists' first—and, so far, only—close glimpse of this strange, sideways-rotating outer planet. Alongside the discovery of new moons and rings, baffling new mysteries confronted scientists. The energized particles around the planet defied their understanding of how magnetic fields work to trap particle radiation, and Uranus earned a reputation as an outlier in our solar system.

Now, new research analyzing the data collected during that flyby 38 years ago has found that the source of that particular mystery is a cosmic coincidence. It turns out that in the days just before Voyager 2's flyby, the planet had been affected by an unusual kind of space weather that squashed the planet's , dramatically compressing Uranus's magnetosphere.

"If Voyager 2 had arrived just a few days earlier, it would have observed a completely different magnetosphere at Uranus," said Jamie Jasinski of NASA's Jet Propulsion Laboratory in Southern California and lead author of the new work published in Nature Astronomy. "The spacecraft saw Uranus in conditions that only occur about 4% of the time."

Magnetospheres serve as protective bubbles around planets (including Earth) with magnetic cores and magnetic fields, shielding them from jets of ionized gas—or plasma—that stream out from the sun in the solar wind. Learning more about how magnetospheres work is important for understanding our own planet, as well as those in seldom-visited corners of our solar system and beyond.

That's why scientists were eager to study Uranus's magnetosphere, and what they saw in the Voyager 2 data in 1986 flummoxed them. Inside the planet's magnetosphere were electron radiation belts with an intensity second only to Jupiter's notoriously brutal radiation belts. But there was apparently no source of energized particles to feed those active belts; in fact, the rest of Uranus's magnetosphere was almost devoid of plasma.

The missing plasma also puzzled scientists because they knew that the five major Uranian moons in the magnetic bubble should have produced water ions, as  around other outer planets do. They concluded that the moons must be inert with no ongoing activity.

Mining old data from NASA's Voyager 2 solves several Uranus mysteries
NASA’s Voyager 2 captured this image of Uranus while flying by the ice giant in 1986. 
New research using data from the mission shows a solar wind event took place during the
 flyby, leading to a mystery about the planet’s magnetosphere that now may be solved.
 Credit: NASA/JPL-Caltech

Solving the mystery

So why was no plasma observed, and what was happening to beef up the radiation belts? The new data analysis points to the solar wind. When plasma from the sun pounded and compressed the magnetosphere, it likely drove plasma out of the system. The  event also would have briefly intensified the dynamics of the magnetosphere, which would have fed the belts by injecting electrons into them.

The findings could be good news for those five major moons of Uranus: Some of them might be geologically active after all. With an explanation for the temporarily missing , researchers say it's plausible that the moons actually may have been spewing ions into the surrounding bubble all along.

Planetary scientists are focusing on bolstering their knowledge about the mysterious Uranus system, which the National Academies' 2023 Planetary Science and Astrobiology Decadal Survey prioritized as a target for a future NASA mission.

JPL's Linda Spilker was among the Voyager 2 mission scientists glued to the images and other data that flowed in during the Uranus flyby in 1986. She remembers the anticipation and excitement of the event, which changed how scientists thought about the Uranian system.

"The flyby was packed with surprises, and we were searching for an explanation of its unusual behavior. The  Voyager 2 measured was only a snapshot in time," said Spilker, who has returned to the iconic mission to lead its science team as project scientist. "This new work explains some of the apparent contradictions, and it will change our view of Uranus once again."

Voyager 2, now in interstellar space, is almost 13 billion miles (21 billion kilometers) from Earth.

More information: Jamie Jasinski et al, The anomalous state of Uranus's magnetosphere during the Voyager 2 flyby, Nature Astronomy (2024). DOI: 10.1038/s41550-024-02389-3www.nature.com/articles/s41550-024-02389-3


Journal information: Nature Astronomy 


Provided by NASA 

Studying the mystery of Uranus's curiously weak radiation belts


'Webb has shown us they are clearly wrong': How astrophysicist Sophie Koudami's research on supermassive black holes is rewriting the history of our universe

By Ben Turner 

How did supermassive black holes get big so fast? Astrophysicist Souphie Koudmani tells us how she and her colleagues are finding out.

An artist's rendering of a black hole (Image credit: Vadim Sadovski via Shutterstock)

A supermassive mystery lurks at the center of the Milky Way. Supermassive black holes are gigantic ruptures in space-time that sit in the middle of many galaxies, periodically sucking in matter before spitting it out at near light speeds to shape how galaxies evolve.

Yet how they came to be so enormous is a prevailing mystery in astrophysics, made even deeper by the James Webb Space Telescope (JWST). Since it came online in 2022, the telescope has found that the cosmic monsters are shockingly abundant and massive in the few million years after the Big Bang — a discovery that defies many of our best models for how black holes grew.

Sophie Koudmani is an astrophysicist at the University of Cambridge searching for answers to this problem. Live Science sat down with her at the New Scientist Live event in London to discuss the cosmic monsters, how they could have formed, and how her work using supercomputers to simulate them could rewrite the history of our universe.

Ben Turner: Why are supermassive black holes so important for understanding our universe?

Sophie Koudmani: In the universe, everything is connected and supermassive black holes play a very important role. They generate a huge amount of energy that comes from the region around the black holes. As gas falls in, its gravitational potential energy is converted into radiation. This makes the gas very hot, and as it heats up it starts glowing.

The gas is heated up to millions of degrees, and its radiation then influences the whole galaxy. It stops gas clumping together to form stars, pausing star formation in a way that's important to produce realistic galaxies. The energy [from supermassive black holes] can then travel out even further and influence the large-scale structure of the universe — which is really important for cosmology and understanding cosmic evolution.

BT: So when you talk about the energy flowing outwards, you're referring to relativistic jets, or near-light speed outflows from some black holes, right?

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SK: Yes. There's three kinds of ways that black holes "'speak"' to their host galaxies. One is through relativistic jets, another is by winds given off by the accretion disk [the cloud-like structure of gas, dust and plasma that orbits black holes] — these are not as thin as jets — and then there is radiation. So generally disks give off X-rays and radiation from other parts of the electromagnetic spectrum.

BT: You touched on this already, but what would galaxies look like if black holes didn't exist?

SK: So what you could get is what is often called "runaway star formation." All of the gas would get very quickly consumed, and you would get balls of stars. This is not what galaxies look like. To get the disk galaxies [we see in our universe] it's really important to have some kind of black hole. You need to get a realistic ratio between gas and stars, without them being eaten up straight away.


Sophie Koudmani. (Image credit: Elodie Guige)

BT: What drew you to studying black holes? What questions do you want to answer about them?

SK: One thing that I really like about supermassive black holes is that they are seemingly simple, but then this incredibly rich physics comes off them. You can actually characterize black holes with just two numbers — their mass and their spin — and that completely tells you what they behave like, it's called the "no hair theorem." From these two numbers you can get all of these different possibilities. For example, some black holes have jets and others don't, some have brightly-glowing accretion disks and others are completely quiet. It's the interaction with the galaxies that brings this out.

So it's a simple object at the center that can be incredibly powerful. It interacts with something that can be quite complex and messy, the galaxy — you get the gas, the dust, the stars, all being held together by dark matter which we don't understand very well. And all of these components interact with each other in ways that are really complex to understand.

BT: It's interesting that you described them as simple, because in relativistic physics they're where all of our equations break down and where we might want to look for theories of quantum gravity. Do they only look simple because our theories of them are?

SK: It depends what you're interested in. If you're interested in what's going on inside the event horizon, then yeah, sure, the singularity is where our theories break down. We don't know exactly about other physical phenomena, like Hawking radiation, that could actually come from inside of the black hole.

If you're worrying about all of this, yes, you have a very difficult job! But if you're thinking about astrophysical black holes, you're interested in the gas flows and radiation around the black hole. As an astrophysicist, you can be quite happy to locate the event horizon, see what it does to the region around it, and be relatively agnostic about what's inside. The location of that horizon itself is uniquely determined by the mass and the spin.

BT: What mysteries has JWST revealed about black holes that we didn't know before?

SK: We didn't know that there would be so many supermassive black holes so early on. They exist in such high numbers [in the early universe] and inside pretty small galaxies, that was surprising.

My PhD was on modeling black holes in small galaxies, it was lucky that I happened to be working on that because it's become very relevant for the early universe. JWST is telling us that black hole activity happened at very early times and in more galaxies than was thought possible. In fact, the activity seems to be more efficient than in the present-day universe.


Two merging black holes. (Image credit: Mark Garlick/Science Photo Library via Getty Images)

BT: Why might that be?

SK: We all know about cosmic expansion — so the Big Bang happens and the whole universe expands — and this means that in the early times of the universe everything was a bit closer together so gas inflows were stronger, this might have helped to feed black holes.

One problem is that black holes and supernovae kind of compete with one another. Both star formation and black holes consume gas. The black hole blows gas away, so do the supernovae, and supernovae also evacuate the gas from the central region, and then black holes can't grow because the supernovae have kicked out all of the gas. It could be that in the early universe, for one reason or another, this doesn't happen as much, and the black hole just wins out in that process.

In fact, there's a strong hint that the black holes win out [in the early universe]. It almost suggests, because of how massive these black holes are, that black holes assembled faster than their host galaxies.

BT: You also mentioned black hole efficiency. What does that mean, how can black holes have efficiency?

SK: There are various ways. One way is, when they draw in gas, how highly accreting [the speed at which the accretion disk grows] is it? There's a thing called a black hole speed limit called the Eddington Limit. We often measure, as a fraction of that theoretical upper limit, how much the black hole is growing by sucking in gas. For some objects measured by the JWST the efficiency is over 100% — so they are really extremely efficient.

That also means that it's not a hard limit, and there's always some theory and assumptions that went into it, and some of those assumptions might be wrong. In fact, Webb has shown us they are clearly wrong in those scenarios because they manage to break the limit and grow even faster.

BT: And so why does that efficiency decrease as we get into the later stages of the cosmos, the local universe?

SK: So if you have more star formation, there's simply less gas around. So galaxies might get progressively more gas poor, some of it being ejected elsewhere, some turned into stars, and some being consumed by black holes. Very old galaxies are usually dominated by their stars, so-called elliptical galaxies.

BT: How do black holes grow in the first place? There are three key ways, right? Take us through them.

SK: So, the first one is to the first generation of stars. So these would have been much more massive than our sun, around 100 times its mass. When these come to the end of their life and collapse, they collapse into black holes. This could be a good starting point [for supermassive black holes], or it could be a challenging one, as we're starting at 100 [solar masses] and we want to get to 1 million.

A much easier starting point would be huge gas clouds. These collapse directly into black holes, and they start off at something like 100,000 times the mass of the sun, that makes it much easier to get to supermassive black hole [mass scales]. And then there is an in-between scenario called nuclear star clusters, where lots of stars spawn in the center of galaxies and these collapse into black holes.


An artist's impression of the LISA detector, and the gravitational waves it will search for. (Image credit: EADS ASTRUM)

BT: There's also another option out there, hypothesized primordial black holes — possible relics from a time before the Big Bang. It's a very out-there theory, do we see much evidence for it?

SK: It is a very out-there theory. We're getting more constraints on it, and it's certainly not ruled out. I think the exciting thing about this question right now is that nothing is ruled out. The constraints get tighter as we push closer and closer to the times these black holes formed.

BT: How could we finally rule it out? What are those constraints?

SK: Some people are saying that, now that we have found massive black holes so early in the universe, that this means they have to have formed from direct collapse. There are several papers published suggesting that the observations prove this.

But what we are now doing is that we are revising our models of how black holes grew in the early universe to see if there are still other options for other models. Especially if black holes grow efficiently, there's still just enough time for them to grow from a very light seed. So I would say right now, the exciting thing is that none of the models are ruled out.

BT: So how are we looking for answers? We've mentioned the JWST spotting earlier and earlier black holes, are there other pathways we're exploring to find answers?

SK: A really cool way is with gravitational waves. [Detecting them] will allow us to map the supermassive black hole population in a whole different way. Because right now, unless a black hole is very close to us and we can map out these stellar orbits, the only way to spot supermassive black holes is if they're in an active phase.

But when we have gravitational wave instruments that can spot supermassive black hole mergers we will have a second channel that will help us estimate their masses. And that would go back to the early universe because these instruments would be incredibly sensitive. Then we can spot merger signals and find viable mechanisms for their growth.

BT: Your work is on using simulations to spot possible growth pathways. How do they help us to find answers?

SK: It's a constant interplay between observation and simulation. So an observation, for example the early supermassive black holes, gives us something to explain. That then means we might need to adjust models to allow for that kind of growth early on. The simulations then help us know what to look for, and when those observations come back we can adjust our models again.

I work very closely with observers, and I'm part of a large program of the JWST that will take observations next year and do follow ups of these supermassive black holes in their infancy to understand them better.

BT: So finally, what areas of new research into giant black holes are you most excited about?

SK: I'm super excited about the gravitational wave detector LISA that will come online in the 2030s then we'll finally be able measure gravitational waves not just from small black holes but supermassive black holes. You need to be in space to do that.

I'm also quite nerdy when it comes to coding and building models, so I'm also excited about technical development. A really interesting example that's all over the news is, of course, AI.

We're using AI to accelerate our simulations, to make them even more accurate, and to try and bridge all the scales from the huge space of the cosmic web all the way down to event horizons. This is something that's impossible to do even directly right now, because the computational resources of even the biggest, best supercomputers find it too intensive, but we can use AI to develop solutions to that.

Editor's note: This interview has been condensed and edited for clarity.



This black hole just did something theoretically impossible

"Having a feast."

By Mark Kaufman on November 7, 2024


An artist's conception of the distant black hole LID-568. Credit: NOIRLab / NSF / AURA / J. da Silva / M. Zamani


The powerful James Webb Space Telescope has revealed a phenomenon once thought impossible.

Astronomers trained the instrument on a number of galaxies in deep space, and at the center of one galaxy spotted a young, dwarf black hole triggering enormous outbursts of gas. Cosmic material traveling near a black hole can get pulled around these gravitationally powerful objects, and some of it gets eaten. But black holes are awfully messy eaters, leading to ejections of gas in potent "outflows." Yet this particular black hole, dubbed LID-568, is feeding ravenously on matter at a rate 40 times faster than thought possible.




"This black hole is having a feast," Julia Scharwächter, an astronomer at the International Gemini Observatory who coauthored the new research published in Nature Astronomy, said in a statement.
SEE ALSO:NASA scientist viewed first Voyager images. What he saw gave him chills.

Scientists found this black hole has exceeded the "Eddington limit," which is basically the maximum brightness an object can achieve and how rapidly it can consume matter. Such a feat could be why astronomers are finding black holes, born early on, that are more massive than such a young object ought to be. (This black hole dwells in a galaxy born around 1.5 billion years after the Big Bang — which is means it's relatively young. The universe is some 13.8 billion years old.) It's possible that black holes may grow massive in a single bout of dramatic feeding. "This black hole is having a feast."

"This extreme case shows that a fast-feeding mechanism above the Eddington limit is one of the possible explanations for why we see these very heavy black holes so early in the Universe," Scharwächter explained.

An artist's conception depicting the ravenously feeding black hole at the center of an early dwarf galaxy. Credit: NOIRLab / NSF / AURA / J. da Silva / M. Zamani



Black holes are fascinating objects. They're unimaginably dense: If Earth was (hypothetically) crushed into a black hole, it would be under an inch across. This profound density gives black holes phenomenal gravitational power. Famously, even light that falls in (meaning passing a boundary called the "event horizon") cannot escape.

To observe the extremely distant black hole LID-568, scientists employed the Webb telescope's Near InfraRed Spectrograph, or NIRSpec, to observe the faint but powerful light from gas emissions beaming from the black hole.
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The investigation of LID-568, however, has just begun. Astronomers want to know how this black hole broke its Eddington limit, which means more viewing with the Webb telescope.

The Webb telescope's powerful abilities

The Webb telescope — a scientific collaboration between NASAESA, and the Canadian Space Agency — is designed to peer into the deepest cosmos and reveal new insights about the early universe. It's also examining intriguing planets in our galaxy, along with the planets and moons in our solar system.

Here's how Webb is achieving unparalleled feats, and likely will for decades to come:

- Giant mirror: Webb's mirror, which captures light, is over 21 feet across. That's over two-and-a-half times larger than the Hubble Space Telescope's mirror. Capturing more light allows Webb to see more distant, ancient objects. The telescope is peering at stars and galaxies that formed over 13 billion years ago, just a few hundred million years after the Big Bang. "We're going to see the very first stars and galaxies that ever formed," Jean Creighton, an astronomer and the director of the Manfred Olson Planetarium at the University of Wisconsin–Milwaukee, told Mashable in 2021.

- Infrared view: Unlike Hubble, which largely views light that's visible to us, Webb is primarily an infrared telescope, meaning it views light in the infrared spectrum. This allows us to see far more of the universe. Infrared has longer wavelengths than visible light, so the light waves more efficiently slip through cosmic clouds; the light doesn't as often collide with and get scattered by these densely packed particles. Ultimately, Webb's infrared eyesight can penetrate places Hubble can't.


"It lifts the veil," said Creighton.

- Peering into distant exoplanets: The Webb telescope carries specialized equipment called spectrographs that will revolutionize our understanding of these far-off worlds. The instruments can decipher what molecules (such as water, carbon dioxide, and methane) exist in the atmospheres of distant exoplanets — be they gas giants or smaller rocky worlds. Webb looks at exoplanets in the Milky Way galaxy. Who knows what we'll find?

"We might learn things we never thought about," Mercedes López-Morales, an exoplanet researcher and astrophysicist at the Center for Astrophysics-Harvard & Smithsonian, told Mashable in 2021.

Already, astronomers have successfully found intriguing chemical reactions on a planet 700 light-years away, and have started looking at one of the most anticipated places in the cosmos: the rocky, Earth-sized planets of the TRAPPIST solar system.


Topics NASA



SpaceX Dragon fires thrusters to boost ISS orbit for the 1st time

By Josh Dinner
SPACE.COM
November 8, 2024

Data from today's reboost to help inform the design for SpaceX's ISS deorbit vehicle.

(Image credit: NASA/Don Pettit)

The International Space Station is going a just tiny bit faster today, after receiving an orbital boost from SpaceX's Dragon spacecraft.

SpaceX's 31st commercial resupply mission lifted off Nov. 4, launching a Dragon cargo vehicle to rendezvous with the International Space Station (ISS), docking to the station's forward-facing port the next day. Today (Nov. 8), for the first time, Dragon performed an orbit-raising maneuver to stabilize the ISS's trajectory in low-Earth orbit.

Such maneuvers are routine for the orbital lab, which requires periodic boosts to maintain its altitude above Earth and prevent its orbital decay into the planet's atmosphere. Historically, this has been accomplished using Russia's Soyuz and Progress vehicles, and other spacecraft, but, for the first time, it has now been performed SpaceX's Dragon. The milestone marks a symbolic beginning of the end for the ISS, as data from the maneuver will be used toward the design of the deorbit vehicle NASA has contracted SpaceX to construct to plunge the decommissioned space station into the Pacific Ocean sometime after 2030.

Today's reboost began with the ignition of Dragon's thrusters around 12:50 p.m. ET (1750 GMT). The burn was expected to last about 12.5 minutes to raise the station's orbit
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"NASA and SpaceX monitored operations as the company’s Dragon spacecraft performed its first demonstration of reboost capabilities for the International Space Station at 12:50pm ET today," NASA posted on X.

Related: SpaceX Dragon cargo capsule arrives at ISS on 31st resupply mission (video)

.@NASA and @SpaceX monitored operations as the company’s Dragon spacecraft performed its first demonstration of reboost capabilities for the International Space Station at 12:50pm ET today. https://t.co/jckgtW5pW8November 8, 2024

Dragon isn't the first U.S.-built spacecraft to lend its fuel to the space station's orbit. NASA tested an ISS orbit reboost using a Northrop Grumman Cygnus cargo vehicle in 2022. The data from Dragon's reboost, however, will ultimately pave the way for a catastrophic "un-boosting" of the space station's orbit.

The ISS has been in continuous use and occupancy for almost 25 years now. NASA has projected the ISS's viability through the end of this decade. Citing aging technology, increasing maintenance requirements and rising costs, the space agency aims to retire the space station no earlier than 2030, and in July, awarded SpaceX the contract to develop the vehicle tasked with safely plummeting the football field-size spacecraft into the sea.

When the burden of ongoing ISS costs are alleviated from its budget, NASA will count on the availability of new commercially operated space stations to continue its research in low-Earth orbit. The space station's retirement will free up financial room for the space agency to expand endeavors like the Artemis Program and other deep space exploration missions.

Jared Metter, director of flight reliability at SpaceX, expressed optimism during a press conference Monday (Nov. 4), saying today's attitude control maneuver was "a good demonstration" of Dragon's capabilities as the company designs the ISS deorbit vehicle.

Though international tensions were inflamed following Russia's invasion of Ukraine in 2022, the U.S.-Russian partnership as it pertains to the ISS has persisted. Dragon's success, however, does eliminate another U.S. reliance on Russia for operation of the space station, should that partnership dissolve.

Between the retirement of the space shuttle in 2011 and the beginning of Dragon's crewed missions, the only way for NASA astronauts to launch to the ISS was aboard Russian spacecraft. SpaceX's Crew Dragon returned the launch of NASA astronauts to American soil in 2020, and has now proven it can maintain the space station's orbit, indefinitely.

While NASA has committed to its ISS partnership through 2030, Russia, as of yet, is only committed through 2028, stating its intent to launch a new Russian space station into polar orbit by 2027.

Mysterious 'Interstellar Tunnel' Found in Our Local Pocket of Space

Space
09 November 2024
By Michelle Starr
A 3D model of the solar neighborhood, within the Local Hot Bubble. (Michael Yeung/MPE)

The Solar System's little pocket of the Milky Way is, interestingly enough, exactly that. Our star resides in an unusually hot, low-density compartment in the galaxy's skirts, known as the Local Hot Bubble (LHB).


Why it's not called the Local Hot Pocket is anyone's guess; but, because it's an anomaly, scientists want to know why the region exists.


Now a team of astronomers has mapped the bubble, revealing not just a strange asymmetry in the pocket's shape and temperature gradient, but the presence of a mysterious tunnel pointing towards the constellation Centaurus.


The new data about the shape and heat of the bubble supports a previous interpretation that the LHB was excavated by exploding supernovae that expanded and heated the structure, while the tunnel suggests that it may be connected to another low-density bubble nearby.


The LHB is characterized by its temperature. It's a region thought to be at least 1,000 light-years across, hovering at a temperature of around a million Kelvin. Because the atoms are spread so thin, this high temperature doesn't have a significant heating effect on the matter within, which is probably just as well for us. But it does emit a glow in X-rays, which is how astronomers identified it, years ago.
A 3D model of the Solar System's position in the Local Hot Bubble. An interactive version can be found here. (Michael Yeung/MPE)

But characterizing something you're physically inside is a lot easier to say than do. Imagine a fish (if a fish had human-like intelligence) trying to describe the shape of its tank without moving from the center. It's tricky – but with the right tools, it becomes easier.


This brings us to eROSITA, the Max Planck Institute of Extraterrestrial Physics' powerful space-based X-ray telescope. Led by astrophysicist Michael Yeung of the Institute, a team of researchers has made use of eROSITA to probe the LHB in greater detail than ever before.


We know, thanks to previous research efforts, that the LHB was likely the product of supernova explosions going off like a string of firecrackers, some 14.4 million years ago. The Solar System's position in the bubble's center is just a fun cosmic coincidence. But the LHB's shape remained poorly-defined – a sort of blobby, chubby knucklebone-like configuration.


One big advantage of eROSITA is its position. Wisps of our planet's atmosphere reach a surprising distance into space, with a large halo of hydrogen known as the geocorona extending as far as 100 Earth radii – over 600,000 kilometers (more than 370,000 miles) – from the surface. When particles blowing from the Sun interact with the geocorona, they create a diffuse X-ray glow very similar to the glow of the LHB.


eROSITA is aboard a space observatory positioned some 1.5 million kilometers from Earth. Sitting in a gravitationally stable position created by Earth's and the Sun's pull, the X-ray observatory is the first of its kind to observe the X-ray sky from completely outside of our glowing geocorona.


The researchers divided up eROSITA observations of the X-ray sky into around 2,000 sections, and painstakingly studied the X-ray light in each to generate a map of the LHB. Their findings revealed that the bubble is expanding perpendicular to the galactic plane, more than in a parallel direction. This is not unexpected, since the vertical directions offer less resistance than the horizontal.

The temperature gradient of the Local Hot Bubble, coded by color. (Michael Yeung/MPE)

The asymmetrical temperature gradient the researchers measured was consistent with the supernova theory for the bubble's creation, with the possibility that stars were exploding in our neighborhood until just a few million years ago.


Their map also refined the known shape of the LHB, allowing for a model to be constructed in three dimensions. The result resembles the outflows of what's known as a bipolar nebula, if a little spikier and bumpier. And there was a hidden surprise.


"What we didn't know was the existence of an interstellar tunnel towards Centaurus, which carves a gap in the cooler interstellar medium," says astrophysicist Michael Freyberg of the Max Planck Institute for Extraterrestrial Physics. "This region stands out in stark relief."


We don't know, yet, what the tunnel connects to. There are a number of objects in the direction it trails off in, including the Gum nebula, another neighboring bubble, and several molecular clouds.


It could also be a clue that the galaxy consists of a whole connected network of hot bubbles and interstellar tunnels, an idea proposed in 1974, and for which little evidence has yet emerged. We might be on the brink of finding that network now – and this, in turn, could help us learn more about the recent history of our galaxy.

The research has been published in Astronomy & Astrophysics.


Chinese rover helps find evidence of ancient Martian shoreline

By Will Dunham  
REUTERS
November 7, 2024

A screen broadcasts a CCTV state media news bulletin, showing an image of Mars taken by Chinese Mars rover Zhurong as part of the Tianwen-1 mission, in Beijing, China, May 19, 2021. 
REUTERS/Thomas Peter/File Photo

WASHINGTON, Nov 7 (Reuters) - With the assistance of China's Zhurong rover, scientists have gathered fresh evidence that Mars was home to an ocean billions of years ago - a far cry from the dry and desolate world it is today.

Scientists said on Thursday that data obtained by Zhurong, which landed in the northern lowlands of Mars in 2021, and by orbiting spacecraft indicated the presence of geological features indicative of an ancient coastline. The rover analyzed rock on the Martian surface in a location called Utopia Planitia, a large plain in the planet's northern hemisphere.

The researchers said data from China's Tianwen-1 Orbiter, NASA's Mars Reconnaissance Orbiter and the robotic six-wheeled rover indicated the existence of a water ocean during a period when Mars might already have become cold and dry and lost much of its atmosphere.

They described surface features such as troughs, sediment channels and mud volcano formations indicative of a coastline, with evidence of both shallow and deeper marine environments.

"We estimate the flooding of the Utopia Planitia on Mars was approximately 3.68 billion years ago. The ocean surface was likely frozen in a geologically short period," said Hong Kong Polytechnic University planetary scientist Bo Wu, lead author of the study published in the journal Scientific Reports, opens new tab.

The ocean appears to have disappeared by approximately 3.42 billion years ago, the researchers said.

With the help of Iconem, a company that digitizes heritage sites, visitors now have virtual access to the Vatican's Renaissance-era treasures, and enhanced tours.

"The water was heavily silted, forming the layering structure of the deposits," Hong Kong Polytechnic University planetary scientist and study co-author Sergey Krasilnikov added.

Like Earth and our solar system's other planets, Mars formed about 4.5 billion years ago. At the time the ocean apparently existed, it might already have begun its transition away from being a hospitable planet.

"The presence of an ancient ocean on Mars has been proposed and studied for several decades, yet significant uncertainty remains," Wu said. "These findings not only provide further evidence to support the theory of a Martian ocean but also present, for the first time, a discussion on its probable evolutionary scenario."

Water is seen as a key ingredient for life, and the past presence of an ocean raises the prospect that Mars at least at one time was capable of harboring microbial life.
"At the beginning of Mars' history, when it probably had a thick, warm atmosphere, microbial life was much more likely," Krasilnikov said.

The solar-powered Zhurong, named after a mythical Chinese god of fire, began its work using six scientific instruments on the Martian surface in May 2021 and went into hibernation in May 2022, likely met with excessive accumulation of sand and dust, according to its mission designer. It exceeded its original mission time span of three months.

Researchers have sought to better understand what happened to all the water that once was present on the Martian surface. Another study, published in August and based on seismic data obtained by NASA's robotic InSight lander, indicated that an immense reservoir of liquid water may reside deep under the surface within fractured igneous rocks.

Reporting by Will Dunham, Editing by Rosalba O'Brien



Mars Rover Finds Evidence of an Ancient Ocean on The Red Planet
08 November 2024
ByDaniel Lawler, AFP
China's Zhurong rover on the surface of Mars. (China News Service/Wikimedia Commons/CC-BY-3.0)

A Chinese rover has found new evidence to support the theory that Mars was once home to a vast ocean, including tracing some ancient coastline where water may once have lapped, a study said Thursday.


The theory that an ocean covered as much as a third of the Red Planet billions of years ago has been a matter of debate between scientists for decades, and one outside researcher expressed some scepticism about the latest findings.


In 2021, China's Zhurong rover landed on a plain in the Martian northern hemisphere's Utopia region, where previous indications of ancient water had been spotted.


It has been probing the red surface ever since, and some new findings from the mission were revealed in the new study in the journal Scientific Reports.

The Zhurong landing site (red cross). Regions of different colors indicate different geologic units. The red box shows the study area. (Tanaka et al., 2014/Wu et al., Scientific Reports, 2024)

Lead study author Bo Wu of The Hong Kong Polytechnic University told AFP that a variety of features suggesting a past ocean had been spotted around Zhurong's landing area, including "pitted cones, polygonal troughs and etched flows".


Previous research has suggested that the crater-like pitted cones could have come from mud volcanoes, and often formed in areas where there had been water or ice.


Information from the rover, as well as satellite data and analysis back on Earth, also suggested that a shoreline was once near the area, according to the study.


The team of researchers estimated that the ocean was created by flooding nearly 3.7 billion years ago.


Then the ocean froze, etching out a coastline, before disappearing a little over 3.4 billion ago, according to their scenario.


Bo emphasised that the team does "not claim that our findings definitively prove that there was an ocean on Mars".


That level of certainty will likely require a mission to bring back some Martian rocks to Earth for a closer look
.
Conceptual illustration of evolution of the nearshore zone in southern Utopia Planitia. (Wu et al., Scientific Reports, 2024)


The coast is always changing

Benjamin Cardenas, a scientist who has analysed other evidence of a Martian ocean, told AFP he was "sceptical" of the new study.

He felt the researchers did not take enough into account how much the strong Martian wind had blown around sediment and worn down rocks over the past few billion years.


"We tend to think of Mars as being not very active, like the Moon, but it is active!" said Cardenas of Pennsylvania State University in the United States.


He pointed to past modelling research which suggested that "even the slow Martian erosion rates" would destroy signs of a shoreline over such a long period.


Bo acknowledged that wind might have worn down some rocks, but said the impact of meteors hitting Mars can also "excavate underground rock and sediment to the surface from time to time".


While the overall theory remains contentious, Cardenas said he tended "to think there was an ocean on Mars".


Finding out the truth could help unravel a greater mystery: whether Earth is alone in the Solar System in being capable of hosting life.


"Most scientists think life on Earth sprung up either under the ocean where hot gases and minerals from the subsurface came to the seafloor, or very close to the interface of water and air, in little tidal pools," Cardenas said.


"So, evidence for an ocean makes the planet appear more hospitable."

© Agence France-Presse

On ancient Mars, carbon dioxide ice kept the water running. Here's how


By Keith Cooper
Space.com 
November 8, 2024

By 3.6 billion years ago, Mars should have become too cold for liquid water, but something kept the rivers flowing.


(Image credit: Peter Buhler/PSI)

A lone researcher may have figured out how Mars was able to support rivers and seas even after the planet had begun to grow cold and its atmosphere thin, and it's all thanks to a cycle of water and carbon dioxide.

We know from geological and mineralogical evidence that, around four billion years ago, Mars was warm and wet enough to have extensive liquid water on its surface, from rivers and lakes to a vast northern sea. This period covers two geological eras: the Noachian, which ran from 4.1 to 3.7 billion years ago, and the Hesperian, which endured from 3.7 to about 3 billion years ago. The Noachian is characterized by warmer conditions, but by its latter stages Mars should have been starting to grow cold as it steadily lost its atmosphere to space. Yet there is still evidence of river channels and seas dating back to the late Noachian and into the Hesperian era. Planetary scientists have been mystified as to how Mars could still be wet at this time, and one theory is that the Red Planet experienced an unexplained period of global warming.


Now, though, researcher Peter Buhler of the Planetary Science Institute in Arizona may have solved the problem, thanks to his modeling of the role of carbon dioxide ice settling onto the south polar cap.

The model "describes the origins of major landscape features on Mars — like the biggest lake, the biggest valleys and the biggest esker system — in a self-consistent way," Buhler said in a statement. "And it's only relying on a process that we see today, which is just carbon dioxide collapsing from the atmosphere."

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Related: Water on Mars: Exploration & evidence

Eskers are long, gravelly ridges left by running water, and their presence near Mars' south pole is a big clue about how events played out on the Red Planet.

Usually, Buhler spends his time modeling the carbon-dioxide cycle on Mars today. During Martian winter, a layer of carbon-dioxide ice settles out on top of the polar caps of water ice. While it is just a thin layer on the north polar cap, the south polar cap has much more, with a permanent layer of carbon dioxide ice 26 feet (8 meters) thick, with more added in winter. This additional carbon dioxide is normally locked away in the Martian dirt, but during what passes as Martian summer it can sublimate into the atmosphere and be transported to the winter pole.

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Buhler wanted to see what effect this process had 3.6 billion years ago, during the early Hesperian when the atmosphere — despite beginning to leak out into space after Mars' magnetic field that had warded off the solar wind shut down — was still much thicker than it is today. He found that a layer of carbon dioxide ice 650 meters (0.4 miles) thick would settle onto Mars' south polar cap each winter.

A Viking 1 image of the southern edge of Argyre Planitia, which is marked by mountains that surround the huge impact basin that was once flooded with water. (Image credit: NASA)

The carbon dioxide did two things. It first acted as an insulator, preventing heat leaking out of the planet's interior from escaping at the south pole. It also added weight and pressure onto the ice cap. Combined, these effects led to temperatures and pressures at the base of the ice cap that allowed the ice there to melt and form a pool of water. Eventually, over many winters, water ice and carbon dioxide ice continued freezing out onto the ice cap while, below, the liquid water built up to such an amount that it began seeping out at the sides of the ice cap.

Once exposed to the cold air, according to the new modeling work, the liquid water would freeze as permafrost. This isn't the end of the story, though. Liquid water would keep on forming behind the ice, looking for ways to escape.

"The only way left for the water to go is through the interface between the ice sheet and the rock underneath it," said Buhler. "That's why on Earth you see rivers come out from underneath glaciers instead of just draining into the ground."

The rivers would still freeze as they popped up above ground, but the volume of water was such that it would keep burrowing under this ice, which eventually formed a frozen ceiling over the rivers many dozens of meters (hundreds of feet) thick. The rivers themselves were only a meter or so deep, but they were long, running for thousands of kilometers away from the south pole.

This is where the eskers come in. They are the remains of these long subglacial rivers, and many have been found extending radially away from the southern polar region.

Even today, we can see the remains of four large river channels flowing into Argyre Planitia, which is a huge impact basin 1,700 kilometers (1,100 miles) wide and 5.2 kilometers (3.2 miles) deep. Over millions of years, the sub-glacial rivers filled Argyre with water to form an ocean as large as the Mediterranean. And, over those millions of years, the meltwater kept on coming, causing Argyre to episodically overflow and flood Mars' northern plains.

"This is the first model that produces enough water to overtop Argyre," said Buhler. "It's also likely that the meltwater, once downstream, sublimated back into the atmosphere before being returned to the south polar cap, perpetuating a pole-to-equator hydrologic cycle that may have played an important role in Mars' enigmatic pulse of late-stage hydrologic activity."

Eventually, Mars grew too cold for even this meltwater process to take place. There was recently a claim of a subsurface lake still existing beneath the south polar ice cap on Mars today, but significant doubt has been cast on this idea.

What's neat about Buhler's model is that it doesn't need to enact any unexplained warming to account for the evidence for water that we see — it's literally the same carbon dioxide cycle that we see on Mars today. Unfortunately, Mars has grown so cold, with so little carbon dioxide available, that the days of widespread liquid water on the Red Planet have been over for billions of years.

Buhler's research was published on Nov. 1 in the Journal of Geophysical Research: Planets.


NASA’s ‘Ingenuity Helicopter’ found ‘otherworldly’ wreckage on the surface of Mars

NASA’s ‘Ingenuity Helicopter’ completed 72 flights on the surface of Mars
During one flight, its camera captured some spacecraft debris in the red sand
Looking like the work of aliens, the shattered remains were in fact man-made


Published on Nov 11, 2024 
by Adam Gray
Edited by Tom Wood

A NASA helicopter found ‘otherworldy’ wreckage on the surface of Mars.

The ‘Ingenuity Helicopter’ came across some spacecraft debris amidst the red sand.

It happened during NASA’s Mars 2020 mission, when the space agency sent up its Perseverance Rover which carried the Ingenuity Helicopter beneath it.

It was originally planned to make five flights over Mars, however, in the end it completed 72 flights on the surface of the red planet.

Why was a helicopter needed?

When the rover couldn’t safely reach places on Mars, the helicopter was used instead.

Speaking of the red planet, a scientist has warned of strange changes to humans living on Mars.

Meanwhile, NASA has shared the clearest view of Mars landscape ever – and the colour of the rocks might surprise you.
NASA/JPL-Caltech

But, let’s get back to the helicopter, which – during action – took a series of images, giving us a greater insight into this other world, and in 2022, it captured a remarkable sight.

What it had stumbled across was the wreckage of a spacecraft, laying there in the planet’s sands, slightly reddened by the contact.

The collection of objects may appear to the untrained eye to have been manufactured on another world, but sadly that’s not the case.

NASA/JPL-Caltech
What the experts say

Speaking to the New York Times, Ian Clark – an engineer who worked on Perseverance’s parachute system – said: “There’s definitely a sci-fi element to it. It exudes otherworldly, doesn’t it?

“They say a picture’s worth 1,000 words, but it’s also worth an infinite amount of engineering understanding.”

So there you have it, it’s not the work of aliens; the shattered remains are in fact man-made

.
NASA
What it actually found

The reality is, if we find spaceship debris on another planet, it’s because we put it there.

What the helicopter actually found was part of the landing equipment used to bring Ingenuity down to the surface of the red planet.
NASA

Mars isn’t the only planet where humans have left their litter; the orbit of Earth is full of debris that we’ve sent up there and no longer need, too.

The Natural History Museum said that around 2,000 active satellites are orbiting Earth.

However, there are around 3,000 more ‘dead’ satellites that we no longer use still floating around up there.

Add to that more debris floating around our planet, which not only poses a danger to spacecraft, but the future hopes of space travel.


3D map reveals our solar system's local bubble has an 'escape tunnel'
November 8, 2024
SPACE.COM

Hot spots and tunnels to neighboring "superbubbles" seem to have been created by supernovas and infant star outbursts.

A 3D model of the Milky Way's "local bubble" created using data from eROSITA. (Image credit: Michael Yeung / MPE)

Using data from the eROSITA All-Sky Survey, astronomers have created a 3D map of the low-density bubble of X-ray-emitting, million-degree hot gas that surrounds the solar system.


The investigation has revealed a large-scale temperature gradient within this bubble, called the Local Hot Bubble (LHB), meaning it contains both hot and cold spots. The team suspects that this temperature gradient may have been caused by exploding massive stars detonating in supernovas, causing the bubble to be reheated. This reheating would cause the pocket of low-density gas to expand.

The researchers also found what seems to be an "interstellar tunnel," a channel between stars directed towards the constellation Centaurus. This tunnel may link the solar system's home bubble with a neighboring superbubble and could have been carved out by erupting young stars and powerful and high-speed stellar winds

Scientists have been aware of the LHB concept for at least five decades. This cavity of low-density gas was first suggested to explain background measurements of relatively low-energy, or "soft," X-rays. These photons, with an energy of around 0.2 electronvolts (eV), can't travel very far through interstellar space before being absorbed.


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Bubble of galaxies spanning 1 billion light-years could be a fossil of the Big Bang

The fact that our immediate solar neighborhood is devoid of large quantities of interstellar dust that could emit these photons suggested the existence of soft X-ray emitting plasma that displaces neutral materials around the solar system in a "Local Hot Bubble." Thus, theories of the LHB were born.


One of the major problems with this theory emerged in 1996, when scientists found that exchanges between the solar wind, a stream of charged particles blown out by the sun, and particles in Earth's "geocorona," the outermost layer of our planet's atmosphere, emit X-ray photons with energies similar to those proposed to originate from the LHB.
Understanding the solar system's local bubble

The eROSITA telescope, the primary instrument of the Spectrum-Roentgen-Gamma (SRG) mission launched in 2019, is the ideal instrument to tackle this conundrum. At 1 million miles (1.5 million kilometers) from Earth, eROSITA is the first X-ray telescope to observe the universe from outside Earth's geocorona, meaning potential X-ray "noise" can be ruled out of observations of photons from the LHB.

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Additionally, eROSITA's All-Sky Survey (eRASS1) collected data during a lull in the sun's 11-year solar cycle when solar winds are weak, called the "solar minimum." This reduced the amount of contamination coming from solar wind exchange.

"In other words, the eRASS1 data released to the public this year provides the cleanest view of the X-ray sky to date, making it the perfect instrument for studying the LHB," team leader Michael Yeung, a researcher at Max Planck Institute of Physics (MPE), said in a statement.



Two versions of eRosita All-Sky Survey Catalogue (eRASS1) data (Right) the X-ray sky over earth (right) X-ray sources. (Image credit: MPE, J. Sanders für das eROSITA-Konsortium)

After dividing the hemisphere of the Milky Way into 2,000 distinct regions, Yeung and colleagues analyzed the light from all these regions. What they discovered was a clear disparity in temperatures in the LHB, with the Galactic North cooler than the Galactic South.

The same team had already established that the hot gas of the LHB is relatively uniform in terms of its density. Comparing this to the gas in cool and dense molecular clouds at the edge of the LHB, the team was able to create a detailed 3D map of the LHB.

This revealed that the LHB is stretched toward the poles of the galactic hemisphere. Hot gas expands in the direction that offers the least resistance, which, in this case, is away from the galactic disk. Thus, this wasn't a huge surprise to the researchers as it is also finding that had been revealed by eROSITA's predecessor, ROSAT, around 3 decades ago.

But, the new 3D map did reveal something hitherto unknown.

"What we didn't know was the existence of an interstellar tunnel towards Centaurus, which carves a gap in the cooler interstellar medium," team member and MPE physicist Michael Freyberg said in the statement. "This region stands out in stark relief thanks to the much-improved sensitivity of eROSITA and a vastly different surveying strategy compared to ROSAT."



The nebula L1527 and its erupting protostar put on a celestial fireworks display, captured by the JWST. Feedback like this could help carve out a network of "tunnels" between stars. (Image credit: NASA, ESA, CSA, STScI)

Excitingly, the team suspects that the Centaurus tunnel in the LHB may just be a part of a network of hot gas tunnels that bore their way between the cool gas of the interstellar medium between stars.

This interstellar medium network would be maintained and sustained by the influence of stars in the form of stellar winds, the supernovas that mark the death of massive stars, and jets blasting out from newly formed stars or "protostars."

These phenomena are collectively referred to as "stellar feedback," and they are believed to sweep across the Milky Way, thereby shaping it.

In addition to the 3D map of the LHB, the team also created a census of supernova wreckage, superbubbles, and dust, which they incorporated into the map to build a 3D interactive model of the solar system's cosmic neighborhood.

This included another previously known interstellar medium tunnel called the Canis Majoris tunnel. This is thought to stretch between the LHB and the Gum nebula or between the LHB and GSH238+00+09, a more distant superbubble.

They also mapped dense molecular clouds at the edge of the LHB that are racing away from us. These clouds could have been built when the LHB was "cleared" and denser material was swept to its extremities. This could also give a hint as to when the sun entered this local low-density bubble.

"Another interesting fact is that the sun must have entered the LHB a few million years ago, a short time compared to the age of the sun [4.6 billion years]," team member and MPE scientist Gabriele Ponti said. "It is purely coincidental that the sun seems to occupy a relatively central position in the LHB as we continuously move through the Milky Way."

You can explore the team's 3D model of our solar neighborhood here.

How can Jupiter have no surface? A dive into a planet so big, it could swallow 1,000 Earths
THE CONVERSATION
SPACE. COM

Why does Jupiter look like it has a surface – even though it doesn’t have one? – Sejal, age 7, Bangalore, India


(Image credit: NASA)

This article was originally published at The Conversation. The publication contributed the article to Space.com's Expert Voices: Op-Ed & Insights.

Benjamin Roulston is Assistant Professor of Physics, Clarkson University

The planet Jupiter has no solid ground – no surface, like the grass or dirt you tread here on Earth. There’s nothing to walk on, and no place to land a spaceship.

But how can th
at be? If Jupiter doesn’t have a surface, what does it have? How can it hold together?

Even as a professor of physics who studies all kinds of unusual phenomena, I realize the concept of a world without a surface is difficult to fathom. Yet much about Jupiter remains a mystery, even as NASA’s robotic probe Juno begins its ninth year orbiting this strange planet.

Jupiter, the fifth planet from the Sun, is between Mars and Saturn. It’s the largest planet in the solar system, big enough for more than 1,000 Earths to fit inside, with room to spare.

Related: Jupiter: A guide to the largest planet in the solar system

While the four inner planets of the solar system – MercuryVenusEarth and Mars – are all made of solid, rocky material, Jupiter is a gas giant with a composition similar to the Sun; it’s a roiling, stormy, wildly turbulent ball of gas. Some places on Jupiter have winds of more than 400 mph (about 640 kilometers per hour), about three times faster than a Category 5 hurricane on Earth.

What They Didn't Teach You in School About Jupiter | Our Solar System's Planets -
 YouTube

Searching for solid ground


Start from the top of Earth’s atmosphere, go down about 60 miles (roughly 100 kilometers), and the air pressure continuously increases. Ultimately you hit Earth’s surface, either land or water.

Compare that with Jupiter: Start near the top of its mostly hydrogen and helium atmosphere, and like on Earth, the pressure increases the deeper you go. But on Jupiter, the pressure is immense.

As the layers of gas above you push down more and more, it’s like being at the bottom of the ocean – but instead of water, you’re surrounded by gas. The pressure becomes so intense that the human body would implode; you would be squashed.

Go down 1,000 miles (1,600 kilometers), and the hot, dense gas begins to behave strangely. Eventually, the gas turns into a form of liquid hydrogen, creating what can be thought of as the largest ocean in the solar system, albeit an ocean without water.

Go down another 20,000 miles (about 32,000 kilometers), and the hydrogen becomes more like flowing liquid metal, a material so exotic that only recently, and with great difficulty, have scientists reproduced it in the laboratory. The atoms in this liquid metallic hydrogen are squeezed so tightly that its electrons are free to roam.

Keep in mind that these layer transitions are gradual, not abrupt; the transition from normal hydrogen gas to liquid hydrogen and then to metallic hydrogen happens slowly and smoothly. At no point is there a sharp boundary, solid material or surface.


An illustration of Jupiter’s interior layers. One bar is approximately equal to the air pressure at sea level on Earth. (Image credit: NASA/JPL-Caltech/SwRI)

Scary to the core

Ultimately, you’d reach the core of Jupiter. This is the central region of Jupiter’s interior, and not to be confused with a surface.

Scientists are still debating the exact nature of the core’s material. The most favored model: It’s not solid, like rock, but more like a hot, dense and possibly metallic mixture of liquid and solid.

The pressure at Jupiter’s core is so immense that it would be like 100 million Earth atmospheres pressing down on you – or two Empire State buildings on top of each square inch of your body.

But pressure wouldn’t be your only problem. A spacecraft trying to reach Jupiter’s core would be melted by the extreme heat – 35,000 degrees Fahrenheit (20,000 degrees Celsius). That’s three times hotter than the surface of the Sun.
Jupiter helps Earth

Jupiter is a weird and forbidding place. But if Jupiter weren’t around, it’s possible human beings might not exist.

That’s because Jupiter acts as a shield for the inner planets of the solar system, including Earth. With its massive gravitational pull, Jupiter has altered the orbit of asteroids and comets for billions of years.

Without Jupiter’s intervention, some of that space debris could have crashed into Earth; if one had been a cataclysmic collision, it could have caused an extinction-level event. Just look at what happened to the dinosaurs.

Maybe Jupiter gave an assist to our existence, but the planet itself is extraordinarily inhospitable to life – at least, life as we know it.

The same is not the case with a Jupiter moon, Europa, perhaps our best chance to find life elsewhere in the solar system.

NASA’s Europa Clipper, a robotic probe launched in October 2024, is scheduled to do about 50 fly-bys over that moon to study its enormous underground ocean.

Could something be living in Europa’s water? Scientists won’t know for a while. Because of Jupiter’s distance from Earth, the probe won’t arrive until April 2030.

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