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Nov 15, 2019, 04:53 AM
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Author Topic: NEWS ON SPACE AND OUR PLANETARY SYSTEM  (Read 639456 times)
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« Reply #2130 on: Oct 21, 2019, 03:40 AM »

Colonizing Mars could be accelerated with microbes, study suggests

The idea challenges the strict no-contamination guidelines that NASA and all space programs have closely adhered to for decades.

Fermin Koop
ZME
10/21/2019

Colonizing Mars has been a growing objective of humanity over recent years. But doing so could mean landing a containment of microorganisms on the planet, according to a new study.

A paper published in the journal FEMS Microbiology Ecology argued that the “primary colonists” of the Red Planet should be “microorganisms” – the bacteria, viruses, and fungi that support many of life’s processes here on Earth.

Jose Lopez, a professor at Nova Southeastern University and one of the authors of the paper, proposed an approach to the colonization of Mars that relies on microbes that could support life in extraterrestrial environments.

    “Life as we know it cannot exist without beneficial microorganisms,” he said in a statement. “To survive in a barren (and as far as all voyages to date tell us) sterile planet, we will have to take beneficial microbes with us.”

The idea challenges the strict no-contamination guidelines that NASA and all space programs have closely adhered to for decades. When it comes to the equipment being sent off to space, typically everything is carefully sterilized and protected from germs and contaminants.

Lopez and the research team argued that introducing helpful microbes could actually kickstart the process of terraforming Mars and sustaining life on the Red Planet. The microbial introduction should not be considered accidental but inevitable, reads the paper.

Back on Earth, microorganisms are critical to many of the processes that sustain life, such as decomposition and digestion. The paper claimed that the best microbes for the job might be extremophiles — organisms that are hyper tolerant of the most extreme environments, and even thrive in them, like tardigrades.

The paper argued for a change in attitude toward microbes in space, viewing them as beneficial versus dangerous. But researchers still don’t know which microbes would help rather than hurt efforts to terraform Mars. Space agencies need to start work now on developing the right kind of organisms to send over.

Everyone from Elon Musk to Jeff Bezos to NASA needs to make a “provocative paradigm shift” in our policies for space colonization, Lopez claimed.

    “This will take time to prepare, discern,” Lopez said. “We are not advocating a rush to inoculate, but only after rigorous, systematic research on earth.”


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« Reply #2131 on: Oct 22, 2019, 03:52 AM »

Black Holes could stunt the growth of dwarf galaxies

In smaller galaxies, large-scale winds from active black holes could hinder the formation of stars.

Rob Lea byRob Lea
ZME
10/22/2019

Black holes at the centre of small dwarf galaxies could slow or even halt the formation of stars via the powerful winds they produce, researchers from University of California, Riverside, have discovered. This suppression of star-formation could have a marked influence on the evolution of such galaxies.

The result seems to confirm the long-held suspicion that supermassive black holes at the centre of galaxies can influence that galaxy’s evolution — including how they grow and the way that they age. But, the research also delivers a surprise; the winds that the astronomers measured coming from the black hole were more powerful than the team reckoned for. This means that models of star formation in dwarf galaxies may require a rethink.

    “We expected we would need observations with much higher resolution and sensitivity, and we had planned on obtaining these as a follow-up to our initial observations,” said Gabriela Canalizo, a professor of physics and astronomy at UC Riverside who led the research team. “But we could see the signs strongly and clearly in the initial observations.

    “The winds were stronger than we had anticipated.”
    Gabriela Canalizo

Thus meaning that black holes don’t just influence the development of larger galaxies, but also play a role in the evolution of smaller dwarf galaxies — galaxies containing anywhere from a few thousand to a few billion stars.

Canalizo continues: “Our findings now indicate that their effect can be just as dramatic, if not more dramatic, in dwarf galaxies in the universe.”

The study — the results of which are discussed in the Astrophysical Journal — used data collected in the Sloan Digital Sky Survey (SDSS), a project which maps 35% of the sky above Earth. In doing so, the survey has been able to identify 50 dwarf galaxies — 29 of which demonstrated clear characteristics of possessing black holes at their centres. A further six of these showed evidence of high-velocity outflows of ionised gas — the powerful winds in question.

The next step for the researchers was to use the Keck telescopes — based in Hawaii — to both detect and measure the properties of these winds, marking the first time this has been achieved.

Discussing what her team found, Canalizo adds: “We found some evidence that these winds may be changing the rate at which the galaxies are able to form stars.”

Studying dwarf galaxies could be the key to understanding how galaxies in general evolve

The study of these smaller galaxies could help scientists answer lingering about galactic evolution in general.

    “Larger galaxies often form when dwarf galaxies merge together,” explains Christina Manzano-King, a doctoral student in Canalizo’s lab and the first author of the paper. As a consequence of this, she continues, dwarf galaxies are particularly useful in understanding how galaxies evolve.

“Dwarf galaxies are small because after they formed, they somehow avoided merging with other galaxies,” she adds. “Thus, they serve as fossils by revealing what the environment of the early universe was like.

    “Dwarf galaxies are the smallest galaxies in which we are directly seeing winds — gas flows up to 1,000 kilometres per second — for the first time.”
    Christina Manzano-King

Explaining what causes these powerful winds, Manzano-KIng points to material being fed into the black hole. This material — usually gas and dust — forms an accretion disc around the black hole. In this disc — which gradually feeds the black hole — conditions are so violent that friction and tremendous tidal forces heats the material. This releases radiative energy which shoves gas out of the galaxy’s centre and into intergalactic space.

This negatively affects the amount of gas available for star formation.

Manzano-King continues: “What’s interesting is that these winds are being pushed out by active black holes in the six dwarf galaxies rather than by stellar processes such as supernovae.

“Typically, winds driven by stellar processes are common in dwarf galaxies and constitute the dominant process for regulating the amount of gas available in dwarf galaxies for forming stars.”

Astronomers believe that winds emanating from black holes can compress gas and thus aid the gravitational collapse of gas clouds, kick-starting star-formation. But, if the wind is too strong and thus expels gas from the galaxy’s centre, rather than aiding the star formation process, gas becomes unavailable and hinders the process.

This is exactly what appears to be happening in the six galaxies that the team’s research highlighted. In these cases, the wind has had a clear detrimental impact on star formation rates.
Rethinking the relationship between black holes and star formation rates

This research may result in a rethinking of models of star formation and the evolution of galaxies. Current models do not take into account the impact of black holes in dwarf galaxies.

“Our findings show that galaxy formation models must include black holes as important, if not dominant, regulators of star formation in dwarf galaxies,” points out Laura V. Sales, assistant professor of physics and astronomy at UC Riverside.

As for the future of this research, the team next plans to investigate characteristics of gas outflows such as mass and momentum.

“This would better inform theorists who rely on such data to build models,” concludes Manzano-King. “These models, in turn, teach observational astronomers just how the winds affect dwarf galaxies.

“We also plan to do a systematic search in a larger sample of the Sloan Digital Sky Survey to identify dwarf galaxies with outflows originating in active black holes.”

Original research: ‘AGN-Driven Outflows in Dwarf Galaxies’ Christina M. Manzano-King, Gabriela Canalizo, and Laura V. Sales.


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« Reply #2132 on: Oct 23, 2019, 03:57 AM »

Some water ice on the Moon is billions of years old — and colonists could drink it all up

Bottoms up!

Alexandru Micu
ZME
10/23/2019

The viability and eventual success of long-term manned missions to the moon depend heavily on us locating a source of water up there. Water on the moon would allow astronauts to live on the moon much longer and for cheaper (which matters a lot when trying to get funding out of politicians) than if they had to ship it up from Earth.

The local drink

Recent research has shown that there may be water ice in the craters near the moon’s poles, and even traces of liquid water across its surface. However, until we understand how this water got there, we won’t have much success predicting where it will be found. A new study looking into the issue reports that lunar ice deposits could have multiple sources, some being more recent while others could be billions of years old.

The team used data on craters near the moon’s south pole, where evidence of water had been previously discovered, recorded by the Lunar Reconnaissance Orbiter. The researchers looked at the age of these craters, and report that any ice they contain couldn’t be older than 3.1 billion years. The ice deposits, the team explains, come in patches across the floor of individual craters, suggesting that they have been exposed to impacts by small meteorites over a long period of time.

The researchers used data from the Lunar Reconnaissance Orbiter to look at craters near the south pole where evidence of water has been found. They analyzed the age of these craters and found that the ice within them could not be older than 3.1 billion years. More evidence for the age of the ice comes from the patterns of deposits, which are patchy across the floor of the crater. This suggests the deposits have been impacted by small meteorites over a long period of time.

Most of the ice deposits seem to be quite ancient. Some of them, the team adds, especially those in smaller craters with sharper edges, appear to be the most recent. The authors say this is quite a surprise as “hadn’t really been any observations of ice in younger cold traps before,” Brown University researcher Ariel Deutsch explained in a statement.

    “There have been models of bombardment through time showing that ice starts to concentrate with depth. So if you have a surface layer that’s old, you’d expect more underneath,” Deutsch adds.

The study fleshes out our understanding of resource availability on the moon, knowledge which can make or break future long-term missions.

    “When we think about sending humans back to the Moon for long-term exploration, we need to know what resources are there that we can count on, and we currently don’t know,” co-author of the study, Professor Jim Head of Brown University, said in the same statement.

    “Studies like this one help us make predictions about where we need to go to answer those questions.”

Along with other recent research looking into how lunar soil (‘regolith’) can be turned into breathable oxygen and raw metal for would-be colonists, the present findings suggest that the moon would be a much more bountiful place to live than we assumed up to now.

The paper “Analyzing the ages of south polar craters on the Moon: Implications for the sources and evolution of surface water ice” has been published in the journal Icarus.


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« Reply #2133 on: Oct 24, 2019, 04:07 AM »


Newly-discovered interstellar object is spewing cyanide gas

Mike Wehner
BGR
10/24/2019

Astronomers spotted an interstellar object passing through our solar system last month. It was only the second time scientists have ever detected such an object, and after some intense investigation, the object — now believed to be a comet or comet-like body — was documented and named for the amateur astronomer who first spotted it.

The comet, called 2I/Borisov, was spotted relatively early in its trip through our system, giving scientists plenty of time to observe it. The first round of studies is already returning some interesting findings, including the fact that the object is dumping cyanogen gas (gas that is at least partly made up of cyanide) as it speeds through our home system.

A new paper published in Astrophysical Journal Letters reveals that interesting finding, which was made thanks to data gathered by an international team of scientists using the William Herschel Telescope. But as seemingly frightening as this discovery seems on the surface, there’s very little to worry about for us here on Earth.

“Interstellar objects are samples of materials from other planetary systems, delivered to our doorstep—or at least to our own solar system,” Professor Alan Fitzsimmons, who led the research, told Universe Today. “The physical nature gives us clues as to how other planetary systems evolve, and the types of small bodies that may exist there. Measuring their composition allows us to compare what we find with decades of studies of comets and asteroids orbiting the sun.”

Fitzsimmons says that while this particular comet appears a bit more “gassy” than the kinds of comets we typically see in our system, the fact that it contains cyanide isn’t particularly shocking.

2I/Borisov’s trajectory has already been plotted and it doesn’t seem that the object will come anywhere near Earth, or even pass through Earth’s orbital path around the Sun, so there’s virtually zero chance any of the comet material will find its way to our planet.

Scientists will continue to observe the object as it gradually passes through our system, and the comet should remain visible for many months to come. You can expect to hear a lot more about it as various research efforts get underway.


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« Reply #2134 on: Oct 25, 2019, 03:56 AM »


The Milky Way is a thief

Mike Wehner
BGR
10/25/2019

We often think of our home galaxy, the Milky Way, as being a self-contained collection of stars, planets, gas and dust. Sure, it’s going to slam straight into the neighboring Andromeda galaxy at some point in the distant future, but for now the Milky Way is pretty much just chilling out, right?

Not so fast.

A new research effort to study the movement of material into and out of our galaxy reveals that the Milky Way is actually growing, sucking up more and more gas, and scientists aren’t sure where this extra material is coming from.

Stars have a habit of pushing things away. During their lives, stars produce powerful stellar winds that push gasses away, and when stars that become supernovas explode, the force of the blast pushes material out at a rapid pace. These forces push gas out of the Milky Way’s disc, but that gas is eventually sucked back up by the galaxy and the cycle of star formation begins again.

This constant recycling should mean that our galaxy is always regaining the same amount of gas that it’s losing, but a new study published in the Astrophysical Journal reveals that’s not the case. In fact, the Milky Way is sucking up significantly more gas than it loses, meaning that there must be an external source.

As for what is providing the galaxy with the additional mass, the researchers can’t say for certain, but they have a few ideas. It’s possible, the scientists say, that the Milky Way is siphoning off gas from much smaller galaxies in its orbit. If this is the case, our galaxy is essentially robbing smaller galaxies of their mass, potentially hindering their ability to birth new stars. It’s also possible that the Milky Way is simply slurping up loose gas from the intergalactic medium.

Going forward, studies of nearby galaxies could reveal whether the Milky Way’s behavior is unique or common among large galaxies, and perhaps reveal the source of this surplus gas. For now, we’ll just have to guess.


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« Reply #2135 on: Oct 26, 2019, 04:10 AM »


Landslides on Mars might not be evidence of ice after all

Mike Wehner
BGR
10/26/2019

When scientists studying Mars discovered a massive landslide on the Red Planet they thought it looked familiar. The cascading material had carved long, curved ridges, and the area was eerily similar to some landslides that have been observed here on Earth. What made that comparison particularly exciting was the fact that on Earth, landslides like this are often associated with the presence of ice beneath the ground.

This, researchers believed, was a clue that something similar may have happened on Mars some 400 million years ago when the landslide is thought to have occurred. Since ice means water, and water means the potential for life, it was a tantalizing idea. Unfortunately, a new investigation suggests that ice and water may not have played a role after all.

It had been thought that the unique landslide formations seen on Mars must have been created with the help of ice, but scientists wanted to be sure. So, using three-dimensional scans of the region as a starting point, scientists tested the possibility that such a feature could be created simply by a landslide moving at a particularly high speed.

What they found was that it would indeed be possible for the sprawling remnants of the landslide to have been produced by material tumbling down from high up on a Martian mountain. An unstable and rocky surface may have allowed such a landslide to reach speeds of well over 200 miles per hour, carrying the material vast distances and forming the unique ridges we see today.

“We’ve shown that ice is not a prerequisite for such geological structures on Mars, which can form on rough, rocky surfaces,” Giulia Magnarini, a Ph.D. student at University College London and first author of the paper, said in a statement. “This helps us better understand the shaping of Martian landscapes and has implications for how landslides form on other planetary bodies including Earth and the Moon.”


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« Reply #2136 on: Oct 28, 2019, 03:34 AM »


Nobody really knows if there are other ‘Earths’ out there

Mike Wehner
BGR
10/28/2019

Are there other Earth-like planets out there in the cosmos? We simply don’t know. Scientists have been peering into space for centuries and, thanks to advancing technology, we have spotted other worlds that might be capable of supporting life, but the evidence is sorely lacking.

To help answer the question, researchers from UCLA came up with a new framework for analyzing the makeup of exoplanets using data from the W. M. Keck Observatory and other high-powered telescopes. Based on their observations, the researchers are making a rather bold declaration: Earth isn’t terribly unique.

The researchers focused on nearby white dwarf stars and the rocky material that orbits them. By studying the light coming from these systems, scientists can determine what elements are abundant. This reveals the composition of the rocky bodies that orbited the star, offering a clue as to what kinds of planets or objects orbited it.

“By observing these white dwarfs and the elements present in their atmosphere, we are observing the elements that are in the body that orbited the white dwarf,” Alexandra Doyle, a UCLA graduate student that led the study, explained. “Observing a white dwarf is like doing an autopsy on the contents of what it has gobbled in its solar system.”

The researchers found that elements like silicon, carbon, and oxygen were present, along with hydrogen and helium. This list of “ingredients,” so to speak, matches up well with our own planet, and suggests that worlds with a similar makeup aren’t terribly rare.

That being said, Earth is the only planet that we know of that hosts life in any form. Astronomers have observed planets both in our own system and elsewhere and, as far as we know, we really struck the jackpot with this blue marble we call home. Rocky worlds with a similar composition to Earth aren’t a guarantee when it comes to finding life, and countless other factors — distance from a star, type of star, an abundance of water, etc. — are believed to play major roles as well.

Rocky worlds like our own being common doesn’t necessarily mean we’ll find life on any of them, but it’s still an interesting data point as we continue our search for life beyond Earth.


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« Reply #2137 on: Oct 29, 2019, 03:36 AM »

The largest stars in the Universe (that we’ve found so far)

Here's some of the largest, plumpest ones out there.

Alexandru Micu
ZME
10/29/2019

You can’t spend much on Earth without noticing the Sun. This great big ball of atomic fire dominates the sky, and for good reason — it’s the largest body in the solar system. However, although it dwarfs anything in its close vicinity, the Sun isn’t that big for a star; actually, it’s pretty much average.

So, are there bigger stars out there? Yes, definitely; our Sun is technically a yellow dwarf, which makes it a bit below the average star size. They get much, much bigger. Here’s some of the largest, plumpest ones out there (that we’ve been able to spot).
But first, a word on stars

There are many different types of stars out there; some bigger, some smaller. Before going any further, however, you have to understand something: stars don’t have nice, tidy boundaries. They don’t have a rigid surface like a rocky planet or moon. Instead, these atomic fireballs have pretty diffuse surfaces as the super-heated mass of gas that makes them up slowly thins out into nothingness.

What astronomers use in lieu of a surface is a star’s photosphere — the level at which the star becomes transparent (i.e. where photons can escape the star). So, going forward, know that if I mention a star’s surface, I’m talking about its photosphere.

The second important thing to keep in mind is that we haven’t ever measured a star directly. Nobody went up to one with a ruler and started adding up distances. What we do have are estimations — reliable estimations, for the most part, but estimations nonetheless. Depending on a range of factors, such as distance or structures around stars or between them and Earth, these estimations can be more or less accurate, and fall within a smaller or larger area of confidence (i.e. “we know it’s between x and y miles/kilometers wide”).

Bigger stars, biggest star

The largest one we’ve spotted in the universe so far is UY Scuti, a star 9,500 light-years away, close to the center of the Milky Way in the constellation Scutum (‘shield’). It’s a dust-enshrouded red supergiant (the largest class of stars out there) that’s around 1,700 times larger than our Sun in diameter. It was first spotted in 1860 by astronomers at the Bonn Observatory (Germany), who christened it BD -12 5055. Subsequent observations showed that BD -12 5055 grows brighter and dimmer over a 740-day period, so it was classified as a variable star. Variable stars regularly expand and shrink as their brightness changes.

Hypergiants are larger than supergiants, which themselves are larger than giant stars. Hypergiants are quite rare and shine brightly. They also lose more mass than smaller stars through stellar winds.

To give you an idea of just how huge UY Scuti is, if it replaced the Sun at the center of our solar system, its photosphere would extend past the orbit of Jupiter. The distance from the Sun to Jupiter is approximately 779 million km, or 484 million miles. Gas emanating from the star would form a nebula extending 400 AU (one astronomical unit, AU, is the distance between the Earth and the Sun). In effect, this would reach far beyond the orbit of Pluto (the average orbiting distance between Pluto and the Sun is 39.5 AU).

But here’s the rub. We don’t know for sure how big UY Scuti is. It also has a habit of changing in size. The shifts in brightness we mentioned earlier come hand-in-hand with variations in its radius, measured with a margin of error of about 192 solar radii. If the lower-most value is correct, UY Scuti would be out-sized by other stars — around 30 known stars would out-size UY Scuti’s smallest estimated size.

Here’s a list of the largest contenders

WOH G64 (1,504 to 1,730 solar radii) — a red hypergiant star in the Large Magellanic Cloud in the constellation Dorado (in the southern hemisphere skies) located about 170,000 light-years away from Earth. This star’s brightness varies over time due, in part, to a torus-shaped cloud of dust that obscures its light. The torus was likely formed by the star during its death throes. WOH G64 was once more than 25 times the mass of the Sun, but it began to lose mass as it neared exploding as a supernova. Astronomers estimate that it has lost enough component material to make up between three and nine solar systems.

Mu Cephei (around 1,650 solar radii) — a red supergiant in the constellation Cepheus, 9,000 light-years from Earth. With more than 38,000 times the Sun’s ​luminosity, it’s also one of the brightest stars in the Milky Way.

V354 Cephei (1,520 solar radii) — a red hypergiant in the constellation Cepheus. V354 Cephei is an irregularly variable star, which means that it pulsates on an erratic schedule.

RW Cephei (1,535 solar radii) — an orange hypergiant in the constellation of Cepheus; also a variable star.
Westerlund 1-26 seen in the infrared spectrum.

Westerlund 1-26 (1,530 to 2,550 solar radii). That’s quite a large estimate interval; if the upper estimate is correct, it would dwarf even UY Scuti, and its photosphere would reach farther than Saturn’s orbit. Westerlund 1-26 stands out as its temperature varies over time, but not its brightness.

KY Cygni (1,420 to 2,850 solar radii) — a red supergiant in the constellation Cygnus. The upper estimate is viewed with skepticism as a likely observational error, while the lower one is consistent with other stars from the same survey and with our understanding of stellar evolution.

VY Canis Majoris (1,300 to 1,540 solar radii) — a red hypergiant star that was previously estimated to be 1,800 to 2,200 solar radii, but that size put it outside the bounds of stellar evolutionary theory and were updated. Still, I have seen this star listed as the largest in some sources.

Betelgeuse (950 to 1,200 solar radii) — a red supergiant in the constellation Orion. Betelgeuse is one of the most well-known stars of its kind, as it’s the ninth-brightest star in the sky and can easily be seen with the naked eye between October through March on a clear night. It’s the closest star on this list and is expected to go supernova pretty much at any time.

Do note that stars, being balls of superhot plasma, don’t follow a linear weight-size relationship like you’d expect in, say, a cannonball, where the bigger shell is obviously heavier. UY Scuti, despite being one of the or the largest star we know, isn’t the most massive (heavy) one. That title comes to R136a1, a Wolf–Rayet star in the Tarantula Nebula some 163,000 light-years away. It has the highest mass and luminosity of any known star, and is also one of the hottest, at around 53,000 K.

Ironically enough, R136a1 weighs in at about 300 times the mass of the Sun but is only about 30 solar radii in size. UY Scuti is just 30 times more massive than the Sun despite being way larger. R136a1’s mass can be explained by its very high surface enhancement of heavy elements (which are dense) and depletion of hydrogen (which is light).


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« Reply #2138 on: Oct 30, 2019, 03:54 AM »


Black holes might not be black holes at all

Mike Wehner
BGR
10/30/2019

Of all the features of our universe, black holes might be the most interesting, as well as the most frightening. These ultra-dense spots in space suck in everything around them, and once a black hole has you in its grasp, there’s quite literally no escaping it.

For a long time, scientists have believed that black holes are impossibly tiny dots of incredible mass, called a singularity. This explanation meshes pretty well with our understanding of physics and how objects move an interact in space. But what if black holes are something completely different? A pair of researcher papers published in The Astrophysical Journal argues that point, and if you can wrap your head around it, it’s one heck of an idea.

In some of the most widely-accepted mathematical equations used to explain the expansion of our universe, black holes aren’t factored in. The researchers in this study attempted to make the math of black holes fit within this framework and discovered that the only way it works is if black holes are in fact not singularities at all.

Instead, the scientists suggest that black holes are actually object made of dark energy. They call these hypothetical objects GEODEs (Generic Objects of Dark Energy) and argue that looking at them in this way could answer a number of questions. Specifically, the theory could reveal where dark energy, which scientists believe is contributing to the expansion of the universe, is collected.

GEODEs, the scientists say, would actually get heavier over time as the universe expands, even without slurping up more matter from their surroundings. In some past observations of black holes and black hole mergers, predictions regarding mass have not worked out as expected. If black holes were in fact GEODEs, the math is far easier to work out.

As interesting as this theory is, it’s far from a sure thing. There’s still an incredible amount of observational work that will need to be done before we have a solid idea of what’s going on in those black pits of nothingness in space.


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« Reply #2139 on: Oct 31, 2019, 04:01 AM »


NASA’s new drones are taking on bizarre shapes

Mike Wehner
BGR
10/31/2019

In the context of space exploration, the term “rover” conjures images of multi-wheeled robots with big, bulky bodies covered in scientific instruments. NASA’s Mars rovers are probably the most iconic of all, but when the space agency is ready to send a spacecraft to Saturn’s Moons, the bots that make the trip will likely look a whole lot different.

NASA recently announced its intentions to send a drone helicopter to Saturn’s moon Titan in the not-so-distant future. An aerial drone will provide scientists with the ability to travel over huge distances much more rapidly than would be the case with a ground-based rover, and the designs being tested are truly out of this world.

The “Shapeshifter” robot project is currently underway at NASA’s Jet Propulsion Laboratory, and the idea is to create a robot that can transform its body into whatever shape would best suit the environment.

In a video showing off the concept of the robot, the machine takes on many different shapes, allowing it to fly, crawl, and even swim as needed. The prototype is a bit less full-featured, but it’s still an impressive creation.

The robot in its current form is capable of rolling along the ground using a rigid frame shaped like a cylinder. This is suitable for flat terrain, and the bot can easily roll over sand and small rocks. When the robot needs to take the skies, however, is when the real fun begins.

The prototype reveals itself to be two robots in one, splitting in half lengthwise. Each half is equipped with its own system of propellers, turning them into independent flying drones that can navigate on their own. Then, when the two halves of the robot reach a new area, the halves can secure themselves together once again, turning the robots into a single unit again.

NASA imagines robots like these traveling to new worlds in teams of up to a dozen, taking on new form factors whenever needed and exploring huge areas far more rapidly than is currently possible with rovers like those on Mars.


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« Reply #2140 on: Nov 02, 2019, 04:35 AM »


NASA’s InSight robot is fighting against Mars to save a vital instrument

Mike Wehner
BGR
11/2/2019

NASA’s InSight lander has been resting safely on Mars for nearly a year now, and it’s doing some seriously great work. Most of the robot’s suite of sensitive instruments have been working as intended, sending back data and recordings of seismic activity on the dusty planet. However, one of the tools, called the “mole,” has fallen well short of expectations.

The instrument is supposed to hammer itself into the surface, pushing itself to a depth of up to 16 feet to gather temperature readings. Unfortunately, the probe has failed to bury itself any deeper than about a foot, but NASA thinks it knows why.

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The self-hammering mole relies on the friction of the surrounding soil to push itself along, but it’s now believed that the soil is simply too loose for the probe to catch a grip. Thankfully, the InSight lander is equipped with an arm that may be able to help.

Using InSight’s long metal arm, the science team will “pin” the mole against the side of its hole, increasing the friction of the surrounding material and hopefully giving the probe a chance to fulfill its destiny.

This operation has been a long time coming, and NASA’s Jet Propulsion Laboratory has had to prepare for the opportunity by removing a shroud surrounding the mole and getting the arm into position. This is made more difficult by the fact that there’s a significant communication delay between Earth and Mars, and the team has to wait to see its commands carried out before it knows how to proceed.

It’s worth noting that the lander’s robotic arm was never designed to do this. It can’t be controlled in real-time, so its handlers can instruct the arm to push for a few moments and then stop in the way that they might if the probe were sitting here on Earth. Instead, they have to tell the robot where to position the arm — in this case, right up against the soil next to the mole — and hope against hope that the exercise works.

However this unfolds, we won’t have to wait long to find out the fate of the mole, but we’ll be keeping our fingers crossed.


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« Reply #2141 on: Nov 04, 2019, 05:07 AM »


What moons in other solar systems reveal about planets like Neptune and Jupiter

11/4/2019
By The Conversation

What is the difference between a planet-satellite system as we have with the Earth and Moon, versus a binary planet – two planets orbiting each other in a cosmic do-si-do?

I am an astronomer interested in planets orbiting nearby stars, and gas giants – Jupiter, Saturn, Uranus and Neptune in our solar system – are the largest and easiest planets to detect. The crushing pressure within their gassy atmosphere means they are unlikely to be hospitable to life. But the rocky moons orbiting such planets could have conditions that are more welcoming. Last year, astronomers discovered a planet-sized exomoon orbiting another gas giant planet outside our solar system.

In a new paper, I argue that this exomoon is really what is called a captured planet.

Is the first detected ‘exomoon’ really a moon?

True Earth analogues, that orbit Sun-like stars, are very hard to detect, even with the large Keck telescopes. The task is easier if the host star is less massive. But then the planet has to be closer to the star to be warm enough, and the star’s gravitational tides may trap the planet in a state with a permanent hot side and a permanent cold side. This makes such planets less attractive as a potential location that could harbor life. When gas giants orbiting Sun-like stars have rocky moons, these may be more likely places to find life.

In 2018, two astronomers from Columbia University reported the first tentative observation of an exomoon – a satellite orbiting a planet that itself orbits another star. One curious feature was that this exomoon Kepler-1625b-i was much more massive than any moon found in our solar system. It has a mass similar to Neptune and orbits a planet similar in size to Jupiter.

Astronomers expect moons of planets like Jupiter and Saturn to have masses only a few percent of Earth. But this new exomoon was almost a thousand times larger than the corresponding bodies of our solar system – moons like Ganymede and Titan which orbit Jupiter and Saturn, respectively. It is very difficult to explain the formation of such a large satellite using current models of moon formation.

In a new model I developed, I discuss how such a massive exomoon forms through a different process, wherein it is really a captured planet.

All planets, large and small, start by gathering together asteroid-sized bodies to make a rocky core. At this early stage in the evolution of a planetary system, the rocky cores are still surrounded by a gaseous disk left over from the formation of the parent star. If a core can grow fast enough to reach a mass equivalent to 10 Earths, then it will have the gravitational strength to pull gas in from the surrounding space and grow to the massive size of Jupiter and Saturn. However, this gaseous accumulation is short-lived, as the star is draining away most of the gas in the disk, the dust and gas surrounding a newly formed star.

If there are two cores growing in close proximity, then they compete to capture rock and gas. If one core gets slightly larger, it gains an advantage and can capture the bulk of the gas in the neighborhood for itself. This leaves the second body without any further gas to capture. The increased gravitational pull of its neighbor drags the smaller body into the role of a satellite, albeit a very large one. The former planet is left as a super-sized moon, orbiting the planet that beat it out in the race to capture gas.

A remnant core as a look back into history

Viewed in this context, the captured planet is unlikely to be habitable. Growing planetary cores have gaseous envelopes, which make them more like Uranus and Neptune – a mix of rocks, ice and gas that would have become a Jupiter if it had not been so rudely cut off by its larger neighbor.

However, there are other implications that are almost as interesting. Studying the cores of giant planets is very difficult, because they are buried under several hundred Earth masses of hydrogen and helium. Currently, the JUNO mission is attempting to do this for Jupiter. However, studying the properties of this exomoon may enable astronomers to see the naked core of a giant gaseous planet when it is stripped of its gaseous envelope. This can provide a snapshot of what Jupiter may have looked like before it grew to its current enormous size.

This exomoon system Kepler-1625b-i is right at the edge of what is detectable with current technology. There may be many more objects like this that could be uncovered with future improvements in telescope capabilities. As astronomers’ census of exoplanets continues to grow, systems like the exomoon and its host highlight an issue that will become more important as we go forward. This exomoon reveals that the properties of a planet are not solely a consequence of its mass and position, but can depend on its history and the environment in which it formed. The Conversation

Exomoons may reveal secrets about how gas giants like Jupiter formed and what is in their core.
JPL/NASA

Bradley Hansen, Professor of Physics and Astronomy, University of California, Los Angeles

This article is republished from The Conversation under a Creative Commons license. Read the original article.


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« Reply #2142 on: Nov 05, 2019, 04:32 AM »


Nasa's Voyager 2 sends back its first message from interstellar space

Nasa craft is second to travel beyond heliosphere but gives most detailed data yet

    In pictures: Voyager 2’s mission so far: https://www.theguardian.com/science/gallery/2019/nov/04/voyager-2-story-of-mission-so-far-in-pictures

Hannah Devlin Science correspondent
Guardian
5 Nov 2019 16.04 GMT

Twelve billion miles from Earth, there is an elusive boundary that marks the edge of the sun’s realm and the start of interstellar space. When Voyager 2, the longest-running space mission, crossed that frontier more than 40 years after its launch it sent a faint signal from the other side that scientists have now decoded.

The Nasa craft is the second ever to travel beyond the heliosphere, the bubble of supersonic charged particles streaming outwards from the sun. Despite setting off a month ahead of its twin, Voyager 1, it crossed the threshold into interstellar space more than six years behind, after taking the scenic route across the solar system and providing what remain the only close-up images of Uranus and Neptune.

Now Voyager 2 has sent back the most detailed look yet at the edge of our solar system – despite Nasa scientists having no idea at the outset that it would survive to see this landmark.

“We didn’t know how large the bubble was and we certainly didn’t know that the spacecraft could live long enough to reach the edge of the bubble and enter interstellar space,” said Prof Ed Stone, of the California Institute of Technology, who has been working on the mission since before its launch in 1977.

The heliosphere can be thought of as a cosmic weather front: a distinct boundary where charged particles rushing outwards from the sun at supersonic speed meet a cooler, interstellar wind blowing in from supernovae that exploded millions of years ago. It was once thought that the solar wind faded away gradually with distance, but Voyager 1 confirmed there was a boundary, defined by a sudden drop in temperature and an increase in the density of charged particles, known as plasma.

The second set of measurements, by Voyager 2, give new insights into the nature of the heliosphere’s limits because on Voyager 1 a crucial instrument designed to directly measure the properties of plasma had broken in 1980.

Measurements published in five separate papers in Nature Astronomy reveal that Voyager 2 encountered a much sharper, thinner heliosphere boundary than Voyager 1. This could be due to Voyager 1 crossing during a solar maximum (activity is currently at a low) or the craft itself might have crossed through on a less perpendicular trajectory that meant it ended up spending longer at the edge.

The second data point also gives some insight into the shape of the heliosphere, tracing out a leading edge something like a blunt bullet.

“It implies that the heliosphere is symmetric, at least at the two points where the Voyager spacecraft crossed,” said Bill Kurth, a University of Iowa research scientist and a co-author on one of the studies. “That says that these two points on the surface are almost at the same distance.”

Voyager 2 also gives additional clues to the thickness of the heliosheath, the outer region of the heliosphere and the point where the solar wind piles up against the approaching wind in interstellar space, like the bow wave sent out ahead of a ship in the ocean.

The data also feeds into a debate about the overall shape of the heliosphere, which some models predict ought to be spherical and others more like a wind sock, with a long tail floating out behind as the solar system moves through the galaxy at high speed.

The shape depends, in a complex way, on the relative strengths of the magnetic fields inside and outside of the heliosphere, and the latest measurements are suggestive of a more spherical form.

There are limits to how much can be gleaned from two data points, however.

“It’s kind of like looking at an elephant with a microscope,” Kurth said. “Two people go up to an elephant with a microscope, and they come up with two different measurements. You have no idea what’s going on in between.”

From beyond the heliosphere, the signal from Voyager 2 is still beaming back, taking more than 16 hours to reach Earth. Its 22.4-watt transmitter has a power equivalent to a fridge light, which is more than a billion billion times dimmer by the time it reaches Earth and is picked up by Nasa’s largest antenna, a 70-metre dish.

The two Voyager probes, powered by steadily decaying plutonium, are projected to drop below critical energy levels in the mid-2020s. But they will continue on their trajectories long after they fall silent. “The two Voyagers will outlast Earth,” said Kurth. “They’re in their own orbits around the galaxy for 5bn years or longer. And the probability of them running into anything is almost zero.”


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« Reply #2143 on: Nov 06, 2019, 04:26 AM »


NASA’s TESS spacecraft is finding hundreds of exoplanets – and is poised to find thousands more

on November 6, 2019
By The Conversation

Within just 50 light-years from Earth, there are about 1,560 stars, likely orbited by several thousand planets. About a thousand of these extrasolar planets – known as exoplanets – may be rocky and have a composition similar to Earth’s. Some may even harbor life. Over 99% of these alien worlds remain undiscovered — but this is about to change.

With NASA’s new exoplanet-hunter space telescope TESS, the all-sky search is on for possibly habitable planets close to our solar system. TESS — orbiting Earth every 13.7 days — and ground-based telescopes are poised to find hundreds of planets over the next few years. This could transform astronomers’ understanding of alien worlds around us and provide targets to scan with next-generation telescopes for signatures of life. In just over a year, TESS has identified more than 1,200 planetary candidates, 29 of which astronomers have already confirmed as planets. Given TESS’s unique ability to simultaneously search tens of thousands of stars for planets, the mission is expected to yield over 10,000 new worlds.

These are exciting times for astronomers and, especially, for those of us exploring exoplanets. We are members of the planet-hunting Project EDEN, which also supports TESS’s work. We use telescopes on the ground and in space to find exoplanets to understand their properties and potential for harboring life.

Undiscovered worlds all around us

Worlds around us await discovery. Take, for example, Proxima Centauri, an unassuming, faint red star, invisible without a telescope. It is one of over a hundred billion or so such stars within our galaxy, unremarkable except for its status as our next-door neighbor. Orbiting Proxima is a fascinating but mysterious world, called Proxmia b, discovered only in 2016.

Scientists know surprisingly little about Proxima b. Astronomers name the first planet discovered in a system “b”. This planet has never been seen with human eyes or by a telescope. But we know it exists due to its gravitational pull on its host star, which makes the star wobble ever so slightly. This slight wobble was found in measurements collected by a large, international group of astronomers from data taken with multiple ground-based telescopes. Proxima b very likely has a rocky composition similar to Earth’s, but higher mass. It receives about the same amount of heat as Earth receives from the Sun.

And that is what makes this planet so exciting: It lies in the “habitable” zone and just might have properties similar to Earth’s, like a surface, liquid water, and — who knows? — maybe even an atmosphere bearing the telltale chemical signs of life.

NASA’s TESS mission launched in April 2018 to hunt for other broadly Earth-sized planets, but with a different method. TESS is looking for rare dimming events that happen when planets pass in front of their host stars, blocking some starlight. These transit events indicate not only the presence of the planets, but also their sizes and orbits.

Finding a new transiting exoplanet is a big deal for astronomers like us because, unlike those found through stellar wobbles, worlds seen transiting can be studied further to determine their densities and atmospheric compositions.

Red dwarf suns

For us, the most exciting exoplanets are the smallest ones, which TESS can detect when they orbit small stars called red dwarfs – stars with masses less than half the mass of our Sun.

Each of these systems is unique. For example, LP 791-18 is a red dwarf star 86 light-years from Earth around which TESS found two worlds. The first is a “super-Earth,” a planet larger than Earth but probably still mostly rocky, and the second is a “mini-Neptune,” a planet smaller than Neptune but gas- and ice-rich. Neither of these planets have counterparts in our solar system.

Among astronomers’ current favorites of the new broadly Earth-sized planets is LHS 3884b, a scorching “hot Earth” that orbits its sun so quickly that on it you could celebrate your birthday every 11 hours.

No Earth-like worlds yet

But how Earth-like are Earth-sized planets? The promise of finding nearby worlds for detailed studies is already paying off. A team of astronomers observed the hot super-Earth LHS 3884b with the Hubble Space Telescope and found the planet to be a horrible vacation spot, without even an atmosphere. It is just a bare rock with temperatures ranging from over 700 C (1300 Fahrenheit) at noon to near absolute zero (-460 Fahrenheit) at midnight.

The TESS mission was initially funded for two years. But the spacecraft is in excellent shape and NASA recently extended the mission through 2022, doubling the time TESS will have to scan nearby, bright stars for transits.

However, finding exoplanets around the coolest stars — those with temperatures less than about 2700 C (4900 F) — will still be a challenge due to their extreme faintness. Since ultracool dwarfs provide our best opportunity to find and study exoplanets with sizes and temperatures similar to Earth’s, other focused planet searches are picking up where TESS leaves off.

The worlds TESS can’t find

In May 2016, a Belgian-led group announced the discovery of a planetary system around the ultracool dwarf they christened TRAPPIST-1. The discovery of the seven transiting Earth-sized exoplanets in the TRAPPIST-1 system was groundbreaking.

It also demonstrated how small telescopes — relative to the powerful behemoths of our age — can still make transformational discoveries. With patience and persistence, the TRAPPIST telescope scanned nearby faint, red dwarf stars from its high-mountain perch in the Atacama desert for small, telltale dips in their brightnesses. Eventually, it spotted transits in the data for the red dwarf TRAPPIST-1, which — although just 41 light-years away — is too faint for TESS’s four 10-cm (4-inch) diameter lenses. Its Earth-sized worlds would have remained undiscovered had the TRAPPIST team’s larger telescope not found them.

Two projects have upped up the game in the search for exo-Earth candidates around nearby red dwarfs. The SPECULOOS team installed four robotic telescopes – also in the Atacama desert – and one in the Northern Hemisphere. Our Exoearth Discovery and Exploration Network – Project EDEN – uses nine telescopes in Arizona, Italy, Spain and Taiwan to observe red dwarf stars continuously.

The SPECULOOS and EDEN telescopes are much larger than TESS’s small lenses and can find planets around stars too faint for TESS to study, including some of the transiting Earth-sized planets closest to us.

The decade of new worlds

The next decade is likely to be remembered as the time when we opened our eyes to the incredible diversity of other worlds. TESS is likely to find between 10,000 and 15,000 exoplanet candidates by 2025. By 2030, the European Space Agency’s GAIA and PLATO missions are expected to find another 20,000-35,000 planets. GAIA will look for stellar wobbles introduced by planets, while PLATO will search for planetary transits as TESS does.

However, even among the thousands of planets that will soon be found, the exoplanets closest to our solar system will remain special. Many of these worlds can be studied in great detail – including the search for signs of life. Discoveries of the nearest worlds also represent major steps in humanity’s progress in exploring the universe we live in. After mapping our own planet and then the solar system, we now turn to nearby planetary systems. Perhaps one day Proxima b or another nearby world astronomers have yet to find will be the target for interstellar probes, like Project Starshot, or even crewed starships. But first we’ve got to put these worlds on the map.

Timeline of discoveries of exoplanetary systems within 50 lightyears of the Sun. Credit: Project EDEN/ Daniel Apai and Benjamin Rackham: https://www.youtube.com/watch?v=8d4WWYyiZPs

Daniel Apai, Associate Professor of Astronomy and Planetary Sciences, University of Arizona and Benjamin Rackham, 51 Pegasi b Postdoctoral Fellow, Massachusetts Institute of Technology

This article is republished from The Conversation under a Creative Commons license. Read the original article.


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« Reply #2144 on: Nov 07, 2019, 04:33 AM »


Astronomers spot a trio of black holes on a devastating collision course

Mike Wehner
BGR
11/7/2019

Black holes are one of the most interesting features of our universe. So incredibly dense that their gravitational pull can swallow up light itself, they are enormously powerful on their own, but when three of them get together? Well, that’s a recipe for some serious fireworks.

As NASA’s Jet Propulsion Laboratory explains in a new post, astronomers using powerful imaging hardware, including three of NASA’s own telescopes, have spotted a trio of black holes in the midst of a cosmic dance. The holes were spotted in a distant galactic collision that could offer hints at the fate that awaits our own Milky Way.

Black holes are thought to exist at the center of most galaxies, and supermassive black holes are the largest and most powerful variety. It’s believed that a supermassive black hole rests at the heart of our own galaxy, but the system known as SDSS J084905.51+111447.2 has not one, not two, but three such black holes, making it an incredible oddity.

To make their discovery, a team of astronomers relied on several different imaging techniques including infrared, X-ray, and optical sensors. Combining all of these observations allowed the scientists to spot the black hole group, and the team describes its findings in a new paper published in The Astrophysical Journal.

As it appears right now, the system is thought to be the result of an ongoing galaxy merger, with the trio of black holes all carrying their own galaxies into the fray. Our home galaxy, the Milky Way, is believed to be on a similar collision course with the neighboring Andromeda galaxy, though it will take several billion years before that occurs.

“We were only looking for pairs of black holes at the time, and yet, through our selection technique, we stumbled upon this amazing system,” Ryan Pfeifle, first author of the study, said in a statement. “This is the strongest evidence yet found for such a triple system of actively feeding supermassive black holes.”


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