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@NASA Yesterday
Today, we’re expressing gratitude for the opportunity to rove on Mars as we mark the completion of a successful mission that exceeded our expectations.
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Oppy's mission was original planned for ninety days. He kept going for fifteen years.
(And isn't it interesting the way we anthropomorphize things? I can't shake the image of this plucky little robot, going on against the odds.)
No, I don't mean Republican members of Congress. Not quite so far away as Ultima Thule -- in fact only a little over halfway to Pluto -- NASA's Juno orbiter has captured images of a volcanic eruption on Jupiter's moon Io:
Image credit: NASA / SwRI / MSSS
Four instruments onboard Juno — a camera called JunoCam, the Stellar Reference Unit, the Jovian Infrared Auroral Mapper and the Ultraviolet Imaging Spectrograph — observed Io for over an hour, providing a glimpse of the moon’s polar regions as well as evidence of an active eruption.
JunoCam acquired the new images of Io on December 21, 2018, at 12:00, 12:15 and 12:20 p.m. GMT before Io entered Jupiter’s shadow.
The images show the moon half-illuminated with a bright spot seen just beyond the terminator, the day-night boundary.
“The ground is already in shadow, but the height of the plume allows it to reflect sunlight, much like the way mountaintops or clouds on the Earth continue to be lit after the Sun has set,” said Dr. Candice Hansen-Koharcheck, JunoCam lead from the Planetary Science Institute.
And once again, this is something that started before the current regime was installed.
Have we reached the point where our major achievements are in the past?
Scientists from NASA's New Horizons mission released the first detailed images of the most distant object ever explored -- the Kuiper Belt object nicknamed Ultima Thule. Its remarkable appearance, unlike anything we've seen before, illuminates the processes that built the planets four and a half billion years ago. . . .
The new images -- taken from as close as 17,000 miles (27,000 kilometers) on approach -- revealed Ultima Thule as a "contact binary," consisting of two connected spheres. End to end, the world measures 19 miles (31 kilometers) in length. The team has dubbed the larger sphere "Ultima" (12 miles/19 kilometers across) and the smaller sphere "Thule" (9 miles/14 kilometers across).
The team says that the two spheres likely joined as early as 99 percent of the way back to the formation of the solar system, colliding no faster than two cars in a fender-bender.
NASA manages to do some good work in spite of the current regime. We've successfully completed the farthest ever fly-by of an object in space:
NASA now has proof that its New Horizons probe completed its record-setting flyby of the Kuiper Belt object Ultima Thule. The mission team confirmed the flypast at 10:31AM Eastern Time after receiving telemetry data indicating that the spacecraft was "healthy." It technically flew past Ultima Thule at about 12:33AM , but the combination of data collection and the six-hour signal travel time left the New Horizons crew waiting until much later to receive the A-OK from their pride and joy.
Scientific data won't arrive until sometime around 200 UTC on January 2nd (9PM ET on January 1st). You'll have to wait a while for an up-close snapshot, then.
The confirmation isn't just a relief for the New Horizons team. This marks the farthest-ever flyby in human history -- at about 4 billion miles from the Sun, Ultima Thule makes Pluto seem like a next-door neighbor by comparison. It also promises a raft of potential scientific insights, including clues to the formation of dwarf planets. Some of those discoveries may take a long time, but they'll be worthwhile if they shed light on the Solar System and the cosmos at large.
So, no pictures yet, but eventually.
This is a lot more exciting that a mythical wall.
I almost feel as though I should spend the day at the planetarium. Almost.
This composite image of Ultima Thule was taken on Dec. 1. Photo: NASA/JHUAPL/SwRI
On New Year's Day, NASA's New Horizons spacecraft is expected to make history by conducting the most distant flyby ever, by zooming past an object a billion miles past Pluto. It's called "Ultima Thule," meaning "beyond the known world.
Why it matters: The spacecraft, which is the same one that sent back dazzling images of Pluto in 2015, is slated to be the first to explore an object in the Kuiper Belt -- a region of icy bodies beyond the orbit of Neptune that are thought to be leftovers from the solar system's early days.
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The goal of the mission is to learn more about the building blocks of planets. "In effect, Ultima should be a valuable window into the early stages of planet formation and what the solar system was like over 4.5 billion years ago," principal investigator Alan Stern wrote in a NASA blog post.
This is reallly exciting for us science geeks. This goes back to the first entry in "Earth: A Biography", which, as you'll no doubt recall, dealt with the origins of the universe and, finally, this planet we're sitting on.
There's a lot more at the link, and it's pretty interesting.
Eleven billion miles from Earth, NASA's long-lived Voyager 2 probe, still beaming back data 41 years after its launch in 1977, has finally moved into interstellar space, scientists revealed Monday, joining its sister ship Voyager 1 in the vast, uncharted realm between the stars.
Voyager 2 moved past the boundary of the heliosphere, the protective bubble defined by the sun's magnetic field and electrically charged solar wind, on Nov. 5. The transition was marked by a sharp decline in the number of charged particles detected by the spacecraft's plasma science experiment, or PLS.
The instrument has not detected any signs of the solar wind since then.
The news came a few days ago, but on cosmic time scales that’s still hot of the presses: LIGO, the twin instrument gravitational wave detectors, in collaboration with the European VIRGO detector, announced the discovery of four new black-hole collisions, measured in the gravity waves given off by those titanic wrecks.
That’s hot stuff: the report of the first gravity-wave detection came just two years ago, paying off a prediction first made (tentatively) by Albert Einstein almost exactly a century earlier in his general theory of relativity.
In its most compact form the general theory boils down to a single equation, just one short line of symbols. The quip is that in relativity, it all boils down to space and time telling matter and energy where to go, while energy and matter tell spacetime what shape to be. A gravity wave is that joke in action: matter-energy in violent motion jostles spacetime into waves we can, only in the last few years, actually see.
The day started off clear and sunny, and then the clouds rolled in to neatly bracket the time when whatever of the eclipse would have been visible from Chicago would have been visible. And then about 2:30, it started to clear up again.
That always happens -- when there are meteor showers, too.
A spinning, solar-powered spacecraft as wide as a basketball court will arrive at Jupiter on July 4 to study the giant planet and to take the highest-resolution images of Jupiter in history.
NASA's robotic Juno probe is carrying seven science instruments designed to help scientists figure out how Jupiter formed and evolved. The planet is the most massive in our solar system -- a huge ball of gas 11 times wider than Earth. Researchers think it was the first planet to form and that it holds clues to how the solar system evolved.
"One of the primary goals of Juno is to learn the recipe for solar systems," Scott Bolton, Juno principal investigator, said at a news conference on June 16. "How do you make the solar system? How do you make the planets in our solar system?"
Spacecraft have been to Jupiter before, but scientists still are puzzled. What's going on under Jupiter's dense clouds? Does it have a solid core? How much water is in its atmosphere? And how deep are those colorful bands and that mysterious giant red spot?
"Jupiter looks a lot like the sun," Bolton said. But it has much more than the sun, and that's really important.
"The stuff that Jupiter has more of is what we're all made out of," he said. "It's what the Earth is made out of. It's what life comes from."
A note: It seems that the Hadean eon of Earth's history might not have been as violent as previously reported: there is evidence that there were oceans as early as 4 billion years ago.
This is a series that I've been thinking about for a while. I'm not sure why. It's really meant to be a survey of life on earth, how it originated and how it developed, but I felt like I should start at the beginning.
The most widely accepted theory of the origins of the universe at this point is the Big Bang Theory: there was a point of very high density and very high temperature which developed an instability and exploded, creating the universe, about 13.8 billion years ago. It wasn't really the universe as we know it at that point, because it was very, very hot, but eventually it cooled enough to allow the formation of things like subatomic particles. Then gravity and the other major forces took over, and we have, first, atoms, then stars. Our sun was one of those stars. Here's what seems to be a pretty accurate exposition of the theory, at Wikipedia. And as you can see from this video, it wasn't really all that straightforward.
In Einstein's formulation, the laws of physics actually break before the singularity is reached. But scientists extrapolate backward as if the physics equations still hold, said Robert Brandenberger, a theoretical cosmologist at McGill University in Montreal, who was not involved in the study.
"So when we say that the universe begins with a big bang, we really have no right to say that," Brandenberger told Live Science.
There are other problems brewing in physics — namely, that the two most dominant theories, quantum mechanics and general relativity, can't be reconciled.
Quantum mechanics says that the behavior of tiny subatomic particles is fundamentally uncertain. This is at odds with Einstein's general relativity, which is deterministic, meaning that once all the natural laws are known, the future is completely predetermined by the past, Das said.
And neither theory explains what dark matter, an invisible form of matter that exerts a gravitational pull on ordinary matter but cannot be detected by most telescopes, is made of.
I sort of like this idea -- considering that most of the world's religious traditions assume that the earth and the universe are cyclic, with no beginning and no end . . . well, food for thought, at the very least.
At any rate, starting about 13.5 billion years ago, we have stars. The sun was one of those stars, formed about 4.5-5 billion years ago in a cloud of molecules -- mostly hydrogen, with a little helium and some heavier elements thrown in for fun. Some of those molecules began to attract each other -- gravity again -- and as the group got bigger, the pull became stronger, pulling in more molecules until, finally, we had ignition. At the core of the sun the pressure and temperature are so intense that we have, in effect, a really, really big fusion reactor.
Now, there was still a lot of dust and gas around the sun, mostly forming a big disc, which contained not only hydrogen and helium, but also heavier elements -- remember, other fusion reactors -- stars -- had been burning merrily along for 8 or 9 billion years, and some had exploded after converting the lighter elements into heavier elements -- carbon, oxygen, iron, nickel, all the way up to uranium: the building blocks of planets.
The creation of the earth was undoubtedly a lot more spectacular than the creation of the sun -- lots of crashing and explosions as actual rocks collided and stuck together.
Here's Neil deGrasse Tyson with a description of the process:
Pretty neat, huh?
So, now we have a sun and a planet -- a whole solar system, actually (well, OK, a whole universe, but for this we're keeping it local) -- so where do we go from here? Well, life, of course. After all, that's what we're most interested in. But we need to wait about a billion years, for things to calm down a little bit, so that's for next time.
Black holes are known for their voracious appetites. These bodies -- formed when a massive star collapses upon itself -- have occasionally been described as the “vacuum cleaners” of the universe and are notorious for their tendency to wreak havoc on the usual laws of physics that govern the rest of the cosmos.
Now, for the first time ever, scientists have witnessed a black hole swallowing a star and ejecting a flare of matter moving at nearly the speed of light -- a rare event that occurs when a star stumbles across a black hole’s gravitational well.
There's even video -- a re-enactment/visualization, of course -- this particular event happened 300 million light years away and took a little bit more than a few minutes to happen. Of course, when you're talking about interstellar phenomena, that counts as current events:
It's been a long time since I've done one of these, but it's Saturday and here's a science article for you: the New Horizons team has published the first findings on the New Horizons flyby of Pluto. A few tidbits:
Pluto:
Pluto
Lastly, Pluto is sweetly colorful. Look at it through New Horizons' color camera and you'll see "spectacular diversity," the researchers write. The pictures we've all seen are no forgery — Pluto really does have a very distinct color palette. The Cthulhu Regio registers as a deep red, the western section of the heart-shaped Tombaugh Regio is a much lighter, pink-ish red, and the eastern half is lighter still. These colors come from refractory organics known as "tholins," the result of frozen nitrogen and methane in the soil (and atmosphere) being irradiated by UV rays and charged particles.
Charon:
Charon is also heavily cratered like Pluto. The New Horizons team believes some of these craters (specifically, the ones located in what's known as Vulcan Planum, which is found to the southeast of Charon's massive canyons) appear be about 4 billion years or older, which could link them to the Late Heavy Bombardment that happened in the early days of our Solar System. Charon also has a massive network of canyons. These fractures cuts across most of Charon's southern hemisphere, with the two largest — named Macross Chasma and Serenity Chasma — run for 1050 kilometers. At its widest, Serenity Chasma measures 60 kilometers across and runs, in places, 5 kilometers deep.
Nix and Hydra:
The reflective properties of Nix indicate that the small moon is likely covered in water ice. Hydra is also non-spherical, measuring 43 kilometers by 33 kilometers, with a diameter of about 41 kilometers. It also has a highly reflective surface, and is likely covered in water ice.
That confounded the New Horizons team. "How such bright surfaces can be maintained on Nix and Hydra over billions of years is puzzling," they write. Radiation or impacts with other objects should have darkened and reddened the surfaces of these moons over time, they say. What's also still unknown with any degree of certainty is the mass, volume, or density of these moons.
As for the bright surfaces, if they are covered with water ice, might that not melt and refreeze after impacts, smoothing out the surface?
A long-standing conundrum related to black holes deals with something known as the “information paradox.” In a nutshell, the laws of quantum mechanics tell us that everything in the universe is encoded with information about its constituent particles’ quantum states. And, this information should never entirely disappear, not even if something gets sucked into a black hole. The fact that this information seems to get irretrievably lost when a black hole inevitably evaporates has frustrated physicists for nearly four decades.
During a lecture at the KTH Royal Institute of Technology in Stockholm on Tuesday, famed British physicist and cosmologist Stephen Hawking presented an idea about how this paradox can be solved. According to him, the quantum-mechanical information about particles falling into black holes doesn’t actually enter the black hole.
“The information is not stored in the interior of the black hole as one might expect, but in its boundary -- the event horizon,” Hawking said, adding that the information is encoded in two-dimensional holograms known as “super translations.”
The problem is that the information is not organized, so that, in practical terms, it is lost, even though it's not. (Don'cha love modern physics?)
I vaguely remember a science-fiction story from years ago in which someone was trapped in orbit around a black hole -- at the event horizon, more or less -- and someone else was trying to rescue them, but it's been a long time and I don't remember the details. The point of that little anecdote is that it may help visualize what Hawking is describing.
One thing that interested me is that I never knew that black holes evaporate, or that it's inevitable.
And Hawking notes that there are other ways out of a black hole short of dissolution. But you'll need to read the article.
At least two as-yet undiscovered planets as big as Earth or larger may be hiding in the outer fringes of the solar system, scientists believe.
The secret worlds are thought to exist beyond the orbits of Neptune, the furthest true planet from the Sun, and the even more distant tiny “dwarf planet” Pluto.
The evidence comes from observations of a belt of space rocks known as “extreme trans-Neptunian objects” (Etnos).
Orbiting the Sun beyond Neptune, Etnos should be distributed randomly with paths that have certain defined characteristics. But a dozen of the bodies have completely unexpected orbital values consistent with them being influenced by the gravitational pull of something unseen.
What surprises me about discoveries like this, and all the planets we're finding orbiting other stars, is the surprise in some quarters. I mean, it seems sort of inevitable that other stars would have planets, if for no other reason than that there's so much stuff floating around in space looking for a home. And we've known for a long time that our own solar system is a little more complicated than a bunch of planets with their attendant moons circling the sun in a nice, orderly fashion.
And, as it turns out, those who pay attention to such things have been thinking for a while that there's something out there:
Astronomers have spent decades debating whether a hidden planet beyond Pluto remained undiscovered.
The new research, published in the journal Monthly Notices of the Royal Astronomical Society Letters, is based on analysis of an effect called the “Kozai mechanism”, by which a large body disturbs the orbit of a smaller and more distant object.
The scientists wrote: “In this scenario, a population of stable asteroids may be shepherded by a distant, undiscovered planet larger than the Earth …”
One problem is that the theory goes against predictions of computer simulations of the formation of the solar system, which state there are no other planets moving in circular orbits beyond Neptune. But the recent discovery of a planet-forming disk of dust and gas more than 100 astronomical units (AU) from the star HL Tauri suggests planets can form long distances away from the centre of a solar system.
The view from out there:
An artist’s impression of one of the two as-yet undiscovered planets. Photograph: Nasa/JPL-Caltech/PA
On top of everything else, been sick for the last week. Starting to feel human again, so here's some catch-up:
All good things must come to an end. Or, if you subscribe to the majority world-view, the wheel of time is bigger than we thought. Which is by way of saying that the days of the Milky Way galaxy are numbered. Granted, the number's quite large -- 4 billion years -- but still.
The Milky Way is one of the dominant galaxies of a cluster known as the Local Group. The other major player in the group is the Andromeda nebula (M31). And according to recent measurements by the Hubble Space Telescope, the two galaxies are traveling through space and dark matter headed directly toward each other.
“After nearly a century of speculation about the future destiny of Andromeda and our Milky Way, we at last have a clear picture of how events will unfold over the coming billions of years,” says Sangmo Tony Sohn of the Space Telescope Science Institute in Baltimore. His colleague Roeland van der Marel confirms the research: “Our findings are statistically consistent with a head-on collision between the Andromeda galaxy and our Milky Way galaxy.”
Can't embed the video from NYT, but it's here. It's kind of a gloss, but you'll get the general idea.
Scientists at MIT have traced 13 billion years of galaxy evolution, from shortly after the Big Bang to the present day. Their simulation, named Illustris, captures both the massive scale of the Universe and the intriguing variety of galaxies -- something previous modelers have struggled to do. It produces a Universe that looks remarkably similar to what we see through our telescopes, giving us greater confidence in our understanding of the Universe, from the laws of physics to our theories about galaxy formation.
This is what it's describing:
It's fascinating, but the video moves a little too fast for me to follow very well. If you want more information, the research paper itself is here; it's behind a paywall, but you can read the Nature article about the project here. And via Towleroad, here's a rather more accessible discussion of the creation of the model at The Guardian.
It's like I've always said: The universe is a fascinating place.
How does 13.6 billion years old sound? That's what astronomers in Australia have found: a 13.6 billion year old star:
A team led by astronomers at The Australian National University has discovered the oldest known star in the Universe, which formed shortly after the Big Bang 13.7 billion years ago.
The discovery has allowed astronomers for the first time to study the chemistry of the first stars, giving scientists a clearer idea of what the Universe was like in its infancy.
"This is the first time that we've been able to unambiguously say that we've found the chemical fingerprint of a first star," said lead researcher, Dr Stefan Keller of the ANU Research School of Astronomy and Astrophysics.
"This is one of the first steps in understanding what those first stars were like. What this star has enabled us to do is record the fingerprint of those first stars."
NASA's Spitzer and Hubble Space Telescopes have spotted what might be one of the most distant galaxies known, harkening back to a time when our universe was only about 650 million years old (our universe is 13.8 billion years old). The galaxy, known as Abell2744 Y1, is about 30 times smaller than our Milky Way galaxy and is producing about 10 times more stars, as is typical for galaxies in our young universe.
This image of the galaxy cluster Abell 2744 was obtained with NASA's Hubble Space Telescope. The zoomed image shows the region around the galaxy Abell2744_Y1, one of the most distant galaxy candidates known, harkening back to a time when the universe was 650 million years old.
How long? Maybe 12 billion years. Not long after the Big Bang. And how far away? I have no idea. But it's quite a distance. The image is from the Hubble Space Telescope, and uses gravity as a lense to magnify very faint, very distant galaxies.
"The Frontier Fields is an experiment; can we use Hubble's exquisite image quality and Einstein's theory of General Relativity to search for the first galaxies?" said Space Telescope Science Institute Director Matt Mountain. "With the other Great Observatories, we are undertaking an ambitious joint program to use galaxy clusters to explore the first billion years of the universe's history."
Simultaneous observations of this field are being done with NASA's two other Great Observatories, the Spitzer Space Telescope and the Chandra X-ray Observatory. The assembly of all this multispectral information is expected to provide new insights into the origin and evolution of galaxies and their accompanying black holes.
Somehow, I find it hard to think of myself as the center of the universe.
