Here’s what happened in the impact crater the day it did in the dinos 0 30

Here’s what happened in the impact crater the day it did in the dinos

The day it went down —

Rock core allows researchers to create an incredible timeline.

Industrial ocean platform.

Enlarge / This is “Liftboat Myrtle,” which housed the drilling operation into Chicxulub Crater.

Geology is a big science. The Earth is a large enough place today, but when you stretch the fourth dimension back across many millions of years, the largeness can get out of hand. Because we lose a lot of detail to the ravages of time, it’s very difficult for geology to get small again—to tell us about what happened in individual locations or over short periods of time.

So it’s not every day that you read a scientific paper titled “The first day of the Cenozoic.” The Cenozoic is the name geologists give to the era spanning the last 66 million years, and it started with the mass extinction event that killed off (most of) the dinosaurs. There were incredible eruptions that contributed to the extinction event and spanned a considerable amount of time.

But the asteroid that struck off the coast of what is the Yucatán Peninsula today was the opposite—it couldn’t have been much more sudden. A recent drilling project recovered a long core of rock from the Chicxulub impact crater, leading to greater clarity about how the calamity played out—including on that first day.

Big enough impact craters actually have a knob of uplifted rock in the center that forms due to the incredible shock forces involved. But the very largest impacts—like Chicxulub—end up with a ring of uplifted rock around the center, as if to mark the bulls-eye. Computer modeling, supported by observations of the deepest bedrock in the core, shows that the rock would have bounced around like jelly. Over 10 minutes or so, a new mountain would have soared into the sky before collapsing and spreading out into a raised ring on the crater floor.

Higher up in the core, a layer of seafloor sediment seems to record a miraculous return of small critters to the crater within just a couple years.

Between the jellified granite and the brave plankton fossils lies about 130 meters of chaotic rock. A team of researchers led by the University of Texas at Austin’s Sean Gulick have analyzed that rock and produced a timeline of that impossibly violent day. They threw just about every tool available at the rock core, including X-ray techniques that image it and identify minerals, to a machine-learning analysis that identified trends in the visible shards of rock, to measurements of magnetism.

The first layer above the messed-up bedrock that formed the peak ring is made up of 40m of broken pieces of melted rock. The researchers say this material was likely flowing out from the center of the crater for some tens of minutes after the impact. It settled into place while it was still hot, and the tiny crystals of magnetite in this rock are all aligned with Earth’s magnetic field at that time.

Here's the timeline of events recorded inside the impact crater.

Enlarge / Here’s the timeline of events recorded inside the impact crater.

The next layer up contains about 10m of pieces of melt in addition to shocked bedrock that was blasted out (roughly) intact. The researchers say this actually appears to be the first part of the “resurge” deposit—material that flowed with seawater as it rushed back into the crater and over the peak ring. Modeling shows that the tsunami generated during the impact would have bounced off the nearest Central American coastline and returned in about an hour. Apart from pushing stuff around, this water probably also caused some explosions as it encountered still-hot melted rock.

The next 80m of rock up from there show the first signs of order. From the bottom of this layer toward the top, the pieces get smaller and less jagged, indicating that tumbled rocks and sediment were more gradually settling out of the water column. This is topped off by a 10cm-thick layer of sand and gravel deposited in ripples, indicating a flow of water with a consistent direction. The researchers interpret this as a later tsunami wave return from the Gulf of Mexico several hours after impact.

The uppermost materials contain combustion byproducts called PAHs and even some charcoal, which likely represents residue from wildfires on land. It’s believed that the impact may have started wildfires worldwide, contributing to the particulate matter that blocked out the Sun and sent temperatures plunging.

While 30% to 50% of the rock struck by the Chicxulub impactor was made up of evaporite deposits like salt and gypsum, almost none of that material is found in the core. That provides more support for the idea that these minerals were vaporized, sending massive amounts of sulfur into the atmosphere where it could form sunlight-blocking particles. Much of the rest of the bedrock was limestone, which would have released CO2, causing the long-term global warming that followed after the short-lived sulfur particles washed out of the atmosphere.

In a world where a centimeter of sediment can take centuries to accumulate, the fact that 130 meters of material was deposited in a day is remarkable. More importantly, it gives you no shortage of clues to look through to learn about one of the wildest events in the geologic record—and the first day of the Cenozoic era.

PNAS, 2019. DOI: 10.1073/pnas.1909479116 (About DOIs).

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Comet from another Solar System looks a lot like our own 0 10

Comet from another Solar System looks a lot like our own

Incoming —

If it weren’t for the orbit, 2I/Borisov would be hard to pick out.

Image of a fuzzy white object on a dark grey field specked with stars.

Enlarge / Comet C/2019 Q4 (Borisov). Note the fuzzy appearance and faint tail.

Interactions among the small bodies of our Solar System are expected to hurl small objects out into interstellar space with some regularity, and the frequency was probably much higher early in the system’s history. Given that the same thing almost certainly happens at exosolar systems—and we now know there are a lot of those—it’s likely that the vast volume of interstellar space is lightly sprinkled with small objects, some of which may sporadically pass through our own Solar System. But up until very recently, we’d had no evidence of their existence.

That situation changed with the discovery of ‘Oumuamua, a strange, cigar-shaped body that was the first confirmed exosolar visitor. But ‘Oumuamua was so strange that it set some astronomers speculating that it could be an alien craft. Earlier this year, however, scientists spotted a second potential exosolar visitor, and this one looked a lot like a comet. Now, the first data on the object, 2I/Borisov, is in, and it’s clearly exosolar in origin but looks so much like our existing comets that we might not have realized where it was from if we didn’t have a good grip on its orbit.

The Crusher

The results come from quick work by a team of European researchers, who got a heads-up about 2I/Borisov’s existence due to a software package they put in place. The code, called “Interstellar Crusher,” is a Python software package that scans the Possible Comet Confirmation Page for new objects and attempts to calculate their orbits as they come in. As we described in our earlier coverage of 2I/Borisov, orbits that have a certain set of properties, called hyperbolic orbits, indicate that a body has come from outside our Solar System. These orbits indicate a body will only pass by the Sun once and originate from a source that’s far outside the plane in which our planets orbit.

Interstellar Crusher quickly flagged 2I/Borisov as having a hyperbolic orbit, and the research team spent some time figuring out if there were any possible alternatives that work. All of these attempts would require at least one (and sometimes more than one) dramatic acceleration by a force other than the Solar System’s gravity. In contrast, its trajectory worked nicely with gravitational forces if the calculations allowed a trajectory far from that of the Solar System’s orbital plane.

An image of 2I/Borisov taken with red and green filters in early September.

An image of 2I/Borisov taken with red and green filters in early September.

Gemini Observatory/NSF/AURA

The calculations indicated an eccentricity of 3.4, when anything much larger than about 1.2 would be considered a sign of exosolar origin. The authors note that you can’t possibly explain this through interactions between 2I/Borisov and our Solar System’s planets simply because the object would never have gotten anywhere close to the planets.

Eccentric yet familiar

From there, the work shifts to imaging using large telescopes in the Canaries and Hawaii. At the time, 2I/Borisov was about three times further from Earth than Earth is from the Sun.

The image reveals that 2I/Borisov looks very much like it would if it had originated in our Solar System. It’s got an extended coma, the cloud of material liberated from a comet as it’s warmed by the Sun. It’s also got a broad and short tail, like other comets we’ve seen. And based on its brightness at that distance, the researchers estimate that the cometary core is about 2km across, which is fairly typical for Solar System comets. Its coloration is similar as well, although possibly slightly more red.

While those results might sound a bit dull to you, they’re really exciting to people in the field. 2I/Borisov is exactly what we expected our exosolar visitors to look like, given that it’s relatively easy to expel cometary bodies from the locations where they formed. But our first exosolar visitor looked like nothing we’ve seen previously which, in the authors’ words, “prompted us to rethink our entire view of the nature of interstellar interlopers.” Relative to that, 2I/Borisov is probably a relief.

Nature Astronomy, 2019. DOI: 10.1038/s41550-019-0931-8  (About DOIs).

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“The Switcher” is real: Witcher 3 on Switch is a blurry, tolerable compromise 0 14

“The Switcher” is real: Witcher 3 on Switch is a blurry, tolerable compromise

Yes, it has wet butts —

How do you shrink such a demanding RPG down to Switch’s weaker specs? This is how.

In good news, you can boot straight into expansion content when loading this version of <em>The Witcher 3</em>. I imagine more than a few fans of the game will use this Switch version to dive deeply into either or both of the expansions.” src=”×450.jpg”></img><figcaption>
<p><a data-height=Enlarge / In good news, you can boot straight into expansion content when loading this version of The Witcher 3. I imagine more than a few fans of the game will use this Switch version to dive deeply into either or both of the expansions.

Since Nintendo’s Switch console launched in 2016, we’ve seen no shortage of holy-cow ports of games we never thought would work on what turned out to be the most underpowered console of this generation. Doom 2016, Dark Souls, Elder Scrolls V: Skyrim, Wolfenstein: The New Colossus—that’s a list of demanding 3D games I never expected to launch on Switch, let alone games I’d actually recommend for the system.

But I do so with a pretty hefty asterisk attached. The charm of these games on Switch comes almost entirely due to them being playable on the go, at which point their severe compromises (image quality, rendering resolution) become much more acceptable. What looks iffy on a full-sized TV is easier to shrug off when seen on a six-inch 720p panel.

This week marks the arrival of arguably the most holy-cow port yet on the portable console: CD Projekt Red’s 2015 action-RPG The Witcher 3. This is a game, after all, whose other console versions required quite a few patches to get their most troublesome spots up to a locked 30 frames per second. We went hands-on over the weekend with the game’s final retail version (which launches for Switch on Tuesday) to answer a crucial question: could we expect playability in CDPR’s acclaimed adventure game on an even weaker system?

Not every polygon came through unscathed

  • In many ways, The Witcher 3 dedicates its Switch polygons where they count.

  • And when pre-baked lighting effects emerge, cinematic scenes can look quite handsome, even if they run closer to 20fps.

  • But while characters and certain scenes can look fantastic, a lot of the game’s default geometry, particularly its foliage, can look quite weird.

  • There’s also the matter of some rampant texture pop-in in some cinematic scenes.

  • Even in this cinematic scene, the effects of reduced screen resolution come into play.

  • Some optimized cinema scenes can look crisp and clear enough.

  • What you’re really looking for is real-time gameplay, and the rest of this gallery focuses on that.

  • We don’t have pixel-counting gear in-house, but in action, this looks on par with Doom 2016‘s Switch port.

  • The physics attached to these trees in a wind storm makes them look pretty convincing—at least, as opposed to some of the lower-poly foliage in other scenes.

  • There’s one wolf and one deer in there. That can be kind of hard to discern, even in action.

  • The view distance is okay, but nothing to scream home about.

  • Low-res Witcher.

  • There’s more than bad weather affecting the visibility in this moment.

  • Witchers can just barge in anywhere, can’t they.

The good news is that our initial impressions reveal a mostly locked 30fps refresh rate—stable enough to where the slightest frame rate hiccups have been nigh unnoticeable in our first few hours of play. The most crucial moments of battle and enemy management aren’t ruined by the on-screen action herking and jerking. This is met by some seriously quick loading times; getting from a cold boot to a loaded game save is rarely more than 60 seconds, and loading times between parts of the world are even faster.

The bad news, as can be seen in the gallery above, is that Witcher 3 on the Switch looks a lot more like Witcher 2. For starters, its apparent resolution is some of the blurriest we’ve ever seen on Switch in both docked and portable modes. While the results look comparable to Doom 2016, Witcher 3 is a much slower game, and it demands that you let your eyes linger over massive, dramatically lit landscapes and towns. The blur draped over all of that scenery is more noticeable than, say, a rapid-fire pulse of shotguns through demons’ faces.

Those landscapes are covered in foliage, a fact that impressed back in 2015 with CDPR’s dense rendering system working nearly as well on console as it did on PC. But that system’s polygon count and texture density have both been scaled back dramatically to get trees, shrubs, and other greenery working on Switch. This was probably done to preserve facial detail on pretty much every human character in the game, which is certainly a preferable compromise, but the disconnect between an emotionally brooding Geralt and a dinky, PlayStation 2-era wall of vines is one fans will have to accept if they want to marathon this version of Witcher 3 on the go.

Other major settings like shadow resolution, ground textures, and hair physics have also been scaled back, which you can argue is acceptable or annoying based on your personal preferences. The lower resolution of the Switch screen makes these downgrades a little more tolerable, in my opinion. But enough of the game’s geometry has been noticeably de-tuned that it stands out in the game’s lengthy, well-written cinema scenes (which, I should note, often struggle in the frame rate department, sometimes dipping into 10-15fps range).

One moment, the game will smother its scenery in some of the most handsome, pre-baked lighting effects you may have ever seen on Switch. The next moment, a tight zoom on Geralt and his allies stutters with texture pop-in and grungy foliage effects nearby. That kind of startling visual contrast shows up in this Switch port more than I expected.

Totally playable—just be warned

I don’t mean to say Witcher 3 is unplayable or ruined by the effort spent getting it into Switch-compatible shape. However, completely new players should be warned that CDPR’s cinematic vision for the game is compromised just enough to take this port out of my running for a clear-cut recommendation. If you’ve already played Witcher 3 and want an excuse to burn through it anew on the go, complete with convenient “fast forward to the expansions” shortcuts, then yes, this port is a great reason to return to Nilfgaard. If you don’t have any other consoles or a decent gaming PC, then “Switcher 3” is absolutely playable. (Plus, in my personal opinion, it’s better than Switch’s Skyrim as an on-the-go RPG, even with low resolutions and other visual compromises.)

But if you do have another hardware option and aren’t necessarily itching for a purely portable RPG, take a breath and look at other systems’ heavily discounted versions before making this your very first way to play the game.

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