UFO'S of UAP'S, ASTRONOMIE, RUIMTEVAART, ARCHEOLOGIE, OUDHEIDKUNDE, SF-SNUFJES EN ANDERE ESOTERISCHE WETENSCHAPPEN

BY MATT WILLIAMS

Artistic rendition of the Chicxulub impactor striking ancient Earth, with Pterosaur observing. Could pieces of the same impact swarm have hit the Moon, too?

Credit: NASA

For decades, scientists have theorized that a massive impact caused the Cretaceous-Paleogene extinction event. This event occurred about 66 million years ago and caused the mass extinction of about 75% of all plant and animal species on Earth (including the non-avian dinosaurs). With the discovery of the massive Chicxulub crater in the Yucatan Peninsula (southern Mexico) in the 1970s, scientists concluded that they’d found the impact responsible. Based on all the available data, the Chicxulub Impact event is believed to have been as powerful as 100,000 billion metric tons (110,231 U.S tons) of TNT.

This blast was more powerful than all the nuclear devices in the world combined and sent an estimated 25 trillion metric tons (~27.5 US tons) of hot dust, ash, and steam into the atmosphere, creating a global winter. But according to new research led by the University of Michigan, an international team of geologists has determined that the impact also created a global tsunami. According to their findings, this tsunami was 30,000 times more powerful than the 2004 Indian Ocean tsunami, one of the largest and most devastating tsunamis on record.

The team was by Molly M. Range, a with the Department of Earth and Environmental Sciences at the University of Michigan, Ann Arbor. She was joined by an international team of researchers from the NOAA’s Pacific Marine Environmental Lab (PMEL) and Geophysical Fluid Dynamics Laboratory (GFDL), the Institute of Environmental Geosciences (IGE), the Geophysics and Spatial Oceanography Studies Laboratory (LEGOS), the University Corporation for Atmospheric Research (UCAR), the PALEOMAP Project, and multiple universities.

The maximum sea surface perturbation heights of the global tsunami.

Credit: Range, M. (et al.)/AGU Advances

To recap, evidence of the Chicxulub Impact is traced to the crater buried beneath the Yucatan Peninsula of southern Mexico. The crater measures 180 km (110 mi) in diameter and 20 km (12 mi) in depth and is centered offshore near the community of Chicxulub (from which it takes its name). Based on the crater’s dimensions, scientists estimate that the meteor that caused it measured about 14 km (8.7 mi) in diameter. Evidence of the impact is also found in the geological record in the form of deposits of iridium and other impact ejecta that were globally distributed.

This led to the scientific consensus that the impact that led to the Chicxulub crater was responsible for the Cretaceous-Paleogene extinction and possibly the volcanic activity that created the Deccan flood basalt in India. For the sake of their study, Range and her colleagues sought to determine the effects this impact had on the world’s oceans, from the initial moment of contact to the point where it became a global tsunami. To do this, the team created the first global simulation of this impact using hydrocode (which models fluid systems in 3D) and a shallow-water ocean model.

As study co-author Brian Arbic – a researcher with the University of Michigan (Ann Arbor), the IGE, and LEGO – told Universe Today via email, the simulation involved three steps. In the first step, the hydrocode was run by co-author Brandon Johnson (Purdue University) and simulated the first ten minutes of the impact. During this time, explained Arbic, the effects were nothing short of cataclysmic:

“[M]aterial from the asteroid, the underlying bedrock of the Earth, sediment, and ocean was displaced tens of kilometers above the atmosphere and (in the other direction) tens of kilometers below the Earth’s surface – in other words, a great big hole was dug out of the Earth. A massive crater was created by this impact, as well as an outward propagating “rim wave”. Most of the energy in the tsunami is due to the rim wave, but there is also a significant secondary effect due to water rushing back into the crater that the impact created.”

The maximum flow velocity of the global tsunami at each grid cell (b).

Credit: Range, M. (et al.)/AGU Advances

The second step was performed by Range as part of her Master’s Thesis at the University of Michigan, Ann Arbor. This consisted of putting the output of the hydrocode into two global shallow-water tsunami propagation models. These included the Modular Ocean Model 6 (MOM6), developed by co-author Alistair J. Adcroft (a research oceanographer from Princeton University), and the Method of Splitting Tsunami (MOST) developed by co-author Vasily Titov – a senior tsunami modeler at the NOAA’s Pacific Marine Environmental Lab.

“Vasily simulated the tsunami with MOST, and the results are fairly similar to those obtained with MOM6,” said Arbic. “Obtaining similar results from two different models gave us more confidence in our results. We will examine differences between shallow-water models and other models in future work.”

The third step consisted of co-author Ted Moore – a Professor Emeritus at the University of Michigan, Ann Arbor – examining the geological record of the Cretaceous-Paleogene boundary for signs of sediment erosion. This revealed that more erosion occurred in the North Atlantic and South Pacific basins than in the South Atlantic and North Pacific. In short, the geological record shows that the seafloor in these regions was eroded and scoured more aggressively, with flow velocities of about 100 meters per second (360 km/h; 224 mph).

Moreover, the model showed that the wavefront propagation velocities, the speed at which waves formed on the surface, were about 200 meters per second (720 km/h; 447 mph). This is consistent with what the team’s model predicted and constitutes the best observational evidence of a global tsunami at the Cretaceous-Paleogene boundary. Their results also indicate that the Cretaceous-Paleogene tsunami was several orders of magnitude more powerful than any observed in recorded history. As Range described it, the effects of the impact were seen worldwide:

“It was a global impact. The tsunami was seen across the globe in 48 hours. Most coastal regions saw waves hit the coastline. Depending on where you look, wave heights could be from 1 meter to hundreds of meters tall. At ten minutes post-impact, the wave that had formed in the Gulf of Mexico was 1.5 km tall. This tsunami has 30,000 times the energy of the 2004 Indian Ocean Tsunami.”

Plate reconstruction and drill site locations (circled) at the age of the K/Pg boundary, showing continental blocks (gray), and modern continental outlines (red), where the K/Pg tsunami was most violent (green).

Credit: Range, M. (et al.)/AGU

This research provides additional insight into one of the most important events in geological history. In addition, said Range, the research has significant implications for planetary defense:

“The Chicxulub event had many important impacts, which have been previously documented – fires, wild swings of temperature (both very hot and very cold), destruction and eventual resetting of the predominant forms of life on Earth, and more. The tsunami was another important impact, and we plan to continue studying this tsunami and its impacts on the geological record that we can still examine. Impacts from large asteroids and meteors could happen again, which is why NASA recently ran the DART mission to see if they could be deflected.”

The paper that describes their findings, titled “The Chicxulub Impact Produced a Powerful Global Tsunami,” recently appeared in the journal AGU Advances.

Further Reading: AGU Advances

{ https://www.universetoday.com/ }

BY EVAN GOUGH

This artist’s impression shows an ultra-hot exoplanet as it is about to transit in front of its host star. Using the ESPRESSO instrument of ESO’s Very Large Telescope, astronomers have found the heaviest element yet in an exoplanet's atmosphere, barium, in the two ultra-hot Jupiters WASP-76 b and WASP-121 b.

Image Credit: ESO

Astronomers have spotted barium in the atmosphere of a distant exoplanet. With its 56 protons, you have to run your finger further down the periodic table than astronomers usually do to find barium. What does finding such a heavy element in an exoplanet atmosphere mean?

It means we’re still learning how strange exoplanets can be.

We’ve made a lot of progress in exoplanet science since astronomers discovered the first ones in the mid-1990s; we now know of thousands of them. In 2001, researchers using Hubble data were the first to observe an exoplanet atmosphere, identifying sodium. Some said it was lucky and wouldn’t happen again. Boy, were they wrong.

Now we have the power to characterize exoplanet atmospheres in more detail than ever. One of our most powerful telescopes is the European Southern Observatory’s (ESO) Very Large Telescope (VLT.) A new study based on observations with the VLT and its ESPRESSO (Echelle SPectrograph for Rocky Exoplanet and Stable Spectroscopic Observations) instrument presents evidence of barium in the atmosphere of the two ultra-hot gas giants.

The study is “Detection of Barium in the atmospheres of ultra-hot gas giants WASP-76b & WASP-121b.” The lead author is Tomás Azevedo Silva, a Ph.D. student at the University of Porto and the Instituto de Astrofísica e Ciências do Espaço (IA) in Portugal. The journal Astronomy and Astrophysics published the research.

WASP-76b and WASP-121b are both ultra-hot Jupiters. WASP-76b has been in the news because of the reported detection of iron in its atmosphere and the possibility that this tidally-locked planet experiences iron rain. Follow-up studies presented other explanations for the data, but the planet is still of great interest to exoplanet scientists.

This illustration of WASP-76b is based on data available in May 2020. As an object of high interest, data keeps coming in.

Image Credit: By Trurle – Own work, CC BY-SA 4.0,

https://commons.wikimedia.org/w/index.php?curid=89954341

WASP-121b is also noteworthy. It’s the first exoplanet where researchers found water vapour in its stratosphere. Both planets are extremely close to their stars and have orbital periods of less than two days. Both planets orbit stars similar to the Sun, with surface temperatures above 1000 C (1830 F.).

Artist’s concept of the hot Jupiter WASP-121b. A new study finds barium in its atmosphere. Image generated using Engine House VFX.

Credit: Bristol Science Centre/University of Exeter

Both of these planets are known for having exotic atmospheres, but the discovery of barium has intensified interest in them. There’s no ready explanation for barium in the upper atmosphere of the planets. “The puzzling and counterintuitive part is: why is there such a heavy element in the upper layers of the atmosphere of these planets?” said lead author Azevedo Silva.

Both Jupiter-sized planets have powerful gravity that should draw heavy elements like barium to their surfaces. But instead, the barium, which is even heavier than iron, is aloft in the upper atmospheres of both planets. “Given the high gravity of the planets, we would expect heavy elements like barium to quickly fall into the lower layers of the atmosphere,” explained co-author Olivier Demangeon, another researcher from the University of Porto and IA.

Barium isn’t up there by itself. These planets’ atmospheres are exotic mixtures of chemicals alien to our atmosphere. The researchers weren’t looking for barium when they found it; they were studying the strange atmospheres as part of their effort to constrain the atmospheric composition and dynamics. They also wanted to lay the “… groundwork for new research regarding their formation and evolution environments,” as they state in their paper.

“This was in a way an ‘accidental’ discovery,” says Azevedo Silva. “We were not expecting or looking for barium in particular and had to cross-check that this was actually coming from the planet since it had never been seen in any exoplanet before.” The team also found vanadium, lithium, manganese, and other elements in the atmospheres. But barium is the heaviest element ever found in an exoplanet atmosphere.

The two planets in the study lend themselves well to atmospheric research. Is finding barium in these atmospheres a signal that we can expect to find them in other ultra-hot Jupiters? Maybe. “Both WASP-76b and WASP-121b represent some of the highest S/N datasets currently available, the presence in both of the studied planets may indicate that this heavy species can be common in the atmospheres of ultra-hot Jupiters,” the paper states.

There’s no barium in Earth’s atmosphere unless we’re watching a fireworks display. How did it get into the upper atmosphere of these planets? “At the moment, we are not sure what the mechanisms are,” explained Demangeon.

The team doesn’t overextend themselves when it comes to those mechanisms. In their paper they write, “The presence of these heavy ionized species at high altitudes in the atmospheres of ultra hot Jupiters may be evidence of unexpected atmospheric dynamics.” Further research will uncover what those dynamics are. Who knows what discoveries are waiting for us in these atmospheres?

Planetary escape may play a role in the detection. Is an unknown mechanism driving heavy elements away? The observations show that the calcium detected on WASP-121b appears to extend beyond the planet’s Roche Lobe. “Finally, we also confirm the clear asymmetric absorption feature of Ca+ on WASP-121b, with an excess absorption at the bluer wavelengths and an effective planet radius beyond the Roche-Lobe, hinting that the signal may arise from planetary atmospheric escape.”

This won’t be the last team of researchers to study these planets. Giant gaseous planets close to their stars present an excellent opportunity to study their atmospheres as their starlight passes through them. And since the orbital period is less than two days, both planets are readily observed with powerful telescopes and instruments. “Being gaseous and hot, their atmospheres are very extended and are thus easier to observe and study than those of smaller or cooler planets,” said Demangeon.

There’s reason for some caution around these results, though. When researchers discovered iron at WASP-76b, and that the iron could possibly fall as rain, people noticed. It isn’t easy to envision a world so different from ours that it can rain iron. But that iron rain discovery was called into question by another study. At this time, scientists aren’t sure if there is iron rain.

Will further research question this barium detection?