Earth Chgs Scientists say giant pieces of ancient alien planet may be lodged under Earth’s surface

marsh

TB Fanatic

Scientists say giant pieces of ancient alien planet may be lodged under Earth’s surface
“Theia” may have slammed into the early Earth and caused the formation of the Moon
Image
Artist interpretation of Theia's impact on the Earth.

Artist interpretation of Theia's impact on the Earth.
(Stocktrek Images/Getty)

By Daniel Payne
Updated: April 3, 2021 - 8:06pm

Scientists seeking to explain a series of seemingly inexplicable formations deep within the Earth’s surface may have found an explanation: They came from outer space.

Researchers with Arizona State University’s School of Earth and Space Exploration said in a recently published paper that the “continent-sized Large Low Shear Velocity provinces” identified in Earth’s mantle—essentially giant formations of rock the origins of which scientists have struggled for decades to explain—may have been formed by Theia, the proto-planet thought to have slammed into the ancient Earth billions of years ago.

The collision between Earth and Theia is hypothesized to have ejected a significant portion of Earth into outer space; those fragments would have eventually coalesced under Earth’s gravity to form the Moon.

In the paper, the Arizona State researchers argue that “the left-over Theia mantle materials may [have sunk] to the bottom of Earth’s mantle and cause[d] the LLSVPs.”

Theia’s geological mantle, they argue, may have been “several percent intrinsically denser than Earth’s mantle,” leading it to sink down through the Earth and form the mysterious provinces.
The Theia impact theory is widely regarded as the prevailing explanation for the Moon’s origin.
 

tanstaafl

Has No Life - Lives on TB
As I think Carl Sagan used to say, more-or-less, we're all literally made up in part of "star stuff" (that is, atoms that came from other stars). We've had at least two known interstellar interlopers inside our Solar System in recent years, including a small one that may have impacted Earth. So why should it come as a surprise to anyone that there might be foreign material as part of the Earth? Although Theia came from our own Solar System and isn't exactly "alien" (more like a wayward relative).
 

West

Senior nut
As I think Carl Sagan used to say, more-or-less, we're all literally made up in part of "star stuff" (that is, atoms that came from other stars). We've had at least two known interstellar interlopers inside our Solar System in recent years, including a small one that may have impacted Earth. So why should it come as a surprise to anyone that there might be foreign material as part of the Earth? Although Theia came from our own Solar System and isn't exactly "alien" (more like a wayward relative).
Wayward relative or a siamese birth?

:D
 

tanstaafl

Has No Life - Lives on TB
Wayward relative or a siamese birth?
I suspect you were just trying to be funny, but you may actually have a case. After all, Pluto and Charon are really a binary astronomical object since as far as I know Charon orbits a point outside the body of Pluto. I don't know about them if there are other large-sized main body/moon(s) in the Solar System that currently do that, although there are probably some smaller objects doing it (but I'm talking about the ones big enough to form more-or-less rounded objects). My point is that if it's actively happening today then I imagine it could have happened to other objects (including Earth) in our Solar System during the last six billion years or so.
 

packyderms_wife

Neither here nor there.
At some point one of the Milky Ways satellite galaxies crashed into the MW and part of it was absorbed. What I've heard postulated is that our solar system was a part of Sagittarius ( I don't know if it was Sat alpha or Sat beta, yes there's more than one), not the MW.
 

packyderms_wife

Neither here nor there.
No link it came up in the google smirch.

Astronomers have known that Sagittarius repeatedly smashes through the Milky Way's disk, as its orbit around the galaxy's core tightens as a result of gravitational forces. Previous studies suggested that Sagittarius, a so-called dwarf galaxy, had had a profound effect on how stars move in the Milky Way.Jun 4, 2020

Sagittarius-collisions.jpeg

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packyderms_wife

Neither here nor there.
.
Did galactic crash trigger solar system formation?
Posted by EarthSky in SPACE | June 4, 2020

The formation of the sun, the solar system and the subsequent emergence of life on Earth may be a consequence of a collision between our galaxy – the Milky Way – and a smaller galaxy called Sagittarius.

Animated diagram of small oval galaxy orbiting around and through large spiral galaxy.


The Sagittarius dwarf galaxy has been orbiting the Milky Way for billions for years. As its orbit around the 10,000 times more massive Milky Way gradually tightened, it started colliding with our galaxy’s disk. The three known collisions between Sagittarius and the Milky Way have, according to a new study, triggered major star formation episodes, one of which may have given rise to the solar system. Image via ESA.

Via European Space Agency (ESA)

The formation of the sun, the solar system and the subsequent emergence of life on Earth may be a consequence of a collision between our galaxy, the Milky Way, and a smaller galaxy called Sagittarius, discovered in the 1990s to be orbiting our galactic home. That’s according to a new study published May 25, 2020, in the peer-reviewed journal Nature Astronomy.

Astronomers have known that Sagittarius repeatedly smashes through the Milky Way’s disk, as its orbit around the galaxy’s core tightens as a result of gravitational forces. Previous studies suggested that Sagittarius, a so-called dwarf galaxy, had had a profound effect on how stars move in the Milky Way. Some astronomers even claim that the 10,000 times more massive Milky Way’s trademark spiral structure might be a result of the at least three known crashes with Sagittarius over the past six billion years.

The new study, based on data gathered by ESA’s galaxy mapping Gaia spacecraft, revealed for the first time that the influence of Sagittarius on the Milky Way may be even more substantial. The ripples caused by the collisions seem to have triggered major star formation episodes, one of which roughly coincided with the time of the formation of the sun some 4.7 billion years ago.

Astrophysicist Tomás Ruiz-Lara of the Instituto de Astrofísica de Canarias in Tenerife, Spain, is lead author of the study. He said in a statement:

It is known from existing models that Sagittarius fell into the Milky Way three times – first about five or six billion years ago, then about two billion years ago, and finally one billion years ago.
When we looked into the Gaia data about the Milky Way, we found three periods of increased star formation that peaked 5.7 billion years ago, 1.9 billion years ago and 1 billion years ago, corresponding with the time when Sagittarius is believed to have passed through the disk of the Milky Way.
Six images of large galaxy with smaller galaxy at different positions in its orbit.


The Sagittarius dwarf galaxy has been orbiting the Milky Way for billions for years. As its orbit around the 10,000 times more massive Milky Way gradually tightened, it started colliding with our galaxy’s disk. The 3 known collisions between Sagittarius and the Milky Way have, according to a new study, triggered major star formation episodes, one of which may have given rise to the solar system. Image via ESA.

Ripples on the water
The researchers looked at luminosities, distances and colors of stars within a sphere of about 6,500 light-years around the sun and compared the data with existing stellar evolution models. According to Ruiz-Lara, the notion that the dwarf galaxy may have had such an effect makes a lot of sense. He said:
At the beginning you have a galaxy, the Milky Way, which is relatively quiet. After an initial violent epoch of star formation, partly triggered by an earlier merger as we described in a previous study, the Milky Way had reached a balanced state in which stars were forming steadily. Suddenly, you have Sagittarius fall in and disrupt the equilibrium, causing all the previously still gas and dust inside the larger galaxy to slosh around like ripples on the water.
In some areas of the Milky Way, these ripples would lead to higher concentrations of dust and gas, while emptying others. The high density of material in those areas would then trigger the formation of new stars. Carme Gallart, also of the Instituto de Astrofísica de Canarias, is a co-author of the paper. Gallart said:
It seems that not only did Sagittarius shape the structure and influence the dynamics of how stars are moving in the Milky Way, it has also led to a build-up of the Milky Way. It seems that an important part of the Milky Way’s stellar mass was formed due to the interactions with Sagittarius and wouldn’t exist otherwise.
The birth of the sun
In fact, it seems possible that even the sun and its planets would not have existed if the Sagittarius dwarf had not gotten trapped by the gravitational pull of the Milky Way and eventually smashed through its disk. Gallart said:

The sun formed at the time when stars were forming in the Milky Way because of the first passage of Sagittarius. We don’t know if the particular cloud of gas and dust that turned into the sun collapsed because of the effects of Sagittarius or not. But it is a possible scenario because the age of the sun is consistent with a star formed as a result of the Sagittarius effect.
Every collision stripped Sagittarius of some of its gas and dust, leaving the galaxy smaller after each passage. Existing data suggest that Sagittarius might have passed through the Milky Way’s disk again quite recently, in the last few hundred million years, and is currently very close to it. In fact, the new study found evidence of a recent burst of star formation, suggesting a possible new and ongoing wave of stellar birth.

Bottom line: A new study suggests that the formation of the sun and the solar system may be a consequence of a collision between our Milky Way galaxy and a smaller galaxy called Sagittarius.

Source: The recurrent impact of the Sagittarius dwarf on the Milky Way star formation history
Read more from ESA
 

packyderms_wife

Neither here nor there.
an older article, it's still interesting.


Milky Way's Galactic Gobbling Leaves Star 'Crumbs'
By Space.com Staff December 05, 2011

  • Sagittarius Galaxy Star Streams


Artist's concept of the four tails of the Sagittarius dwarf galaxy (orange clump on left of the image) orbiting the Milky Way. The bright yellow circle to the right of the Milky Way's center is our sun (not to scale). We can see the Sagittarius galaxy's star tails stretching across the sky. (Image credit: Amanda Smith, Institute of Astronomy, University of Cambridge )

Our Milky Way galaxy is a messy eater, leaving streams of star "crumbs" spread across the sky after chomping its smaller neighbors, a new study reports.

Astronomers have found two such streams emanating from the Sagittarius dwarf galaxy, torn off by the Milky Way's huge gravitational pull. The two newfound star tails are in the southern galactic hemisphere, and they meet up with two others previously known from Sagittarius in the northern galactic hemisphere.

"Sagittarius is like a beast with four tails," study co-author Wyn Evans, of the University of Cambridge in the United Kingdom, said in a statement.


Sagittarius used to be one of the brightest of the Milky Way's satellite galaxies. But the Milky Way's immense gravity has torn it apart, dispersing half of Sagittarius' stars and virtually all of its gas over the last billion years or so, researchers said. [Video: Milky Way Shreds Dwarf Galaxy into Four Star Streams]

Before the new study, Sagittarius was known to have two tails, both in the northern galactic sky. In 2006, astronomers noticed that one of these tails was forked in two.

"That was an amazing discovery," said lead author Vasily Belokurov, also of the University of Cambridge. "But the remaining piece of the puzzle, the structure in the south, was missing until now."

To solve the puzzle, Belokuroz and his team analyzed data from the latest Sloan Digital Sky Survey (known as SDSS-III), which uses an 8.2-foot (2.5-meter) telescope in New Mexico to scan the heavens.

The researchers looked at maps of more than 13 million stars, eventually spotting the two new star streams branching off from Sagittarius. One stream is fatter and brighter than the other, and it's more enriched with iron and other metals than its dimmer companion, researchers said.

Because each succeeding generation of stars produces and distributes more metals than the last, the team concluded that the brighter stream is younger than the fainter one.

The team submitted its findings to the Astrophysical Journal, and posted its study on the physics and astronomy site arXiv Nov. 30.

Splitting of the star streams

The researchers aren't sure what caused the galaxy's star tails to split. One possibility, they said, is that Sagittarius was once part of a binary galactic system, like the present-day Small and Large Magellanic Clouds. Sagittarius and its putative partner could each have generated a leading and trailing tail upon falling into the Milky Way, yielding four streams in total.

A collision with a massive clump of dark matter or another satellite galaxy could also have split each of the streams into two, researchers said.

Finally, another theory posits that debris from the chomped-on Sagittarius may have simply spread into different streams at different points in time, the result of different epochs having different patterns of galactic wobble and movement.

However the streams took their final shape, researchers said, they provide further evidence that our Milky Way galaxy has devoured up a number of its smaller neighbors that strayed too close.

Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcom and on Facebook.
Join our Space Forums to keep talking space on the latest missions, night sky and more! And if you have a news tip, correction or comment, let us know at: community@space.com.
 

packyderms_wife

Neither here nor there.
Maybe some peoples strong sense of entitlement is galactic in origins? :xpnd:


The Milky Way kidnapped several tiny galaxies from its neighbor

Date:October 10, 2019Source:University of California - RiversideSummary:A team of astronomers has discovered that several of the small -- or 'dwarf' -- galaxies orbiting the Milky Way were likely stolen from the Large Magellanic Cloud, including several ultrafaint dwarfs, but also relatively bright and well-known satellite galaxies, such as Carina and Fornax.Share:
FULL STORY

Just like the moon orbits the Earth, and the Earth orbits the sun, galaxies orbit each other according to the predictions of cosmology.

For example, more than 50 discovered satellite galaxies orbit our own galaxy, the Milky Way. The largest of these is the Large Magellanic Cloud, or LMC, a large dwarf galaxy that resembles a faint cloud in the Southern Hemisphere night sky.
A team of astronomers led by scientists at the University of California, Riverside, has discovered that several of the small -- or "dwarf" -- galaxies orbiting the Milky Way were likely stolen from the LMC, including several ultrafaint dwarfs, but also relatively bright and well-known satellite galaxies, such as Carina and Fornax.

The researchers made the discovery by using new data gathered by the Gaia space telescope on the motions of several nearby galaxies and contrasting this with state-of-the-art cosmological hydrodynamical simulations. The UC Riverside team used the positions in the sky and the predicted velocities of material, such as dark matter, accompanying the LMC, finding that at least four ultrafaint dwarfs and two classical dwarfs, Carina and Fornax, used to be satellites of the LMC. Through the ongoing merger process, however, the more massive Milky Way used its powerful gravitational field to tear apart the LMC and steal these satellites, the researchers report.

"These results are an important confirmation of our cosmological models, which predict that small dwarf galaxies in the universe should also be surrounded by a population of smaller fainter galaxy companions," said Laura Sales, an assistant professor of physics and astronomy, who led the research team. "This is the first time that we are able to map the hierarchy of structure formation to such faint and ultrafaint dwarfs."

The findings have important implications for the total mass of the LMC and also on the formation of the Milky Way.
"If so many dwarfs came along with the LMC only recently, that means the properties of the Milky Way satellite population just 1 billion years ago were radically different, impacting our understanding of how the faintest galaxies form and evolve," Sales said.

Study results appear in the November 2019 issue of the Monthly Notices of the Royal Astronomical Society.

Dwarf galaxies are small galaxies that contain anywhere from a few thousand to a few billion stars. The researchers used computer simulations from the Feedback In Realistic Environments project to show the LMC and galaxies similar to it host numerous tiny dwarf galaxies, many of which contain no stars at all -- only dark matter, a type of matter scientists think constitutes the bulk of the universe's mass.

"The high number of tiny dwarf galaxies seems to suggest the dark matter content of the LMC is quite large, meaning the Milky Way is undergoing the most massive merger in its history, with the LMC, its partner, bringing in as much as one third of the mass in the Milky Way's dark matter halo -- the halo of invisible material that surrounds our galaxy," said Ethan Jahn, the first author of the paper and a graduate student in Sales' research group.

Jahn explained that the number of tiny dwarf galaxies the LMC hosts may be higher than astronomers previously estimated, and that many of these tiny satellites have no stars.

"Small galaxies are hard to measure, and it's possible that some already-known ultrafaint dwarf galaxies are in fact associated with the LMC," he said. "It's also possible that we will discover new ultrafaints that are associated with the LMC."
Dwarf galaxies can either be satellites of larger galaxies, or they can be "isolated," existing on their own and independent of any larger object. The LMC used to be isolated, Jahn explained, but it was captured by the gravity of the Milky Way and is now its satellite.
"The LMC hosted at least seven satellite galaxies of its own, including the Small Magellanic Cloud in the Southern Sky, prior to them being captured by the Milky Way," he said.
Next, the team will study how the satellites of LMC-sized galaxies form their stars and how that relates to how much dark matter mass they have.
"It will be interesting to see if they form differently than satellites of Milky Way-like galaxies," Jahn said.
 

packyderms_wife

Neither here nor there.
Original article from 2016
.


Scientists are saying Earth is made up of two planets that violently collided over 4 billion years ago

Kayleigh Lewis,
The Independent
Feb 2, 2016, 3:59 AM


Joaquin from space


Copyright: 2015 EUMETSATA "violent, head-on collision" created Earth as we know it, ground-breaking new research has revealed.

A planetary embryo called Theia, thought to be around the size of Mars or Earth, collided with Earth 4.5 billion years ago when our planet was just 100 million years old.

It was already known that Theia and Earth collided, but the new evidence from the UCLA-led scientific team shows it was less of a side swipe, as previously thought, and more of a "head-on assault".

The force of the impact resulted in early Earth and Theia, together to form a single planet, with a piece breaking off and entering its gravitational pull to form the moon.

Researchers studied moon rocks from three Apollo missions and compared them with volcanic rocks found in Hawaii and Arizona.

To their surprise, no difference was found in the oxygen isotopes and it was established that the rocks from each shared chemical signatures.

Edward Young, lead author of the new study and a UCLA professor of geochemistry and cosmochemistry, said, “We don’t see any difference between the Earth’s and the moon’s oxygen isotopes; they’re indistinguishable.

“Theia was thoroughly mixed into both the Earth and the moon, and evenly dispersed between them. This explains why we don’t see a different signature of Theia in the moon versus the Earth.”

According to Professor Young, Theia was growing and would likely have become a planet, had it not been destroyed in the collision.

The research, funded by Nasa, the Deep Carbon Observatory and a European Research Council advanced grant (ACCRETE) andpublished in the journal Science, also raised questions about Earths origins.

They include, whether the collision would have removed any water contained by Earth - before asteroids rich in water hit our planet tens of millions of years later.

Read the original article on The Independent. Copyright 2016. Follow The Independent on Twitter.
 
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