An ancient earth inside Earth? Harvard scientists say YES

Dear readers and followers,

a study presented at the Goldschmidt conference in Sacramento, California, claims that the previously inexplicable isotope ratio from the depths of the Earth may be an “echo” of the ancient Earth that existed before the collision with another celestial body, which is estimated to have led to the formation of the Moon around 4,5 billion years ago.

According to the authors of the study, the ratio may represent a signal from a material that existed prior to the moment of the collision.

Scientists of the +Harvard University led by Associate Professor Sujoy Mukhopadhyay believe that only a portion of the Earth melted as a result of the collision, and that in the depths of our planet’s mantle there still exists a part of the ancient Earth.

Scientists have studied the isotope ratio of noble gases from the depths of the Earth’s mantle and compared it to the isotope ratio of the gases found closer to the surface. They found that the ratio of 3He to 22Ne from the surface layers of the mantle is much higher than the one of its deeper layers.

The analysis of the 129-Xenon and 130-Xenon ratio also confirms the hypothesis suggested by the researchers. Material which has been rendered to the surface from the deep mantle has a lower ratio than the one which is typically located near the surface.

Since the 129-Xenon is produced by the radioactive decay of 129-Iodine, these isotopes indicate thatthe ancient part of mantle was formed during the first 100 million years of the Earth’s evolution. Scientists believe that this theory explains the differences between the isotope ratios of noble gases in different parts of the Earth.

As Professor Mukhopadhyay said: “The geochemistry indicates that there are differences between the noble gas isotope ratios in different parts of the Earth, and these need to be explained. The idea that a very disruptive collision of the Earth with another planet-sized body, the biggest event in Earth’s geological history, did not completely melt and homogenize the Earth challenges some of our notions on planet formation and the energetics of giant impacts. If the theory is proven correct, then we may be seeing echoes of the ancient Earth, from a time before the collision“.

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NASA observed an asteroid collision creating a huge cloud: rocky planet creation ?

Dear readers and followers,

The NASA's telescope, called Spitzer Space Telescope (SST) has spotted an eruption of dust around a young star, possibly the result of a smashup between large asteroids. This type of collision can eventually lead to the formation of planets.

Credit image: +NASA Jet Propulsion Laboratory 

Scientists had been regularly tracking the star, called NGC 2547-ID8, when it surged with a huge amount of fresh dust between August 2012 and January 2013. While dusty aftermaths of suspected asteroid collisions have been observed by Spitzer before, this is the first time scientists have collected data before and after a planetary system smashup. The viewing offers a glimpse into the violent process of making rocky planets like ours.

Credit image: +NASA Jet Propulsion Laboratory / +The University of Arizona 

Rocky planets begin life as dusty material circling around young stars. The material clumps together to form asteroids that ram into each other. Although the asteroids often are destroyed, some grow over time and transform into proto-planets. After about 100 million years, the objects mature into full-grown, terrestrial planets. Our moon is thought to have formed from a giant impact between proto-Earth and a Mars-size object.

In the new study, Spitzer set its heat-seeking infrared eyes on the dusty star NGC 2547-ID8, which is about 35 million years old and lies 1,200 light-years away in the Vela constellation. Previous observations had already recorded variations in the amount of dust around the star, hinting at possible ongoing asteroid collisions. In hope of witnessing an even larger impact, which is a key step in the birth of a terrestrial planet, the astronomers turned to Spitzer to observe the star regularly. Beginning in May 2012, the telescope began watching the star, sometimes daily. A dramatic change in the star came during a time when Spitzer had to point away from NGC 2547-ID8 because our sun was in the way. When Spitzer started observing the star again five months later, the team was shocked by the data they received: a very thick cloud of dusty debris now orbits the star in the zone where rocky planets form. As the scientists observe the star system, the infrared signal from this cloud varies based on what is visible from Earth. For example, when the elongated cloud is facing us, more of its surface area is exposed and the signal is greater. When the head or the tail of the cloud is in view, less infrared light is observed. By studying the infrared oscillations, the team is gathering first-of-its-kind data on the detailed process and outcome of collisions that create rocky planets like Earth.

The team is continuing to keep an eye on the star with Spitzer. They will see how long the elevated dust levels persist, which will help them calculate how often such events happen around this and other stars, and they might see another smashup while Spitzer looks on.

Source: NASA

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