Category Astronomy/Space

Early Earth’s Hot Mantle may have led to Archean ‘Water World’

An artist’s rendering of Earth during the Archean eon, with a hazy atmosphere, few landmasses and a global ocean. Credit: Alec Brenner, Harvard University

Earth’s sea level has remained fairly constant during the last 541 million years, but a new study suggests the planet may have been covered by a vast global ocean 4 to 3.2 billion years ago.

The new findings challenge earlier assumptions that the size of the Earth’s global ocean has remained constant over time and offer clues to how its size may have changed throughout geologic time, according to the study’s authors.

Most of Earth’s surface water exists in the oceans. But there is a second reservoir of water deep in Earth’s interior, in the form of hydrogen and oxygen attached to minerals in the mantle.

A new study in AGU ...

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Early Universe Explosion Sheds Light on Elusive Black Hole

Black hole Goldilocks
The new black hole was found through the detection of a gravitationally lensed gamma-ray burst. Image: Carl Knox, OzGrav.

Scientists discover one of the first black holes of its kind. Intermediate mass black holes (100 to 100,000 times the mass of the sun) have only been directly detected once before (LIGO, last year). They form an important link between the smaller black holes left behind after the deaths of stars, and the supermassive black holes which lurk in the hearts of every galaxy.

The astrophysicists also find that there are about 40,000 of these objects in the neighbourhood of our galaxy.

The recently discovered ‘Goldilocks’ black hole is part of a missing link between two populations of black holes: small black holes made from stars and supermassive giants in the nucle...

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String Theory Solves Mystery about How Particles Behave Outside a Black Hole Photon Sphere

An artist’s impression of a “string” passing near a black hole. As the string approaches the black hole, it is gradually stretched. Then, as it moves past the black hole, it begins to vibrate. The image to the left, which was captured by the Event Horizon Telescope, represents the shadow of the supermassive black hole at the center of the galaxy M87, including the ring of light around it. (Credit: EHT Collaboration; Kavli IPMU (Kavli IPMU modified EHT’s original image)).

A paper by the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) Director Ooguri Hirosi and Project Researcher Matthew Dodelson on the string theoretical effects outside the black hole photon sphere has been selected for the “Editors’ Suggestion” of the journal Physical Review D...

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Stellar Eggs near Galactic Center hatching into Baby Stars

ALMA pseudo-color composite image of the gas outflows from stellar eggs in the Galactic Center region. Gas moving toward us is shown in blue and gas moving away from us is shown in red. Credit: ALMA (ESO/NAOJ/NRAO), Lu et al

Astronomers found a number of stellar eggs containing baby stars around the center of the Milky Way using the Atacama Large Millimeter/submillimeter Array (ALMA). Previous studies had suggested that the environment there is too harsh to form stars. These findings indicate that star formation is more resilient than researchers thought.

Stars form in stellar eggs, cosmic clouds of gas and dust which collapse due to gravity. If something interferes with the gravity driven contraction, star formation will be suppressed...

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