Category Astronomy/Space

An Inconstant Hubble Constant? Research suggests fix to cosmological cornerstone

Pictured is the supernova of the type Ia star 1994D, in galaxy NGC 4526. The supernova is the bright spot in the lower left corner of the image. Image credit: ESA/Hubble

More than 90 years ago, astronomer Edwin Hubble observed the first hint of the rate at which the universe expands, called the Hubble constant. Almost immediately, astronomers began arguing about the actual value of this constant, and over time, realized that there was a discrepancy in this number between early universe observations and late universe observations.

Early in the universe’s existence, light moved through plasma – there were no stars yet – and from oscillations similar to sound waves created by this, scientists deduced that the Hubble constant was about 67...

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Rare 4,000-year Comets can cause Meteor Showers on Earth

The meteoroid stream of long-period comet Thatcher from CAMS data. Outer blue ellipse is the orbit of Neptune. Photo: P. Jenniskens / SETI Institute

Researchers report that they can detect showers from the debris in the path of comets that pass close to Earth orbit and return as infrequently as once every 4,000 years.

Comets that circle the Sun in very elongated orbits spread their debris so thin along their orbit or eject it out of the solar system altogether that their meteor showers are hard to detect. From a new meteor shower survey published in the journal Icarus, researchers now report that they can detect showers from the debris in the path of comets that pass close to Earth orbit and are known to return as infrequent as once every 4,000 years.

“This creates a situational ...

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Alien Radioactive Element Prompts Creation Rethink

This false-colour composite from NASA Spitzer Space Telescope and NASA Chandra X-ray Observatory shows the remnant of N132D. Credit: NASA/JPL-Caltech/Harvard-Smithsonian CfA. 

The first-ever discovery of an extraterrestrial radioactive isotope on Earth has scientists rethinking the origins of the elements on our planet.

The tiny traces of plutonium-244 were found in ocean crust alongside radioactive iron-60. The two isotopes are evidence of violent cosmic events in the vicinity of Earth millions of years ago.

Star explosions, or supernovae create many of the heavy elements in the periodic table, including those vital for human life, such as iron, potassium and iodine.

To form even heavier elements, such as gold, uranium and plutonium it was thought that a more violent event ma...

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Stunning Simulation of Stars being Born is most realistic ever

Snapshot from the first full STARFORGE simulation. Nicknamed the “Anvil of Creation,” a giant molecular cloud with individual star formation and comprehensive feedback, including protostellar jets, radiation, stellar winds and core-collapse supernovae.

First high-resolution model to simulate an entire gas cloud where stars are born. A team including Northwestern University astrophysicists has developed the most realistic, highest-resolution 3D simulation of star formation to date. The result is a visually stunning, mathematically-driven marvel that allows viewers to float around a colorful gas cloud in 3D space while watching twinkling stars emerge.

Called STARFORGE (Star Formation in Gaseous Environments), the computational framework is the first to simulate an entire gas cloud — 1...

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