Category Astronomy/Space

Scientist...

Why are some rocks on the moon highly magnetic?

A large impact could have briefly amplified the moon’s weak magnetic field, creating a momentary spike that was recorded in some lunar rocks. Scientists may have solved the mystery of why the moon shows ancient signs of magnetism although it has no magnetic field today. An impact, such as from a large asteroid, could have generated a cloud of ionized particles that briefly enveloped the moon and amplified its weak magnetic field.

Where did the moon’s magnetism go? Scientists have puzzled over this question for decades, ever since orbiting spacecraft picked up signs of a high magnetic field in lunar surface rocks...

Besides particles like sterile neutrinos, axions and weakly interacting massive particles (WIMPs), a leading candidate for the cold dark matter of the universe are primordial black holes—black holes created from extremely dense conglomerations of subatomic particles in the first seconds after the Big Bang.

Primordial black holes (PBHs) are classically stable, but as shown by Stephen Hawking in 1975, they can evaporate via quantum effects, radiating nearly like a blackbody. Thus, they have a lifetime; it’s proportional to the cube of their initial mass. As it’s been 13.8 billion years since the Big Bang, only PBHs with an initial mass of a trillion kilograms or more should have survived to today.

However, it has been suggested that the lifetime of a black hole might be consider...

In the intriguing realm of star-forming galaxies, the key factor isn’t the total amount of gas but rather its strategic distribution within the galaxy.

Researchers at the International Centre for Radio Astronomy Research (ICRAR) made the discovery about galaxies by studying the gas distribution that helps create stars.

Using CSIRO’s ASKAP radio telescope located at Inyarrimanha Ilgari Bundara, the CSIRO Murchison Radio-astronomy Observatory, researchers explored the gas distribution in about 1,000 galaxies as part of the WALLABY survey.

Lead author Seona Lee, a PhD student at The University of Western Au...