Galaxies Without Dark Matter

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Four years ago, peter van doccam observed to unusual galaxies that seemd to lack dark matter. Many researches were critical of it, questioning how such galaxies could form without dark matters pull. Well, this week in nature, peter has a new paper that looks at those galaxies in detail and makes another bold claim about how they formed. And it involved something called a bullet collision. What happens is the gas stays behind and is separated from the original galaxies. And that gas enterns stars. So you get these pristine galaxies formed in one longo effectively out of this gas that was left behind in the collision.

00:47 The mystery of the missing dark matter

Dark matter makes up most of the matter in the Universe, and is thought to be needed for galaxies to form. But four years ago, astronomers made a perplexing, and controversial discovery: two galaxies seemingly devoid of dark matter. This week the team suggests that a cosmic collision may explain how these, and a string of other dark-matter-free galaxies, could have formed.

Research article: van Dokkum et al.

News and Views: Giant collision created galaxies devoid of dark matter

08:39 Research Highlights

How fossil fuel burning has caused levels of helium to rise, and a high-efficiency, hybrid solar-energy system.

Research Highlight: Helium levels in the atmosphere are ballooning

Research Highlight: Flower power: ‘Sunflower’ system churns out useful energy

10:49 Researchers experiences of the war in Ukraine

We hear the stories of scientists whose lives have been affected by Russia’s invasion of Ukraine, including researchers who have become refugees, soldiers and activists in the face of a horrifying conflict.

Nature Feature: How three Ukrainian scientists are surviving Russia’s brutal war

20:46 Imaging the black hole at the centre of the Milky Way

Last week, a team of researchers released an image of Sagittarius A*, the supermassive blackhole at the centre of our galaxy. We hear how they took the image and what it is revealing about these enormous objects.

Nature News: Black hole at the centre of our Galaxy imaged for the first time

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