Earth may hold vast resources of hydrogen fuel - now the race is on to extract it.

Hello and welcome to New Scientist’s weekly roundup of the best stories in science and technology. This week we’re talking about…

The gold hydrogen rush: Does Earth contain near-limitless clean fuel?

We know there are stores of hydrogen held within Earth which can be burned without producing carbon dioxide. If the estimates that the planet holds trillions of tonnes of such “gold hydrogen” are correct, tapping into it could dramatically accelerate the transition to net zero. Prospectors around the world are racing to find these natural reserves, but some are going a step further – one company in Oman is testing whether we can stimulate the ground to increase the amount of hydrogen being produced.

The Ingenuity helicopter’s Mars mission is over, but it left a legacy

The first helicopter to fly on another world has landed for the final time. NASA’s Ingenuity drone was intended to make just five flights, but it wildly outperformed its original mission, going for 72 flights over three years. Ingenuity scouted the Martian landscape for the Perseverance rover and proved that unmanned aircraft are a viable way to explore areas too treacherous for any rover to reach. After demonstrating how well a flying craft can work on another planet, several will follow in Ingenuity’s path, including the Dragonfly craft planned to launch to Saturn’s moon Titan in 2028.

AI can better retain what it learns by mimicking human sleep

To avoid a phenomenon in AI called “catastrophic forgetting” – in which models trained to do a new task lose the ability to carry out tasks they had previously mastered – researchers have found that having their AI mimic sleep can help. This includes having the AI take a break from training and review what it learned, similar to how humans consolidate memories while sleeping. The researchers also saw improvements when they included a period where the AI consumed data made by mashing together several concepts – for example, an animal identification model might be shown a giraffe crossed with a fish – which can imitate the complex way our brains work while dreaming.

More from New Scientist

• Ever seen a parrot scooting along a branch using its beak to hang on? Scientists have named this type of locomotion “beakiation”.
• Psychologist Pete Etchels on why we don’t need a digital detox – and why describing ourselves as “addicted” to our phones is counterproductive.
• Is there a new law of thermodynamics? We may need to at least supplement the second law in light of the finding that heating and cooling seem to be fundamentally different processes.

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Chelsea Whyte, US Editor.