Yearly round-up: The biggest science stories of 2024

As humanity completed another revolution around the Sun, the march of progress continued, with science throwing up some fascinating findings this year.

With 2024 coming to an end, we take a look at some of the biggest stories in the world of science this year.

The hottest year on record

A polar bear rests on ice cubes that were brought to its enclosure during a heatwave at Prague Zoo in Prague, Czech Republic, July 10, 2024.

A science 'story' which perhaps escaped no one—2024, if you didn't already know, was the hottest year since global records began in 1850.

As heatwaves and extreme weather events gripped the world, scientists warned that 2024 would end with it being the first year in which the Earth is more than 1.5 degrees Celsius hotter than it was in the 1850-1900 pre-industrial period, when industrial scale burning of fossil fuels began.

According to the European climate agency Copernicus, the world experienced an average of 41 more days of extreme heat in 2024 due to climate change

Prior to this, 2023 was the hottest year on record, and 2024 topping it made the past 10 years the warmest 10 years on record.

HIV prevention drug shows immense promise

This scanning electron microscopic (SEM) image shows the presence of numerous human immunodeficiency virus-1 (HIV-1) virions (spherical in appearance) budding from a cultured human lymphocytes in this 1989 image obtained from Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia, on March 5, 2019.

The US Food and Drug Administration (FDA) in 2022, approved the drug lenacapavir as a treatment for HIV/AIDS.

Two years since, findings from the two drug trials sponsored by lenacapavir maker Gilead Sciences have shown immense promise, with results published this year showing success rates of 96 per cent and 100 per cent respectively.

In fact, the results were so tunning that the journal Science dubbed it the 'breakthrough of the year'.

In search of extraterrestrial life

Image showing Europa orbiting Jupiter.

The never-ending search for extraterrestrial life continued this year, with NASA launching a major mission to look for conditions that could support life in Europa, one of the moons of the oldest planet in the solar system—Jupiter.

Among Jupiter's 90+ moons, NASA chose to target Europa because scientists believe the moon's sub-surface ocean may harbour life.

The Clipper spacecraft, the largest ever to have been sent to another planet/moon by NASA, is equipped with instruments to analyse whether Europa has conditions to support life.

Findings from Clipper will help scientists decide the potential of future missions that would search for life.

A perfect storm

The aurora borealis, also known as the 'northern lights’, caused by a coronal mass ejection on the Sun, illuminate the skies over the WWII monument in the southwestern Siberian town of Tara, Omsk region, Russia May 11, 2024.

The most dramatic geomagnetic storm in over two decades gave Earthlings a glimpse of ethereal auroras in places people would least expect.

The northern lights were seen as far south as Florida as an ethereal glow lit up the skies across the world on May 10 and 11.

Far-reaching auroras were spotted again across the US and other places in October, and many expect next year to bring even more spectacular sights.

The reason behind these rare sightings is the sun, which is currently nearing the end of its 11-year cycle of fluctuating activity, a period known as the solar maximum. During this period, the sun launches elevated levels of radiation a solar flares and sends out charged particles in the form of coronal mass ejections.

When these charged particles hit the Earth's atmosphere, the planet's magnetic field drags these particles to the poles, where they energise molecules of gas, sparking a release of excess energy that create the colourful glow we call auroras.

Although periods of intense solar activity occur every 11 years, storms like the one seen in May are rare as ejected material from the sun has to hit the Earth, which is a tiny target in the grand scale of things.

With the sun nearing the climax of it's 11-year activity cycle, many expect 2025 to bring even more auroras.

Mapping a fruit fly's brain

Screengrab from a video showing a model of an adult fruit fly's brain.

"Over 140,000 neurons are joined together by more than 490 feet of wiring, as long as four blue whales placed end to end."

The quote above from an article in The New York Times describes the brain of an adult fruit fly, which is the size of a poppy seed.

Yet, it took hundreds of scientists over a decade to fully map it, which they managed with the help of an AI model.

The mammoth effort came to fruition in October when a nine-paper package was published in the journal Nature, detailing the findings.

The computerised model brain which scientists reconstructed also behaved exactly like a fruit fly would in several simulations.

The discovery despite it's literal small size was massive: previously, the only organism to have its brain fully mapped out was a tiny worm with a mere 385 neurons in its entire nervous system.

Scientists this year also released a data set charting the neurons, synapses, and connections in a tiny piece of the human brain, and future work into brain mapping promises exciting findings.

Detecting Alzheimer's

Image showing brain scans. For representational purposes.

Millions of people around the world are estimated to have Alzheimer's, but detection, thus far, was a complex affair that required a sample of cerebrospinal fluid or a brain positron emission tomography (PET) scan, facilities that are often not avalable at primary health centres.

This year, however, scientists found that a simple blood test could accurately detect Alzheimer's in patients: in a study that tested blood samples from 1,200 older adults, scientists found that Alzheimer's detection via blood tests proved to be 88 to 92 per cent accurate when compared to tests using cerebrospinal fluid and PET scans.

Although further finetuning is required, this development could pave the way for drastic changes to Alzheimer's detection and treatment in the years to come.

Human-Neanderthal breeding timeline

An artist's impression of cave dwellers during the hunter-gatherer era of humankind. For representational purposes.

While it's known that us humans (Homo sapiens) at one time bred with the Neanderthals (Homo neanderthalensis), scientists this year were able to pinpoint when the two species started interbreeding.

Comparing segments of Neanderthal and human history, and analyising the genomes of ancient and modern humans, scientists were able to establish when humans and Neanderthals lived together in Eurasia, indicating when they interbred.

The study found that Homo sapiens and Homo neanderthalensis lived side-by-side for around 7,000 years—from 50,500 years to 43,500 years ago—around which time they are believed to have interbred.

Gene editing with a dash of AI

Illustration for representational purposes.

You may already have heard of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) technology that allow geneticists to cut and edit parts of DNA.

Now, researchers have taken CRISPR a step further by pairing it with large language models (LLMs) similar to those behind AI chatbots such as ChatGPT.

The result? OpenCRISPR-1, an open-source gene editor that research teams across the world can access. The team behind the tech at Profluent suggest that AI can make gene editing safer and more accurate, and have emphasized that their tech is for ethical use only.

New moons around old planets

An artist's impression of Neptune. For representational purposes.

For scientists, our solar system appears to be a gift that keeps on giving.

Up until this year, astronomers were only aware of Uranus having 27 moons and Neptune having 14.

However, in 2024, three new additions were made, with two new moons spotted orbiting Neptune, and one orbiting Uranus.

While the three new entrants are tiny—14 miles and 8 miles across for Neptune's two moons, respectively, and 5 miles across for Uranus' new moon—they are nonetheless fascinating discoveries, given that the trio are the faintest moons ever spotted using land-based telescopes.

Oldest reptile skin

Image showing reptilian skin. For representational purposes.

While fossils have been found aplenty around the world, fossilised remains typically consist of bones, teeth, eggshells, and fecal matter. Finding remains of soft tissue, however, is rare, making it difficult for scientists to reconstruct anything beyond skeletal frames of creatures that walked the Earth way before us.

This year, however, researchers stumbled upon what is believed to be the oldest known fossilised reptile skin, dated at over 300 million years old. While the creature it belongs to has yet to be identified, scientists believe it lived during the late Paleozoic era. Researchers think the skin could have belonged to an iguana-sized reptile known as Captorhinus aguti, but confirmation is still pending.

Google's Willow brings the 'Quantumania'

Representative image indicating multiple universes 

One wouldn't normally imagine the Marvel Cinematic Universe comes up when speaking of scientific breakthroughs, but Google's Willow quantum chip has brought the mania.

This chip can reportedly solve complex problems in minutes, that would normally take supercomputers ten septillion years. For reference, that is akin to squaring the age of the universe -- 13.7 billion years.

Google's announcement has set the stage for a renewed debate on the possibility of a multiverse -- which is that there might be multiple universes which are interconnected.

The founder of Google's Quantum AI team, Hartmut Neven, suggested that the success of the chip lent credibility to the notion that quantum computation was occurring across multiple parallel universes. This idea was pushed by David Deutsch, a physicist, who linked the idea that quantum mechanics might prove a multiverse exists to the Many Worlds Interpretation (MWI) of quantum mechanics. Deutsch even suggested that quantum computers might function using parallel universes for specific calculations.

Hugh Everett, in the 1950s, first suggested the idea, saying that each time something takes place in the quantum world, the outcome is split into many different possibilities, each of which enter its own universe.

Multiverses are often seen in fiction, like in Marvel films, or the more recent Everything Everywhere All at Once. However, this idea remains speculative and is not yet widely accepted in scientific circles.