The 2010s were banner years for science, seeing breakthroughs in everything from human evolution and disease treatment to space and artificial intelligence. Here are 14 of the greatest scientific discoveries and advancements of the decade. 

1. Neanderthal Genome Shows They Interbred with Modern Humans // 2010

About 19 years ago, biologist Damian Labuda at the University of Montreal found an unknown piece of DNA on the X chromosome of non-African peoples. He was unable to determine how it arrived in the human genome, however. In 2010, another team of researchers sequenced the Neanderthal genome, and with it, researchers found that same piece of DNA Labuda had discovered. The DNA snippet wouldn’t have made the interspecies leap from Neanderthal to Homo sapiens if the two had not interbred shortly after modern humans migrated from Africa. Though further research by the University of Berne in Switzerland showed children resulted from these interspecies unions less than 2 percent of the time, about 2 percent of the genome of Eurasian peoples today is Neanderthal.

2. HIV Transmission is Tackled with “Treatment as Prevention” // 2011

With the findings of study HPTN 052, the HIV Prevention Trials Network discovered that antiretroviral therapy (ART) for people infected with HIV also drastically reduced transmission rates of the virus. The study took about 10 years to conduct. When HIV-positive participants began ART early—meaning they still had a pretty healthy immune system—transmission of the virus to their HIV-negative sexual partners dropped by 93 percent. When HIV at any stage was fully suppressed due to the treatment, there was no transmission observed. The findings of HPTN 052 underscore the importance of treatment as prevention by showing that, regardless of the stage of the virus, ART treatment can inhibit transmission and set us on a path to eliminating HIV and AIDS altogether.

3. Physicists Finally Find the Higgs Boson // 2012

In 2012, physicists finally discovered the Higgs boson—about 50 years after its existence was first theorized. Dubbed the “god particle,” it’s responsible for giving all other particles mass, allowing them to join together and become something more, like stars. Using the large hadron collider at CERN in Switzerland, researchers confirmed the discovery by two different detectors. Peter Higgs, who first suggested this particular boson could exist in 1964, was there to experience the elation of the discovery himself. With the Higgs boson identified, the standard model of particle physics, which had about 500 years of work behind it and explains the fundamental forces of the universe, was finally complete.

4. The Curiosity Rover Lands on Mars // 2012

NASA // Public Domain

In 2012, NASA triumphantly landed a plutonium-powered rover, called Curiosity, on the surface of Mars. It was the size of a compact car with incredibly sophisticated technology, a science lab on wheels that would set out across the Red Planet to see what it could find. Curiosity has sent back jaw-dropping images of Martian landscapes, scooped up soil samples and tested their chemical makeup, explored geological formations, observed atmospheric events, and even captured photos of Mars’s two moons eclipsing the sun.

5. Immunotherapy Blazes a New Path for Cancer Treatment // 2013

Battling cancer is often a long and difficult road, but immunotherapy may offer more hope. The process turns the traditional methods of fighting cancer on its head—now, instead of targeting tumors themselves with chemotherapy drugs, treatment harnesses the patient’s immune system to fight the tumors on its own, just like it would attack any other pathogen. The method can take two routes: Either the patient’s T-cells (the cells that target illnesses) are set loose to destroy cancer by removing a protein receptor that inhibited their disease-fighting activity, or modified T-cells are infused into the patient’s bloodstream. Studies on immunotherapy showed promising results of shrinking tumors and full remission, particularly on hard-to-treat lung cancers. Immunotherapy drugs won’t work for every patient, but researchers continue to investigate and modify their approaches. Thanks to this discovery, in 2013 we turned a corner into better and more effective cancer treatment.

6. Genetic Lineages Show Birds Evolved from Dinosaurs // 2014

For four years, scientists studied 48 bird species—a group that represented every major type of modern bird—and sequenced, assembled, and compared their genomes. It was the largest bird dataset in history, and as a result, researchers could finally support a commonly held belief: that birds evolved from dinosaurs. The first lineages of modern birds date back about 100 million years, but their amazing biodiversity emerged within a period of about 10 million years right after most dinosaurs went extinct 66 million years ago. The study’s results are further evidence that the dinosaurs’ extinction allowed birds, mammals, and other forms of life to rapidly evolve and diversify.

7. New Horizons Beams Back Stunning Photos of Pluto // 2015

When New Horizons first transmitted high-quality close-up colorized photos of Pluto and Charon, one of the dwarf planet’s five moons, back to Earth, it caused both awe and wonder. Now, we could see in detail the ground’s surface, in all its jagged frozen-water mountainous and chasm-filled glory. But we also learned that in recent history, the landscape was constantly being resurfaced, so craters and pockmarks found on other planets are scarce on both Pluto and Charon. Whatever was—or is—working to smooth out those surfaces is still being investigated.

8. CRISPR-Cas9 Revolutionizes Genetic Engineering // 2015

Scientists have been editing genes since the 1970s. But in 2015, that process became much easier with the introduction of Clustered Regularly Interspaced Short Palindromic Repeats, or CRISPR-Cas9. This technology allows scientists to genetically engineer any living organism, from crops and bugs to animals and people, by precisely snipping out and replacing pieces of unwanted DNA with the help of a protein called Cas9. CRISPR hasn’t been without controversy, though. The technology gives us the ability to make designer babies—ones with specific genes edited before birth. But is it ethical? We may be able to edit out genetic diseases or change eye color, but that doesn’t necessarily mean we should.

9. Ancient Human Ancestor Homo naledi Broadens Our Family Tree // 2015

Lee Roger Berger research team, Wikimedia Commons // CC BY 4.0

In 2013, two spelunkers discovered a treasure trove of humanlike bones in Rising Star Cave in South Africa. They contacted paleoanthropologist Lee Berger who then, with a team of six women scientists, retrieved the bones and studied them for the next two years—ultimately finding and announcing in 2015 a new species of ancient human ancestor. Homo naledi had small brains, pronounced brow lines, apish pelvises, human-like hands, flat feet, and small teeth. Intriguingly, the 250,000-year-old bones bear traits common to Australopithecus, which lived about 2 million years ago, suggesting that Homo naledi could be an offshoot of the genus Homo. More than 1500 fossils were in the cave and Berger believes it was part of a burial ritual to leave dead kin there, though he thinks Homo naledi brains were too small for them to be able to accurately navigate a dark cave.

10. AI Beats a Human Player at Go // 2016

The ancient game of strategy called Go is more than 2500 years old and substantially more difficult than chess. And until 2016, human players always had an edge over artificial intelligence, which could not compute how to beat a real person. That year, though, Google’s DeepMind division programed a new AI system called AlphaGo. The system stored about 30 million moves in its memory that humans had played in the game, and was able to predict a human’s next move correctly 57 percent of the time. In AlphaGo’s first public tournament, it stomped the other computer system it played; in its next public tournaments, it destroyed reigning European Go champ Fan Hui and Go world champion Lee Sedol. Researchers immediately began to consider how else the new advanced AI technology could be used.

11. Einstein’s Prediction of Gravitational Waves is Confirmed // 2016

Based on his general theory of relativity, Albert Einstein predicted the existence of gravitational waves—waves moving energy throughout the universe in a way similar to electromagnetic radiation—in 1916. They remained elusive, though, for the next century—until 2016, when a team of scientists found the first direct evidence that they exist. Evidence came in a unique way: a chirp sound heard when two black holes, a billion light years away, crashed into one another. The collision warped the fabric of space-time, causing the sound. These gravitational waves fulfilled Einstein’s last prediction and capped 40 years of work by scientists.

12. Earth Experiences Its five Hottest Years on Record // 2014-2018

The National Oceanic and Atmospheric Administration (NOAA) has monitored climate and temperature changes since 1880—and never before have its scientists seen temperatures like this. The period of 2014 to 2018 carries the distinction of being the hottest years on record, thanks to anthropogenic climate change. Plus, in those same years, no place on Earth experienced any record cold temperatures. And the repercussions of continuing climate change are severe: drastic unexpected weather changes and disastrous events, like increased flooding, wildfires, droughts, and more. Temperature extremes and melting ice caps are so severe now that they can even be seen from space.

13. Astronomers Capture the First Photo of a Black Hole // 2019

Event Horizon Telescope Collaboration

It’s hard to study something you’ve never actually seen—just ask all the researchers who’ve worked on black holes over the past 200 years. But because of the two-year-old Event Horizon Telescope, black hole researchers don’t have to struggle without a visual anymore. This year, the telescope captured the first-ever photo of one: a supermassive black hole in the middle of the M87 galaxy. It looks like a bright ring of light surrounding a central dark circle, the hole itself where massive amounts of gravity suck everything in. The image paves the way for scientists to determine exactly how the universe began—and its possible end, as well.

14. FDA Approves Long-Sought Treatment for Cystic Fibrosis // 2019

About 90 percent of patients with cystic fibrosis—a progressive, life-threatening genetic disease affecting the respiratory and digestive systems—have a mutation on the CFTR gene called F508del. And until this year, they had no treatment options. In 2019, 30 years after the gene was identified, the FDA approved the first drug to treat the genetic cause of the disease rather than just the symptoms, giving new hope to cystic fibrosis patients. Clinical trials of the drug, Trikafta, showed significant improvement in participants’ lung function. There may not be a cure for the disease—yet—but it brings the prospects of one closer.