From finding the building blocks for life on Mars to breakthroughs in gene editing and the rise of artificial intelligence, here are six major scientific discoveries that shaped the 2010s - and what leading experts say could come next.Are we alone?We don't yet know whether there was ever life on Mars - but thanks to a small, six-wheeled robot, we do know the Red Planet was habitable.Shortly after landing on August 6, 2012, NASA's Curiosity rover discovered new evidence that rivers flowed there billions of years ago.The proof has since multiplied, showing there was in fact a lot of water on Mars - the surface was covered in hot springs, lakes, and maybe even oceans.Curiosity also discovered what NASA calls the building blocks of life, complex organic molecules, in 2014.Two new rovers will be launched next year - America's Mars 2020 and Europe's Rosalind Franklin rovers, looking for ancient microbes."Going into the coming decade, Mars research will shift from the question 'Was Mars habitable?' to 'Did (or does) Mars support life?'" said Emily Lakdawalla, a geologist at The Planetary Society.Einstein was right (again)Launched in 2009, the Kepler mission helped identify more than 2 600 planets outside of our solar system, also known as exoplanets - and astronomers believe each star has a planet, meaning there are billions out there.Kepler's successor TESS was launched by NASA in 2018, as we scope out the potential for extra-terrestrial life.SEE: First-ever image of a black hole and its fiery haloWe also got our first glimpse of a black hole this year thanks to the groundbreaking work of the Event Horizon Telescope collaboration."What I predict is that by the end of the next decade, we will be making high quality real-time movies of black holes that reveal not just how they look, but how they act on the cosmic stage," Shep Doeleman, the project's director, told AFP.But one event from the decade undoubtedly stood above the rest: the detection for the first time on September 14, 2015 of gravitational waves, ripples in the fabric of the universe.The first image of a black hole. (Event Horizon Telescope Collaboration).The collision of two black holes 1.3bn years earlier was so powerful it spread waves throughout the cosmos that bend space and travel at the speed of light. That morning, they finally reached the Earth.The phenomenon had been predicted by Albert Einstein in his theory of relativity, and here was proof he was right all along.Three Americans won the Nobel prize in physics in 2017 for their work on the project, and there have been many more gravitational waves detected since.Welcome to the CRISPR eraClustered Regularly Interspaced Short Palindromic Repeats (CRISPR) - a family of DNA sequences - is a phrase that doesn't exactly roll off the tongue.But the field of bio-medicine can now be divided into two eras, one defined during the past decade: before and after CRISPR-Cas9 (or CRISPR for short), the basis for a gene editing technology.In 2012, Emmanuelle Charpentier and Jennifer Doudna reported that they had developed the new tool that exploits the immune defense system of bacteria to edit the genes of other organisms.It is much simpler than preceding technology, cheaper and easy to use in small labs.READ | Could gene editing technology ever work as an effective treatment for cancer?Charpentier and Doudna were showered in awards, but the technique is also far from perfect and can create unintended mutations.Experts believe this may have happened to Chinese twins born in 2018 as a result of edits performed by a researcher who was widely criticized for ignoring scientific and ethical norms.Still, CRISPR remains one of the biggest science stories of recent years, with Kaelin predicting an "explosion" in its use to combat human disease.Immunotherapy to the foreFor decades, doctors had three main weapons to fight cancer: surgery, chemotherapy drugs, and radiation.The 2010s saw the rise of a fourth, one that was long doubted: immunotherapy, or leveraging the body's own immune system to target tumor cells.One of the most advanced techniques is known as CAR T-cell therapy, in which a patient's T-cells - part of their immune system - are collected from their blood, modified and reinfused into the body.For William Cance, scientific director of the American Cancer Society, the next decade could bring new immunotherapies that are "better and cheaper" than what we have now.Meet the relativesThe decade began with a major new addition to the human family tree: Denisovans, named after the Denisova Cave in the Altai Mountains of Siberia.Scientists sequenced the DNA of a female juvenile's finger bone in 2010, finding it was distinct both from genetically modern humans and Neanderthals, our most famous ancient cousins who lived alongside us until around 40 000 years ago.The mysterious hominin species is thought to have ranged from Siberia to Indonesia, but the only remains have been found in the Altai region and Tibet.We also learned that, unlike previously assumed, Homo sapiens bred extensively with Neanderthals - and our relatives were not the brutish simpletons previously assumed but were responsible for artworks, such as the handprints in a Spanish cave they were credited for crafting in 2018.They also wore jewelry, and buried their dead with flowers - just like we do.Next came Homo naledi, remains of which were discovered in South Africa in 2015, while this year, paleontologists classified yet another species found in the Philippines: a small-sized hominin called Homo luzonensis.Right upper teeth of the Homo luzonensis. (Callao Cave Archaeology Project)."This discovery has led to a revolution in our ability to study human evolution and how we came to be in a way never possible before," said Vagheesh Narasimhan, a geneticist at Harvard Medical School.READ | Scientists may have discovered a new human species. It lived on a tiny island in the Philippines at the same time as Homo sapiens.One exciting new avenue for the next decade is paleoproteomics, which allows scientists to analyse bones millions of years old.AI levels upMachine learning - what we most commonly mean when talking about "artificial intelligence" - came into its own in the 2010s.Using statistics to identify patterns in vast datasets, machine learning today powers everything from voice assistants to recommendations on Netflix and Facebook.So-called "deep learning" takes this process even further and begins to mimic some of the complexity of a human brain.It is the technology behind some of the most eye-catching breakthroughs of the decade: from Google's AlphaGo, which beat the world champion of the fiendishly difficult game Go in 2017, to the advent of real-time voice translations and advanced facial recognition on Facebook.ALSO READ | Scientists and researchers reveal 13 dark technology scenarios that keep them up at night"In applied research, I think AI has the potential to power new methods for scientific discovery," from enhancing the strength of materials to discovering new drugs and even making breakthroughs in physics, said Henry Kautz, a computer science professor at the University of Rochester.