Chemists are perpetually discovering new substances, pharmaceuticals, and remarkable new revelations regarding the chemical mechanisms that support the world we inhabit. The year 2025 has been alike, with the Chemistry World team remaining diligent in our efforts to keep readers informed about the most compelling and significant breakthroughs within the chemical sciences. Throughout the past year, we’ve covered over 300 new studies that captivated and astonished us. Although it’s impractical to revisit each one, here’s a recap of some notable research highlights from this year.
Chemistry in space
Grasping the chemistry on planets outside our own holds the ability to potentially resolve some of the most profound inquiries about the emergence of life, the cosmos, and reality itself. In 2025, some extraordinary experiments provided intriguing new revelations.
In January, scientists disclosed findings from the Osiris-Rex mission, where a probe was dispatched to the asteroid Bennu, extracted a sample, and returned it to Earth seven years later. This precious payload indicated that the asteroid is abundant in carbon, nitrogen, and ammonia. Even more fascinating was that the sample included more than 30 distinct amino acids – comprising 14 of the 20 that form proteins locally produced on Earth – and all five of the nucleobases present in RNA and DNA. The amino acids from Bennu exhibit both left- and right-handedness – in contrast to the homochiral forms found in terrestrial biology.
2025 also yielded fresh results from the Mars rover explorations. A study that cross-verified data collected by the Curiosity, Pathfinder, and Opportunity rovers demonstrated that ferrihydrite – in addition to haematite – contributes to the planet’s distinctive reddish appearance. Since ferrihydrite is formed in cool water, the results suggest that water may have remained on Mars’ surface longer than previously thought.
The existence of liquid water on Mars several millions of years ago would necessitate warmer climates, likely influenced by substantial levels of carbon dioxide in the planet’s atmosphere. However, this raises the question: where has all the carbon dioxide gone? In April, Curiosity identified significant concentrations of carbonates in the form of high-purity siderite minerals within Mars’ Gale crater – believed to be an ancient desiccated lake. These findings support evidence of an unbalanced historic carbon cycle, where carbon was absorbed into lake sediments.
Additional highlights in astrochemistry included a theory put forth by theoretical chemists that clarifies the prevalence of highly unsaturated organic molecules in the interstellar medium, and the discovery of cyanocoronene in the Taurus cloud – marking it as the largest entirely aromatic molecule uncovered in space. At the same time, astronauts aboard the International Space Station conducted the inaugural fermentation experiment in space, generating <a title="Miso Fermented on the International Space Station Is Out of This World | Chemistry World" href="https://www.chemistryworld