Ancient Roman structures have always been a major attraction for both common people and researchers. The durability of those magnificent architectural feats like the Pantheon of Rome has made researchers curious about how they are standing tall nearly after two thousand years of the height of the Roman empire. While The longevity of these structures can be attributed largely to Roman concrete, question still prevails about the speciality and the materials used in the concrete itself. 

Ingredients of Roman concrete

According to the study published in the journal Science Advances, an international team of researchers led by the Massachusetts Institute of Technology (MIT) found that not only are the materials slightly different from what we may have thought, but the techniques used to mix them were also different.

One key ingrediant was pozzolan, or ash. The Romans used ash from the volcanic beds of the Italian city Pozzuoli and shipped it all over the empire. The silica and alumina in the ash react with lime and water in a pozzolanic reaction at ambient temperatures, resulting in a stronger, longer lasting concrete.
Another key ingredient is lime clasts, or small chunks of quicklime.

These clasts give Roman concrete its self-healing capability. Concrete weathers and weakens over time, but water can infiltrate its cracks and reach the clasts. When they react with the water, the clasts create crystals called calcites that fill in the cracks.

Difference with modern day cement

The high-temperature kiln process used today to make modern day Portland cement, grinds all materials into fine powder. It eliminates the lime clasts which results into the lack of the self-healing properties of Roman cement.

The Romans utilized a method known as hot mixing, which involves combining quicklime with pozzolan, water and other ingredients and then heating them up. The MIT team found that this method helps unlock the lime clasts’ self-healing abilities, and can result in faster setting than cement made with a quicklime-water solution called slaked lime.

In a finding published in the journal Science Advances on May 14, 2025, researchers have unleashed fresh evidence that Venus is still alive geologically. Venus and Earth had similar sizes and exploded by comparable amounts of water billions of years ago. This shared origin has raised questions like why Venus became extremely uninhabitable while Earth is flourishing in a cradle of life. After more than thirty years, NASA’s Magellan spacecraft tracked the surface of Venus, and scientists found the hot material rising signals from the interior of the planet, signalling that the crust is still getting shaped.

Venus May Still Be Geologically Active, Scientists Say

According to Research revealed that Venus is active geologically, shaping its surface by internal heat. Scientists analysed the large, ring-shaped structures called coronae, formed when a hot mantle pushes the crust upside down and collapses into circular depressions.

Gael Cascioli, an assistant scientist at NASA’s Goddard Space Flight Centre, said this gives valuable insight into subsurface motion. Out of 75 Coronae, analysed with the help of NASA’s Magellan spacecraft data, 52 sit above the active, buoyant mantle plumes, which is very hard to believe.

Similarities Between Venus and Early Earth

Anna Gulcher, the co-lead of the study, said that these ongoing processes are similar to the Earth. Venus holds 100s of coronae, particularly within the thin crust and high thermal places.

Venus’ Surprisingly Thin Crust

Justin Filiberto of NASA’s Astromaterials Research Division found that the Venus crust could break off or melt when it exceeds just 65 km in thickness, a thin barrier.

Crustal Recycling and Volcanic Activity

The crust shearing not just shaped the surface but also recycled the materials, such as water in the interior of Venus, which triggers the volcanic activity and the shifts of the atmosphere. The mechanism resets how the geology, atmosphere and crust on Venus work simultaneously.

Upcoming Missions to Unveil More

The future missions include NASA’s VERITAS and DAVINCI. Further, ESA’s EnVision is going to provide high-resolution data for validating the findings. Suzanne Smrekar put emphasis on these missions could change our understanding of Venue geology together with clues of the Earth’s past.

Last month, astronomers using the James Webb Space Telescope made headlines by announcing they had detected hints of the chemicals dimethyl sulphide (DMS) and dimethyl disulfide (DMDS) on the exoplanet K2-18b, located 124 light-years away from the Earth. These chemicals are only produced by life such as marine algae on Earth, meaning they are considered potential “biosignatures” indicating life. recent follow-up research questions the reliability of this finding. A new study led by researchers from the University of Chicago reanalysed the James Webb Space Telescope (JWST) data and found the evidence for DMS far less convincing than previously reported.

Weakening of signals

According to a recent arxiv preprint, yet to be peer-reviewed, Rafael Luque, Caroline Piaulet-Ghorayeb, and Michael Zhang, used a joint approach by combining all JWST observations across its key instruments (NIRISS, NIRSpec, and MIRI). They found that the supposed DMS signal becomes significantly weaker when all data are considered together. Differences in data processing and modelling between the original studies also cast doubt on the initial results.

According to the team, even when DMS-like signals appear, they are weak, inconsistent, and can often be explained by other, non-biological molecules like ethane. The researchers stressed the importance of consistent modelling to avoid contradictory interpretations of planetary atmospheres.

Spectral Complexity

Molecules in an exoplanet’s atmosphere are typically detected through spectral analysis, which identifies unique “chemical fingerprints” based on how the planet’s atmosphere absorbs specific wavelengths of starlight as it passes or transits in front of its host star.

The difference between DMS and ethane a common molecule in exoplanet atmospheres is just one sulfur atom, and current spectrometers, including those on the JWST, have impressive sensitivity, but still face limits. The distance to exoplanets, the faintness of signals, and the complexity of atmospheres mean distinguishing between molecules that differ by just one atom is extremely challenging. The recent claim of a “3-sigma” detection of DMS falls short of the scientific standard for confirmation. The team calls for more rigorous standards in both scientific publication and media reporting.