In a study published in Nature Communications, scientists from MIT have proposed that shallow meltwater ponds may have provided critical refuges for early complex life during one of Earth’s most extreme ice ages — the “Snowball Earth” period, which occurred between 635 and 720 million years ago.

During this time, the planet was believed to be encased in ice, with global temperatures plummeting to as low as -50°C. Despite the harsh conditions, complex cellular life — known as eukaryotes — managed to survive. The new research suggests that these life forms could have found sanctuary in small, briny pools formed on the surface of equatorial ice sheets.

“Meltwater ponds are valid candidates for where early eukaryotes could have sheltered during these planet-wide glaciation events,” said lead author Fatima Husain, a graduate researcher in MIT’s Department of Earth, Atmospheric and Planetary Sciences, in a media statement. “This shows us that diversity is present and possible in these sorts of settings. It’s really a story of life’s resilience.”

The team drew parallels between ancient equatorial ice sheets and modern Antarctic conditions. They studied contemporary meltwater ponds on Antarctica’s McMurdo Ice Shelf — an area first dubbed “dirty ice” by explorers in the early 20th century. These ponds, formed by sun-warmed dark debris trapped within surface ice, provided a modern analog to the possible melt environments of the Cryogenian Period.

Samples taken from these Antarctic ponds revealed clear signatures of eukaryotic life. Using chemical and genetic analysis, including the identification of sterols and ribosomal RNA, the researchers detected algae, protists, and microscopic animals — all descendants of early eukaryotes. Each pond supported unique communities, with differences shaped largely by salinity levels.

“No two ponds were alike,” Husain noted. “There are repeating casts of characters, but they’re present in different abundances. We found diverse assemblages of eukaryotes from all the major groups in all the ponds studied.”

These findings suggest that meltwater ponds — overlooked in previous hypotheses — could have served as vital “above-ice oases” for survival and even diversification during Snowball Earth.

“There are many hypotheses for where life could have survived and sheltered during the Cryogenian, but we don’t have excellent analogs for all of them,” Husain explained. “Above-ice meltwater ponds occur on Earth today and are accessible, giving us the opportunity to really focus in on the eukaryotes which live in these environments.”

The study was co-authored by MIT’s Roger Summons, Thomas Evans (formerly MIT), Jasmin Millar of Cardiff University, Anne Jungblut of the Natural History Museum in London, and Ian Hawes of the University of Waikato in New Zealand.

By uncovering how life may have persisted through Earth’s frozen past, the research not only deepens understanding of our planet’s history — it may also help inform the search for life on icy worlds beyond Earth.

At the launch of the biography Divine Scientist chronicling the life of legendary Indian chemical engineer Prof. Man Mohan Sharma, Mukesh Ambani, CMD of Reliance Industries, offered a moving tribute that captured the intellect, values, and national impact of his former teacher.

Prof. Sharma is a renowned chemical engineer, who became the first Indian engineer to be elected as a Fellow of Royal Society, the UK in 1990.

Here are the four key insights Ambani shared about Prof. Sharma:

1. The Alchemist of Minds

Ambani recalled how Prof. Sharma transformed his understanding of chemical engineering — and leadership. “He had the power to convert curiosity into knowledge, knowledge into commercial value, and both into everlasting wisdom,” he said. Choosing ICT over IIT Bombay, Ambani said Sharma’s first lecture confirmed he’d made the right decision.

2. Master of ‘Economics of Chemistry’

“He wasn’t just a scientist — he taught us how molecules make money,” said Ambani. He fondly remembered calling Sharma a “Bania chemical engineering professor” for blending scientific brilliance with business sense — a philosophy that informed Reliance’s rise in the petrochemicals industry.

3. Sustainability Visionary

Long before sustainability became a buzzword, Prof. Sharma taught his students to turn every ‘by-product’ into a ‘co-product’. “He insisted nothing should be wasted,” said Ambani. That vision shaped Reliance’s integrated manufacturing strategy, from crude oil to consumer products.

4. A Silent Architect of Economic Reforms

Prof. Sharma wasn’t just a scholar — he was a behind-the-scenes changemaker. Ambani revealed how Sharma, alongside his father Dhirubhai Ambani, lobbied for deregulating India’s chemical industry. “He told policymakers: if you want India to grow, end the license raj and build scale,” said Ambani. “He is not just our Guru — he is a Rashtra Guru.”

The emotional address underscored the enduring influence of a teacher whose lessons extend far beyond the classroom — into boardrooms, factories, and the future of India.

Imagine diving into the ocean’s depths, descending further than the eye can see, into a cold, almost completely dark world where every movement feels like a gamble. For some of the ocean’s most formidable predators—like tuna and swordfish—this is no mere adventure; it’s a necessity. A new study reveals that these apex hunters are making regular, long-distance plunges into the twilight zone, a mysterious and dark layer of the ocean, to fill their stomachs. And what they’re finding there could change the way we think about ocean ecosystems and the future of commercial fishing.

For decades, oceanographers knew that large fish like tuna and swordfish occasionally ventured into the depths of the ocean, but the purpose of these dives remained unclear. Were these predators hunting for food, or were they just exploring? A recent breakthrough by MIT oceanographers has answered that question—and the results are more astonishing than anyone could have imagined.

In a pioneering study published in ICES Journal of Marine Science, an MIT team led by Ciara Willis has found that these fish are relying heavily on the twilight zone, a dark, cold layer between 200 and 1,000 meters below the surface, for as much as 60% of their diet. This discovery reveals a much deeper connection to this enigmatic zone than scientists previously realized.

“We’ve known for a long time that these fish and many other predators feed on twilight zone prey,” says Willis, a postdoc at the Woods Hole Oceanographic Institution, in a press statement. “But the extent to which they rely on this deep-sea food web for their diet has been unclear.”

The Hidden Feast

The twilight zone—often overlooked in marine research—has been gaining attention for its rich ecosystem. It’s a vast, underexplored region teeming with strange creatures, from tiny lanternfish to massive squid, all adapted to live without sunlight. While the surface waters are teeming with life, they offer less concentrated food for large predators. By contrast, the twilight zone is like a dense buffet, providing predators like bigeye tuna, yellowfin tuna, and swordfish a more reliable food source.

“This is a really understudied region of the ocean, and it’s filled with all these fantastic, weird animals,” Willis says. “We call it the ‘deep ocean buffet.’”

The deep sea creatures in the twilight zone have evolved to migrate vertically—swimming to the surface to feed at night and returning to the depths by day to avoid predators. For the big predators of the open ocean, this behavior creates a prime opportunity to feast. Bigeye tuna, yellowfin tuna, and swordfish dive regularly into these depths to hunt. But until recently, scientists didn’t know just how important this food source truly was.

“We saw the bigeye tuna were far and away the most consistent in where they got their food from,” Willis explains. “The swordfish and yellowfin tuna were more variable, meaning that if large-scale fishing were to target the twilight zone, bigeye tuna might be the ones most at risk.”

The Price of Overfishing the Deep

This discovery comes at a critical time. The growing interest in commercial fishing in the twilight zone, despite its often unpalatable fish species, has raised alarms. These creatures are increasingly being harvested for fishmeal and fish oil, products commonly used in animal feed and other industries. However, as researchers point out, this could have dire consequences for tuna and swordfish populations.

“There is increasing interest in commercial fishing in the ocean’s twilight zone,” says Willis. “If we start heavily fishing that layer of the ocean, our study suggests that could have profound implications for tuna and swordfish, which are highly reliant on this region.”

The team’s findings underscore the need for careful management of the twilight zone’s resources. Given that tuna and swordfish rely on this zone for up to 60% of their food, disruptions to the ecosystem here could have cascading effects on the open ocean and the global fishing industry.

“Predatory fish like tunas have a 50% reliance on twilight zone food webs,” Willis warns. “If we start heavily fishing in that region, it could lead to uncertainty around the profitability of tuna fisheries.”

As the twilight zone becomes a target for increasing commercial interest, scientists are calling for greater caution in how we approach the deep ocean’s complex food web. What lies in the shadows of the ocean’s depths may be far more crucial to our marine ecosystems than anyone has realized.