Over the past 25 years, Futura has explored the fascinating link between the physics of the extremely small and the extremely large, with a special focus on neutrinos—subatomic particles that are incredibly hard to detect. This year, 2026, marks both the 25th anniversary of Futura and the 70th anniversary of the discovery of the neutrino. One of the most intriguing mysteries in this field was the solar neutrino problem, which suggested that the Sun might be almost out of fuel, despite its bright appearance in the sky. The Sun's energy is generated by nuclear fusion in its core, a process that releases not only light but also neutrinos. While photons—particles of light—take about a million years to travel from the Sun’s core to its surface, neutrinos can escape almost instantly. This means that if the Sun’s fusion reactions were to slow down suddenly, Earth would not notice the change for a very long time. In the decades after the neutrino was first discovered in the 1950s, experiments detected far fewer neutrinos than expected, leading to speculation that the Sun might be nearly extinguished. The solar neutrino problem was first identified in the 1960s by physicists Ray Davis and John N. Bahcall. Early calculations by Bahcall predicted a certain number of neutrinos should be coming from the Sun, but Davis's experiments detected only about a third of that number. Even after Richard Feynman verified the calculations, the discrepancy remained a mystery until advances in heliosismology—using sound waves to study the Sun's interior—confirmed that the Sun's internal structure matched the standard solar model. Further research into the energy levels of neutrinos detected on Earth showed they aligned with the Sun’s high internal temperature, pointing to a solution in neutrino physics itself. Scientists discovered that there are different types of neutrinos, such as muon and tau neutrinos, and proposed that they might change, or "oscillate," between types during their journey from the Sun to Earth. This idea, first suggested by Bruno Pontecorvo and Vladimir Gribov in 1969, explained the missing neutrinos. Later experiments, including Super-Kamiokande in Japan and the Sudbury Neutrino Observatory in Canada, confirmed these oscillations, solving the long-standing mystery. Today, neutrino research continues to offer insights into the origins of the universe, the nature of dark matter, and even the Earth's interior.