In 1981, Luis (left) and Walter Alvarez collected samples of layered sedimentary rocks in Gubbio, Italy, at the 65-million-year-old boundary between the Cretaceous (lower) and Paleogene (upper, formerly called Tertiary) geologic time periods.
1980: The Alvarez Hypothesis – Linking Asteroid Impact to Mass Extinction

The Alvarez Hypothesis suggests an asteroid impact caused the mass extinction at the K-Pg boundary, highlighted by the high iridium levels in Italian clay and the Chicxulub crater discovery

On May 18, 1980, Mount St. Helens, a stratovolcano in southwestern Washington State, USA, experienced a violent eruption, spewing ash and steam into the atmosphere.
1980: The Explosive Eruption of Mount St. Helens

The 1980 eruption of Mount St. Helens, marked by a massive ash cloud and landscape devastation, highlighted the explosive power of Cascade volcanoes

The world is now more electronically interconnected than ever before, resembling a vast spider's web of connectivity.
1979: The Evolution of the Internet – From Mainframes to the World Wide Web

The internet, evolving from 1950s mainframe computers to today's World Wide Web, revolutionized communication and information access globally

A 2006 photo of a wind turbine farm located between the San Jacinto and San Bernardino mountains near Palm Springs, California. This wind farm, comprised of more than 4,000 turbines, generates sufficient electricity to supply power to Palm Springs and the neighboring Coachella Valley.
1978: Harnessing the Power of Wind – The Evolution of Wind Energy

Wind power has evolved from ancient windmills to modern turbines, becoming a key player in global renewable energy with a growing contribution to electricity generation

Black smokers and tube worm communities at "Strawberry Fields" in the Endeavour Hydrothermal Vent Field in the northeastern Pacific Ocean, situated approximately 7,380 feet (2,250 meters) below sea level.
1977: Exploring Deep-Sea Hydrothermal Vents – Earth’s Underwater Volcanic Wonders

Deep-sea hydrothermal vents, discovered in the 1970s, are underwater volcanic structures hosting unique ecosystems reliant on chemosynthesis

Main image: A 12-inch-diameter (30.5 centimeters) gold-plated copper disc called the Voyager Golden Record. Two of these discs are carrying recorded songs, greetings, and images from Earth on a journey through the galaxy. Inset: An artist's concept of the Voyager spacecraft.
1977: Voyager Golden Record – Humanity’s Cosmic Time Capsule

NASA's Voyager probes carry the Golden Record, a cosmic time capsule showcasing Earth's diversity and culture, designed to last billions of years in space

A 2007 photograph of thriving temperate vegetation along the Hall of Mosses Trail in the Hoh Rainforest, located in Olympic National Park, Washington state, USA.
1976: Exploring the Lush World of Temperate Rainforests

Temperate rainforests, distinct from tropical rainforests, are rich ecosystems found in specific global regions. Characterized by heavy rainfall and old-growth forests, they include the renowned Hoh Rainforest in the Olympic National Park, a UNESCO Biosphere [...]

High-resolution image of a single-celled bacterium called Magnetospirillum magnetotacticum, or MS-1, containing a linear chain of magnetosomes composed of the mineral magnetite. The cell measures approximately 0.00008 inch (2 microns) in length.
1975: Unveiling the Mystery of Magnetoreception – Nature’s Unique Navigation System

Magnetoreception, a unique navigational sense observed in various species, allows alignment with Earth's magnetic field. Discovered by Salvatore Bellini and further studied by Richard Blakemore, this sense remains a captivating mystery in animal behavior and [...]

Gorgeous clusters of Monarch butterflies occupying limited spaces as they "overwinter" among trees in the Monarch Butterfly Biosphere Reserve in Angangueo, Mexico.
1975: The Remarkable Journey of Monarch Butterflies – Unraveling the Mysteries of Insect Migration

Fred Urquhart's groundbreaking research on Monarch butterflies revealed their extraordinary 2,000-mile migration, a multi-generational journey that remains a subject of fascination and study in the world of insect migration

An illustration (not to scale) depicting over two dozen GPS satellites orbiting approximately 12,500 miles (20,000 kilometers) above the Earth's surface, with an orbital tilt of about 55°. The system is designed to ensure that at least four satellites are visible, positioned at least 15° above the horizon, anywhere in the world at any given time.
1973: The Evolution and Impact of the Global Positioning System (GPS)

GPS, initially a military technology, has evolved into a critical global tool for navigation, communication, and scientific research, with widespread civilian and commercial applications