How Mars may have looked about four billion years ago

How Mars Lost Its Magnetic Field—and Then Its Oceans

Chemical changes inside Mars's core caused it to lose its magnetic field. This, in turn, caused it to lose its oceans. But how?
Coal mining, Anthracite Region of Pa. Loaded cars being placed on cage to be raised to surface. Post card from between circa 1930 and circa 1945.

When Did Americans Start Using Fossil Fuel?

The nineteenth-century establishment of mid-Atlantic coal mines and canals gave America its first taste of abundant fossil fuel energy.
Young female and her little son planting tree in one of city parks on summer day

Building Community and Urban Tree Canopy

Long before the COVID-19 pandemic, Black communities and other reformers in New York City recognized the ameliorative social effects of greening urban spaces.
International Gemini Observatory/NOIRLab/NSF/AURA/B. O'Connor (UMD/GWU) & J. Rastinejad & W Fong (Northwestern Univ) Image processing: T.A. Rector (University of Alaska Anchorage/NSF’s NOIRLab), J. Miller, M. Zamani & D. de Martin (NSF’s NOIRLab)

Explaining GRB 221009A, the Greatest Cosmic Explosion Humanity Has Ever Seen

The brightest gamma-ray burst ever observed, GRB 221009A behaved in unexpected ways that might help us understand how they occur.
Nelsa Teresinha sits on the debris of her house which was destroyed by the flood on September 7, 2023 in Muçum, Brazil.

What’s A World Without Climate Justice?

The climate crisis has weaponized emergency for the sake of action, overlooking the injustices inflicted on vulnerable communities for centuries.
Ali Wallace, 1905

Ali: Alfred Russel Wallace’s Right-Hand Gun

Wallace wouldn't have become a famous naturalist without help from colonial networks and hundreds of locals, including his indefatigable Sarawak servant, Ali.
Guarana Fruit

Guaraná: Stimulation from the Amazon to the World

Long cherished by Indigenous peoples for its medicinal and stimulating properties, guaraná remains a key element of Brazilian identity.
Aerial view of Barringer crater in Arizona

The Eight Best Hidden Impact Craters on Earth

Many impact craters on Earth have been erased thanks to wind, water, and plate tectonics. But scientists have clever ways to find them.
Enigma machine

Teaching AI, AKA Artificial Intelligence

AI is everywhere. So naturally, we pulled together a syllabus of stories on the subject. Use these to inspire classroom discussion or educate your grandpa.