STEM Challenges

Dark energy is the dominant component of the universe — yet we have almost no idea what it is. Explore the leading explanations, from Einstein's cosmo...

In 1998 two rival teams of astronomers set out to measure how fast the universe's expansion was slowing down. What they found instead shook cosmology ...

Scientists around the world are using extraordinary experiments — from detectors buried miles underground to the world's most powerful particle accele...

We know dark matter is real — but we have no idea what it is made of. Scientists have proposed many candidates, from exotic new particles to ancient b...

Einstein's general relativity predicts that mass bends light. Astronomers have turned this effect into a powerful tool to map the invisible — using th...

In the 1970s, astronomer Vera Rubin made a startling discovery: stars at the edges of galaxies orbit just as fast as stars near the center. This defie...