Everything you’ve ever seen or experienced on Earth was once a nebulous collection of floating gas and dust. Science is starting to understand how those particles came to take the forms you recognize ...

Stars have a life cycle: they’re born, they pass through middle age, and they die. The birth of a star determines much of how it lives that life. For that reason, researchers study star-forming ...

The Center for Astrophysics | Harvard & Smithsonian High Energy Astrophysics division focuses on X-ray astronomy and instrumentation involved in observations of high-energy sources. This research aims ...

For the first 380,000 years or so after the Big Bang, the entire universe was a hot soup of particles and photons, too dense for light to travel very far. However, as the cosmos expanded, it cooled ...

Matter and energy are the two basic components of the entire Universe. An enormous challenge for scientists is that most of the matter in the Universe is invisible and the source of most of the energy ...

Stars are the source of almost all of the light our eyes see in the sky. Nuclear fusion is what makes a star what it is: the creation of new atomic nuclei within the star’s core. Many of stars’ ...

The Center for Astrophysics | Harvard & Smithsonian Solar, Stellar & Planetary Sciences (SSP) division research is directed toward understanding star and planet formation and the physical processes in ...

About 13.8 billion years ago, the Big Bang gave rise to everything, everywhere, and everywhen—the entire known Universe. What caused the Big Bang? What happened that first moment at the beginning of ...

Humans have studied the stars for thousands of years. To many cultures, stars were the metaphor for constancy, while everything else moved and changed. Modern stellar astronomy showed that stars do ...

The Sun is the best laboratory we have for studying stars and how they influence the planets orbiting them. Space- and ground-based observatories monitor day-to-day fluctuations in the Sun’s light, ...

Black holes are some of the most fascinating and mind-bending objects in the cosmos. The very thing that characterizes a black hole also makes it hard to study: its intense gravity. All the mass in a ...

Interstellar space — the region between stars inside a galaxy — is home to clouds of gas and dust. This interstellar medium contains primordial leftovers from the formation of the galaxy, detritus ...