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 ...

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 ...

Supernovas are some of the brightest events in the universe, occasionally outshining entire galaxies at their peak. Many supernovas can be seen from billions of light-years away, and nearby supernovas ...

Looking for hidden structures and unusual stars that reveal the Milky Way’s history. Since our galaxy grew by merging with and eating other galaxies, traces of that violent past are visible in the ...

All the atoms and light in the universe together make up less than five percent of the total contents of the cosmos. The rest is composed of dark matter and dark energy, which are invisible but ...

As astronomers build increasingly larger observatories capable of seeing more objects in the sky, the amount of data they collect has gone beyond what humans can analyze without help. Instead, ...

Capturing the first image of a supermassive black hole using the Event Horizon Telescope (EHT). This image of the black hole at the center of the nearby galaxy M87 reveals how gravitation affects the ...

Throughout the last century of scientific discovery, as well as the history of popular culture and science fiction, black holes have been a source of fascination and mystery. One thing is certain: ...

Finding and describing new exoplanets using TESS and other observatories. TESS is designed to observe stars closer to the Solar System than those studied by other observatories, providing targets for ...

The Center for Astrophysics | Harvard & Smithsonian Radio & Geoastronomy (R&G) division explores the Universe using the low-energy portion of the electromagnetic spectrum, including the radio, ...