Along with the major planets — Earth, Jupiter, and so forth — the Solar System is home to many small bodies including asteroids, comets, Kuiper Belt objects like Pluto, and their satellites. While the ...

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 ...

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 ...

CfA astronomers helped lead a study discovering changes in the bright ring around M87's black hole, confirming the theoretical understanding of the variable and turbulent flow of material around black ...

The Milky Way is our galactic home, part of the story of how we came to be. Astronomers have learned that it’s a large spiral galaxy, similar to many others, but also different in ways that reflect ...

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 ...

When stars die, their fate is determined by how massive they were in life. Stars like our Sun leave behind white dwarfs: Earth-size remnants of the original star’s core. More massive stars explode as ...

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 ...

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 ...

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 ...

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 ...

Mapping the structure of galaxy clusters using the hot plasma that fills the space between galaxies. Even though this plasma’s density is low, its temperature can reach hundreds of millions of degrees ...