Cygnus X-1
Astronomy

The Discovery of Black Holes: From Theory to Actuality

December 27, 2019

Although Einstein was skeptical about the existence of black holes, his own theory suggested otherwise. Bringing us closer to the discovery of black holes was an observation regarding the behavior of collapsing stars. A mysterious object called Cygnus X-1 at last delivered proof. […]

gamma rays burst from a dying star
Astronomy

Star Collapse and Black Holes: Exploring the Connection

December 9, 2019

What gives stars their power? And what happens when a star runs out of fuel? Exploring the various theories behind star collapse and the stages of collapse—including white dwarfs and neutron stars—eventually leads us to black holes. […]

The first image taken of a black hole
Astronomy

Einstein on Black Holes: Why He Rejected His Own “Child”

December 9, 2019

Black holes are a direct consequence of Einstein’s Theory of General Relativity. However, when examining the views of Einstein on black holes, we see that he was skeptical. Interestingly, an astronomer’s efforts to solve Einstein’s field equations end up pointing toward the existence of black holes. […]

An artistic rendering of a solar eclipse
Astronomy

Eclipse Glasses Not Required

August 21, 2017

The Smithsonian Astrophysical Observatory has created a free Smithsonian Eclipse app, allowing users to watch a live NASA stream of the eclipse as it moves across the country. […]

image of the eagle nebula by the hubble telescope
Astronomy

Hubble Images—Exploring the Birthplace of Stars

June 27, 2017

Among the incredible Hubble cloud images, none has been received with greater public acclaim than the detailed 1995 snapshot of newborn stars emerging from giant pillars of gas and dust inside the Eagle Nebula. This image looks like a fantasy landscape out of a dream or a children’s story. Get ready to explore this image in the context of galactic interstellar clouds, the process of star formation, and the impact of young stars on their interstellar environments. […]

Astronomy

Stonehenge: A Remarkable Relic of Archeoastronomy

February 9, 2017

Ancient astronomers achieved remarkable feats that were built on many thousands of years of watching the sky. How did they accomplish so much without using the technology we have available today? Welcome to the study of archeoastronomy. […]

Moons of the Solar System
Astronomy

Great Moons of Our Solar System

January 6, 2017

By Frank Summers, Ph.D, Space Telescope Science Institute Everyone memorizes the names of the eight planets. But how many of us have memorized the seven […]

Dark matter in the center of galaxy cluster Abell 520
Astronomy

Dark Matter: MACHOs or WIMPs?

December 14, 2016

By Sean Carroll, Ph.D., California Institute of Technology In the hunt for dark matter, there are several candidates that could make up this mysterious substance. One of […]