Posts by 

Christopher Crockett

What are elliptical galaxies?

Elliptical galaxies are among the largest single star systems in the universe and are built by the collisions of many smaller galaxies.

What lives between the stars?

The interstellar medium is the stuff between the stars. Made up mostly of hydrogen and helium gas, it contains all the material needed to make stars and planets. It is shaped by stellar winds, dying stars, galactic magnetic fields, and supernova explosions.

Why does the sun shine?

The sun generates about 400 billion billion megawatts of power and it has done so for five billion years. Nuclear fusion - combining lighter atoms to make heavier one - is what makes it possible.

What is a black hole?

Black holes are the remnants of very massive stars with gravity so strong that not even light can escape.

Spiral arms found inside an elliptical galaxy

Astronomers have discovered young spiral arms in the center of the giant elliptical galaxy Centaurus A. The spiral arms formed shortly after a collision with another galaxy several hundred million years ago.

What is the apogalacticon?

The apogalacticon marks where the sun is farthest from the heart of the Milky Way on its 250 million year orbit around the galactic center.

X-rays reveal the violent side of the universe

X-ray astronomy studies interstellar gas heated to millions of degrees around extreme environments like black holes, neutron stars, and colliding galaxies.

How VLBI reveals the universe in amazing detail

Very Long Baseline Interferometry, or VLBI, links together widely separated radio telescopes to allow astronomers to see the universe in more detail than ever.

Colliding galaxies become hotbeds of star formation

These Ultra Luminous InfraRed Galaxies emit a trillion suns worth of infrared light, driven by bursts of star formation in colliding galaxies.

What is sidereal time?

Explanation of sidereal time, or star time. New Year's celebrations on Mercury. How Venus spins backwards and is the slowest rotating planet in the solar system.