light
Smaller, Ground-Based Telescopes can Study Exoplanet Atmospheres too
The next step to understanding exoplanets is to understand their atmospheres better. Astronomers can determine a planet's mass, density, and…
How Far Does Light Travel in a Year?
Light travels at a speed of 299,792,458 m/s (1080 million km/h; 671 million mph), which works out to about 9,460.5…
Finite Light — Why We Always Look Back In Time
Light's finite speed make all gazing a ride in a time machine. Only a photon truly lives in the moment.
How Does Light Travel?
Since ancient times, scientists have debated the true nature of light. Despite the progress we've made, there are still mysteries…
Astronomy Cast Ep. 412: The Color of the Universe
What color is the Universe? Turns out this isn't a simple question, and one that scientists have really been unable…
Astronomy Cast Ep. 411: The Science of Sunset Colors
We all enjoy beautiful, multicolored sunsets. But what causes the brilliant oranges, pinks and purples that we see, and why…
Astronomy Cast Ep. 405: Method Not Found
Last week we talked about knowledge, what we do and don’t know. This week we talk about questions which are…
Astronomy Cast Ep. 398 – Seeing Things: Emitting, Reflecting, Ionizing Light Sources
Astronomers gather electromagnetic radiation with the telescopes: mostly visible light. But sometimes they've got to be clever about where they…
The Journey of Light, From the Stars to Your Eyes
This week, millions of people will turn their eyes to the skies in anticipation of the 2015 Perseid meteor shower. But what happens on less…
A Red Moon – NOT a Sign of the Apocalypse!
On most evenings, the Moon will appear as a bright yellow or white color in the night sky. But on…