The Moon has been one of the most important theoretical stepping stones to our understanding of the universe. We’ve long understood that it could also be our literal stepping stone: humanity’s first destination beyond our atmosphere.

It never gets dark anymore. Not REALLY dark, anyway. Not like it used to. Light pollution is not only making it more difficult to see the night sky, but it's also affecting our health. For the past century and a half, since the dawn of...

Why does everyone use a 7 day week, and where did it come from? Where do the names of the days come from? And who can we blame for Mondays? Here’s the true story of one of the oldest human customs still in use today. It gets a little...

In this video Paul Andersen shows conceptual thinking in a mini-lesson on molecular-level structures.


TERMS
Molecular-level structures - locations of atoms in
a molecule
Function - an activity or purp
ose for a...

A mini-lesson on patterns at varying scale.

in this video Paul Andersen shows conceptual thinking in a mini-lesson on INSERTTITLEHERE.


TERMS
Complex structures - structures that consist of many different and conne
cted parts
Microscopic structures - structures...

These three stars can easily be seen with the naked eye, but it took some fancy telescopes for us to realize how weird they really are!

When photographed under a 3D microscope, grains of sand appear like colorful pieces of candy and the stamens in a flower become like fantastical spires at an amusement park. Gary Greenberg reveals the thrilling details of the micro world.

Join the Amoeba Sisters in discovering how to use a dichotomous key to identify organisms. This video also touches on the importance of scientific names. Table of Contents: Intro 00:00 What is a Dichotomous Key? 0:29 Scientific Names vs....

Astronomers are predicting that two stars are likely to merge and explode, and it may happen soon... on a cosmic timescale. Plus, scientists break up a meteorite and find the oldest solid matter ever discovered on earth.

Astronomers once gazed upon the night sky and counted every star in the galaxy by hand. The process has evolved since then, but the thirst for celestial knowledge remains the same. Join astrophysicist Emily Levesque for an anecdote-rich...

Before moving on from Jupiter to Saturn, we’re going to linger for a moment on Jupiter’s moons. There are 67 known moons, and 4 huge ones that we want to explore in greater detail. Ganymede is the largest - larger, in fact, than any...

Wanda Diaz Merced studies the light emitted by gamma-ray bursts, the most energetic events in the universe. When she lost her sight and was left without a way to do her science, she had a revelatory insight: the light curves she could no...

This week we build on our naked eye observations from last week and take a look at the cyclical phenomena that we can see at work in the universe.

Today on Crash Course Astronomy, Phil invites you to head outside and take a look at all the incredible things you can see with your naked eye.

How many stars are there in the universe? This question leads Hank to a couple other questions - How many stars can we see from Earth? How many stars are there in our galaxy? - but the answer to the original question proves elusive.

The Andromeda galaxy is heading straight toward our own Milky Way. The two galaxies will inevitably collide. Will that be the very last night sky our solar system witnesses?

Paul Andersen shows you how to find stomata in a dicot and monocot leaf using finger nail polish and transparent tape. A microscope is required to actually see the stomata.

Howcast - Buying a diamond ring is one of the biggest investments you’ll ever make, so get the most bling for your buck.

Howcast -Learn about diamond clarity grading from private jeweler Kate Hemphill in this Howcast video.

Since the invention of the first light microscope, microscopy has evolved so much. We are now able to see things at an atomic level. In this video, we will learn who invented the light microscope and the many other breakthroughs that...

We deal with light on a daily basis, and it has wave-like characteristics that are essential to many natural and technological processes. The wave nature of light aids in the explanation of a number of important optical phenomena,...

How and why scientists are searching for Planet X / Planet Nine / Planet 9.

Find out how you can view T. Coronae Borealis, the new visitor in our night sky.