Light tells the story of the universe. Since light takes time to travel, the farther out into space we look:
What is the most distant thing in space that we can see without a telescope?
In the 1920s, Edwin Hubble and fellow astronomers at Mount Wilson Observatory were the first to discover galaxies beyond the Milky Way. What else did they discover?
According to the Big Bang theory, the universe was born about 13.8 billion years ago. At the moment of the Big Bang, the universe was:
In 1964, astronomers working with a radio telescope in New Jersey accidentally discovered something that came to be known as the cosmic microwave background. What was it?
In 2009, the Planck satellite was launched into space to measure light in the microwave band. It orbits:
Albert Einstein's famous equation E=mc2 shows the relationship been an object's mass (m) and its energy (E). What does 'c' represent?
Normal matter is everything we can touch and see, including dogs, trees, planets, stars, and galaxies. It makes up how much of the total mass-energy in our universe?
Dark matter is invisible, so how do scientists know it exists?
How did dark energy get its name?