Spring, Summer, Autumn and Winter. These are the seasons we experience here on Earth as our planet completes an orbit around the Sun. But what’s going on? Why do we experience such different temperatures and weather over the course of 365 days? Do other planets experience the seasons like we do?

We’ve all seen the classic science fiction space explosions, full of flames and loud sounds. Beautiful on the screen but, totally lacking in any kind of… science. What’s wrong with science fiction? What would chemical and nuclear explosions really look like? What would we hear? And what are some natural explosions that nature detonates in space?

In order to allow for a static Universe, Albert Einstein introduced the concept of the Cosmological Constant Lambda to make the math work out. Once it was discovered that the Universe was actually expanding, he threw the number out calling it his “biggest blunder”. But thanks to dark energy, the Cosmological Constant is back.

When Edwin Hubble observed that distant galaxies are speeding away from us in all directions, he discovered the reality that we live in an expanding Universe. Hubble worked to calculate exactly how fast this expansion is happening, creating the Hubble constant – which astronomers continue to refine and reference in their research.