“An ancient Greek scientist, Eratosthenes, calculated the size of the Earth using shadows. He was less than 1% off.”

"And it is this outward flow of energy that keeps the star from imploding. So when the fuel runs out, thats exactly what happens."

Editor's note: Pulsars are rapidly spinning neutron stars, extremely dense stars composed almost entirely of neutrons and having a diameter of only 20 km (12 miles) or less.

Editor's note: According to the Royal Museums Greenwhich, The Pleiades were "one of the most easily recognisable star clusters in the night sky is the Pleiades, also known as the ‘Seven Sisters’ or M45."

Editor's note: While we don't know of any ratio like this, we can't say it's 100% unique.

"100-400 billion stars in our galaxy alone. Estimated upwards of 2 trillion galaxies in the observable universe, which for all we know might only be a tiny fraction.

So that’s roughly 800,000,000,000,000,000,000,000 stars, each likely with planets, moons, and entire systems.

To quote Carl Sagan, we really are just a mote of dust suspended in a sunbeam."

"The sun produces so ridiculously much energy that even here on earth 150 million km away it can be blazingly hot in the midday sun.

But if you took 1m3 of the sun's core, and compared it to 1m3 of human body, our human bodies actually output more energy per volume. It's just that the sun is unimaginably large."

Editor's note: Data from Hubble and the European Space Agency’s Gaia space telescope suggests there is less certainty about the collision of the two galaxies, with there being roughly a 50% chance of the merge in the next 10 billion years. 

Additional thumbnail credits: Sony Pictures Releasing International, Alex-mit / Getty Images/iStockphoto