By Saurabh
Astronauts report that space leaves a distinct scent on their suits, like hot metal or seared steak. It’s caused by atomic oxygen and dying stars’ molecules reacting when exposed to air inside spacecraft.
Not all planets have stars. Billions of “rogue planets” drift through the galaxy in complete darkness, unanchored to any solar system.
If you could scoop a sugar-cube-sized chunk of a neutron star, it would weigh about a billion tons on Earth. That’s the mass of every human on Earth, in your hand.
Einstein was right: time slows down near strong gravity. For example, near a black hole, a few hours could equal thousands of years elsewhere in the universe.
What we see, stars, planets, galaxies, makes up less than 5% of the cosmos. The rest is dark matter (27%) and dark energy (68%), which we still don’t fully understand.
Astronomers estimate 200 billion trillion stars exist in the observable universe, far more than all the grains of sand on Earth’s beaches.
Hercules–Corona Borealis Great Wall, a massive cluster of galaxies, spans over 10 billion light-years. That’s one-tenth the size of the entire observable universe!