The universe is unbelievably big – trillions of stars and even more planets. Soo… there just has to be life out there, right? But where is it? Why don’t we see any aliens? Where are they? And more importantly, what does this tell us about our own fate in this gigantic and scary universe?
The Hayabusa2 spacecraft has just completed one of the most intricate procedures in space exploration. The first mission to deliver rovers onto an asteroid has now descended to its surface for a sample, before returning back to Earth in 2020.
Where are all the aliens? The universe is too big and too old, why have we not met aliens yet? Do they live in computers? Were they wiped out by an ancient super intelligence? Or are we just to primitive to understand their motives? Whatever the answer is, it is incredibly important for our own future.
Today we’re rounding out our planetary tour with ice giants Uranus and Neptune. Both have small rocky cores, thick mantles of ammonia, water, and methane, and atmospheres that make them look greenish and blue. Uranus has a truly weird rotation and relatively dull weather, while Neptune has clouds and storms whipped by tremendous winds. Both have rings and moons, with Neptune’s Triton probably being a captured iceball that has active geology.