The universe is so vast that we might have to wait a really, really long time before picking up any alien signals. And even if we do hear something, it might be too late. Imagine getting a message from someone, but they sent it ages ago, and by the time it reaches us, they could be history. If you use Drake's equation and figure there could be 10,000 intelligent civilizations, consider this: there are around 250 billion stars in our galaxy. That's like looking for one specific house in a city of 25 million houses. #space #universe #cosmos