Any images at all from space even, like with Hubble and JWST. They seem so unfathomably far away.
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Same way we send TV signals around the world: radio waves. They’re the ideal medium for long range communications, and we’ve been making better and better antennas for over 100 years.
Robotic probes in deep space communicate with Earth using ‘high-gain’ radio antennas, which are designed to send a very narrow beam of radio waves in one very specific direction. By keeping the waves tightly focused, you can greatly reduce the drop-off in signal strength over distance, though you have to aim the antenna very carefully. There’s also a network of *massive* radio antennas down here on Earth, which are designed to listen carefully to a very small area of sky, aimed at the spacecraft’s expected location.
There’s a network of giant antennas and radio telescopes called across the globe called the Deep Space Network that handles this work.
Those aren’t even far away. Voyager 1 and 2 were launched in 1977. Voyager 1 is almost 15,000,000,000 miles away and we are still recieving data. That’s 15 billion. Pluto is 3 billion miles.
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