How do telescopes see so far into space? Since celestial bodies are thousands & millions of light years away, How can NASA telescopes capture an image of planets & galaxies that far?

Question

I quite frankly understand the concept of light years and how light has to travel before we (humans on earth) can process that image. For example, the sun that we see in the sky is actually the sun 8 minutes prior to when we were viewing it, because it takes 8 minutes for the light of the sun to travel to earth.

With that, how do these mega-telescopes work (Hubble and James Webb)? And does it mean we’ll never be able to see how planets and galaxies look in present time?

In: 15

Answer 1

>And does it mean we’ll never be able to see how planets and galaxies look in present time?

Not unless we figure out how to break the laws of physics as we currently understand them. We would have to figure out a way to make something travel faster than light. Either a signal or a ship. Right now we can only send signals at light speed. Ships travel significantly slower.

JWST and Hubble work by using very large mirrors to reflect and focus light onto a sensor. The larger the mirror, the more light it can collect. The idea that telescopes see farther into space is misleading. We “see” just as far as they do when we look up into the night sky. Our eyes just aren’t sensitive enough to register the light coming from extremely distant or dim objects. But we can still see stars hundreds of light years away. Our eyes and telescopes aren’t magically reaching out into the distance to detect things. They are both sensors that wait for a signal to reach them. The difference is the area used to collect the signal and the sensitivity of the sensor. Telescopes use extremely sensitive sensors and will take hours or days or weeks staying focused on a single object to gather enough light for a single image.