It mainly depends on the telescope please be more specific if you want a more specific answer.
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If you had a telescope on a planet 3000 light years away and zoomed in on Earth, you would see the Earth as it was 3000 years ago. Due to the time it takes for light to travel, you would not be seeing Earth in real-time, but rather how it appeared 3000 years in the past.
13.7 billion light years is as we can see. This is because the light is still traveling to us and we are yet to see it.
A telescope can cover distances of thousands or even millions of light-years, depending on its size and capabilities. Telescopes can observe objects in the far reaches of the universe, allowing us to study celestial bodies that are incredibly distant from Earth.
Something like 14 billion light years. That's a great distance compared to the length of my kitchen. But we don't know how big it is compared to the size of the whole universe, because we don't know how much farther past that the universe extends.
The Hubble Space Telescope can see objects billions of light-years away, allowing it to observe galaxies, stars, and other celestial objects located far beyond our own Milky Way galaxy. It has contributed significantly to our understanding of the universe's vastness and complexity.
you can see planets but using telescope or the kepler mission or satellites, though if you are using a telescope, what you see is not how the planet is right now because of the speed of light. Even when you look in the mirror, you are seeing yourself, but in fact you are look at yourself which is a billionth of a second ago. Also the sun light, it takes 8 minutes for the sun light to hit the Earth.
The M31 in Andromeda is, estimated at 2.5 million light years away.
12.8 billion light years away.
The Chandra telescope was built to observe X-rays.
With the naked eye, you can see stars up to about 1000 light years away. You can also see the Andromeda Galaxy. That's about 2.5 million light years away. That's the most distant object visible to the naked eye. Binoculars show it easily. With a 3" refracting telescope can see stars down to at least magnitude 9, plus some galaxies beyond Andromeda. The biggest telescopes can see to over 10 billion light years.
The Hubble telescope with the light-collecting power of the W. M. Keck Telescopes can see 13 billion light years away based on the furthest detected galaxy to date. In comparison looking up into the sky on a very clear night, the Triangulum Galaxy can sometimes be seen by the naked eye. This is a distance of 3.14 million light years. The Andromeda Galaxy is also sometimes visible. This is a distance of 2.5 million light years.