pdf link to paper
Astronomer: We can use earth’s atmosphere as a massive telescope

Distant starlight passing through the Earth’s atmosphere is refracted by an angle of just over onedegree near the surface. This focuses light onto a focal line starting at an inner (and chromatic)boundary out to infinity – offering an opportunity for pronounced lensing.

more…

YouTube Video
Turning Earth Into a Telescope | The Terrascope

When it comes to telescopes, bigger is better. That’s why we’re investing billions of dollars into a new generation of “extremely large telescopes”, such as the Thirty Meter Telescope (TMT). But is 30 meters truly extreme? Could it be possible to ever build a telescope on the scale of a planet? In a new research paper by our very own Professor David Kipping, a solution for turning the Earth into a “Terrascope” is presented. Join us on a journey though the history of telescope inventions as well David’s own personal journey to devising this new radical approach to the telescope.

Tau.Neutrino said:

pdf link to paper
Astronomer: We can use earth’s atmosphere as a massive telescope

Distant starlight passing through the Earth’s atmosphere is refracted by an angle of just over onedegree near the surface. This focuses light onto a focal line starting at an inner (and chromatic)boundary out to infinity – offering an opportunity for pronounced lensing.

more…

Read the pdf. Ok, it makes sense. Or does it?

Let’s think this through, at midday, any time during the day, out to late at night, the light the telescope would observe would be swamped by sunlight scattered off the Earth.

So it would only be useful for objects near the Sun. But then even if the light from cities was masked, then the light received would still be swamped by both sunlight refracted in a ring through the atmosphere and reflected moonlight.

So, mollwollfumble’s proposed “blind spot telescope” is better.

mollwollfumble said:

Tau.Neutrino said:

pdf link to paper
Astronomer: We can use earth’s atmosphere as a massive telescope

Distant starlight passing through the Earth’s atmosphere is refracted by an angle of just over onedegree near the surface. This focuses light onto a focal line starting at an inner (and chromatic)boundary out to infinity – offering an opportunity for pronounced lensing.

more…

Read the pdf. Ok, it makes sense. Or does it?

Let’s think this through, at midday, any time during the day, out to late at night, the light the telescope would observe would be swamped by sunlight scattered off the Earth.

So it would only be useful for objects near the Sun. But then even if the light from cities was masked, then the light received would still be swamped by both sunlight refracted in a ring through the atmosphere and reflected moonlight.

So, mollwollfumble’s proposed “blind spot telescope” is better.

Could a large ring of light in space be used in this way like a galaxy lens, say the colour of the ring could be changed?

Tau.Neutrino said:

mollwollfumble said:

Tau.Neutrino said:

pdf link to paper
Astronomer: We can use earth’s atmosphere as a massive telescope

Distant starlight passing through the Earth’s atmosphere is refracted by an angle of just over onedegree near the surface. This focuses light onto a focal line starting at an inner (and chromatic)boundary out to infinity – offering an opportunity for pronounced lensing.

more…

Read the pdf. Ok, it makes sense. Or does it?

Let’s think this through, at midday, any time during the day, out to late at night, the light the telescope would observe would be swamped by sunlight scattered off the Earth.

So it would only be useful for objects near the Sun. But then even if the light from cities was masked, then the light received would still be swamped by both sunlight refracted in a ring through the atmosphere and reflected moonlight.

So, mollwollfumble’s proposed “blind spot telescope” is better.

Could a large ring of light in space be used in this way like a galaxy lens, say the colour of the ring could be changed?

No Gravity to bend the light

black holes as galaxy lens telescopes have been proposed

the telescope orbits the black hole and captures the lensing?

Tau.Neutrino said:

Could a large ring of light in space be used in this way like a galaxy lens, say the colour of the ring could be changed?

No Gravity to bend the light

black holes as galaxy lens telescopes have been proposed

the telescope orbits the black hole and captures the lensing?

The colour of the ring, yes. But it would be a heck of a task to remove the sunlight (more than 250,000 times brighter) from the result, and the colour of a galaxy is similar to the colour of our Sun.

You don’t need gravity to bend light if you have refraction from the atmosphere.

Black holes are problematic because there are none nearby, because those we know about generate a lot of light from the accretion disk, because a solar mass black hole is only about 6 km across, and because it’s the wrong shape to focus well.

A better option would be to use the atmosphere of a planet further from the Sun. Not Saturn because the light from the rings would get in the way. Similar problems with moons that have atmospheres, the light from the planet would interfere. Jupiter, Mars, Venus, Pluto and Eris wouldn’t be as good as Uranus or Neptune, i suspect (but could be wrong).

Uranus or Neptune? They’re far enough out to have less problem with sunlight. Have thick atmospheres. Smaller moons than Earth’s moon so less problems with moonlight. Large diameter collects more light. No city lights to worry about. Vaguely possible. I think it could work.