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5

Yes, isotopic ratios can be readily established by spectroscopy. Molecules where the constituent atoms differ by one mass unit have different vibrational and rotational energy levels and the gaps between them depend on the reduced mass of the molecule. For example, in a diatomic molecule $$ \mu = \frac{m_1 m_2}{m_1 + m_2}$$ and the vibrational frequencies ...


1

This might not be the type of telescopes your are thinking about, but as IACTs (Imaging Atmospheric Cherencov Telescopes) in the end also measure light in (or near) the optical range, their mirrors are of similar build. The important arrays (H.E.S.S., VERITAS and MAGIC) have, at least partially, mirrors made of glass or with a glass surfaces, coated on the ...


3

You've pretty much answered it yourself. Very large telescopes are expensive to build, and there are diminishing returns for large instruments operating under Earth's atmosphere. Air turbulence (what is known as "seeing") limits the resolving power of the telescope - its ability to distinguish small details and make high resolution images. It's an ...


0

I'd like to add more inputs on the physics behind telescope resolution. The telescope resolution is given by its primary mirror size which produces a "quasi" punctual image for each light source it sees, that is called a airy disk. The airy disk size is inversely proportional to the telescope primary mirror diameter and like pixels on a LCD screen the lower ...


4

Amateur telescope and mirror maker here. Not sure if I qualify as a "citable source" but anyway, here it is: All metals will eventually tarnish. It may take a long time, but it will happen. The process is not entirely chemical always. Sometimes it's purely mechanical (abrasion). Other times it's in between. Surface phenomena are complex. Even gold-coated ...


7

Aluminium coating is a relatively recent process - it became available around the 1920s or 1930s. The Hale telescope arrived just in time to take advantage of this new technology. (It requires a reasonably good vacuum to work, which probably explains why it took a while to come along.) Before that - around the mid-1800s - various chemical "silvering" ...


0

Light pollution isn't as much of a problem in space as it is on Earth because you're in a vacuum. Imagine making a small black disk and holding it up at arms-length to cover the Sun....it's not going to simulate the effects of an eclipse, you're not going to get to see the corona and background stars because the rest of the sky is still flooded with light - ...


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As Joe Blow explains, there is an orbit, at the L2 point, 1.5 million km directly further away from the Sun/Earth, where a satellite could remain permanently in the Earth's shadow, though it would not be completely shadowed - the Sun would still appear as a narrow ring around the blocking Earth This would be a great advantage in terms of cooling the ...


3

The mindboggling GAIA spacecraft-telscope sort of does what you suggest! That's kind of the closest concept to what you describe. Just as explained in JamesS answer, if you were that far away you wouldn't be in orbit around the Earth. But, GAIA's L2-like orbit is kind of the closest thing to what you say. Explanation: https://en.wikipedia.org/wiki/Gaia_(...


3

Its a nice idea, but it wouldn't work. To stay in the Earth's shadow a telescope would need to orbit the Earth in the same time the earth orbited the Sun so that it always stayed on the opposite side. For its orbit to be this long it would need to be a long way out, remember geosynchronous orbit (one orbit in 23h 56min 4sec) is at a distance of 42,164 km. ...



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