What astronomy tools have been used to study Neptune?

Answer 1

Well, we can take pictures in different filters, which bring out different features. We also take spectra, which can tell us the composition of the atmosphere. Detailed position analysis can be done by taking lots of pictures to figure out the mass and so forth.

Answer 2

In 1613, Galileo observed Neptune with his telescope at a moment when it happened to be very near Jupiter, but he thought it was just a star and did not know or realise what he was looking at.

So one tool we use is our brains and their ability to figure out and make sense of what our eyes are telling us. And sometimes our brains let us down.

In 1846 Galle turned a more powerful telescope on the area of the sky where LeVerrier had predicted a planet perturbing the motion of Uranus might be found and discovered Neptune.

The probe Voyager 2 passed by Neptune in July to September 1989, and discovered 6 new moons orbiting inside the orbits of Triton and Nereid the two known at that point in time: Naiad, Thalassa, Despina, Galatea, Larissa and Proteus. It took photographs during its flyby over several days in July and September.

We have measured the magnetic fields of Neptune, found it to have rings, analysed its atmosphere, calculated the heat it gives off, measured its wind speed, followed its Dark Spot waxing and waning, and worked out its surface temperature. The Hubble Space Telescope has been deployed as have spectrometers.

But most reports I have seen do not mention the instrumentation and equipment used to make these measurements and calculations. Hence your very reasonable question. But I have the same problem as you have.

The scientists don't let on. It is not their style to draw attention to the tools they use. We just get to see the results and conclusions but not how they arrived at them.

Answer 3

Voyager II wandered by and took some pictures about 20 years ago. Other than that only really expensive stuff like Hubbel or Keck can see it well enough to pick up the storms that wander across the face of the planet.