It can be seen and weighed (it has a satellite) and visited (a probe went by).
Scientists can see Neptune with telescopes. Also, they have many photos of it from when the Voyager 2 passed by.
No, Neptune still exists.
No. There is no life on Neptune. Neptune is too cold to sustain any sort of life that is found on Earth and it does not have a solid surface. Grass only exists on Earth.
Linguistic Evidence
Evidence that exists about saturated fats and why they are bad for you is that they cause clogged arteries and hear.
There is no evidence that Neptune has ANY inhabitants; let alone a king.
food
Techinically, Forever. But, we don't know that Neptune exists, so we can't say for sure.
There is no concrete evidence that supports the claim that nothing exists. The absence of evidence for the existence of something does not prove that nothing exists. The concept of nothingness is often philosophical and abstract, rather than something that can be proven empirically.
No credible evidence exists to date.
fond
No. Neptune is a planet, while a constellation is a pattern of stars in the sky. The thing about constellations is that they do not really exist; Neptune is real and the stars are real, but the PATTERN of the stars exists only in our own minds.