1) The Voyager 2 spacecraft in 1989.
2) The Hubble Space telescope.
3) Earth based methods, especially spectroscopy.
No humans have visited the planet Neptune.
yes humans could live on Neptune. No they cant Neptune is a gas planet
Neptune is a gas giant, so it is uninhabitable to humans.
No. There is no oxygen in Neptune's atmosphere
Without any heating systems or life support systems, any planet past Earth (Mars, Jupiter, Saturn, Uranus, and Neptune) would be too cold for humans to live. Also Neptune is a gas giant which has no solid surface to land on, so you could not even be on Neptune. So to answer your question directly, no Neptune is not the only planet that is too cold for humans to survive.
Neptune is a planet.
There no oxygen, life, and neptune is a gas planet so it is highly flamable. (Believe it or not)
neptune is a huge gas giant. it has winds reaching up to 159 miles per hour. it is the 8th planet from the sun.
Planet Neptune is the eighth planet from the sun.
Neptune is an outer planet. It is the outermost planet in the solar system.
Neptune's vision is blue and it is the 8th planet. There is Neptune because it is a planet.
Neptune is the eighth planet from the sunneptuneNeptune.