exoplanet

As these so-called exoplanets were being discovered, scientists began to develop instruments to analyse the chemical composition of their atmospheres.

While many exoplanets are Venus-like, the study suggests that astronomers should narrow their focus to exoplanets which are more like Earth.

"Studying connections between different atmospheric layers is very important for all planets, whether it's an exoplanet, Jupiter or Earth," Wong said.

Planets about the size of Uranus and Neptune -- so-called sub-Neptune planets -- are among the most common exoplanets discovered to date.

Astronomers have detected more ice giant-sized bodies outside of our solar system than any other kind of exoplanet.