What are sub-Neptune planets?

Key findings

• The star, known as HD110067, is located approximately 100 light-years away in the constellation Coma Berenices and is about 20% less massive than our Sun.
• The six planets were detected by observing minute dimming of the star's brightness as each planet transited, or passed in front of, the star from our perspective on Earth
• The orbital resonance of these planets i.e their orbits are synchronised in such a way that they have remained stable for about 4 billion years.

About Sub-Neptune planets

• These are the most commonly observed type of planet in our galaxy.
• They could be rocky worlds with thick atmospheres of hydrogen and helium gas, or perhaps composed of rock and ice with warm, water-rich atmospheres.
• These planets have radii between that of the Earth and Neptune.

Key points about Neptune

• It's the last of the planets in our solar system.
• It's more than 30 times as far from the sun as Earth is.
• Neptune is very similar to Uranus. It's made of a thick fog of water, ammonia, and methane over an Earth-sized solid center.
• Its atmosphere is made of hydrogen, helium, and methane.
• Structure and Surface
  • Neptune is encircled by six rings and is an ice giant.
  • It is made of a thick soup of water, ammonia, and methane flowing over a solid core about the size of Earth.
  • It has a thick, windy atmosphere.
• Time on Neptune
  • One day on Neptune goes by in 16 hours.
  • Neptune has such a long journey around the Sun it takes 165 Earth years to go around once.

Q1) What is Methane?

It is a colourless, odourless gas that occurs abundantly in nature and as a product of certain human activities. Methane is the simplest member of the paraffin series of hydrocarbons and is among the most potent of the greenhouse gases. Its chemical formula is CH4.

Source: Six alien planets dancing in sync found. They have been stable for 4 billion years