Scientists detect two water worlds 218 light years away

Subject :Science and Technology

Context:

Two alien planets about 218 light years away from Earth have found a twin in the ocean worlds of Europa and Enceladus — moons orbiting Jupiter and Saturn, according to a new study.

About Keplar 138c and 138d:

The exoplanets, Kepler-138 c and Kepler-138 d are likely water worlds.
They are also larger-scale versions of Enceladus (Saturn’s moon) and Europa (Jupiter’s moon).
These twin planets of the same size and mass are more massive than Earth but lighter than ice giants Uranus and Neptune.
They are different from the planets in our solar system, which is chiefly composed of rocky planets like Earth and gas giants like Jupiter.
These exoplanets, along with Kepler-138 b,orbit Kepler-138, a red dwarf star. The star is smaller and cooler than the Sun, a yellow dwarf star.
The volume of the two alien worlds was three times that of Earth and mass twice as big.
The new planet takes 38 days to complete an orbit. It is in the habitable zone, meaning it is located in an orbit that receives just the right amount of heat from its star to allow water to exist in a liquid form.

Goldilocks Zone:

It refers to a habitable zone in the planetary system where the temperature is neither too high nor too low.
Such conditions could allow for the presence on the planet’s surface of liquid water – a key ingredient for life.
- If a planet is too close to the star it orbits, any water on the surface quickly boils off, forming a steam atmosphere.
- If the planet is too far from the star, any water on the surface freezes.
The habitable zone (or “Goldilocks zone”) is the range of orbital distances from a star at which liquid water can exist on the surface of a planet.
This range of distances changes depending on the size and temperature of the star.
Earth is in the habitable zone of the sun – one of the reasons our planet has liquid water like oceans and lakes.