1253 GMT September 20, 2019
Rocky planets with an atmosphere and orbit that allow for the existence of liquid water are said to lie in the habitable zone, UPI reported.
For an exoplanet, a stable orbit inside the habitable zone doesn't guarantee habitability in perpetuity.
New research suggested neighboring giant planets can have a sizable influence on whether or not an exoplanet remains habitable. More often than not, giant neighbors have a negative impact on an exoplanet's habitability.
Planetary scientists studied 147 extrasolar planetary systems with giant planets.
They found giant neighbors can negatively affect an exoplanet's habitability even without altering its orbit.
Nikolaos Georgakarakos, a researcher in the department of physics at New York University Abu Dhabi, said, "While in the majority of investigated systems the presence of the gas 'giants' shrank the habitable zone, they still left sufficient room for habitable Earth-like planets to be there.
“This is an important insight to inform follow-up investigations. It would not make sense to search for Earth 2.0 in a system where a giant planet stirs the orbit of any neighboring terrestrial planet in the habitable zone so much that its climate collapses."
However, a giant neighbor can sometimes help stabilize an exoplanet's orbit, keeping the planet within the habitable zone.
Siegfried Eggl, an associate researcher at NASA Jet Propulsion Laboratory (JPL), said, "Under certain conditions, the presence of a giant planet can actually increase the size of the habitable zone, which is the area where your terrestrial planet receives the right amount of light in order to support liquid water on its surface.
“This is quite remarkable since the continuous gravitational pull of giant planets on their terrestrial neighbors mostly spells trouble for habitability."
The scientists published their findings in a new paper published in the Astrophysical Journal.