Land. A new study shows that other stars could have as many as seven terrestrial planets in the absence of a gas giant like Jupiter.
This is the conclusion of a study led by UC Riverside astrobiologist Stephen Kane, published this week in the journal Astronomical Journal.
The search for life in outer space usually focuses on what scientists call the “living zone”, the area around the star in which the planet’s orbit could be liquid water oceans – a condition for life, as we know it.
Kane studied a nearby solar system called Trappist-1, which has three Earth-like planets.
“It made me think about how many living planets a star has, and why our star has only one,” Kane said. “It didn’t seem fair!”
His team created a model system in which they simulated planets of different sizes orbiting their stars. The algorithm took into account gravitational forces and helped test how the planets interacted with each other over millions of years.
They found that some stars could support as many as seven, and a star like our sun could potentially support six planets with liquid water.
“More than seven, and the planets are getting too close to each other and destabilizing each other’s orbits,” Kane said.
Why, then, does our solar system have only one habitable planet if it can support six? This helps if the motion of the planets is circular rather than oval or irregular, minimizing any close contact and maintaining stable orbits.
Kane also suspects Jupiter, which has doubled the suitability of our system twice as much as any other planet in the solar system combined.
“It has a big impact on the population of our solar system because it’s massive and interferes with other orbits,” Kane said.
Only a few stars are known to have several planets in their populated areas. Moving forward, Kane plans to look for additional stars surrounded by completely smaller planets. These stars will be the main targets for direct imaging with NASA telescopes, as in the Friendly Exoplanetary Observatory of the Jet Propulsion Laboratory.
Kane’s study found one such star, Beta CVn, which is relatively close at a distance of 27 light-years. Since it does not have a planet resembling Jupiter, it will be included as a single star, tested on several residential areas of the planets.
Future research will also include the creation of new models that study the chemistry of the atmosphere of residential zone planets in other stellar systems.
Such projects offer more than new ways of finding life in space. They also offer scientists to understand the forces that can change life on our own planet one day.
“While we know that the Earth has been inhabited for most of its history, many questions remain about how these favorable conditions have evolved over time and the specific drivers behind these changes,” Kane said. “By measuring the properties of exoplanets whose evolutionary pathways may be similar to our own, we get a preview of the planet’s past and future – and what we need to do to determine its habitat.”
According to new estimates, there are as many as six billion Earth-like planets in our galaxy
Stephen R. Kane and others. Dynamic packaging in the living area: the case of beta-CVn, Astronomical Journal (2020). DOI: 10.3847 / 1538-3881 / ab9ffe
Provided by the University of California, Riverside
Citation: An amazing number of exoplanets could have taken life (2020, July 31), obtained on July 31, 2020 from https://phys.org/news/2020-07-exoplanets-host-life.html
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