Star Wars-style planets with TWO SUNS are more capable of housing alien life than those which orbit a single star
- Astronomy student Joni Clark created simulations of a variety of so-called binary systems - solar systems with two suns - to see how far habitable zones within them could spread
- This is because the two suns orbit each other and create a safe zone which reduces the threat to those planets from solar winds
- This gives those planets within such binary systems more potential to be habitable than those in single sun set-ups
PUBLISHED: 16:33 GMT, 14 June 2013 | UPDATED: 16:33 GMT, 14 June 2013
Planets in solar systems that have two suns - similar to the fictional Tatooine planet from the film Star Wars - have more potential for supporting alien life than planets with single suns, according to an astronomy student.
Joni Clark from New Mexico State University simulated various types of systems including binary - systems with two suns - to test whether the planets within these systems were more or less capable of being habitable.
She discovered that in binary systems, the gravitational pull of the two suns orbiting around each other reduces the threat to those planets from solar winds, for example, increasing the chance of life surviving and water sources forming.
An artist's impression of Kepler-35 b - a planet that orbits around a pair of sun-size stars. The discovery of Kepler-35b and another twin sun planet, Kepler-34 b, was announced in January 2012. Planets in solar systems that have two suns - similar to the fictional Tatooine planet from the movie Star Wars - have more potential for supporting life than planets with single suns, claims an astronomy student
WHAT IS A BINARY SYSTEM?
A binary system is a system of two objects in space - traditionally stars - which are so close that their respective gravitational pulls causes them to orbit around each other.
They do this because they orbit around a central mass that keeps them in a fixed position.
Binary suns and star systems are featured heavily in the Star Wars in the system in which the planet Tatooine is located.
In the Discovery program Alien Planet, the planet Darwin IV orbits a binary system.
In The Hitchhiker's Guide to the Galaxy, the planet Magrathea orbits a binary system.
In Escape To Witch Mountain and Return From Witch Mountain, Tony and Tia's home planet orbits two suns.
In Star Trek Voyager, there is a system with two suns and in Doctor Who, Gallifrey -the home planet of the Time Lords- has two suns in its planetary system.
Clark told Space.com: '[The stars] calm each other down.
'It's like a really good marriage. They vent to each other, and they're not focused on anything else.
'They slow each other down and that causes increased magnetic protection of the planets.'
After modeling a variety of systems, Clark, along with astrophysicist Paul Mason from the University of Texas concluded that stars 80 per cent as big as the sun, if close enough together, could increase the chances of being able to sustain life.
An example of an existing planet in a binary system is the Kepler-35 b - a planet that orbits around a pair of sun-size stars.
The discovery of Kepler-35b and another twin sun planet, Kepler-34 b, was announced in January 2012.
Another binary system is the Kepler-47 system.
It is a star system with at least two planets in orbit around the pair of stars located 5,000 light-years away from Earth.
When the suns in a binary system occupy a similar mass they orbit each other in a way that reduces the amount of solar wind they create.
Solar wind is a stream of charged particles released from the upper atmosphere of a sun.
It is mostly made up of electrons and protons and this stream of particles can vary in temperature and speed.
The particles escape a sun's gravitational pull because of their high kinetic energy and the high temperature of the plasma around the sun - called the corona.
This diagram shows the Kepler-47 system. Kepler-47 is a binary star system with at least two planets in orbit around the pair of stars located about 5,000 light-years away from Earth. This image shows a habitable zone in which planets that may support life could reside. Clark's study found that the habitable zone in binary systems is 40 per cent larger than in single-star systems
If the suns are similarly matched their speed and temperature is more regulated. This reduces how many particles escape which in turn leads to less solar wind.
Clark's stars also need to fully orbit one another within 10 to 30 days to extend the wider habitable zone - dubbed the 'Goldilocks Zone'.
The planets within these binary systems would still die out at a similar rate to those within single-starred systems, yet the 'habitable zone' increases by around 40 per cent.
However, Clark claims that if they drift too far apart, this puts a significant gravitational strain on the orbiting planets within that system.
Clark's findings were reported in Astrobiology Magazine, a web-based publication sponsored by the NASA astrobiology program.
She also found that some 'p-type' planets - planets that orbit both stars within the same binary system were hit with 0.7 percent less flux from solar winds than Earth is currently exposed to in our single-star system.
Although this level of flu depends on the planets' position within their binary solar system.
Planets that only orbit one of the suns in a binary system are more at risk, and in cases where the two suns are too far apart or greatly differ in mass to create a synchronised movement, the planet orbiting the second sun can be hit with double the amount of solar flux it gets hit with.
This is because these planets are more prone to be tidally locked in one position, usually with one side permanently turned toward its sun.This side then receives the full brunt of any solar flux.
In binary systems, like the artist's impression pictured, its more likely that rocky planets with water sources can form because they're not at as much risk from solar assaults, compared to planets in systems with single stars. This means such planets could house alien life
Planets that orbit the first sun in a binary system, though, behave in the same way planets do in a single star system.
In binary systems its more likely that rocky planets with water sources can form because they're not as much risk from solar assaults, compared to planets in systems with single stars.
Living conditions on these planets would vary because of cloud cover.
Planets with high cloud cover would be insulated and protected from ultraviolet radiation.
'It also leaves the potential open for smaller planets that have less magnetic field protection to remain habitable because in a sense they don't have to protect themselves from as much as they would in a single star case,' continued Clark.
