Life Beyond the Milky Way

For years, the idea of life outside of Earth has intrigued many. It has been pictured in sci-fi movies, television shows and even novels. There have been countless interpretations of the possibilities that could arise, but recently, scientists may have discovered an exoplanet, which is a planet outside of the solar system, that could bring the idea of life on other planets one step closer to reality.

In August 2016, astronomers discovered an exoplanet, called Proxima b, that orbits around the star Proxima Centauri. Proxima b has a mass 1.3 times that of Earth’s, according to astrophysicist Damien Segransan, and scientists believe that the exoplanet could sustain life, as it has similar properties to Earth. Senior Ankita Chatterjee sees the possible implications that this discovery has on humanity.

“Obviously, there’s been a lot of research in astronomy that has been looking for a planet that could possibly support life because the Earth’s carrying capacity is going to be reached pretty soon,” Chatterjee said. “I think that if scientists have potentially discovered a planet that can support life and has all of the chemicals necessary to sustain life, that would definitely positively affect us.”

Researcher Guillem Anglada-Escude and his team have found that Proxima b orbits in the star’s habitable zone, known as the Goldilocks zone, which is the region where liquid water could exist on a planet. Liquid water is an essential resource in supporting life of any kind, so the fact that Proxima b orbits in the Goldilocks zone greatly increases its ability to possibly sustain life. This, however, is not the most unique trait of Proxima b. The work of researcher Dorian Abbot suggests an estimate of 60 billion exoplanets that orbit in the habitable zone in the Milky Way and therefore could have liquid water.

What does make Proxima b so unique is the star system it is in: Alpha Centauri. The Alpha Centauri star system includes Proxima Centauri, the red dwarf star that Proxima b orbits around, making Proxima b the closest potentially habitable exoplanet to Earth.

Proxima Centauri, pictured in red to signify a red dwarf star, is located approximately four light years away. The star is the smallest of three in the Alpha Centauri star system, which also includes Alpha Centauri A and Alpha Centauri B. Image created on Piktochart.
Proxima Centauri, pictured in red to signify a red dwarf star, is located approximately four light years away. The star is the smallest of three in the Alpha Centauri star system, which also includes Alpha Centauri A and Alpha Centauri B. Image created on Piktochart.

This distance indicates that Proxima b is the most easily accessible exoplanet for scientific research, setting it apart from previously discovered exoplanets that could sustain life. This is significant because further research would be the first step to uncovering life on other planets.

“It’s exciting but I think they need to actually confirm the results more,” Chatterjee said. “There’s been a lot of findings like this that say that [a planet] can potentially support life, but after a lot of research has been done, it’s been found that it actually can’t.”

Freshman Joe Flewelling, however, feels differently about this discovery than Chatterjee.

“There are other places that are like this [Earth],” Flewelling said. “There’s more hope in the world or in the galaxy than I could have thought of.”

Some researchers, including professor Rory Barnes, have similar viewpoints to that of Chatterjee’s and raised doubts about the habitability of Proxima b. Because Proxima b orbits a red dwarf, which is 0.1 percent as bright as the Earth’s sun, the habitable zone and the exoplanet itself are closer to its sun than the Earth is to its own sun. Planets that are closer to the sun have a higher chance of being tidally locked, meaning that one side of the planet permanently faces the sun and the other side in darkness, similar to the moon.

Despite this, Barnes pointed out that tidally locked planets could still support life. If the planet has an atmosphere, winds could redistribute heat and lessen the divide between the two temperature extremes of tidally locked planets.

Red dwarf stars also emit x-ray and ultraviolet radiation through intense flares, and these flares could eliminate an exoplanet’s atmosphere. While a magnetic field would protect a planet from these violent flares, scientists don’t know if Proxima b has a magnetic field or atmosphere or not. Though Proxima b certainly holds potential to support life, more research about the exoplanet is necessary before scientists can determine the habitability of the exoplanet with certainty.

Though further research is necessary, freshman Veronica Hui believes that this discovery could have a significant impact on scientific research, regardless of whether the exoplanet is habitable or not.

“It brings the whole technology step onto another level because we’re researching on something that’s outside of this level,” Hui said. “It would also increase scientific discoveries because there could be many different types of plants, species of plants, and animals that probably are not on this planet.”

This displays an artist’s interpretation of how Proxima b may look. While the image shows the planet as having a cloud cover, scientists are not yet sure if the exoplanet has a cloud cover or atmosphere. Image from Wikimedia Commons.
This displays an artist’s interpretation of how Proxima b may look. While the image shows the planet as having a cloud cover, scientists are not yet sure if the exoplanet has a cloud cover or atmosphere. Image from Wikimedia Commons.

The research company Breakthrough Initiatives, which aims to find evidence of life outside Earth, has already launched a project called Breakthrough Starshot to reach the Alpha Centauri star system. They plan to develop probes that can travel at 20 percent of the speed of light, which would allow them to reach Alpha Centauri in 20 years; however, the probes’ high speeds mean that the amount of information they’d be able to collect is limited to a few hours.

Researcher René Heller of the Max Planck Institute for Solar System Research has offered an alternative method. Heller suggests that if the probes were traveling at a slower speed, they could orbit the Alpha Centauri stars after being sucked in by the gravitational pull. Compared to the method pitched by Breakthrough Initiatives, this would allow the probes to collect more in depth information about the Alpha Centauri star system and Proxima b. While Heller’s idea does have its advantages, the probe would have to travel at 4.6 percent of the speed of light and would take 95 years to reach Alpha Centauri.

Heller proposes that both methods should be used, instead of it being a matter of one or the other. This is especially because more research is needed in order for scientists to made concrete findings to be made conclusions about Proxima b. Though there is still much to be discovered about the exoplanet before its habitability can be determined, Proxima b certainly raises many potential possibilities.