Exoplanets have always excited scientists and researchers as they present the possibility of life outside our planet. After all, many of these planets outside our solar system have unique characteristics that could prove beneficial as human beings seek to understand whether there is life on other planets and what life exists in these other planetary systems. In the quest for more answers, eyes are now on Proxima b, an exoplanet. We look at whether we have struck gold or still have some distance to cover before we find what we are seeking.
Outlining Proxima b
This planet orbits Proxima Centauri, a star that is closest to the Sun (which the Earth orbits). Its proximity to its star makes it a good selection as scientists have reasons to believe that its conditions may be similar to that of the Earth. But are they? Let’s consider its main features:
- Location: This planet is about 4.24 light years from our planet.
- Size: It is comparatively similar to our planet, measuring about 1.07 times the size of our planet.
It orbits its star every 11.2 days on average.
What Makes a Planet Habitable
Finding an exoplanet that almost mimics the Earth in terms of proximity to its star and size always excites researchers. But does every planet that meets these features automatically get the green light? Hardly. For a planet to be habitable by humans, it must meet the characteristics below:
Location
The distance from the star matters a lot as it affects surface temperatures. If the planet is too close to its star, the water evaporates fast, and if it is too far, the water freezes. The right balance is necessary for the planet to have liquid water, which is essential, not just for human life but for other lives, too.
Water
The focus in any exploratory research regarding habitability is always on water. After all, water is the source of life – it is necessary to support life in various forms and is essential for biochemical reactions.
Energy
Every planet must have a sustainable source of energy. The more sources, the more sustainable life on the planet will be, as this will support the different ecosystems and will allow inhabitants to switch to different options when some dwindle.
Stability
A star’s stability plays a crucial role in the climate of a planet. If a star can provide sustainable energy with minimal fluctuations, the climate will be stable. But if the changes are extreme, life on the planet will take a hit as this affects the temperatures and availability of liquid water.
Gases
Every habitable planet must have a range of gases that support human life and plant growth. It also needs gases that can protect the inhabitants from harmful solar radiation while regulating the surface temperatures.
Elements
Besides a stable atmosphere, a planet must also boast key elements such as carbon and phosphorus. These play a part in the making of biological molecules, such as lipids and proteins, that are essential for life.
Magnetic field
As the planet orbits the star, it requires a magnetic field supported by its core. This field ensures that the planet remains safe from harmful radiation that can damage its atmosphere and expose its inhabitants to uninhabitable conditions.
Geological activities
While scientists are not actively looking for active volcanoes, they pay attention to geological processes such as erosion. These imply that there is active nutrient recycling on the planet, thus creating diversity, which is important for a sustainable climate.
Scientists must also review the climate patterns over a long period to understand their reliability and variation. A habitable planet should have clear patterns that all prove to be suitable for inhabitants.
How Does Proxima b Compare
Current research shows that this exoplanet has several features that could support its habitability, as follows:
- Nearness to its star. This planet is close enough to its star to maintain the temperatures required to maintain liquid water. Compared to what we get from the Sun, it receives about 67% of the same energy from its star.
- An ideal size. The planet is similar in size to the Earth, with a size 1.07 times that of the Earth and a mass 1.3 times that of the Earth. Preliminary research suggests the planet is rocky.
While the planet may win on the above fronts, researchers have raised the following concerns:
- Likelihood of radiation. The star that Proxima b orbits is known for its extreme stellar flares whose radiation can pose a risk to life on the planet. If humans are to live on this planet, there would be a need to assess the magnetic field and atmosphere on the planet and verify their ability to withstand these flares.
- The question of atmosphere. Current research is yet to establish if the planet has an atmosphere. Without this, regulating surface temperatures, sustaining breathable air, and protecting inhabitants from radiation would prove challenging. If researchers can prove that an atmosphere exists, they will also need to assess its suitability for various forms of life.
- Temperature variations. Per the preliminary reports, one side of the planet faces the star while the other does not, even as the planet orbits. As such, the side that faces away from the star is extremely cold, while that near the star could have extremely high temperatures. Researchers have reason to believe that the habitable area would be between the two extremes, which does not leave much room for habitation.
- Liquid water assessment. Water is necessary for all life forms. At this moment, there is no proof that the planet has liquid water and more research on the same is ongoing.
Scientists have also been unable to uncover geological activities on the planet and are looking into them.
Conclusion
The excitement about Proxima b is evident. After all, the planet is near its Sun, has a similar size and mass to the Earth, and seems to have key habitable features. However, most of the research on the planet is speculative at this point. Researchers have yet to assess its physical conditions to a point where they can make an informed analysis and recommendations. So, for now, human beings can sit back and watch as there is indeed hope that we can have life on this planet.