After decades of research dedicated to finding another Earth-like planet, scientists believe they are close to a breakthrough discovery. A recent development made Northwestern University has allowed researchers to combine 3D climate modeling with atmospheric chemistry to filter through the countless planets in the galaxy. This, among other exciting discoveries, has armed the space exploration community with the tools they need to find the Holy Grail of planets. 

Specifically, scientists are searching for exoplanets, or planets that orbit a star. However, this can’t be any type of star. It needs to be a dwarf star like our own sun, which is a yellow dwarf star. Additionally, some scientists speculate that red dwarf stars may not emit enough photons to support life, further narrowing our search for a habitable planet. Theoretically, if an exoplanet is close enough to these stars, it can enter a habitable zone, an orbital region that can support liquid water on the surface of exoplanets.

Scientists have coined this region as the Goldilocks Zone, as it is not too hot and not too cold, but just right. Exoplanets in the Goldilocks Zone also have a breathable atmosphere that contains nitrogen, oxygen and other trace gases that are present in our own atmosphere. While both Mars and Venus are located in the Goldilocks Zone, what’s left of liquid water on Mars is frozen in permafrost and Venus’ water was boiled off its 460° celsius surface. This just goes to show how perfect the conditions must be for a life-supporting exoplanet to exist. Check out the video below to learn more about the conditions that are required to exoplanets to support life.

As astronomically rare these specific exoplanets may be, recent developments, like the one mentioned earlier, have given scientists the confidence and capabilities to continue the search. The study conducted by Northwestern University involved 3D chemistry modeling has revealed a number of important conclusions. By looking at how a star’s radiation affects the exoplanet’s atmosphere, researchers were able to why some planets that were thought to be potentially life-sustaining may be receiving too much ultraviolet radiation from their active star. On the other hand, stars that are inactive are much more likely to allow their orbiting exoplanets to hold liquid water, a key component to life. 

Another advanced method astronomers are using to locate exoplanets is called Transit Photometry. Essentially, as a planet passes in front of a star, it blocks a small percentage of the star’s light, dimming it for a short period. By measuring the amount of light dimmed, as well as how long and how often it is dimmed, scientists are able to make several conclusions about the orbiting exoplanet, most importantly its size. With the use of spectroscopic methods, researchers can accurately determine the planet’s mass, which can be used to calculate the planet’s density. This important piece of information is the first step to understanding the composition of the potentially life-sustaining exoplanet.

In 2018, NASA’s Explorer program launched the Transiting Exoplanet Survey Satellite (TESS) on top of a Falcon 9 rocket. Using Transit Photometry, TESS is projected to survey 20,000 exoplanets during its 2-year mission. TESS has already found more than 1,200 possible exoplanets, which researchers are now exploring to learn more about these new findings. However, as scientists learn more about the different properties that are needed for an optimal life-sustaining planet, they are growing more confident that their search will accelerate exponentially.

Unless you’re a major science buff or work in the astronomy field, you’ve probably already asked yourself why all of this matters and why we are spending so much money on these projects (and yes, they cost a lot of money). As NASA explains “curiosity and exploration are vital to the human spirit”, and supporting these human instincts is as essential as satisfying the need for artistic expression. As much as dance and painting can help keep the spirit whole, so too can exploration and discovery of the unknown. 

Additionally, space exploration has many groundbreaking scientific discoveries, which have benefited us in completely unrelated ways, such as artificial limbs, insulin pumps, and scratch-resistant lenses. Without the desire to explore our solar system and beyond, such scientific achievements may never have been discovered. Space exploration can also promote international cooperation, as technology and data are being shared between nations. Finally, space exploration is advancing industries such as medicine, artificial intelligence and engineering, as we look for new ways to keep our astronauts safe while working in these extreme environments. 

As the search for a second Earth continues, it’s important to remember that the protection of our own planet should always be a priority. While it’s possible that day may eventually come where the survival of the human race is dependent on a new home, the fact is that Earth is completely capable of maintaining itself and its inhabitants for another estimated 1.75 billion years. In terms of the average lifespan of even the most long-standing species, the chances that humans will be around in their present form for another 1.75 billion years is highly unlikely. Although space exploration should continue for the advancement of the human race, our current climate change crisis should be at the top of the priority list for all major countries. Click here to learn more about the current state of our environmental crisis.