Thousands of light-years from Earth, there could be another planet hospitable to life. Kepler 69c. And you’re about to travel to this alien world to see that life with your own eyes. What would it be like to make this epic journey so far across the Universe? What kind of planet would you be likely to find upon arrival? And if you did discover life, what would it look like?
Located 2,383 light-years from Earth, in the Cygnus constellation, is a potential super-Earth. At least that’s what it’s often referred to as. Kepler 69c is an exoplanet about 1.7 times larger than our planet. And it could also be around 3.5 times more massive. But there’s a catch. We don’t really know if this planet is located within the habitable zone of its star.
If it’s too close, Kepler 69c would be too hot for liquid water to exist on its surface. If it’s too far from its sun, well, then it would be nothing more but a frigid world. What we do know is that Kepler 69c orbits its star about 40% closer than Earth orbits the Sun. And that could mean that it isn’t actually a super-Earth. It could be a super-Venus.
So if you traveled all the way here would you find life? Or a thick, scorching atmosphere boiling every drop of water on the planet? Before you begin your journey to Kepler 69c, there’d be one very important thing to keep in mind. It’s far away. Almost 600 times further away than Proxima Centauri, our closest neighboring star.
Even if you could travel 1% of the speed of light, you wouldn’t get there anytime soon. At this speed, you could whip around the Earth in just over 13 seconds. But to get to Kepler 69c? That would take you about 238,000 years. To even make this trip possible, you’d need a super-advanced hibernation pod.
You don’t want to grow too old and die before you could even get to your destination, right? Well, hibernation technology that could make you sleep for over 200,000 years doesn’t exist yet. But hey, this is What If. Anything is possible. By the time your ship makes its arrival, any life that may exist on Kepler 69c today could evolve or advance into something entirely different.
Think about it this way. Three hundred thousand years ago, humans were just beginning to create stone tools and spears. And look at you now, making a trip across the galaxy. Looking back at the planet you left behind, who knows what changes would happen to our human civilization during your trip? No matter what, it’s way too late to turn around now.
Based on the planet’s distance from its star, we know that Kepler 69c receives a similar amount of sunlight as Venus. And despite being more massive than Earth, it has a relatively low density. All this means is that instead of metals, this rocky planet is made of silicate and carbonate minerals. That could make things a little complicated.
You see, with all these minerals in the crust, Kepler 69c could have a really thick atmosphere. To make things worse, this atmosphere would be composed mostly of carbon dioxide. Uh oh, did you choose the wrong super-Earth to travel to? Sure, if Kepler 69c is anything like Venus, it would be a pretty hot planet.
All because, similar to Venus, its clouds would trap the heat and create an extreme greenhouse effect. Kepler 69c’s atmosphere would be caught in an endless cycle of getting thicker and hotter. But nobody said this world should be habitable for you. Oh no. You’d likely instantly melt and suffocate the moment you took off your helmet.
Like I said, life on this planet would be completely different from what you’d imagine. As you made your approach, you’d find surface temperatures as high as 475 °C (900 °F). And the atmospheric pressure would be over 90 times that of Earth at sea level. It would be like being 900 m (3,000 ft) deep in the ocean. Except you’d be on dry land.
With conditions like this, you’d likely not find anything resembling an ocean here. Just like on Venus, the high temperatures would boil away all the water. Whatever life you could potentially encounter on this planet, it would need to be able to survive in these brutal conditions. Or it would have to exist somewhere else besides the surface.
One place you could discover life on Kepler 69c would be up in the clouds. Around 50 km (30 mi) up, temperatures would be much, much cooler. They would range from about 30 to 70°C (86 to 158°F). And with its low density, this planet could have a surface gravity that would be just over 70% of what is found on Earth.
This weaker gravity could allow lifeforms to thrive in the sky, where Kepler 69c is most hospitable. Life could just be floating freely in the atmosphere. This would be another way in which this planet could have far more in common with Venus than with Earth. Probes around Venus have picked up traces of a gas that could be a potential sign of life, phosphine.
If you discovered phosphine in Kepler 69c’s atmosphere, it could be the result of bacteria that don’t require oxygen to survive. But be ready to hold your nose. This smelly gas has an odor similar to decaying fish. On Earth, the bacteria that produce phosphine often live in swamps or wetlands. But on Venus or Kepler 69c, this bacteria could exist in the thick, oxygen-less atmosphere itself.
So in the end you may have just traveled a very, very long way to find the smallest and stinkiest of lifeforms. On the upside, you’ve just discovered extraterrestrial life. Why not see if there are any other hospitable planets in this neighborhood with more advanced lifeforms? Like on Kepler 22b.
- “Kepler-69 And The Solar System – Exoplanet Exploration: Planets Beyond Our Solar System”. 2022. exoplanets.nasa.gov.
- “Exoplanet-Catalog – Exoplanet Exploration: Planets Beyond Our Solar System”. 2022. exoplanets.nasa.gov.
- “A POTENTIAL SUPER-VENUS IN THE KEPLER-69 SYSTEM”. Kane, Stephen R., Thomas Barclay, and Dawn M. Gelino. 2013. The Astrophysical Journal 770 (2): L20. doi:10.1088/2041-8205/770/2/l20. iopscience.iop.org.
- “Scientists assess potential for super greenhouse effect in Earth’s tropics”. Laurie J. Schmidt. 2018. climate.nasa.gov.
- “Venus”. 2022. solarsystem.nasa.gov.