Kepler Has Spotted Two Of The Most Earth-Like Planets Yet

Illustration for article titled Kepler Has Spotted Two Of The Most Earth-Like Planets Yet

The amazing Kepler Space Telescope has now catalogued over 1,000 exoplanets. Among them are eight new planets located within habitable zones, including two that astronomers say are the most Earth-like planets yet. Here's what we know about Kepler-438b and Kepler-442b.


Illustration: David A. Aguilar (CfA)

Prior to yesterday's announcement by scientists at the Harvard-Smithsonian Center for Astrophysicists, the most Earth-like planets were Kepler-186f and Kepler-62f. Respectively, they are 1.1- and 1.4-times the size of Earth, and receive 32% and 41% as much light.

The two new planets, which may be terrestrial, both orbit red dwarf stars that are smaller and cooler than our Sun. They're both in the so-called Goldilocks Zone, which means they receive enough sunlight such that liquid water can remain stable on the surface — an important prerequisite for life.

Kepler-438b takes 35 days to revolve around its host star and it has a diameter just 12% larger than Earth. There's a 70% chance that it's terrestrial. This exoplanet receives about 40% more light than Earth, and has a 70% chance of being in the habitable zone. For comparison, Venus gets twice as much solar radiation as we do here on Earth. It's located 470 light-years away.

Kepler-442b features an orbit of 112 days and has a diameter that's about one-third larger than Earth. It has a 60% chance of being rocky. This exoplanet receives about two-thirds as much light as Earth, and has a 97% chance of being in the Goldilocks Zone. It's located 1,100 light-years from Earth.

Unfortunately, the vast distances involved will make it difficult to make more precise observations, but I suspect that over time, and with more sophisticated telescopy, we'll learn more about these promising potentially habitable candidates.


You can find out more here.



It's always great and fascinating to hear about potentially habitable exoplanets, but it's so frustrating how unknown it is if we will ever be able to travel to planets in other solar systems. For something that is less than ten light years away, it's somewhat possible in the near future, but for 470 light years and 1,100 light years away it feels impossible.

I always imagine the likely near-future scenario where we have a telescope that can spot vegetation or even more advanced life on a planet ~10 light years away. Would we start scrambling to figure out how to get there, or would it just remain a future dream?

There are things we predicted as impossible 50 years ago that are commonplace now, but there are things we took as givens that never really happened. I tend to think FTL travel is impossible, and if a workaround exists it won't be feasible for several hundred years. There are still ways to send people to solar systems a few light years away within a fairly reasonable time frame, but probably nothing will happen before I die.