Kepler-438b: Have we Found Earth’s Long Lost Twin?

Featured Image Credit: NASA

In the field of space, scientists made a key discovery in January of this year. Kepler-438b was found in the distant constellation of Lyra,  an exoplanet that has been determined to be the most Earth-like of all exoplanets discovered so far!

The Kepler mission was initiated by NASA to find planets orbiting a central star outside of our solar system that are similar in structure and properties to Earth. To find these planets, scientists use techniques such as the transit and radial velocity methods as well as direct imaging. The mission has been successful in finding over 1,000 exoplanets in numerous constellations,  eight of which are within the habitable zones of their respective central stars. Essentially, the habitable zone is one in which the planet may harbour life due to the presence of liquid water (this sometimes births the debate if ‘water’ is a true necessity for life and if we have an Earth-centric approach to the definition).  Earth, within its own system, sits in the same ‘goldilocks’ region – not too hot to burn under the Sun’s extreme flares, nor too cold to freeze.

Of the more than 1,000 verified planets found by NASA's Kepler

Kepler’s Hall of Fame. Credit to: NASA Ames/W Stenzel

Kepler -438b is slightly larger than Earth, is speculated to be rocky and completes its orbit around its red dwarf star every 35 days. It is extremely difficult to directly image such planets, but inferences such as these are made on ideas like what type of star the planet orbits, the amount of solar radiation given off these stars, how long the orbit is and any other nearby environmental clues.

So we can all just technically leave Earth and move in with our alien friends on Kepler-438b now…right? Wrong. As exciting as this discovery was for scientists given that this exoplanet can be considered “Earth’s sister”, there is one key piece of information that has reduced the chances of life actually existing. Unfortunately,  the planet experiences periods of superflare activity from its parents star every 100 days. Now what’s the problem with this you ask? The superflare activity is much more violent than the stellar flares that Earth experiences from the Sun. This would mean that any “life” on Kepler-438b would be sterilized to death.

Although this discovery was exciting yet disappointing for the scientific community and space-junkies like myself, it does not mean that the search for Earth’s twin stops. The Kepler mission has other candidates that own very good potential to be the next Earth, such as Kepler-22b. In addition to this, the upcoming James Webb Space Telescope is set to launch in 2018, which will provide immensely clear resolution images of the universe beyond with a massive 6.5 m diameter mirror. In the mean time, we can continue to live our lives here on home Earth.

Depiction of the James Webb Space Telescope. Credit: NASA

Flash animation by NASA of Kepler-438b’s orbit:

Original paper including Kepler-438b’s discovery: Caldwell, D. A., Torres, G., Kipping, D. M., Ballard, S., Batalha, N., Borucki, W. J., … & Barclay, T. (2015, January). Validation of Twelve Small Kepler Transiting Planets in the Habitable Zone. In American Astronomical Society Meeting Abstracts (Vol. 225).

Leena is a current undergraduate student in her final year of the Honours Life Sciences (BSc .) program at McMaster University. Her experience in taking a minor in Business has broadened her interests in the cross-sectional fields of science, business and health studies. When she is not busily writing, she assists students in branding themselves for success through the use of McMaster’s Learning Portfolio.



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