In the coming weeks we will travel to the most special exoplanets. Today we begin our space journey at a distance of more than 3,800 light years from Earth. Welcome to the Kepler-70b (or KOI-55 b), where the average temperature is higher than the surface of the Sun.

We do not place the spacecraft on the surface of the Kepler-70b, because the spacecraft will evaporate immediately upon its landing. This also applies to the very thick carbon composite heat shield on the underside of our spaceship. No, we keep a safe distance.

Kepler-70b – literally – hell. On the surface, the temperature is 6800 degrees Celsius. The surface temperature of the sun is 6000 degrees Celsius. The planet was once the size of Jupiter, until its parent star Kepler-70 reached one of its last stages of life eighteen million years ago. The star swelled, causing the gas giant Kepler-70b to disappear in the outer layers of the dying star. An exoplanet lost its atmosphere and remained a smaller planet. It is surprising how the exoplanet has ever escaped this event.


Kepler-70b with parent star Kepler-70 in the background.

The distance between the planet and its Type B parent star is less than a million kilometers. This has its advantages. Kepler-70b orbits its parent star four (!) Times every day on Earth. A Kepler-70b year takes 345 minutes, or 5.8 hours. Blow out Christmas candles four times a year and celebrate New Year’s Eve: so tired.

How long is a flight to Kepler-70b?
Even if we travel at the speed of light to Kepler-70b, the flight will last more than 3,800 years. Suppose we travel about 100 kilometers per hour, then the journey would take 45 billion years. By comparison: our universe is 13.7 billion years old and our solar system is about 5 billion years old.

The future of Kepler 70 and the planets
The parent star Kepler-70 will turn into a white dwarf in the future after the last portion of the star’s fuel (helium) is used up. Then the star shrinks and the gaseous field becomes as small as Earth.

Astronomers expect Kepler-70b to completely evaporate one day. That might include Kepler-70C, another exoplanet 1.2 million kilometers from Kepler-70.

To the next destination
We’ll come home next week. Just 64 light-years from Earth, we visit a blue exoplanet. This alien world looks friendly, but appearances can be deceiving …