The Close Yet Distant Exoplanet Proxima Centauri b
Die Entdeckung des Exoplaneten Proxima Centauri b [1] ist beachtlich. Aus dem Kanon der bislang bestätigten Exoplanetenentdeckungen hebt er sich aus vielen Gründen hervor – um nur zwei zu nennen: Zum einen umkreist der Planet …
- September 1, 2016
The discovery of the exoplanet Proxima Centauri b marks a significant milestone in the field of astronomy. This planet stands out among the confirmed exoplanets for several reasons. For one, it orbits its host star within a zone where water could theoretically exist, although it remains uncertain whether Proxima Centauri b possesses an atmosphere. Furthermore, it is the closest known star to our Solar System, located just over eight and a half light minutes from Earth, making it a prime candidate for future studies using advanced telescopes like the E-ELT.
However, the prospect of sending a mission to this cosmic neighbor raises intriguing questions about the time it would take for humans to reach Proxima Centauri. While it is difficult to predict future technological advancements, one can imagine that our descendants might find the limitations of 21st-century space travel amusing. For instance, the star US 708, which travels at an impressive speed of 1157 ± 53 km/s relative to the Milky Way, would still take about 1085 years to cover the distance of 4.24 light-years from the Sun to Proxima Centauri.
After more than a year in space, the New Horizons spacecraft has traveled over 36.3 astronomical units from the Sun. As of today, the light travel time between the Sun and New Horizons is approximately 302 minutes, or more than five hours. If New Horizons were to embark on a journey to Proxima Centauri at its current speed of 14.5 km/s, the trip would take an astonishing 87,725 years, highlighting the challenges of interstellar travel.
If humanity were to construct a spacecraft capable of maintaining a constant speed of 100 km/s—an entirely optimistic scenario—the journey to Proxima Centauri would still take over 12,720 years. To put this into perspective, this timeframe would take us back to an era when the last Ice Age was still shaping many regions on Earth, making life challenging for our ancestors.
To achieve more feasible travel times, spacecraft would need to reach speeds of at least 1/100th the speed of light. Even a hypothetical vessel traveling at 3000 km/s would require a minimum of 424 years to reach Proxima Centauri. Interestingly, one could consider sending Greenland sharks on such a journey, as recent studies suggest they might live longer than any other vertebrates, with one specimen estimated to be around 392 ± 120 years old.
Clear Skies, Stefan Oldenburg
