Astronomers on a search for extraterrestrial life have located “Earth’s twin” outside our solar system – Proxima Centauri b – orbiting its nearest star.
Scientists discovered the planet by tracking how its host star’s light reflects off of it; its host star lies only 11.2 days away, making this world potentially habitable.
Proxima Centauri
Proxima Centauri is the closest star to Earth and may contain a planet about the size of Earth called Proxima Centauri b, believed to orbit around every 11-12 days and be habitable enough for liquid water to exist on its surface. Proxima Centauri’s discovery marks a significant achievement for exoplanet research. Proxima Centauri b represents one of many milestones achieved by exoplanet research as an exoplanet researcher since it represents potentially habitability within its star’s “habitable zone,” which allows liquid water to exist on its surface.
Astronomers discovered the planet by measuring the gravitational wobble caused by its gravitational attraction on Proxima Centauri star. This discovery confirmed a previous prediction that it is most likely rocky and approximately 1.3 times bigger than Earth. With its proximity and large size, Proxima Centauri makes for one of the ideal candidates for habitable exoplanets.
Discovering an alien planet has ignited much excitement, and the James Webb Space Telescope set for launch next year can observe it closely. By watching how its atmosphere retains heat while responding to its host star as it travels around its orbit, insight may emerge into its composition and whether life could survive there.
Scientists predict that, if Proxima Centauri b has a thick atmosphere comprising mostly water molecules, its orbit may become tidally locked, meaning one side always faces its parent star and vice versa. Under such circumstances, temperature should remain roughly equivalent on both the dark side and bright side, providing ideal conditions for liquid water to exist as an essential requirement of life.
Proxima Centauri b is subject to high levels of radiation from its orbit, including X-rays and ultraviolet radiation that would kill anything living on its surface. However, its atmosphere might help shield some of this harmful radiation and redistribute some of it more evenly across its surface.
Astronomers will have to wait for its transit as seen from Earth before conducting direct observations through telescopes, so ascertaining its size, mass and composition will become much simpler.
Though the chances of discovering a liveable planet around Proxima Centauri may be slim, it represents an exciting step forward in our efforts to understand what other exoplanets may look like and is also evidence of recent decades’ incredible advances in finding alien worlds near and far from Earth.
Proxima b
Scientists recently made waves when they announced the discovery of Proxima Centauri b, our stellar neighbor located only 6 light years from Earth. Proxima Centauri b boasts conditions suitable for supporting oceans of liquid water and may contain elements necessary for life – not that this alone should get us excited! But, science doesn’t only find Proxima Centauri b intriguing: Proxima Centauri b has also proven exciting due to other reasons as well.
Beginning early this month, German magazine reports started spreading that Proxima Centauri contains an Earth-sized exoplanet which may provide habitability. Proxima Centauri is an M-type red dwarf star which emits cooler and less intense light compared to our Sun.
Dr. Angsgar Reiners from the University of Zurich led a research paper published in Nature that detailed an innovative technique for monitoring planet surface. To do so, they utilized the High-Accuracy Radial Velocity Planet Searcher (HARPS) at La Silla Observatory in Chile to monitor Proxima Centauri for signs of planet formation – specifically any deviation in starlight that indicated something is pulling on it gravitationally.
HARPS can break down light coming from an object into different wavelengths, giving researchers insight into its composition and size. The team systematically searched for light that had been altered by planets. Furthermore, they looked for any signature of atmospheres–the protective layers which shield living creatures from radiation or stellar winds–that may exist on these distant worlds.
No one was disappointed: an enveloping layer could be seen, with signs of rocky terrain and liquid water present. Furthermore, due to how planets form around red dwarf stars, it’s likely that their planet would be tidally locked to their star – meaning one side always faces toward its source and the other always away – meaning its average temperature would likely hover around -2deg Celsius, making it suitable for life.
Researchers were able to confirm the existence of this planet through follow-up observations using an instrument known as Echelle Spectrograph for Rocky Exoplanets and Stable Spectroscopic Observations, also known as ESPRESSO. Astronomers using this instrument could more precisely calculate both its size and orbit – and its data indicated it is around 30% bigger than Earth with one orbit taking 11.2 days. Astronomers determined its orbit was located 5% of its star’s distance – placing it firmly within its habitable zone.
No matter its proximity, however, Proxima Centauri b is currently too distant for us to reach any time soon using current rocket technology. But that doesn’t mean it won’t pay off eventually: scientists hope that NASA’s James Webb Space Telescope, currently under construction, may allow them to observe Proxima Centauri b and its atmosphere more closely so they may gain a better idea of whether there could be life on Proxima Centauri b’s surface and atmosphere more thoroughly so they may gain clues into whether there could be life forms there that might exist on Proxima Centauri b’s surface and atmosphere; ultimately it may make the trip worthwhile