What we know about Proxima B so far

Artist's impression of the Proxima B
Artist’s impression of Proxima B

Photo credit: ESO

“The potential [of life] is there. I’d say we haven’t found any reason why life couldn’t be there yet.” – Coughlin, a SETI astronomer working with NASA’s Kepler planet-hunting mission

In recent astronomical news, a team of researchers led by astronomer Guillem Anglada-Escudé at Queen Mary University in London has lit up the astronomical community with the discovery of the first known exoplanet of our closest neighbouring star, Proxima Centauri, that could potentially harbour life.

A snapshot

  • Proxima B was named after the team of researchers in London that discovered it.
  • Proxima B was discovered using the Wobbler Method
  • Proxima B is an exoplanet that orbits around our closest neighbouring star Proxima Centauri.
  • One orbit takes roughly 11.2 days.
  • Proxima B may or may not be able to harbour life
  • Proxima B may be tidally locked

Fact 1 – Proxima B was discovered using the wobble method

Proxima B was discovered based on doppler shift using the wobble method. Based on the Wobble Method, researchers can discover planets based on the wave frequency emitted by a Star with two underlying premises. One, Stars emit a constant amount of radiation, and two, Doppler’s theory that waves emitted from an object moving towards it occur more frequently than waves emitted from an object further away from it. Thus, it is plausible that you will be able to determine the presence of a planet if there are changes in wave frequencies.

This is indicative of discovering a planet as planets tug the Star away from its centre of mass and its energy resulting in a slight change in colour, as argued by Doppler. As there were changes in higher frequency waves (incoming) being observed as a bluer colour and lower frequency wave (outgoing) emits a redder colour will be observed occurring in a pattern, it suggests that there may be a planet that orbits Proxima Centauri every 11 days when the pattern restarts.

Fact 2 – Proxima B could harbour life

Whether Proxima B could harbour life has been heavily debated. From what we know, there are a few educated guesses that support the theory of Proxima B harbouring life and some observations in opposition.  

In support of Proxima B harbouring life, optimists have argued that as Proxima B is located within the Habitable (“Goldilocks”) Zone of Proxima Centauri. This by definition signifies that the surface water should be neither too hot nor cold to be used by nature. That is, liquid water is a possibility there and enough of it to sustain life.

However, some have argued that due to the close proximity of Proxima B to its Sun (only 7 million km) and the fact that Proxima Centauri is a red dwarf star which is argued to be highly active and constantly emitting powerful rays of energy, the radiation emitted by Proxima Centauri could be destructive and have already eliminated the possibility of a functioning atmosphere altogether. To give a bit of perspective, Mercury is located just under 58 million kilometers away from our Sun and average temperature conditions range from 700 Kelvin (~426.9℃) to 100 Kelvin(~-173.2℃) at night. From these extreme fluctuations in temperature throughout the day, it is almost impossible for water to keep water on Mercury, and similar predictions could be made about Proxima B.

Optimists have then subsequently argued that as Proxima Centauri is a moderate red dwarf, the extreme effects may be a lot less milder on Proxima B. Furthermore, if the existence of an atmosphere on the newly discovered exoplanet could moderate the temperature even further leaving the planet with even milder conditions.

This debate is unlikely to dissipate in the meantime and it will certainly be interesting to see how it plays out. However, ultimately until we find out more information about Proxima B, it may be too soon to tell.

Fact 3 – Proxima B may be tidally locked

Due to the close proximity of the Proxima B to its Sun which are constantly orbiting, the possibility of tidal locking is definitely possible. This was further supported by the team of researchers acknowledgement that it could be true. This means that one side of the planet will always be facing the Sun while the other side experiences coldness throughout the day and would significantly influence the potential utility of this exoplanet.

Fact 4 – Proxima B is likely to be a rocky planet

Following Doppler Spectroscopy, the doppler shifts indicated that the presence of a planet with a mass around 1.3x greater than the Earth however its density is unknown. Using previously identified exoplanets as precedent, Proxima B would have be rocky, based on the discovered mass.

Some of you may be wondering if it is possible for us to visit Proxima B. Some have argued that it may be too soon for us to do so. According to Nicola Davis from The Guardian, the possibility of visiting Proxima B is low at this point as it would take around 70,000 years for a probe to reach Proxima B if it were released today. However, sending a probe to Proxima B may be likely using unconventional methods.

Fact 5 – StarChips

Previously, a research program known as the ‘Breakthrough Starshot’ was planning on sending centimetre-long spacecrafts known as ‘Starchips’ to the Alpha Centauri star system. These Starchips due to their extremely small size and construction may travel up to speeds of 20% of the speed of light and may very well be an extremely viable candidate for the long journey to Proxima B if we were to launch one today. If they were to send a fleet of their Starchips to Proxima B today, it may only take them just over 2 decades to get there.

If there is anything missing from this article, do feel free to let us know by leaving us a comment down below! We are extremely thrilled about this discovery and what it means about planetary discovery in the future.

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