Previously dismissed as stellar bursts, astronomers now believe mysterious signals are coming from an Earthlike planet.
First discovered in 2009, the planet, named GJ 581d, was first discovered in 2009 orbiting the star Gliese 581 some 20.5 million light-years away, dismissed last year as noise from distant stars. The Nature World News writes, the Gliese 581d planet has conditions that could support life, and is twice the size of Earth and likely to be a rocky world,
Discovered using a spectrometer that measures its Dopler shift, or ‘wobble’ – small changes in the wavelength of light emitted by a star, caused by the orbit of the planet.
Habitability of planets can be measured based on how they affect the star that they orbit, according to this theory,
According to Metro.co.uk initial observations have indicated that GJ 581d has a surface temperature that is cool enough to allow water to pool on the surface – meaning it has the potential to support life.
Last year however, scientists rescinded their theory , and blames their mistake on noise in the data caused by internal star activity, and not the presence of a hospitable world.
Researchers from Queen Mary University of London (QMUL) and University of Hertfordshire however have shown that GJ 581d was not masquerading as a planet.
Dr. Guillem Anglada-Escudé, who led the study, said in a news release, “The existence (or not) of GJ 581d is significant because it was the first Earth-like planet discovered in the ‘Goldilocks’-zone around another star and it is a benchmark case for the Doppler technique,”.
What is this Goldilocks-zone? It’s the distance from a star that will allow a planet habitable conditions that are “just right” for life.
The statistical technique used in the 2014 have prompted Scientists that the problem was due to this reason.
The method has worked just fine in the past for larger planets because the effect of these planets on their host star has been too significant to ignore. However, if the same approach is used to the considerably smaller GJ 581d results are skewed. The same techniques make it almost unmanageable to locate the smallest planet signals close to or within the noise caused by the stellar variability.
The QMUL team, using a more accurate model on the existing data, has put GJ 581d back in the forefront as a likely candidate for a habitable planet outside of our solar system.
The new findings were reported in the journal science.