Home » Work » ‘Habitable’ planet GJ 581d previously dismissed as noise probably does exist

‘Habitable’ planet GJ 581d previously dismissed as noise probably does exist

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Anyone who knows me professionally knows I have been a fervent supporter of SETI.

SETI, otherwise known as the Search for Extra Terrestrial Intelligence program, was started by Berkeley way back when to process data from Radio based Telescopes such as Arecibo in Puerto Rico, and find ‘anomalies’ – that is – ‘noise’ among the white noise of space that was clearly not random.

SETI was successful.

Back in 2008 SETI found definitive evidence of life i the form of sporadic bursts of radio activity which at first were dismissed as random bursts from a nearby pulsar – until a certain scientist suggested “slowing down those bursts” – implying Einstein’s relativity may provide a time shifting effect on the bursts and there may be massive amounts of information in those bursts.

That scientist was right. There was massive amounts of radio traffic received once the recording was played back at a fraction of it’s original speed, which was much like listening to 100 years worth of radio activity right here on planet earth in a fraction of a second.

Over the next five years, the US Government will be slowly demonstrating to the public that we are most definitely not alone.

And the scientist who suggested a review of radio material – sparked a review revolution of stellar information acquisition.

The scientist who sparked the revolution also asked a few other important questions which hadn’t been asked before:

  1. Why is the primary method of researching and discovering extra terrestrial intelligence leveraging radio, when the vast majority of our own communications on planet earth have shifted away from radio to other mechanisms? (Implying: Shouldn’t we be leveraging our other known methods of communication to ascertain the existence of extra terrestrial life?)
  2. Life on Planet Earth is abundant, and with microbial life surviving meteoric impacts, it is reasonably safe to assume life is abundant in space. So shouldn’t we reclassify our search accordingly and search for evidence of extra terrestrial life like ourselves?

In any case, as scientists pour over their data, a newly habitable planet was found that was previously once dismissed as noise because of the narrow filter being used to ascertain life.

Here’s the story:

esearchers are confident the planet named GJ 581d, identified in 2009 orbiting the star Gliese 581, does exist, and that last year’s claim was triggered by inadequate analyses of the data.

 The planet candidate was spotted using a spectrometer which measures the ‘wobble’, small changes in the wavelength of light emitted by a star, caused as a planet orbits it. In 2014 researchers revisiting the data said that the ‘planet’ was actually just noise in the data caused by starspots. The possible existence of the planet was widely dismissed without further questioning.

But now researchers from QMUL and University of Hertfordshire have questioned the methods used to challenge the planet’s existence. The statistical technique used in the 2014 research to account for stellar activity is simply inadequate for identifying small planets like GJ 581d.

The method used before has worked when identifying larger planets in the past because their effect on the star was so significant as to negate errors in the findings. However, it makes it almost impossible to find the smallest planet signals close to or within the noise caused by the stellar own variability.

Using a more accurate model on the existing data the researchers are highly confident that the signal of GJ 581d is a real one, despite stellar variability.

Leading author of the paper, Dr Guillem Anglada-Escudé, said: “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.

“There are always discussions among scientists about the ways we interpret data but I’m confident that GJ 581d has been in orbit around Gliese 581 all along. In any case, the strength of their statement was way too strong. If they way to treat the data had been right, then some planet search projects at several ground-based observatories would need to be significantly revised as they are all aiming to detect even smaller planets. One needs to be more careful with these kind of claims”

More on the original story can be found here.

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