While detecting how alien observers might be able to locate our planet Earth, a group of scientists from Queens University Belfast in the UK and the Max Planck Institute for Solar System Research in Germany have discovered that at least nine exoplanets are ideally placed to observe the transits of our planet.
The latest finding has created a lot of enthusiasm and made the scientists excited and curious further and they have now started looking for alien planets that can spot our planet Earth.
Moreover, some significant parts of the distant sky have also been identified by the team from where various planets in our Solar System could be seen to pass in front of the Sun.
According to them, the planets Mercury, Venus, Earth, and Mars are actually much more likely to be spotted than the more distant Jovian planets Jupiter, Saturn, Uranus, and Neptune, despite their much larger sizes.
Talking about their all new exciting research Robert Wells, a PhD student at Queens University Belfast said, "Larger planets would naturally block out more light as they pass in front of their star."
"However the more important factor is actually how close the planet is to its parent star - since the terrestrial planets are much closer to the Sun than the gas giants, they'll be more likely to be seen in transit," Robert was quoted further while interacting with reporters.
To look for worlds where civilisations would have the best chance of spotting our Solar System, the astronomers searched for parts of the sky from which more than one planet could be seen crossing the face of the Sun.
They found that three planets at most could be observed from anywhere outside of the Solar System and that not all combinations of three planets are possible.
"We estimate that a randomly positioned observer would have roughly a 1 in 40 chance of observing at least one planet," said Katja Poppenhaeger, from Queens University Belfast.
"The probability of detecting at least two planets would be about ten times lower, and to detect three would be a further ten times smaller than this," said Poppenhaeger.
Of the thousands of known exoplanets, the team identified 68 worlds where observers would see one or more of the planets in our Solar System transit the Sun. Nine of these planets are ideally placed to observe transits of Earth, although none of the worlds is deemed to be habitable.
In addition, the team estimated that there should be about 10 currently undiscovered worlds which are favourably located to detect the Earth and are capable of sustaining life as we know it.
To date, however, no habitable planets have been discovered from which a civilisation could detect the Earth with our current level of technology.
The study has recently been published in the journal Monthly Notices of the Royal Astronomical Society.
(With PTI inputs)