In the last few decades , we went from knowing the existence of just a smattering of planets to the fruition that planets are extremely rough-cut in our galax . Since then , thanks to procession in both ground- and space - based telescopes , the number has continued to grow . Now NASA has corroborate we have pass the 5,000 mark of substantiate exoplanets , with 5,005 strange new worlds orbiting in the Milky Way .
“ It ’s not just a number , ” Jessie Christiansen , skill track for the Exoplanet Archive and a enquiry scientist with the NASA Exoplanet Science Institute , said in astatement . “ Each one of them is a new world , a brand - new planet . I get excited about every one because we do n’t recognize anything about them . ”
The first exoplanet – well , the first two – was announced on January 9 , 1992 , by radio astronomers Aleksander Wolszczan and Dale Frail . These two reality were orbit the pulsar PSR 1257 + 12 , a special kind of neutron star , the tight core of a star topology that get going supernova .
“ If you may find satellite around a neutron star , planets have to be fundamentally everywhere , ” Wolszczan said . “ The major planet production process has to be very robust . ”
These5,005 planet ( and maybe 8,500 candidatesyet to be confirmed ) are but a cliff in the sea of all the planets that are await to exist in our galaxy . Hundred of billion mankind are there to be discovered , some we have n’t learn up near before , such asHot Jupitersandsuper - Earths .
And with so many worlds out there , there is apparently the question of life . Will we find evidence that some of these world are inhabited ? Something for upcoming telescopes to puzzle out , for certain , but the grounds is build that the foundational alchemy of living on Earth has confining connection to molecules and interpersonal chemistry visualise elsewhere in the creation . Our little corner of the cosmos is hopefully not that special .
“ To my mentation , it is inevitable that we ’ll obtain some kind of life somewhere – most likely of some primitive sort , ” Wolszczan say .
Of the 5,005 worlds bring out , 30 percent of them are throttle giants like Jupiter and Saturn . Thirty - five percent are Neptune - sized , while 31 pct are Super - earth , a few times bigger than our satellite but not quite as prominent as Neptune . And finally , 4 per centum are terrene , small rocky major planet the size of Earth or smaller .
There is still so much to find out about these distant worlds : how they formed , how they evolved , and what they are like at this second . This milestone is just a admonisher to go further and discover even more .
