 There was a good deal of interest in the 2004 transit as scientists attempted to measure the pattern of light dimming as Venus blocked out some of the Sun 's light , in order to refine techniques that they hope to use in searching for extrasolar planets . Current methods of looking for planets orbiting other stars only work for a few cases : planets that are very large ( Jupiter @-@ like , not Earth @-@ like ) , whose gravity is strong enough to wobble the star sufficiently for us to detect changes in proper motion or Doppler shift changes in radial velocity ; Jupiter or Neptune sized planets very close to their parent star whose transit causes changes in the luminosity of the star ; or planets which pass in front of background stars with the planet @-@ parent star separation comparable to the Einstein ring and cause gravitational microlensing . Measuring light intensity during the course of a transit , as the planet blocks out some of the light , is potentially much more sensitive , and might be used to find smaller planets . However , extremely precise measurement is needed : for example , the transit of Venus causes the Sun 's light to drop by a mere 0 @.@ 001 magnitude , and the dimming produced by small extrasolar planets will be similarly tiny . 
 <a href='dey_it' title='1'><mark>There</mark></a> was a good deal of interest in the 2004 transit as scientists attempted to measure the pattern of light dimming as Venus blocked out some of the Sun <a href='null_genetive' title='2'><mark>'s</mark></a>light , in order to refine techniques that they hope to use in searching for extrasolar planets . Current methods of looking for planets orbiting other stars only work for a few cases : planets <a href='null_relcl' title='3'><mark>that</mark></a><a href='drop_aux' title='4'><mark>are</mark></a>very large ( Jupiter @-@ like , not Earth @-@ like ) , whose gravity is strong enough to wobble the star sufficiently for us to detect changes in proper motion or Doppler shift changes in radial velocity ; Jupiter or Neptune sized planets very close to their parent star whose transit <a href='uninflect' title='5'><mark>causes</mark></a> changes in the luminosity of the star ; or planets which pass in front of background stars with the planet @-@ parent star separation comparable to the Einstein ring and cause gravitational microlensing . Measuring light intensity during the course of a transit , as the planet <a href='uninflect' title='6'><mark>blocks</mark></a> out some of the light , <a href='drop_aux' title='7'><mark>is</mark></a>potentially much more sensitive , and might be used to find smaller planets . However , extremely precise measurement is needed : for example , the transit of Venus <a href='uninflect' title='8'><mark>causes</mark></a> the Sun <a href='null_genetive' title='9'><mark>'s</mark></a>light to drop by a mere 0 @.@ 001 magnitude , and the dimming produced by small extrasolar planets will be similarly tiny . 
It was a good deal of interest in da 2004 transit as scientists attempted to measure tdapattern of light dimming as Venus blocked outt some of the Sun  light , in order to refine techniques dat they hope to use in searchin for extrasolar planets . Current methods of lookin fa planets orbiting other stars only wrk for a few cases : planets very bigass ( Jupiter @-@ like , not Earth @-@ like ) , whose gravity is strong enough to wobble thdatar sufficiently for us to detect changes in proper motion or Doppler shift changes in radial velocity ; Jupiter or Neptune sized planets very close to their parent star whose transit cuz changes in the luminosity of the star ; or planets which pass in front of background stars w thedaanet @-@ parent star separation comparable to the Einstein ring and cause gravitational microlensing . Measuring light intensity during the darse of a transit , as the planet block out sum of the light , potentially much more sensitive , and mite b used to find smaller planets . However , extremely precise measurement is needed : for example , the transit of Venus cacushe Sun  light to drop by a mere 0 @.@ 001 magnitude , and the dimming produced by small extrasolar planets will bbsimilarly tiny .