Why is Detecting Extrasolar Planets so Hard?
Stars are much larger, more massive, and brighter than planets. A lone planet is very difficult to detect at stellar distances. A planet close to a much brighter star is even harder to detect because the star’s light overwhelms the planet’s feeble light. Detecting a planet orbiting another star is like watching a large forest fire from a distant mountaintop and trying to see a fire fighter holding a burning match. So astronomers must discover extrasolar planets indirectly using the Doppler effect and high resolution spectroscopy. document.getElementById(‘adsense_placeholder_2’).innerHTML = document.getElementById(‘adsense_ad_2_hidden’).innerHTML; Doppler Effect The Doppler effect allows astronomers to tell if a star is moving towards or away from us by shifts in spectral lines. If a spectral line from a star is shifted to longer wavelengths, a red shift, it is moving away from us. If it is shifted to shorter wavelengths, a blue shift, the star is moving towards us. A larger shift tells
