Free Astronomy Magazine March-April 2022

MARCH-APRIL 2022 we can solve by selecting a telescope dedicated to that longer-wave- length radiation. As to the science to be performed by the JWTS, high sensitivity in the in- frared region of the spectrum means a wealth of observational opportu- nities. We’ll consider the two exam- ples mentioned above. Readers of this magazine are aware of the complexities of both finding habitable exoplanets and determin- ing whether the detection of life – simple or complex, actively trying to communicate or content in their iso- lation – is going to be something our current technologies enable. Like brown dwarfs, comets, Kuiper belt objects, debris disks, planets in our own Solar System, and any new ob- jects yet to be discovered (all of these objects also being future Webb targets), exoplanets are not shining prominently like the stars they orbit or have been set adrift from. Their emission is stronger in the infrared than the visible. Be- cause of this, there is more informa- tion to be obtained, and more to be learned, by collecting data at these longer wavelengths. The problem, of course, is the proximity of these planets to their host stars, which have made direct imaging of most exoplanets all but impossible. Webb combines greater sensitivity than ever available with onboard corona- graphs on its NIRCam and MIRI in- struments to both “block out” the associated star and directly image exoplanets in the infrared. This is something that observation from the ground on Earth is made compli- cated by due to the very molecules that have made life possible at all – water vapor and carbon dioxide in our atmosphere, which absorb the very same infrared wavelengths we want to measure. If we take the span of 100 million years to be a chapter in a history book of the universe, we currently find ourselves at a distant Chapter 138. Despite only having started to read backwards to uncover the plot of the book from somewhere near the very end of the very last sen- tence of this current chapter, we’ve made remarkable progress at skim- ming through nearly all of the chap- ters, albeit with some great difficulty in turning the book back to its intro- A n artist’s view of the mirrors, de- tectors, and support structures on Webb − all placed on the opposite side of the telescope’s sunshields from the Sun, which is shown as a bright- ening glow to the lower-right. [NASA GSFC/CIL/Adriana Manrique Gutierrez]