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Giuseppe Cataldo

New Worlds
with the James Webb Space Telescope by NASA's JPL Scientist Giuseppe Cataldo

SpaceInfo had the great pleasure to meet Giuseppe Cataldo, who worked, among other amazing projects, on the James Webb Space Telescope. The following article was written by him.

Nearly a year ago, on July 12, 2022, the entire world stood amazed before the first images and data revealed by the largest and most powerful space telescope in human history, James Webb. A project twenty-five years in the making, James Webb has stood to the expectations of the engineers who designed and built it, the scientists who had been looking forward to using such a sophisticated machine to make impactful discoveries, and all the astronomy fans who could not wait any longer to admire details of the universe as never seen before.

I’m writing as an engineer who was offered to work on Webb in 2014 to tackle some challenges with the mathematical models of its thermal system. At the time, I was still a PhD student focused on finalizing my thesis at the Massachusetts Institute of Technology (MIT). I was shocked to receive such a request given the complexity and delicacy of this “engineering jewel”, as Webb already used to be defined, which required highly specific technical skills and a high degree of responsibility. This was unthinkable for me, then only twenty-eight years old. Nonetheless, these feelings turned into joy and determination when hearing words of encouragement from my boss, who convinced me to accept. He knew some classes I had taken at MIT would have helped me make the difference. Thus my adventure with Webb began, which contributed to create a real time machine capable of detecting the light of the most ancient astronomical objects (the “first light”), studying the evolution of galaxies, unveiling the mysteries that still surround the formation of stars, and describing the physical and chemical composition of planets outside our solar system.

The study of exoplanets, as these planets are called, represents a relatively young area of investigation for scientists since two new worlds were discovered around a pulsar in the constellation Virgo in 1992. Only seven years later a planet was observed passing in front of its star, allowing astronomers to study the composition of its atmosphere. In a planetary system, in fact, the light of the host star (like our Sun), in passing through the atmosphere of a planet orbiting around it, is diffracted much like a prism decomposes white light in a rainbow of colors, thus revealing the elements the planet atmosphere is made of. Specifically, different types of chemicals in the atmosphere absorb different colors of the starlight spectrum, so the colors that are missing tell astronomers which molecules are present. Starting with ground telescopes and even the Hubble Space Telescope, since 2003 several telescopes have been hunting for and analyzing exoplanets including the Microvariability and Oscillations of Stars Telescope (MOST), the Spitzer Space Telescope, the Convection Rotation and planetary Transits (CoRoT) telescope, Kepler and the Transiting Exoplanet Survey Satellite (TESS). James Webb has joined this highly respected group of telescopes capable of providing us unprecedented data on these exotic worlds that fill our universe. While Webb was not designed to detect exoplanets, it can follow up on those that have been discovered by such telescopes and target them for analysis.

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Image Credits:

  1. Giuseppe Cataldo (cover)

  2. NASA/JPL-Caltech/R. Hurt (IPAC)

  3. NASA, ESA, CSA, Joseph Olmsted (STScI)


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