Adler Planetarium Director Delivers a Spellbinding Levy Lecture
At the virtual Levy Lecture held on August 4, the crowd was spellbound by “Through the Eyes of Hubble,” a presentation by Michelle Nichols, Director of Public Observing at the Adler Planetarium. Ms. Nichols used an array of slides to show the majesty and mystery of the solar system, and demonstrated why Hubble has been so monumentally important to NASA and the general scientific community around the world.
Offering first a foundation of common terminology of such things as solar system, galaxy, universe, and nebula, Ms. Nichols then presented some historical context. She showed a photo of a professorial-looking man in a suit. This man, Lyman Spitzer, Jr. was the astrophysicist who in 1946 conceived of the idea of putting a telescope into space.
Fast forward a few decades … The Hubble telescope and the Space Shuttle were being developed and built at the very same time. Ms. Nichols showed photographs of the Hubble telescope’s mirror, which is not even 10 feet in diameter. It was designed to fit in the payload bay of the shuttle, and on April 24, 1990 the Hubble telescope hitched a ride on Discovery as it blasted into space.
The very next day, April 25, the Discovery crew used the robotic arm in the payload bay to release the telescope into orbit: Mission accomplished — sort of. The first pictures coming back from Hubble were pretty good, but they were not as sharp as the scientists expected. Reviewing all the preliminary work done before launch, NASA determined that when the mirrors were ground, one of the calibration instruments was not correct. The error was 1/50th the size of a human hair — so small, and yet this error prevented the pictures from being precise. The images coming back from Hubble were still usable, but NASA needed to develop a plan to fix the mirror.
NASA got to work and developed two instruments that would fix the error. In 1993, as part of the mission for the shuttle Endeavor, astronauts installed COSTAR (Corrective Optics Space Telescope Axial Replacement), an instrument that would correct the mirror’s flaw. The second instrument was an updated version of the Wide Field Planetary Camera. The instruments contained their own optics to correct the flaw without having to replace the existing mirror.
Both instruments worked perfectly; the error was corrected. In 2009, Wide Field Planetary Camera 2 was replaced by Wide Field Planetary Camera 3. Ms. Nichols shared photos comparing the differences of photographs taken by Hubble in various years: the 1990 Hubble, the 1993 Hubble, and the Hubble with a new camera. The advances in technology have delivered astounding images that defy imagination.
Ms. Nichols showed photos of stars being born, of stars dying and views of the universe with space dust filtered out. The images are stunning, unusual, and other-worldly.
Ms. Nichols’ enthusiasm and passion for astronomy comes through with every slide. She loves astronomy and loves to share it with anyone who cares to listen. The audience of 350+ was riveted and most stayed for the question and answer period that followed the last slide.
Anne Matsumoto, who described herself as a novice, said, “Great presentation. Michelle is so knowledgeable and shares her info in a way that a novice viewer like myself finds valuable and fascinating. Thanks so much.”
By Wendi Kromash as published in the Evanston RoundTable