The James Webb Space Telescope launches Friday
Historic launch is the culmination of a 25-year, multi-billion NASA project that will transform the way we see the universe
Special to the Daily
This week, on Christmas Eve, arguably the most pivotal NASA instrument to be created during our lifetime is launching into space. The James Webb Space Telescope, known as “Webb,” will launch from French Guiana in South America at 5:20 a.m. Friday.
A total of $8.8 billion and over 100 million hours of estimated work have been put into building this project over the past 25 years, all culminating in this week’s pivotal launch date.
Capturing a new picture of the universe
Building on the legacy of the Hubble Space Telescope, Webb has been designed to answer one of humanity’s greatest questions: How did our universe form?
Webb was built to detect the infrared light needed to create a picture of what the universe looked like about 100 million to 250 million years after the Big Bang. This is not only much further back into the history of time than what has been observed before, but also unique in that this is around the time we estimate that the first stars and galaxies began to form.
Similarly, Webb’s advanced observations of infrared light will allow us to see inside dust clouds well enough to be able to anticipate where stars and planets might be being born nearby. This higher resolution is currently unattainable with today’s current missions and instruments.
The science community envisages the information provided by Webb to dramatically transform our current understanding of black holes, dark matter and galaxy evolution over time. For instance, Webb might help us determine if black holes cause the formation of galaxies, or vice versa.
Actual matter, such as human beings, or Neptune, makes up less than 5% of the universe. Dark matter and energy make up the remaining 95%, and we know practically nothing about it other than that it exists. While Webb will not be able to detect dark matter directly, its ability to measure the effects that dark matter has on its surroundings has the potential to answer some major questions about its behavior.
How is Webb special?
Many compare the capabilities of Webb to those of the Hubble Telescope, one of humanity’s most impressive scientific telescopes for space research for over three decades. There are three main differences between the two that enable Webb’s advanced capabilities.
First, Webb’s mirror is far more massive than Hubble’s. Webb carries 21 feet of gold-plated hexagonal mirrors that will fold out after reaching its destination orbit to create one large mirror. This larger mirror surface area, approximately 6.25 times that of Hubble, allows Webb to collect light far farther into the infrared spectrum in order to peer further back in time compared to Hubble.
A recent article by NASA’s Goddard Space Flight Center kindly puts this into context by stating that Hubble is able to see “toddler galaxies” whereas Webb will be able to see “baby galaxies.”
The creation of this incredible mirror was a huge feat for humanity. This is not only because of its size, but also because it requires a cold enough temperature in order to prevent irrelevant sources of infrared from skewing observations. Along with 18 hexagonal mirrors, Webb will also carry a tennis-court sized sunshield to keep the Sun’s heat and light from meddling with its measurements.
Second, Webb will be launched over 2,752 times farther into space than Hubble. Hubble is located in orbit only about 340 miles from the surface of Earth, whereas Webb will be launched into orbit at the Earth-Sun L2 Lagrange point, located about 0.93 million miles from the Earth’s surface. An important distinction here is that Hubble is located within Earth’s orbit, whereas Webb is not. The Earth-Sun L2 Lagrange point is a pocket of space that allows Webb to remain faced away from the sun but also stay fixed at the same distance from Earth while we orbit the sun.
The combination of both the first and second distinctions above allow for the third differentiator of Webb when compared to its peers: Webb will provide over 16 times the coverage of infrared light we are currently able to achieve with Hubble.
Hubble focuses mainly on observing ultra-violet and visible wavelengths of light. It is, however, also able to observe a tiny portion of infrared light, which is what led scientists to realize the true magic of observing the infrared part of the electromagnetic spectrum.
If you take a moment to look up comparisons of Hubble’s visible and infrared views of distant celestial objects, you will find that, with the infrared views, we can appreciate hordes more galaxies that appear to be nonexistent in the images measuring only visible wavelengths.
This discovery laid the foundations for the design of the Webb telescope, which is focused primarily on measuring infrared light. Infrared light wavelength is measured from about 0.75 microns up to a few hundred microns on the electromagnetic spectrum. To put Webb’s dexterity into perspective, Hubble has beautifully provided wavelength coverage from about 0.8 to 2.5 microns on the infrared spectrum, but Webb will be able to provide measurements of light between 0.6 up to 28 microns, or about 16 times the coverage of Hubble.
T-minus two days to liftoff
A thousand and one problems can occur between now and the end of Webb’s expected mission life of about 5.5 years (with a potential extension of up to 10 years). Over the next few months, mission engineers will remotely align and calibrate the telescope’s instruments, and it will perform its first observations after six months.
If everything runs smoothly, we may have an entirely different perspective on the origin of our home, and potentially even our species, in less than a decade’s time.
The James Webb Space Telescope will drastically change our understanding of the universe, and that path to discovery officially begins with the launch this week. NASA will be live-streaming the 5:20 a.m. launch on NASA TV, YouTube, and on its website and social media accounts. This is a historic moment that is well worth waking up for, or at least watching a rerun of later in the day.
Elizabeth Zadik is a first-year masters student in aerospace engineering sciences at University of Colorado Boulder.
What: NASA launch of the James Webb Space Telescope
When: Friday, Dec. 24 at 5:20 a.m.
Where: NASA TV, YouTube channel, website or social media accounts