NASA's James Webb Space Telescope Will Travel 1 Million Miles To Unlock Secrets Of The Universe
NASA confirmed yesterday that the James Webb Space Telescope (JWST), an international program led by NASA with its partners, European Space Agency (ESA) and the Canadian Space Agency, is set to launch on December 25th at 7:20 a.m. EST with a 32 minute launch window in Kourou, French Guiana. The launch has been pushed back on a couple of occasions, once for an unforeseen incident and most recently due to weather conditions. But with all eyes on the most advanced telescope ever to be launched into space, everyone is hopeful that they will be given a Christmas present of finally being able to watch as the JWST is launched into space.
One of the major differences between JWST and its predecessor, the Hubble Space Telescope, is that it will not orbit around the Earth, but rather around the Sun. This orbital path will take the telescope on a journey placing it 1 million miles (1.5 million kilometers) away from Earth at what is called the second Lagrange point or L2. The unique aspect to this path is that it allows JWST to stay in line with the Earth as it orbits the Sun, which permits the satellite's large sunshield to protect the telescope from the light and heat of the Sun, Earth, and Moon.
The direction of the Earth and Sun matter because Webb primarily observes light, which can be felt as heat. JWST will be observing the very faint signals of extremely distant objects, therefore it needs to be shielded from any bright, hot sources. The sunshield acts as a protector for the sensitive mirrors and instruments, which will be responsible for sending back all the images and data that scientists and astronomers are hoping unlock a plethora of unanswered questions about our universe. Teams will be taking advantage of all four of those instruments on Webb to observe these quasars. Those include: the Near-Infrared Spectrograph (NIRSpec); the Near-Infrared Camera (NIRCam); the Near-Infrared Imager and Slitless Spectrograph (NIRISS); and the Mid-Infrared Instrument (MIRI).
The Webb Telescope will be using spectroscopy in order to gather both detailed images and data to send back to be analyzed. Spectroscopy incorporates spreading light out into a spectrum in order to analyze the intensity, or brightness, of individual colors, or wavelengths. Light from space is directed through a spectrograph during a spectroscopic observation, which then spreads the light out into its component wavelengths. As the light hits the detectors, it can measure the intensity of each individual wavelength of light. Information about temperature, composition, density, motion, and distance can be gathered from the difference in brightness with wavelength, and the presence or absence of specific wavelengths. All four of the instruments on JWST have spectroscopy modes.
The final instrument out of the four that was readied for launch was the Mid-Infrared Instrument (MIRI). George Reike, professor of astronomy at the Unversity of Arizona, and Gillian Wright, director of the UK Astronomy Centre recently spoke about MIRI and why it is so special—because of the wavelengths it covers, the science that it enables, its technology challenges, and the way it was built.
The other three instruments observe wavelengths up to 5 microns. MIRI adds the ability of wavelengths out to 28.5 microns and increases its range of science. This capability allows JWST to study everything from protostars and their surrounding protoplanetary disks, the energy balance of exoplanets, mass loss from evolved stars, circumnuclear tori around the central black holes in active galactic nuclei, and much more.
As it pertains to the study of quasars and supermassive black holes, teams will utilize all the components of the four instruments as they gather imagery and data. Eduardo Banados, of the Max Planck Institute for Astronomy in Heidleberg, Germany explains, "These quasars are very special objects. That is why we want to provide the best characterization possible of each with Webb."
JWST will hopefully open up an expanse of the universe in ways that will provide answers to long held questions, such as why almost every known galaxy has a black hole near its center, and when exactly do they come into existence. Teams of astronomers and scientists are on standby to search and unlock the answers to these questions and many more. As JWST works alongside its predecessor Hubble, we await what will most likely be a much more detailed picture of the origin of our universe.
