This past December, NASA launched the James Webb Space Telescope (JWST) in collaboration with the European Space Agency and the Canadian Space Agency. This revolutionary mission is the largest and most intricate space observatory and is set to accomplish a multitude of scientific goals.
James Webb Space Telescope vs. Hubble Space Telescope
JWST can be considered a successor of the Hubble telescope, which was launched in 1990. The Hubble Space Telescope has given us many beautiful and fascinating images of space, and has helped astronomers make many key discoveries. Some of these discoveries include uncovering the age of the universe and the fact that most major galaxies have black holes at their center.
While the JWST will expand on some of the science the Hubble has accomplished, the two space telescopes have some key differences. The JWST is orbiting the sun at a distance of one million miles away from Earth, while the Hubble is orbiting Earth at a distance of 340 miles away from our planet. Also, the Hubble observes light at optical and ultraviolet wavelengths, while the JWST is primarily detecting infrared light.
Why Infrared?
The JWST has had thousands of scientists working on it for over 20 years. Throughout these 20 years, this telescope ended up costing around a total of 10 billion dollars. The choice of having JWST be solely an infrared telescope was a well-thought out decision intended to maximize the scientific capabilities of the telescope. This also allows the JWST to explore space in ways that the Hubble couldn’t.
Cosmic objects that are very distant from us are more challenging to view, and are often highly redshifted. In astronomy, redshift refers to the wavelength of light being increased and shifted into longer and redder wavelengths as objects move further away. Many distant objects in space are pushed out of the visible and ultraviolet wavelengths into the infrared. This is called redshifting, because objects in space will appear redder if they are moving away from us and bluer if they are moving toward us.
By designing JWST to detect infrared wavelengths, scientists will be able to gain more knowledge about the distant universe.
What will JWST accomplish?
JWST has many scientific objectives, which can be broken down into four general categories. These categories are First Light and Reionization, The Assembly of Galaxies, The Birth of Stars and Protoplanetary Systems and finally Planetary Systems and the Origins of Life.
First Light and Reionization refers to the telescope detecting the first galaxies ever formed, and understanding more about these galaxies. The Assembly of Galaxies category will aim to understand more about properties of galaxies and black holes. The third grouping will focus on gaining information on star forming regions in space. Finally, Planetary Systems and Origins of Life will aim to study exoplanets, or planets outside our solar system, to see if these planets have liquid water. This category will also focus on the formation of planets, which will help us develop a better understanding of how Earth was formed.
Outside of those four main areas of study, JWST will also observe objects in our own solar system, including Mars, Jupiter, Saturn, Neptune, Pluto, minor planets, asteroids and comets.
How long will the telescope be active?
This telescope has a lifespan of at least five years, but scientists are hopeful that it will end up being used for at least 10. Unfortunately, the telescope will be too far from Earth for any repair or update missions, like the Hubble had, so once JWST runs out of fuel, it will be out of commission.
On February 11, the first images from the JWST were received. The images show a sun-like star that is 360 lightyears away.
This is only the beginning of an exciting new era in astronomy that will help scientists in their ongoing journey of obtaining a deeper understanding of the universe.