Publish : 20 Nov 2021, 08:45 PMUpdate : 20 Nov 2021, 08:46 PM
As the launch nears, Dhaka Tribune’s Nabban Haque sat with Dr Lamiya Ashraf Mowla, Dunlap Fellow at the Dunlap Institute for Astronomy and Astrophysics at University of Toronto and member of the Canadian team guaranteed time on the JWST, to discuss what makes the iconic Hubble Space Telescope’s replacement special
Is there really a big difference between Hubble and the JWST?
There are numerous differences between the two space telescopes, the most obvious among them being size. Whereas Hubble is the size of a small bus, the JWST closer to the size of a tennis court. It is the largest and most ambitious space telescope that has been built, so far.
Moreover, comparing Hubble to the JWST is kind of like comparing an old landline to today’s smartphones. While Hubble observed in the UV to near infrared range, the JWST can capture high-resolution infrared images. Being able to observe infrared is crucial to studying the birth of galaxies, stars, and planets out of the dust and gas of the cosmos.
Hubble was launched in 1996 and supposed to stay in service for 10 years but is still going strong after three decades in service, although it has needed some maintenance every now and then. The JWST has much more advanced technology, being almost 100 times more sensitive than its predecessor, and it is going to need every edge it can get.
That sounds ominous. What do you mean by that?
Hubble and the JWST are not only very different machines, but they are also going to be used in very different ways. Hubble orbits the earth, and this allows for astronauts to carry out maintenance through space missions, as needed. There will be no such opportunity with the JWST, as it will literally be out of our reach.
Collected from the JWST website
After take-off from Earth, the JWST is going to careen through space for about a month before reaching its destination on the other side of the Sun. Along the way, it is going to unfold mirror deployments and other devices necessary to send signals back to earth.
That seems extremely risky! Why the long trek?
It is extremely risky and that is primarily why there have been so many delays. Construction of the JWST began in 1996, just as Hubble was launched, and it was supposed to be ready by 2007. However, it has been delayed by nearly a decade and a half because the team are acutely aware that there is only one chance to get it right after launch.
As for why the telescope needs to get to its spot on the other side of the Sun, it is to do with minimizing resistance from gravity. The telescope will be stationed at Lagrange point, a point at which the gravitational force from the Sun and the Earth cancels each other out. This way, the telescope does not need to spend precious fuel to fight off gravity.
What exactly is the main goal of the JWST?
The main goal of the JWST is to find some of the first galaxies ever born, as well as clues to the birth of stars and protoplanetary systems. It takes about 13 billion years for photons from the first galaxies to reach us as they are the farthest away, so the light is in the infra-red spectrum by the time it gets here and specific sensors are needed to detect it.
Another crucial factor in meeting the goal is time. Unlike Hubble, the JWST will have shelf life of only five years. As a result, any budding astronomers who wish to use it need to start taking steps to contact the relevant authorities as soon as possible.
JWST: A giant new eye in the sky
As the launch nears, Dhaka Tribune’s Nabban Haque sat with Dr Lamiya Ashraf Mowla, Dunlap Fellow at the Dunlap Institute for Astronomy and Astrophysics at University of Toronto and member of the Canadian team guaranteed time on the JWST, to discuss what makes the iconic Hubble Space Telescope’s replacement special
Is there really a big difference between Hubble and the JWST?
There are numerous differences between the two space telescopes, the most obvious among them being size. Whereas Hubble is the size of a small bus, the JWST closer to the size of a tennis court. It is the largest and most ambitious space telescope that has been built, so far.
Moreover, comparing Hubble to the JWST is kind of like comparing an old landline to today’s smartphones. While Hubble observed in the UV to near infrared range, the JWST can capture high-resolution infrared images. Being able to observe infrared is crucial to studying the birth of galaxies, stars, and planets out of the dust and gas of the cosmos.
Hubble was launched in 1996 and supposed to stay in service for 10 years but is still going strong after three decades in service, although it has needed some maintenance every now and then. The JWST has much more advanced technology, being almost 100 times more sensitive than its predecessor, and it is going to need every edge it can get.
That sounds ominous. What do you mean by that?
Hubble and the JWST are not only very different machines, but they are also going to be used in very different ways. Hubble orbits the earth, and this allows for astronauts to carry out maintenance through space missions, as needed. There will be no such opportunity with the JWST, as it will literally be out of our reach.
After take-off from Earth, the JWST is going to careen through space for about a month before reaching its destination on the other side of the Sun. Along the way, it is going to unfold mirror deployments and other devices necessary to send signals back to earth.
That seems extremely risky! Why the long trek?
It is extremely risky and that is primarily why there have been so many delays. Construction of the JWST began in 1996, just as Hubble was launched, and it was supposed to be ready by 2007. However, it has been delayed by nearly a decade and a half because the team are acutely aware that there is only one chance to get it right after launch.
As for why the telescope needs to get to its spot on the other side of the Sun, it is to do with minimizing resistance from gravity. The telescope will be stationed at Lagrange point, a point at which the gravitational force from the Sun and the Earth cancels each other out. This way, the telescope does not need to spend precious fuel to fight off gravity.
What exactly is the main goal of the JWST?
The main goal of the JWST is to find some of the first galaxies ever born, as well as clues to the birth of stars and protoplanetary systems. It takes about 13 billion years for photons from the first galaxies to reach us as they are the farthest away, so the light is in the infra-red spectrum by the time it gets here and specific sensors are needed to detect it.
Another crucial factor in meeting the goal is time. Unlike Hubble, the JWST will have shelf life of only five years. As a result, any budding astronomers who wish to use it need to start taking steps to contact the relevant authorities as soon as possible.