In some exciting news on the space front, the James Webb Space Telescope, which launched on Christmas Day in 2021, has reached its final destination. Webb is the most powerful telescope ever built and is about the size of a tennis court. Over this last month, it had to undergo a series of complicated maneuvers and unfolding to be fully deployed. It was quite a nerve-wracking feat for the engineers and scientists! So, what will the telescope be up to, one million miles away from Earth? Its mission is to better understand the early days of our universe: it will be able to capture images of the very first stars in the universe! Webb also will help us determine how quickly the universe is expanding, and it will even seek out exoplanets and their atmospheres to see if they’re habitable – or inhabited. This will be done with a technique called “transmission spectroscopy,” where starlight filtered through the planetary atmospheres will be analyzed for chemical composition.
Webb will directly observe a part of space and time never seen before, gazing back over 13.5 billion years ago. Light (ultraviolet and visible) emitted from these stars has been stretched or “redshifted” due to the universe expanding and so it arrives today at longer wavelengths, in the infrared part of the electromagnetic spectrum. Hubble could see only visible light; Webb will not only be able to “see” this infrared light, it will do so with unprecedented high resolution and sensitivity. Over the next few months, the infrared telescope’s mirrors will be adjusted and instruments aboard will be tested in order to start taking imagery and measurements.
The telescope will remain in a special orbit around a point in space called Lagrange Point 2 (L2), that helps keep its position stable relative to the Earth and the Sun. At Lagrange points, the gravitational pull of two large masses precisely equals the centripetal force required for a small object to move with them. These points in space can be used to reduce fuel consumption needed to remain in position. L2 is ideal because it’s close enough to communicate with the Earth and it can keep the Sun, Earth and Moon behind the spacecraft for solar power, while protecting it from big swings in temperature. This is important order for the Webb telescope’s instruments to work properly. L2 also provides a clear view of deep space. The first images from the telescope are expected to be released this summer – I can hardly wait!