One year from now, NASA will launch a telescope called Webb. This telescope’s full name is the James Webb Space Telescope, and it is the successor to the Hubble Telescope. Hubble changed the way we see the universe by orbiting Earth and observing space in both optical and ultraviolet wavelengths. Webb’s orbit won’t be around our Earth, but our Sun, and it’ll further extend our visibility into the stars capturing data in infrared.
Our Earth is 150 million km away from the Sun. Hubble orbits Earth at 570 km, and our Moon orbits at 384,400 km. Webb will be launched 1.5 million km away, to the second Larange point, also known as L2. At this distance, Webb will no longer orbit the Earth, it’ll orbit the Sun. Webb will stay in the same spot with relation to the Earth, following alongside the Earth as they both orbit the Sun.
This is not the only piece of human-made equipment to operate at L2. The other was the Herschel Space Observatory, operated from 2009 to 2013. Herschel was the largest infrared telescope ever launched. Herschel ended operation in April of 2013 because it relied on coolant and… the coolant ran out.
Webb ramps up the abilities of both Hubble and Herschel. Below you’ll find some simple comparisons which outline the differences between the three bits of hardware.
– Herschel: Wavelength range 60 to 500 microns
– Herschel: Mirror 3.5 meters
– Webb: Wavelength range 0.6 to 28.5 microns
– Webb: Mirror 6.5 meters
– Hubble: Wavelength range 0.8 to 2.5
– Hubble: Mirror 2.4 meters
Per NASA: “The wavelength ranges were chosen by different science: Herschel looked for the extremes, the most actively star-forming galaxies, which emit most of their energy in the far-IR. Webb will find the first galaxies to form in the early universe, for which it needs extreme sensitivity in the near-IR.”
Light takes time to travel, so light we see bouncing off of or emitting from something closer to us started its journey more recent than something we see that’s further away. A human can see our Sun – that light started emitting from the Sun around 8 minutes before it hits our eye.
A telescope able to see further away can also see further back in time, so to speak. According to NASA, Hubble can see the equivalent of “toddler galaxies”, while Webb will be able to see “baby galaxies.” With Webb, We’ll be able to see the first stars that ever popped up in our universe.
At the point at which this article is posted, March 30, 2020, the plan remains that NASA’s launch for Webb is scheduled for March 30, 2021. That’s one year from now. Situations like our current global pandemic with COVID-19 could change a lot between now and then, but the plan (for now) remains the same. Cross your fingers and hope for the best!