The First Thing That James Webb Will See

After a long wait of 25 years, several  budget overruns, and unprecedented delays, James Webb Space Telescope was finally launched.  A 10 billion dollar time machine working in its full swing can make anyone ecstatic. And the  fact that it will collaborate with the Event horizon telescopes in the future to capture  the first image of the Milky Way’s black hole, Sagittarius A* (pronounce A star),  makes it even more exciting. But when is Webb going to return its first  image of the cosmos? What is the first thing it will focus on? And most importantly,  what are its long-term plans? The first few months are going to be intense.  Firstly, getting a telescope so big to its final destination is a big task in itself. Webb will  orbit the Sun near L2, a gravitational stablility solar orbit that’s roughly 1 million miles from  Earth on the opposite side of our planet from the sun. Secondly, we are talking about a telescope  with a primary mirror composed of 18 hexagonal mirror segments, and unfolding the mirror into  one big unit is another feat to accomplish. So to be precise, in the first month, the  James Webb Space Telescope will undergo several maneuvers and course corrections to  attain its final orbit around the L2 point. In the second month, the alignment  of mirror segments will begin. It will possibly take 60 to 90 days after launch  for the primary mirror segments to align to work together as a single optical surface. Then,  perhaps, by the end of the third month, Webb will be able to take the first science-quality images,  and by this time, it will also complete its journey to its L2 orbit position. At this moment,  it would only be taking blurred and casual images, possibly of some bright stars, just for the sake  of optimization. So the next few months will go into calibrating and optimizing its cameras and  other instruments. And finally, after six months of its launch, Webb will be in a position  to begin its most awaited science missions, and the year of Cycle 1 of a series of  spectacular observations will begin. Webb’s cycle 1 observations include everything  from looking for atmospheres on nearby rocky exoplanets to probing the universe’s earliest  galaxies. Since Webb is a telescope for all, to be a part of its Cycle 1 observations,  more than 1200 proposals were received. From these, the panel underwent a double-blind  process and selected 266 final proposals from scientists in 41 countries, amongst  which women will lead a third of them. All these proposals will be collectively  given a view time of 6000 hours, and all of these come under the category of  General observer or GO programs. Apart from this, 460 hours will be devoted to Early Release  Science programs designed to put the telescope’s instruments through their paces.  Finally, nearly 4,000 hours will be dedicated to Guaranteed Time Observations or the GTO  programs awarded explicitly to scientists who helped build the telescope’s hardware  and software. I know the total number of these hours is way more than the number of hours  available in a year. But such a schedule has been intentionally made so that Webb is never  left idle from observing the cosmos. Moreover, the total observation time within  Cycle 1’s GO programs is split among various subcategories. These include 32% for galaxies,  23% for exoplanets, 12% for stellar astrophysics, down to 6 % dedicated to our solar system.  Further, there will be small programs consuming 25 hours or less of observation time, medium  programs requiring between 25 to 75 hours, and large programs requiring more than  75 hours of the observation window. Now coming to all the GO programs, the maximum  time of 208.6 hours has been given to the COSMOS-Webb proposal. In this, Webb will look at  thousands of the earliest galaxies formed within a billion years of the big bang. These galaxies are  so faint that observing them has always been out of range of the existing telescopes. But Webb  is capable of looking at much fainter things. So it is expected to reveal a bag full of  information about the universe’s history, especially about a period from 400,000  to one billion years after the big bang, where the first stars and galaxies emerged. Coming to its next big project, about 141.7 hours of observations have been dedicated to studying  the atmospheres of a dozen exoplanets in a never seen before manner. The James Webb Space Telescope  will employ its giant mirror to watch these worlds transit their host stars and block the  starlight while passing in front of them. This will allow the researchers to work out the  basic composition and structure of any atmosphere present there. Most of these target worlds  include super-Earths and sub-Neptunes. However, the most exciting  planetary target will be TRAPPIST-1, a transiting planetary system  about 40 light-years from Earth. This system is thought to comprise seven  Earth-sized worlds orbiting a single red dwarf star and is one of the prime targets of Webb. Webb  will have a total of 5 programs solely dedicated to the observations of TRAPPIST-1. TRAPPIST-1c,  which is the system’s second innermost world, is thought to be too hot to support life. So  Webb will assess the temperature of TRAPPIST-1c to look for an atmosphere on that planet. It  will observe this planet for nearly 18 hours. The planetary observations don’t end  here. Apart from studying foreign worlds, Webb will undertake extensive studies about our  solar system. For example, Webb will study 59 trans-Neptunian objects, which are the icy  bodies lying beyond the orbit of Neptune. And this observation campaign will last  nearly 100 hours. In addition to this, Webb hopes to observe an interstellar object  passing through our solar system, just like Oumuamua in 2017 or Comet Borisov in 2019. However, these programs are just for Webb’s cycle 1 of observations. In the long run,  it will also carry out some tricky missions. And one of the trickiest ones would be to image  our galaxy’s black hole with the event horizon telescope. The observations of dark matter and  the birth of stars are also on the list. Webb has been designed to have an overall mission  lifetime of at least five and a half years. And on the brighter side, it can  also last longer than ten years. We still have to wait a little more to get our  hand at the marvelous images from the telescope, but its bucket list of observations  tells us the wait is going to be worth it.

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