Although the images released last week by the James Webb Space Telescope Team are not officially considered ‘first light’ images of the new telescope, they feel like it. These spectacular views give us an idea of how powerful JWST is and how much-infrared astronomy will improve.
After the lengthy process of focusing the telescope’s mirror segments, the images were released. Engineers claim JWST’s optical performance exceeds all expectations, and astronomers are ecstatic.
“It has not broken any laws of physics but it does lie at the very highest end of possibilities due to the extraordinary efforts by many over decades,” stated Mark McCaughrean (the European Space Agency’s Senior Advisor for Science & Exploration) on Twitter.
In their excitement, astronomers started posting comparison images — from JWST to previous telescopes — showing the evolution in resolution.
Andras Gaspar, an Astronomer working with JWST’s Mid-Infrared Instrument, MIRI, has compiled images using the WISE (Wide Infrared Survey Explorer), telescope to JWST’s view of the Large Magellanic Cloud. It is a small satellite galaxy of the Milky Way.
He realized Spitzer had also captured an image LMC. He created a comparison of three telescopes and it can be seen in the lead image.
“To be honest, WISE with its forty cm diameter telescope is only half the size Spitzer’s [85cm primaries], but both are tiny compared JWST [6.5m primaries]” Gaspar posted on Twitter. “This is what you get if you have a large aperture!” Resolution and sensitivity. MIRI even gives mid-IR! HST [Hubble Space Telescope] can’t get this wavelength.”
Engineers, as well as astronomers, are often amazed at how high JWST is achieving. This might surprise you. That may surprise you. Yes, they do, but ground tests may not tell the whole story. Marshall Perrin at the Space Telescope Science Institute, deputy project scientist for Webb, explained on Twitter.
“Yes we had tested the whole optical train in cryo Houston, but that didn’t actually tell us its ultimate performance,” he wrote. The ground environment for testing was in many ways different from space.
Perrin explained how gravity plays a part, explaining that JWST’s Mirrors are intended to have a specific shape in Zero-G, but they were invariably deformed during ground tests.
The telescope’s performance in Zero gravity is unknown. It can also not be tested on the ground to see if it will vibrate from the spacecraft. Perrin explained that while the JWST ground test could replicate the temperatures in space using Johnson Space Center’s thermal vacuum chamber, some effects in this chamber can cause optical instabilities.
The author wrote, “A performance prediction cannot be just an expression of a wish or a hand wave. It has to be based in quantitative mathematical models and budgets that include assessing risks and uncertainties.”
Even though predictions are useful, they are not always accurate. Let’s just enjoy the joy that JWST offers us.
The official first light images are scheduled to arrive in July.
Webb is sometimes called “the replacement for Hubble”, but we prefer to use the term “successor”. Webb, in fact, is the scientific successor for Hubble. Webb was inspired by Hubble results. Hubble’s research inspired us to seek out longer wavelengths, to “go above” what Hubble has done. More distant objects are redshifted more than others, and their light moves from the UV to the nearinfrared. This is why an infrared telescope is required for observations of these distant objects (such as the first galaxies created in the Universe).
Webb is not meant to replace Hubble. Its capabilities are also different. Webb will look at the Universe mostly in the infrared while Hubble studies it more at ultraviolet and optical wavelengths (though it does have some infrared capacity). Webb also has more mirrors than Hubble. Webb can see further back than Hubble’s time horizon because it has a greater light collection area. Hubble orbits around the earth very closely, while Webb will remain 1.5 million km away at the Lagrange (L2) second point.
The James Webb Space Telescope, also known by Webb or JWST is a large, space-based observatory. It’s optimized for infrared wavelengths and will enhance and extend the discoveries made with the Hubble Space Telescope.
Webb will investigate the formations of new stars in our universe. To see the very beginning stars and galaxies of our universe’s early days, we need to look far into space. This is because light-time takes to travel between here and time.
The sharpness and number of pixels used to create an image of an astronomical object determine its beauty and quality. Webb is comparable to Hubble in both quality and sharpness. Webb images are infrared and can be transformed by computer to a visible image (just like Spitzer’s beautiful pictures). Webb is also able to see visible light orange and red. Webb images may be slightly different than Hubble’s but will still be just as beautiful.
Webb’s purpose is to look into the future to find the first stars and galaxies to form in the universe. It also allows you to view dust clouds from nearby to examine the formation and evolution of stars and planets.
Webb will use a primary mirror 2.5 times larger than Hubble’s, and 6 times more in area, to achieve this. This will give it greater light-gathering powers. It will also feature infrared instruments which have a greater wavelength coverage and a higher sensitivity than Hubble. Webb will also operate further from Earth, with a stable operating temperature, higher pointing, and a greater observing efficiency that Hubble.
Webb will have the ability to provide information about the compositions and atmospheres of exoplanets. It will use transit technology to monitor the atmospheres of planetary planets. A transit is when a star’s parent planet moves across the disc. Webb will also bring coronographs so that exoplanets can be photographed near bright stars. Take into account how far the exoplanets afar from us are, and how small these planets are in comparison. We didn’t even know what Pluto looked really like until we were capable of sending an observatory to fly directly near it. Pluto is located in our own solar system.
Webb will have the ability to view the universe in the quarter of a million years (possibly back up to 100,000,000 years) following the Big Bang. That’s when the first galaxies and stars were formed.
Webb will operate at the second Sun–Earth Lagrange point, approximately 1,000,000 miles (1.5million km) from Earth. This will make Webb unreachable for any manned vehicle planned for the future.
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Steven Burnett has over 15 years of experience in a range of industries and domains. Steven has a flair for gathering data and information through extensive research efforts, and has a strong set of skills to cover almost any domain with ease and produce reports that are easy to understand and aid in making well-informed decisions. You can get in touch with him here. Phone No: +1 315-447-6937 Email: steven.b@coinlaw.io
