10 Reasons We Should Be Excited about the James Webb Space Telescope

Destined for launch in October, 2018, the James Webb Space Telescope will open our eyes to the Universe like never before.

October next year will see the launch of one of the most important space exploration missions of recent decades. NASA has described the new James Webb Space Telescope as the formal successor to Hubble, which itself has proven immensely successful since its launch in 1990. A truly spectacular feat of engineering, the telescope sports a primary mirror of 21’4” (6.5 metres), making it nearly three times bigger than that of Hubble. Once it blasts off next year in an Ariane 5 rocket from its launch base in French Guyana, it will begin its journey to almost four times further away than the Moon.

#1. Understanding the Early Universe

Big BangNASA, WMAP Science Team

With its ability to see infrared wavelengths as well as in the visible spectrum, the telescope’s unprecedented resolution will allow us to see billions of years back in time to when the very first stars and galaxies formed after the Big Bang. In other words, we’ll be able to view the Universe when the first light emerged from the cosmic dark ages, some 300 million years after its formation. Now some 46 billion light years away, the most distant and oldest objects in the Observable Universe will reveal themselves to us. Being able to view these incredibly ancient young galaxies will improve our understanding of how the Universe works and how it was created.

#2. Observing Alien Worlds


Powerful enough to resolve a penny 24 miles (40 km) away, the Webb will allow us to learn more about the surfaces and atmospheres of many exoplanets. Even more importantly, however, the telescope should be able to reveal the composition of alien atmospheres. Thanks to the extended wavelength coverage, it will be possible to detect elements and compounds like methane, oxygen and carbon dioxide in planets light-years away, including those in the TRAPPIST-1 system. In other words, truly Earth-like planets will be characterised for the first time, and we’ll be a major step closer towards finding life and habitability among the stars.

#3. Enjoying the Perfect View

Lagrange Point 2NASA

While Hubble resides in low Earth orbit at a distance of 375 miles (600 km), James Webb will observe from close to a million miles (1.5 million km) away. This is the approximate location of Earth’s second Lagrange point, a region where the telescope will orbit the Sun while still being able to stay in line with the Earth. Observing from this location allows for an uninterrupted view of the Universe, far away from light and heat sources such as those emitted by the Earth or Moon. At the same time, a powerful sunshield will protect the telescope, keeping the science instruments and mirrors at the rear operating under a chilly, but optimal, -388°F (-225°C)

#4. Revealing Extrasolar Planets

Planets EverywhereESO, M. Kornmesser

Thousands of extrasolar planets have been discovered to date, many of them by the highly successful Kepler mission. Webb will deploy several methods of detecting exoplanets, including the ability to use its infrared vision to detect heat coming from them. It is also equipped with a coronagraphic capability, allowing it to block out the light from host stars (which are many millions of times brighter than planets) and observe larger planets directly as distinct points of light. Webb will also use the transit method to detect minute drops in star brightness as exoplanets pass in front of their hosts.

#5. Hunting for Planet 9

Planet NineNASA, Tom Ruen

Many scientists believe that a large undiscovered planet lurks in the outer solar system, owing to mysterious gravitational anomalies effecting certain Kuiper Belt Objects far beyond the orbit of Pluto. If indeed Planet 9 exists, Webb should have the capabilities of being able to image it directly and fully characterise it by using infrared spectroscopy to detect its atmospheric composition. Planet 9 is expected to reside as much as 1,200 AU away at its aphelion (furthest distance from the Sun), which is some 30 times further away than Pluto. Nonetheless, if discovered, Planet 9 will be the first true planet discovered since Neptune in 1846.

#6. Studying the Solar System

Solar SystemPixabay

Aside from looking billions of years into the past, Webb will be more than capable of studying our own solar system in an unprecedented level of detail. Aside from being able to take impressive photographs of the planets, asteroids and comets, it will also be able to resolve objects that are impossible to see with most other telescopes, either ground- or space-based. There remain many questions still unanswered about our own corner of the galaxy, and Webb will be capable of mapping the surfaces and analysing compositions of far off objects. NASA has even stated that it should be powerful enough to examine the volcanic emissions of Jupiter’s lively moon Io.

#7. Building on Hubble’s Success

Hubble Space TelescopeNASA

Webb is more like a science successor to Hubble rather than a replacement, since it carries a larger payload of instruments and is designed to fulfil a greater range of goals. For a start, Webb is primarily intended to observe at infrared wavelengths. This makes it easier to observe the most distance objects as well as elemental signatures on the electromagnetic spectrum. By contrast, Hubble can only observe a much smaller portion of the infrared range. Ultimately, Webb will be able to see galaxies so far away that they’ve been redshifted to such an extent they’ve literally been kicked off the visible spectrum.

#8. Providing a Decade of Answers

James Webb Space Telescope MirrorsNASA

Once launched in October next year, Webb will undergo a sixth-month commissioning process, which includes the month-long journey to its destination. The total mission lifetime is intended to last at least five and a half years, although it is hoped that the telescope will function for upwards of ten years. Unfortunately, because of the great distances involved, it will not be possible to service Webb, whereas Hubble was easily accessible residing in low Earth orbit. Nonetheless, Webb will carry enough fuel to last at least ten years, while five years of scientific operations will be accounted for by extensive testing of the flight system.

#9. Measuring the Effects of Dark Matter

Galaxy Clusters Illustrating the Effects of Dark MatterNASA, ESA, D. Harvey

Dark matter has confounded scientists for more than a century. Nonetheless, astronomers are adamant that it exists, owing to the otherwise unexplained gravitational effects it has on galaxies and galaxy clusters. Although Webb cannot observe dark matter directly (nothing can), it is equipped with the tools necessary to measure its effects. Webb will be able to accurately detect the amount of baryonic (normal) matter that makes up galaxies, allowing scientists to calculate the amount of dark matter present to account for their gravitational effects. This will allow them to better determine the role that dark matter plays in the evolution of the Universe.

#10. Uniting the World

Webb Space Telescope DecalNASA

If there is one thing that can and should unite all of humanity, it’s the exploration of the Universe. Although NASA is the lead partner, the project is supported by space agencies and government and private organizations from all over the world. Main contributors include the European Space Agency and the Canadian Space Agency. As such, Webb is the result of a truly multinational endeavour which, as it so happens, has cost almost 9 billion dollars. The launch itself will be taking place at the ESA-operated Guiana Space Centre in French Guiana, an overseas region of France located in South America.

The James Webb Space Telescope is so powerful that it will be able to reveal the Universe in a level of detail that we’ve never seen. Just like Hubble before it, it’s quite likely that Webb’s greatest discoveries will be those that we cannot even begin to imagine today. What great mysteries do you think Webb will reveal to us? Let me know in the comments below!

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