When the Hubble Space Telescope was launched in 1989, it promised to deepen our understanding of the universe with every image it captured. Over 30 years, it fulfilled this promise by observing distant stars and galaxies and even measuring the age of the universe. Now, as we continue to explore the mysteries of space, it’s time to answer new questions with the help of the James Webb Space Telescope.
After three decades and millions of images, Hubble has reached its observational limits. In 2016, it captured an image of Galaxy GNZ11, which is 32 billion light-years away. However, due to the universe’s expansion, the light we see from it shows the galaxy as it was 13.4 billion years ago, just 400 million years after the Big Bang. Hubble can’t see further back because it can’t observe wavelengths beyond the near-infrared range.
As light from distant galaxies travels, its wavelength stretches due to the universe’s expansion. By the time it reaches Hubble, it’s often stretched beyond what Hubble can detect. To see the earliest objects in the universe, we need to observe infrared light, which is where the James Webb Telescope comes in.
Development of the James Webb Telescope began in 1996, requiring new technologies to be invented. It needs a massive sunshield to keep it extremely cold and special sensors that work at cryogenic temperatures. Unlike Hubble, James Webb will primarily observe in the infrared range, allowing it to see things Hubble cannot.
When stars and planets form, they are often hidden behind large clouds of dust that absorb visible light. Hubble can see these clouds but not what’s behind them. Observing in infrared light reveals the activity behind these dusty clouds. While there have been other infrared telescopes, none match the detail and capability of James Webb.
The resolution of a telescope depends on the size of its mirror. A larger mirror means higher resolution. The Spitzer Infrared Telescope has a mirror 0.85 meters in diameter, while Hubble’s is 2.4 meters. James Webb’s mirror is a massive 6.5 meters wide, giving it incredibly precise resolution—enough to see a penny from 40 kilometers away. This precision is crucial for discovering distant galaxies and planets.
One of James Webb’s most exciting goals is to find and study distant Earth-like planets. It will focus on stars with known planets, measuring the small dip in light as a planet crosses in front of a star. This helps determine the planet’s size, and by measuring dips in multiple wavelengths, it can reveal more information.
Atoms and molecules absorb light at different wavelengths, so measuring these dips can indicate which molecules are in a planet’s atmosphere. For example, if there’s a dip at around 1.15 and 1.4 micrometers, it suggests the presence of water vapor, as H2O absorbs more light at those wavelengths.
James Webb will observe a wide range of wavelengths, from visible light to mid-infrared, making it perfect for detecting molecules common on Earth, like CO2, oxygen, and nitrogen. With its sensitivity, it can discover distant planets similar to Earth, helping us learn more about our planet and bringing us closer to understanding if we are alone in the universe.
As we eagerly await the launch of the James Webb Telescope, we can look forward to the groundbreaking scientific discoveries it will bring.
Research the concept of infrared light and its importance in astronomy. Create a presentation explaining how the James Webb Telescope uses infrared technology to observe the universe. Include examples of celestial phenomena that can be observed in infrared but not in visible light.
Construct a simple model of a telescope using materials like cardboard tubes and lenses. Explain how the size of a telescope’s mirror affects its resolution, using the James Webb Telescope as a reference. Present your model and findings to the class.
Conduct an experiment to simulate the expansion of the universe using a balloon and markers. As you inflate the balloon, observe how the distance between the marked points increases. Relate this to how light from distant galaxies stretches, and discuss why this necessitates the use of infrared telescopes like James Webb.
Using online databases, analyze data from exoplanet observations. Focus on how scientists use light dips to determine the presence of molecules in a planet’s atmosphere. Create a report on how the James Webb Telescope will enhance our understanding of exoplanets and their atmospheres.
Participate in a class debate on the future of space exploration and the role of advanced telescopes like the James Webb. Discuss the potential scientific discoveries and ethical considerations of exploring distant planets. Prepare arguments for both the benefits and challenges of investing in space technology.
When the Hubble Telescope launched in 1989, it promised to expand our understanding of the universe with every picture it took. After 30 years of service, it did exactly that. From observing distant stars and galaxies to measuring the exact age of our universe, Hubble answered many questions. Now it’s time to answer the next set of questions as we continue to uncover the mysteries of our universe.
In this video, we’re going to look at the James Webb Space Telescope, what it will observe, and how it could find the most Earth-like planets with the highest chance of supporting life. After 30 years and millions of pictures later, the Hubble Telescope has reached its limit in terms of how far back into the universe it can observe. Hubble’s furthest observation was made in 2016 when it captured an image of Galaxy GNZ11. This galaxy is 32 billion light-years away, but due to the expansion of space, the light we see from it shows the galaxy as it was 13.4 billion years ago. Although this is just 400 million years after the Big Bang, Hubble is unable to see anything further than this since it’s limited by the range of wavelengths it can observe.
As the light from distant galaxies travels, its wavelength is stretched by the constant expansion of space. By the time the light reaches Hubble, it’s stretched to a wavelength outside of Hubble’s viewing range. Anything that’s stretched to a wavelength above near-infrared is unobservable by Hubble. To observe the most distant and earliest objects in our universe, we need to observe the infrared light that comes from them. This is where the James Webb Telescope comes in.
When development began in 1996, many of the technologies needed for the telescope had yet to be invented. An enormous sunshield is required to keep the telescope at an extremely low temperature. Special wavelength sensors that can operate at cryogenic temperatures also had to be developed for this telescope. James Webb will observe primarily in the infrared range, which will allow it to see things that Hubble couldn’t see. When stars and planets are first forming, they’re often hidden behind enormous clouds of dust that absorb visible light. Hubble can observe these magnificent clouds, but it can’t see what’s going on behind them.
Observing in infrared light reveals just how much is happening behind these dusty clouds. However, James Webb won’t be the first infrared space telescope. Over the years, there have been several infrared telescopes in space, but none have had the detail and capability that James Webb will have. The resolution of a telescope is limited by the number of wavelengths it can fit across its mirror. A larger mirror allows for a higher resolution. The Spitzer Infrared Telescope has a mirror just 0.85 meters in diameter. Hubble’s mirror is slightly larger at 2.4 meters, but James Webb will have an enormous mirror measuring 6.5 meters wide. This will give the telescope an incredibly precise resolution, capable of observing a penny from 40 kilometers away. This level of precision will be required to discover the most distant galaxies and planets in our universe.
One of the most impressive goals of the James Webb Telescope is to find and analyze the most distant Earth-like planets in our universe. To do this, James Webb will focus on a single star known to have planets orbiting it. As a planet crosses in front of the star, the telescope will measure a small dip in light. At first, this will help determine the size of the planet, but measuring dips in multiple wavelengths will provide even more information. Since atoms and molecules absorb light at different wavelengths, measuring dips at specific wavelengths will indicate which molecules are present in the planet’s atmosphere. If the telescope measures a dip in light at around 1.15 and 1.4 micrometers, we can infer that the planet’s atmosphere contains water vapor, as H2O absorbs a larger amount of light at those wavelengths.
James Webb will be able to observe a large range of wavelengths from visible light through to mid-infrared. This will be perfect for detecting various kinds of molecules that are common on Earth, such as CO2, oxygen, and nitrogen. Along with Webb’s incredible sensitivity, it will be able to discover extremely distant planets that bear a striking resemblance to our own. Finding these Earth-like planets will teach us more about our own planet while bringing us one step closer to proving that we are not alone in this vast cosmic arena.
As we patiently await the launch of the James Webb Telescope, we can look forward to the incredible scientific discoveries it will make.
Telescope – An optical instrument designed to make distant objects appear nearer, containing an arrangement of lenses or mirrors or both that gathers visible light, permitting direct observation or photographic recording of distant objects. – The astronomer used a powerful telescope to observe the rings of Saturn in great detail.
Infrared – A type of electromagnetic radiation with wavelengths longer than visible light but shorter than radio waves, often used in astronomy to detect heat emitted by celestial objects. – Infrared telescopes can detect the heat emitted by stars and galaxies that are not visible in regular light.
Galaxies – Massive systems consisting of stars, stellar remnants, interstellar gas, dust, and dark matter, bound together by gravity. – The Milky Way and Andromeda are two of the billions of galaxies in the universe.
Light – Electromagnetic radiation that can be detected by the human eye, essential for observing and understanding astronomical phenomena. – The speed of light is a fundamental constant in physics, crucial for calculating distances in space.
Universe – The totality of known or supposed objects and phenomena throughout space; the cosmos; everything that exists, including all matter and energy. – The Big Bang theory is a scientific explanation of how the universe began expanding from a hot, dense state.
Stars – Luminous celestial bodies made of plasma, held together by gravity, and generating energy through nuclear fusion in their cores. – Stars are classified by their spectral types, which indicate their temperature and composition.
Planets – Celestial bodies orbiting a star, massive enough to be rounded by their own gravity, but not massive enough to cause thermonuclear fusion. – The discovery of exoplanets has expanded our understanding of the potential for life beyond our solar system.
Wavelengths – The distance between successive crests of a wave, especially points in a sound wave or electromagnetic wave, used to characterize different types of radiation. – Different wavelengths of light are used in astronomy to study various aspects of celestial objects.
Resolution – The ability of an optical instrument to distinguish small details and separate closely spaced objects in an image. – The resolution of the Hubble Space Telescope allows it to capture detailed images of distant galaxies.
Atmosphere – The layer of gases surrounding a planet or other celestial body, held in place by gravity, which can affect astronomical observations. – Earth’s atmosphere can distort starlight, which is why many telescopes are placed in space.
