What is the importance of the James Webb Space Telescope launched by NASA? How is it different from the Hubble space telescope? Know more here.
NASA’s James Webb Space Telescope was launched by rocket early on December 25 2021 from South America’s north-eastern coast, thus opening a new era of astronomy.
The Webb telescope will reach its destination in solar orbit about 1.6 million km from Earth (about four times farther away than the moon) after travelling 2 weeks in space. The Webb’s special orbital path will keep it in constant alignment with the Earth as the planet and telescope circle the sun in tandem.
By comparison, Webb’s 30-year-old predecessor, the Hubble Space Telescope, orbits the Earth from about 550 km away, passing in and out of the planet’s shadow every 90 minutes.
Webb mainly will view the cosmos in the infrared spectrum, allowing it to gaze through clouds of gas and dust where stars are being born, while Hubble has operated primarily at optical and ultraviolet wavelengths.
Launch of Webb space telescope:
It was launched on an Ariane 5 ECA rocket from French Guiana in South America.
Features of Webb Space Telescope:
It is the most powerful infrared telescope launched by NASA. The telescope is the result of an international collaboration between NASA, the European Space Agency (ESA), and the Canadian Space Agency.
Webb will reveal new and unexpected discoveries, and help humanity understand the origins of the universe and our place in it. The telescope will also study the atmospheres of a wide diversity of exoplanets.
- Exoplanets: An exoplanet is any planet beyond our solar system. Most orbit other stars, but free-floating exoplanets, called rogue planets, orbit the galactic centre and are untethered to any star. Exoplanets are made up of elements similar to those of the planets in our solar system, but their mixes of those elements may differ. Some planets may be dominated by water or ice, while others are dominated by iron or carbon.
It will also search for atmospheres similar to Earth’s, and the signatures of key substances such as methane, water, oxygen, carbon dioxide, and complex organic molecules, in hopes of finding the building blocks of life.
Image source: nasa.gov
Objectives of the Webb space telescope:
- Search for the galaxies that formed the very beginning after the Big Bang.
- Determine the evolution of galaxies from their earlier formation until now.
- Observe the stages of the formation of stars until the formation of planetary systems.
- Measure the physical and chemical properties of planetary systems and investigate the potential for life in such systems.
Hubble Space telescope:
NASA has called the Webb telescope the successor of Hubble.
The Hubble Space Telescope was launched into low Earth orbit in 1990 and has made more than 1.4 million observations, including tracking interstellar objects, capturing a comet colliding with Jupiter, and discovering moons around Pluto.
Hubble has captured galaxies merging, probed supermassive black holes, and has helped scientists understand the history of the universe.
Differences between Hubble and Webb Telescope:
- Webb Space Telescope has four scientific instruments to observe primarily in the infrared range and provide coverage from 0.6 to 28 microns.
- The instruments on Hubble mainly focus on the ultraviolet and visible parts of the spectrum. It could observe only a small range in the infrared from 0.8 to 2.5 microns.
- Webb’s primary mirror has a diameter of 6.5 meters which will have a larger field of view.
- Webb also carries a large sun shield measuring about 22 meters by 12 meters.
- Hubble’s mirror was much smaller, about 2.4 meters in diameter hence it covered a lesser field of view.
- Hubble orbits around the Earth at an altitude of about 570 km.
- Webb will not orbit the Earth. It will orbit the sun at about 1.5 million kilometres away from Earth.
- Webb will orbit with the earth but by staying fixed in the same spot with relation to the Earth and the Sun.
- Area of study
- Webb’s near- and mid-infrared instruments will help study the first formed galaxies, exoplanets, and birth of stars.
- Hubble studied the toddler stage of galaxies while Webb can observe the baby stage too.
Difference between Webb and Herschel space observatory:
In 2009, the European Space Agency launched an infrared telescope named the Herschel Space Observatory. It also orbits the Sun-like how Webb would.
- The primary difference between Webb and Herschel is the wavelength range: Webb covers 0.6 to 28 microns, while Herschel covers 60 to 500 microns.
- Herschel’s mirror is 3.5 meters in diameter, while Webb’s primary mirror has a diameter of 6.5 meters.
Prospects of Webb telescope
Webb’s instruments make it ideal to search for evidence of potentially life-supporting atmospheres around many of the newly documented exoplanets and to observe worlds of Mars and Saturn’s icy moon Titan.
This telescope is set open a whole new world of information about the universe and will bring about a revolution in the astronomical world.