The most detailed snapshot ever taken of our cosmos is coming soon. This is to be expected
Get ready to travel back into the universe earlier this week as scientists prepare to reveal the most detailed snapshot ever taken of our cosmos.
One of the first full-color images released from the new James Webb Space Telescope (JWST) promises to catapult us further into the past than we’ve ever seen before.
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“We will give humanity a new view of the cosmos,” said NASA administrator Bill Nelson.
The image, which will reveal some of the earliest galaxies and stars that formed after the Big Bang 13.8 billion years ago, is one of four to be released at 12:30 a.m. (AEST) on Wednesday.
“What I’ve seen has moved me as a scientist, as an engineer, as a human being,” said NASA deputy administrator Pam Melroy.
Along with the deepest views of the universe, other images the team promised to blow our heads include:
- The spectacular dust cloud known as the Carina Nebula, the birthplace of stars
- A group of colliding galaxies called Stephan’s Quintet
- A large gas bubble known as the Southern Ring Nebula that surrounds a dying star
The JWST data will also include a chemical fingerprint of the atmosphere of a hellish alien planet about half the mass of Jupiter known as WASP-96b.
Seeing the light (first)
Launched on Christmas Day last year, the $13 billion JWST is the largest and most powerful telescope ever to exist in space.
Since then, scientists from NASA, the European Space Agency and the Canadian Space Agency have tested four of their instruments and aligned 18 parts of the 6.5-meter gold-plated mirror.
This telescope uses infrared cameras and sensors to peer into parts of the universe in detail that other telescopes cannot.
In March, the team released sharp test images of a star 2,000 light-years away, against the backdrop of an ancient galaxy billions of light-years away, providing the first taste of what JWST can do.
Then in June, a micro-meteorite crashed into one of the segments, just before the telescope started taking the first full-resolution images we’re about to see.
Nonetheless, scientists say it performs twice as well as expected.
So what do we know about the galaxies, stars, and planets the team chose to fascinate us? And how spectacular are these new images?
To understand it, we need to look back at some of the images taken by the Hubble Space Telescope over the years.
Travel back to deep time
As the universe expanded, light from the earliest galaxies and stars was stretched or shifted to longer, redder wavelengths as it moved toward us.
The earliest galaxies we have seen so far existed between 400 million and 800 million years after the Big Bang.
These galaxies were captured by the Hubble Space Telescope in a famous image called the Ultra Deep Field.
The image, taken more than 20 years ago, took two weeks to create and captures more than 10,000 ancient galaxies in the constellation Fornax.
JWST can detect objects at much longer wavelengths than Hubble, so it can peer further into the past, and promises to fill the critical gap between the Big Bang and the earliest galaxies and stars detected by Hubble.
To do this, the team has selected a patch of sky known as SMACS 0723 in the constellation Volans.
This region contains a number of large galaxy clusters that lie between us and more distant galaxies and stars.
The mass of this cluster acts like a magnifying glass, distorting space and amplifying light that comes from far away.
In May, scientists created one of the deepest images of the universe ever taken while testing a fine telescope guidance system.
Images were taken using 72 exposures over 32 hours.
The full-resolution images taken by the telescope’s main instrument promise to look even more spectacular.
Carina Nebula
The Carina Nebula is located about 7,600 light-years away in the southern constellation Carina.
It is one of the largest and brightest stellar nurseries in the sky, with pillars of dust several light-years high filled with large, young stars.
A collection of Hubble images released in 2018 shows what it looks like in optical light (the light we see with our eyes), and in near-infrared light, which can penetrate dust in pillars to see new stars.
The image at the top of this page shows what an optical and near infrared image looks like combined into a full color image.
While JWST does not take pictures in optical light, it takes a much longer wavelength of infrared light than the Hubble telescope, so it will cut further through the dust and be able to see this nebula in even more detail.
Quintet Stephan
JWST will also give scientists a clearer picture of how stars form when galaxies collide in a cosmic tug-of-war.
Quintet Stephan is located in the constellation Pegasus.
It contains different types of stars ranging from young, blue stars to old, red stars.
Four of the five galaxies in the quintet are about 290 million light-years away.
The two galaxies tearing apart in the center of the image are surrounded by a halo of gas and young stars less than 10 million years old.
The fifth galaxy, in the upper left corner, is about 40 million light years from us and is filled with bright new stars.
However, however spectacular this image may be, most of the stars in the quintet are too far away for Hubble to see or are shrouded in dust.
Southern Ring Nebula
The Southern Nebula is located 2,000 light-years away in the constellation Vela.
At the heart of this huge bubble of expanding gas, known as a planetary nebula, is not one, but two stars.
The smaller star, known as a white dwarf, is the only thing left of the red giant star that spewed all of its gas into space before collapsing. The intense heat from the small, dense remnant of the star causes the gas to glow.
A peek deeper into this process will help scientists understand more about the life cycle of stars and the evolution of galaxies like our Milky Way.
When dying stars disappear as planetary nebulae, they may sprinkle the cosmos with heavy elements such as iron, silver, and gold and contribute to the next generation of stars.
WASP-96b
In addition to producing never-before-seen images of galaxies and stars, JWST will also release information about the atmospheres of an exoplanet — a planet that orbits a star outside our Solar System.
When a planet passes in front of its star, light passing through its atmosphere can be captured by telescopes, which divide the light into different wavelengths.
Different wavelengths produce rainbow-like colors.
This technique, known as spectroscopy, identifies molecules such as water, carbon dioxide and methane, which absorb light at specific wavelengths.
This technique can also give us information about the temperature and movement of the planets.
WASP-96b is an alien planet located nearly 1,150 light years from Earth.
Slightly larger than Jupiter, it reaches scorching temperatures of up to 1,027 degrees as it circles its star every 3.4 days.
Gas giants like WASP-96b are among the most common types of the more than 5,000 alien planets that have been detected to date.
Observations from ground-based telescopes show WASP-96b is a cloudless world with a sodium-rich atmosphere.
In the future, JWST will look at rocky Earth-like planets, which are more difficult to study because they are smaller and not as bright as Earth.
The team says the images and data released this week are just a glimpse of what’s to come from the telescope as the science mission kicks off its 20-year program.
And it won’t be long before the deepest space image record is broken again.
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