NEW YORK (NYTIMES) – In a brief event at the White House on Monday (July 11) evening, President Joe Biden unveiled an image that Nasa and astronomers hailed as the deepest view yet into our universe’s past.
The image, taken by the James Webb Space Telescope – the largest space telescope ever built – showed a distant patch of sky in which fledgling galaxies were searing their way into visibility just 600 million years after the Big Bang.
The president praised Nasa for its work that enabled the telescope and the imagery it will produce.
“We can see possibilities no one has seen before,” he said, “we can go places no one has gone before.”
Biden’s announcement served as a teaser for the telescope’s big cosmic slideshow coming on Tuesday morning, when scientists reveal what the Webb has been looking at for the past six months.
For Biden, the reveal of the images was also a chance to engage directly with an event that will almost certainly stir wonder and pride among Americans – at a time when his approval ratings have plummeted as voters recoil at high food and gasoline prices and Democrats question his ability to fight for gun control and abortion rights.
One of the most ambitious of the Webb telescope’s missions is to study some of the first stars and galaxies that lit up the universe soon after the Big Bang 14 billion years ago.
Although Monday’s snapshot did not quite provide that, it proved the principle of the technique and hinted at what more is to come from the telescope’s scientific instruments, which astronomers have waited decades to bring online.
As the telescope “gathers more data in the coming years, we will see out to the edge of the Universe like never before,” said Priyamvada Natarajan, of Yale University, an expert on black holes and primeval galaxies, in an email from India.
She added, “It is beyond my wildest imagination to be alive when we get to see out to the edge of black holes, and the edge of the universe.”
Bill Nelson, the former Florida senator selected to lead Nasa, touted the telescope’s scientific potential at the White House event.
“We are going to be able to answer questions that we don’t even know what the questions are yet,” he said.
What image did NASA and Biden show?
On Friday, Nasa released a list of five subjects that Webb had recorded with its instruments. But Biden showed off only one of them at the White House on Monday.
The image goes by the name of SMACS 0723. It is a patch of sky visible from the Southern Hemisphere on Earth and often visited by Hubble and other telescopes in search of the deep past.
It includes a massive cluster of galaxies about 4 billion light-years away that astronomers use as a kind of cosmic telescope. The cluster’s enormous gravitation field acts as a lens, warping and magnifying the light from galaxies behind it that would otherwise be too faint and faraway to see.
Thomas Zurbuchen, Nasa’s associate administrator for space science, described this image as the deepest view yet into the past of our cosmos. Later images will surely look back even further, he added.
Marcia Rieke of the University of Arizona, who led the building of NIRCam, one of the cameras on the Webb telescope that took the picture, said, “This image will not hold the ‘deepest’ record for long but clearly shows the power of this telescope.”
What about the rest of the images?
Nasa will show other pictures at 10.30am Eastern time (10.30pm in Singapore) on Tuesday in a live video stream you can watch on Nasa TV or YouTube. They will be shown off at the Goddard Space Flight Centre in Greenbelt, Maryland.
The pictures constitute a sightseeing tour of the universe painted in colours no human eye has seen – the invisible rays of infrared, or heat radiation. A small team of astronomers and science outreach experts selected the images to show off the capability of the new telescope and to knock the socks off the public. Among the cosmic images are old friends to astronomers both amateur and professional, who now get to see them in new infrared raiments.
There is the Southern Ring Nebula, a shell of gas ejected from a dying star about 2,000 light-years from here, and the Carina Nebula, a huge swirling expanse of gas and stars including some of the most massive and potentially explosive star systems in the Milky Way.
Yet another familiar astronomical scene is Stephan’s Quintet, a tight cluster of galaxies about 290 million light-years from here in the constellation Pegasus.
The team will also release a detailed spectrum of an exoplanet known as WASP-96b, a gas giant half the mass of Jupiter that circles a star 1,150 light-years from here every 3.4 days. Such a spectrum is the sort of detail that could reveal what is in that world’s atmosphere.
How does the Webb compare with the Hubble telescope?
The Webb telescope’s primary mirror is 6.5 metres in diameter, compared with Hubble’s, which is 2.4 metres, giving Webb about seven times as much light-gathering capability and thus the ability to see further out in space and so deeper into the past.
Another crucial difference is that Webb is equipped with cameras and other instruments sensitive to infrared, or “heat”, radiation. The expansion of the universe causes the light that would normally be in wavelengths that are visible to be shifted to longer infrared wavelengths that are normally invisible to human eyes.