We compared shots from the James Webb Telescope to its predecessor, Hubble

Have you ever seen Stardust? The 32nd edition of “Nights of the Stars” takes place on August 5, 6 and 7. It is also possible to observe them with the naked eye, binoculars or a telescope. But none will be as precise as the world’s most powerful James Webb Space Telescope (JWST), which makes it possible to observe space in great detail. One of its latest images, released by NASA on Tuesday, August 2, shows star dust and star-forming regions in the Cartwheel Galaxy.

The James Webb Telescope, the result of a collaboration between American, European and Canadian space agencies, should make further observations in space possible. And so we must go back in time to understand the structure of the universe. A comparison with its predecessor, the Hubble Telescope, which had already taken similar shots, allows us to appreciate this technological leap. Franceinfo asked astrophysicist Eric Lagadec, stardust expert and president of the French Society of Astronomy and Astrophysics, to compare the James Webb and Hubble images.

Cartwheel Galaxy

The Cartwheel Galaxy is 500 million light years from Earth. Two space telescopes were able to immortalize it, but James Webb’s shot shows much more detail than Hubble’s.

In the 2010 Hubble image, we assumed, without actually seeing them, that the black area inside the large blue circle was the result of a collision between dust, the Cartwheel Galaxy, and another galaxy. “New stars form as dust and gas collapse.”Eric Lagadec explained.

Image of the Cartwheel Galaxy obtained using the Hubble Space Telescope, released in 2010  (ESA/Hubble and NASA)

James Webb’s image shows these dense regions of gas and dust more clearly. “With infrared, we can now observe dust. Sometimes we can even see through it, but it depends on the condition and properties of this dust,” Eric Lagadek analyzes. Finally, from the almost completely black background of the Hubble image, we move to a background decorated with dozens of distant galaxies visualized by James Webb.

Image of the Cartwheel Galaxy obtained using the James Webb Space Telescope and released on August 2, 2022.  (Image: NASA, ESA, CSA, STScI, Webb ERO Production Team)

Southern Ring Planetary Nebula

Its scientific name is “NGC 3132”, but it is also called the “Austral Ring Nebula” or the “Eight Shards Nebula”. This expanding gas cloud is about 2,000 light-years away. It is therefore one of the closest known planetary nebulae to Earth, according to NASA.

The central star visible in the middle in the Hubble image released in 1998 is dying. “As a result, it contracts and heats up. This will excite the surrounding gas and give the different colors captured by Hubble”, Eric Lagadek describes.

Image of the planetary nebula in the Southern Ring (NGC 3132) taken by the Hubble Telescope and published in 1998.  (Hubble Heritage Team (STSCL/AURA/NASA))

In James Webb’s picture, the red and more distant parts are actually cold gas, because it has already been expelled by stars and dust. It is invisible with Hubble, but JWST’s infrared technology makes it possible to image this gas.

Image of the planetary nebula in the Southern Ring (NGC 3132) taken by the new James Webb Telescope and released on July 12, 2022.  (NASA, ESA, CSA, STScI)

Karina Nebula

It looks like a steep hill in these images. It is actually one edge of the Carina Nebula. Called the “Cosmic Cliff,” these magical formations lie at the edge of a giant gaseous cavity within NGC 3324, located about 7,600 light-years away, we learn on James Webb’s website.

Shades of yellow and red in the two images again represent regions of dust and gas, where new stars form, explains Eric Lagadek.

An edge image of the Carina Nebula taken by the Hubble Telescope, released in 2008  (NASA / ESA / Hubble Team Heritage)

James Webb’s picture is so precise that it allows you to observe a lot of detail. Areas with more or less dust are distinct in the figure, as are mountain levels. “This picture is beautiful!” Delighted Eric Lagadek, who admitted to making it his mobile phone wallpaper.

An edge image of the Carina Nebula was taken by the new James Webb Telescope and released on July 12, 2022.  (NASA, ESA, CSA, STScI)

Stefan’s Quintet

Stephan’s Quintet is a group of five galaxies located in the constellation Pegasus. Interactions between these galaxies create star-forming regions, Eric Lagadek explains. “With Hubble, we see more stars and hot gas, with the Web more dust and cold gas.” Astrophysicist describes.

Stefan's quintet image taken by the Hubble telescope and released in 2009  (ESA / Hubble)

The image below is the largest to date by James Webb, and covers one-fifth the diameter of the moon. It contains more than 150 million pixels and was created from about 1,000 individual image files, according to the telescope’s website.

Image of Stefan's quintet taken by the new James Webb Telescope and released on July 12, 2022.  (NASA, ESA, CSA, STScI)

What is most impressive is the amount of galaxies visible in the distance. Amount of celestial bodies yet to be discovered.

Leave a Comment