On Tuesday, August 2, NASA released a rare and stunning image of a galaxy 500 million light-years away, the Cartwheel Galaxy, whose rings appear in unprecedented clarity thanks to the brand-new James-Webb Space Telescope.
Like our Milky Way, astronomers believe that the Cartwheel Galaxy was once a spiral galaxy. But a spectacular event shaped it: the collision with another smaller galaxy (not visible in the image). Two rings then formed from the center of the collision, similar to the ripples in concentric circles caused by a stone thrown into water. This is what earned it its evocative name.
The first ring, more in the center, is very bright, and the second, on the outside, has been expanding for 440 million years. During its expansion, the ring hits the gas around it, triggering star formation.
The Cartwheel galaxy is still in a state “transient”NASA said in its statement. If the James-Webb telescope “It gives us an idea of [son] current state, it also gives us an idea of what has happened to it in the past, and how it will develop in the future”.
engineering gem
This galaxy has already been observed by the Hubble Space Telescope, but the infrared capabilities of James-Webb are revealing new details hitherto hidden, allowing one to see through a large amount of dust. The composite image, from observations by the telescope’s two science instruments, also features two other smaller galaxies, as well as many others in the background.
A $10 billion engineering gem, the James-Webb Telescope was launched from Kourou, French Guiana last December. It is now 1.5 million kilometers from Earth.
Named for James Edwin Webb, NASA’s second administrator (1961-1968), this telescope is about a hundred times more sensitive than its predecessor Hubble. Imagined by NASA from the launch of Hubble in 1990 and built from 2004, with the collaboration of the European (ESA) and Canadian (CSA) space agencies, the James-Webb telescope is equipped with a 6 scale mirror. .5 meters, which gives a surface and therefore a sensitivity seven times greater than its predecessor. A size large enough to detect the heat signature of a bumblebee on the Moon.
Another difference from its predecessor: its observation mode. Where Hubble observes space primarily in the domain of visible light, James-Webb ventures into a wavelength beyond the eye: the near and mid-infrared. A radiation that any body, star, human or flower emits naturally.
Its precision will allow us to better understand the formation of stars and galaxies and to observe exoplanets, of which astronomers are discovering more and more examples, in an attempt to identify, perhaps one day, other planets that harbor life.