NASA's James Webb telescope, which has been continuously collecting images and spectral data from space for two years, marks its second anniversary by revealing a fascinating interaction between two galaxies. These observations have led to a series of significant discoveries that have enriched the astronomical community worldwide.

"Since President Biden and Vice President Harris unveiled the first image from the James Webb telescope, Webb has continued to reveal the secrets of the universe," said NASA Administrator Bill Nelson. "With incredible images from the farthest reaches of space, almost to the beginning of time, Webb's capabilities illuminate our cosmic environment and inspire future generations of scientists, astronomers, and explorers."

"In just two years, Webb has transformed our view of the universe, enabling top-tier science that prompted NASA to pursue this mission," said Mark Clampin, Director of the Astrophysics Division at NASA Headquarters in Washington. "Webb provides insights into long-standing mysteries of the early universe and begins a new era of studying distant worlds, while returning images that inspire people worldwide and pose exciting new questions to be answered. It has never been possible to explore every aspect of the universe as it is now."

Webb's ability to capture infrared light, which is beyond the visible spectrum of the human eye, allows for a detailed view of galaxies known as Arp 142. These galaxies, known by the names NGC 2936 (Penguin) and NGC 2937 (Egg), are captured in a complex mutual gravitational dance. The observations use a combination of near and mid-infrared light from the NIRCam (Near Infrared Camera) and MIRI (Mid-Infrared Instrument), allowing a clear view of stars and gas mixing as a result of their interaction.

The interaction between the Penguin and the Egg began 25 to 75 million years ago when they first passed by each other. Since then, these galaxies will continue their cosmic dance, undergoing several additional interactions before finally merging into one galaxy in a few hundred million years.

The Penguin was once a spiral galaxy, and now its galactic center shines like an eye, while its disrupted spiral arms form the beak, head, spine, and spread tail. Like all spiral galaxies, the Penguin is rich in gas and dust. During the interaction, the galactic gravity causes the gas and dust to collide and ripple, leading to the formation of new stars. These areas can be seen as fish in the beak and feathers in the tail of the galaxy.

Around these new stars is a smoke-like material that includes carbon-containing molecules known as polycyclic aromatic hydrocarbons, which Webb exceptionally reveals. The dust, shown as a fainter, deeper orange arc, also extends from the beak to the tail of the galaxy.

The Egg retains its shape
On the other hand, the Egg retains its compact shape. As an elliptical galaxy, it is filled with aging stars and has much less gas and dust that could be pulled in to form new stars. If both galaxies were spiral, each would have ended the first "twirl" with new star formations and curly tails known as tidal tails.

Another reason for the Egg's unperturbed appearance is that these galaxies are approximately the same mass, which prevents the smaller elliptical galaxy from being swallowed or distorted by the Penguin. It is estimated that the Penguin and the Egg are about 100,000 light-years apart, which is quite close in astronomical terms. By comparison, our Milky Way and its nearest neighbor, the Andromeda galaxy, are about 2.5 million light-years apart. They will also one day meet, but not for about 4 billion years.

Additional galaxies
Look to the upper right to spot a galaxy that is not part of this "dance." This galaxy, cataloged as PGC 1237172, is 100 million light-years closer to Earth. It is also quite young, filled with new, blue stars. Switch to Webb's image of only mid-infrared light to see how PGC 1237172 practically disappears. Mid-infrared light mainly captures cooler, older stars and an incredible amount of dust. Because the star population of this galaxy is so young, it "disappears" in mid-infrared light.

Also, look at the background. Webb's image is flooded with distant galaxies. Some have spiral and oval shapes, like those in the Penguin's "feathers," while others are scattered and shapeless. This is evidence of the sensitivity and resolution of the telescope's infrared instruments. Compare Webb's view with a 2018 observation that combines the infrared light of NASA's retired Spitzer Space Telescope and the near-infrared and visible light of NASA's Hubble Space Telescope. Although those observations lasted only a few hours, Webb revealed many more distant, redder, and dustier galaxies than previous telescopes — another reason to expect Webb to continue expanding our understanding of everything in the universe.

More about the James Webb telescope
The James Webb telescope is designed to study the universe at infrared wavelengths, allowing scientists to see through dust and gas and uncover hidden stars and galaxies. Its advanced cameras and instruments enable incredibly detailed observations that surpass the capabilities of previous telescopes like Hubble. In addition to providing fascinating images, the Webb telescope also delivers important data on the chemical composition and temperatures of observed objects, aiding in the understanding of the formation and evolution of the universe.

The Webb telescope is the result of international collaboration between NASA, ESA (European Space Agency), and CSA (Canadian Space Agency). It was launched on December 25, 2021, and has since continuously collected data that enables numerous scientific studies and discoveries. Its unique position in space, about 1.5 million kilometers from Earth at the L2 point, allows it to continuously observe distant objects without interference from Earth's atmosphere or sunlight.

NASA continues to push the boundaries of science and technology, and the James Webb telescope plays a key role in this endeavor. Its capabilities provide invaluable data that will shape our understanding of the universe for generations to come.

Source: National Aeronautics and Space Administration