James Webb, the world’s most powerful space telescope developed and operated by NASA, has unveiled an unprecedented view of Arp 220, a pair of merging galaxies located approximately 250 million light-years away.
According to Space magazine, Arp 220 currently exhibits a spiral-like shape similar to our Milky Way galaxy, with swirling tails in its outer regions that began their cosmic dance around 700 million years ago and may continue for a considerable time afterward. When the Arp 220 galaxies began their merger, the abundant gas and dust triggered the formation of intense starbirth, mainly concentrated in their dusty central region.
Merging galaxy Arp 220 – Image: NASA/ESA/CSA
“The amount of gas in this tiny region equals that of the entire Milky Way galaxy,” described the James Webb team.
Over 200 star clusters have been packed within this 5,000-light-year region, causing the central starburst to radiate with intense brightness, emitting a luminous glow resembling a six-winged star with each wing as a sharp, vivid streak. However, this intense star formation abruptly ceased about 100 million years ago, transitioning the galaxy into a post-starburst phase.
Arp 220 had previously been detected by NASA’s Hubble Space Telescope over three decades ago in 2022, followed by additional observations using NASA’s Chandra X-ray Observatory.
Nevertheless, with the “divine eye” of James Webb, it has now been observed with unprecedented clarity.
This is also a window of time for Earth to gaze into its own future. Our galaxy, a “monster” in the realm of galaxies, will undergo galactic mergers in the next 2 billion years and 4-5 billion years. The first one will be with a dwarf galaxy, and the subsequent merger will be with a formidable counterpart—the Andromeda galaxy, also known as the Milky Way’s sister.
The merger of the colossal galaxies—the Milky Way and Andromeda—will last for approximately 10 billion years, undoubtedly giving birth to numerous new stars. However, there is a possibility of Earth’s demise, as researchers predict that the collision could potentially eject our planet from the Sun’s habitable zone.