It is not too typically that astronomers are puzzled when making a space-related discovery, however the above picture from NASA‘s Hubble telescope managed to do exactly that. Of all of the instruments at our disposal for exploring outer area, Hubble has repeatedly confirmed to be among the finest. The 31-year-old telescope has made numerous discoveries over time, whether or not or not it’s answering questions on our personal Photo voltaic System or investigating galaxies hundreds of thousands of light-years away.
In 2021 alone, Hubble has been as much as lots. It is captured a big ‘eye’ in the midst of a constellation, realized new details about Jupiter’s Nice Crimson Spot, and even recognized a ‘ghost’ galaxy totally devoid of darkish matter. All of this has occurred regardless of a scare earlier this yr — one which precipitated Hubble to go offline for a month attributable to a nasty laptop glitch.
NASA simply shared certainly one of Hubble’s newest discoveries, and it could be one of the head-scratching of all the yr. Trying on the picture above, all appears fairly regular at first. The image reveals a big cluster of galaxies deep in area, with Hubble specializing in two of them. The primary one, labeled ‘single picture,’ is a run-of-the-mill galaxy with a shiny middle and quite a few stars surrounding it. The place issues get fascinating is with the galaxy labeled ‘reflection.’ Not solely does it appear like a galaxy mirroring itself, nevertheless it’s additionally a replica of the ‘single picture’ galaxy above it. In different phrases, there are three sightings of the identical galaxy for no obvious cause. After first recognizing the ‘double’ galaxy in 2013, astronomer Timothy Hamilton admitted he and his workforce “have been actually stumped.”
If it sounds not possible for there to be three situations of the very same galaxy, that is as a result of it’s. What’s actually taking place right here is one thing referred to as ‘gravitational lensing’ — a visible trick that happens when a considerable amount of matter distorts gentle from different galaxies. Gravitational lensing is a reasonably well-known factor as we speak, however in 2013 when Hamilton found these perplexing galaxies, that wasn’t the case.
On this specific state of affairs, NASA explains the lensing as follows: “A exact alignment between a background galaxy and a foreground galaxy cluster produces twin magnified copies of the identical picture of the distant galaxy. This uncommon phenomenon happens as a result of the background galaxy straddles a ripple within the material of area.” One other approach to consider it’s like wavy reflections current in a swimming pool. When the afternoon solar is shining shiny on an outside pool, the sunshine from the solar seems on the underside of it with swirling, wavy reflections. As Richard Griffiths from the College of Hawaii explains, “The ripples on the floor act as partial lenses and focus daylight into shiny squiggly patterns on the underside.”
That is primarily what’s taking place within the picture on the prime of this text, albeit on a a lot bigger scale. A ripple in area is taking gentle from the only picture galaxy, magnifying and distorting it, and that is what’s seen with the reflection galaxy. That is an ideal oversimplification of all of the science and analysis that went into attending to this reply, however that is finally how the picture is defined. If something, it is an ideal reminder of how a lot we nonetheless must find out about area. In simply 8 years, astronomers went from not understanding this picture to having a logical clarification for it. Within the subsequent 8, 16, or 32 years, who is aware of what different mysteries we’ll even have solutions to.