Using data from NASA’s Spitzer Space Telescope and ESA’s Gaia space observatory, astronomers have found a weird new feature in our Milky Way galaxy. Scientists have discovered what appears as a break in the Sagittarius spiral arm of our galaxy. According to NASA, the new feature looks like a “splinter poking out from a plank of wood.” This “splinter” is made up of star-forming gas clouds and young stars. Our Milky Way, like more than two-thirds of the galaxies we know, is spiral in shape with its spiral arms panning out at an angle.
The two major spiral arms of our Milky Way — Scutum-Centaurus and Perseus — contain new, old and dying stars while the two minor arms — Norma and Sagittarius — are not so distinct and mainly contain star-forming processes and interstellar gas packets. The Milky Way has two less significant minor arms or spurs. One of the spurs is Orion, the home of our solar system.
Now, some 4,000 light-years away from our place in this cosmic traffic — all the stars are moving together — lies the newly founded splinter in the Sagittarius arm. According to a statement by Michael Kuhn, the lead author of the study, the newfound structure “really stands out at an angle of nearly 60 degrees” in the Sagittarius Arm that has a pitch angle — the angle of spiralling out compared to a circular orbit — of about 12 degrees.
The scientists do not yet fully understand why all that star material forms into these spiral arms. While astronomers have discovered groups, local groups and clusters of galaxies in an estimated number of more than 100 billion, they have not been able to completely model and map our own Milky Way galaxy. The reason is the fact that since we live in the Milky Way, we cannot have a full view of it unless we look at it from the outside. For example, you can see the moon or the sun in their entirety and their round structure, but you cannot see the earth. If you try to describe what you see of the Earth, your answer will be either a bunch of buildings, beaches or mountains.