A Neue imageThe Hubble Space Telescope perfectly illustrates why astronomers must be careful about distance in space.
Two galaxies floating in the dark, almost 1 billion light-years from each other, are two beautiful spirals of golden snail-like shapes, seemingly caught up in the act. They are named SDSS J115331 & LEDA 2073461. Despite their appearances, they don’t interact at all.
They are separated by a considerable distance. Their alignment is a beautiful line-of sight coincidence.
Galaxies can collide in outer space. dark matter superhighwaysGalaxy cluster nodes are where they flow towards a common galactic center.
This is believed to be the only way to create a supermassive. Black holesAt their centers, they grow to masses billions times larger than the Sun. When galaxies merge with each other, their central black hole also merges.
Space is vast and contains many things. Scientists must be cautious when interpreting objects that seem to be in the exact same area. Are they interconnected, or do they overlap with vast distances between?
Distance is one of our most valuable tools for understanding the Universe. Without accurate distance measurements, many objects can’t accurately be sized, massed, or brightened.
It can be difficult to measure distances within a space. You cannot tell how far something is by just looking at it.
Type Ia supernovae with a known intrinsic brightness are useful tools for measuring distance in space.
For relatively close objects, we can use parallax – the way objects move across the sky in relation to each other.
However, seeing individual objects beyond a certain distance makes them difficult to see. Scientists therefore rely upon Other toolsAs the Universe expands, light is reflected off distant objects.
This is how we know that SDSS J115331 & LEDA 2073461 don’t have a huge collision. However, there are other clues: The galaxies appear to be far too small; a collision would not. They can be messed up.
Distances can be difficult to determine even in the vicinity the Milky Way. Scientists recently discovered that there was a source for gamma radiation. They were further away than they imagined. Scientists were able make this connection because of the similar shape and alignment between the radiation source and the radiation source.
While scientists may not be able better understand the effects of galactic collisions or mergers on their galaxy, overlapping galaxies can help them to understand spiral galaxies.
If a distant galaxy is backlit, interstellar dust can be more easily seen in the foreground galaxy. This alignment has been used by scientists to map interstellar dust distribution in multiple galaxies.
It’s not known if Hubble will use his image of SDSS J115331 & LEDA J2073461 for this purpose. It’s beautiful to behold.
This image can be downloaded as a wallpaper from The Hubble website.
