**1. Introduction**

The observation of the Sun, the solar system, and the vast regions laying outside are commonly called *astronomy*.

In the whole range of observations of our neighborhood (**Figure 1**), we study the Sun, the Moon, the rocky planets, and the gas giants. In the last decades, the space probes sent around the solar system have enhanced our exploration capacity, that is, to go from hazy photographs to high-resolution mapping of most of our planetary bodies, even of their moons. Additionally, dwarf planets (Ceres and Vesta) and asteroids have been visited and mapped. This, in itself, it is a unique civilizational achievement in terms of exploration.

In between Mars and Jupiter, the asteroid belt is found. Further and mostly after Neptune's orbit is the Kuiper belt. Eventually, the very possible Oort cloud, a reservoir of visiting comets, is vastly beyond the orbit of (90377) Sedna (**Figure 1**).

Our solar system is located in between two arms of a spiral galaxy, within what is often called a "finger" named the *Orion spur* (**Figure 2**). The center of our galaxy, the *Milky Way*, is the seat of a supermassive black hole (SMBH) called *Sagittarius A\** [3].

#### **Figure 1.**

*Extracted from ref. [1], this is the solar system. The upper left is defined by Jupiter's orbit, upper right reaches Pluto's orbit, the Kuiper belt, and the perigee of (90377) Sedna. Bottom right is the orbit of (90377) Sedna, which is barely seen in the bottom left alongside the inner Oort cloud, which is thought to be the source of comets. Image credit: NASA/CalTech.*

**Figure 2.** *The Milky Way. Extracted from ref. [2], image credit: NASA/Adler/U. Chicago/Wesleyan/JPL-Caltech.*

Our galaxy is located on a fringe of what could be called *mycelium* filaments. In other words, detectable matter at the cosmological level, tends to agglomerate in threads, interconnected by groups of larger material aggregations, not unlike the spread of fungal mycelium in Earth's soil, punctuated by the presence of "nodes," from which mycelium filaments extend. Of particular importance to our galaxy "suburb" is a large area void of matter (**Figure 3**). The *Local Void* has been mapped synthetically with a great resolution recently [4].

The overall observable universe is a sphere, centered on the location of the one observing. For us, it is planet Earth. When mapped, this sphere, so far, extends outwards in a radius of 46.5 billion light-years (440 Ym), as a comoving distance. The

#### **Figure 4.**

*Extracted from ref. [6], scanning from the dark energy spectroscopic instrument (DESI), from the center, earth, toward the further seen so far, about one billion years after the big bang.*

sloan digital sky survey (SDSS), mapping of the observable universe [5], was done not by direct distance, but in signed velocity from the observation point, deducting mostly from the red-shifting of the observations. The faster the positive red-shifting velocity, the further away the colocation to the observer (**Figure 4**).
