It’s sometimes easy to forget that those blinking spots in the night sky are thousands of stars that are several times bigger than our Sun or perhaps a little smaller. But they’re enormous, hot, and distant, so exactly how are stars useful to humanity?
This is how stars are useful
Stars have been used for navigation since ancient times, and spiritually important to religion and mythology since antiquity. Stars are also the source of the elements we’re made of. In addition, the study of stars (astronomy) has led to many modern scientific breakthroughs.
Isn’t it mind-blowing to think our material comes from those distant orbs? The importance of stars is thus unparalleled. If we think about the far future, stars will be even more actively crucial in our lives as they might host habitable planets, which we may colonize, or maybe we might use them as a significant energy source for spacecraft.
Let’s begin with how stars are used for navigation to understand their ancient impact on humanity.
How are stars used for navigation?
There are currently 58 officially designated stars that are used for navigation. Some of them include Rigel, Betelgeuse, Bellatrix, Vega, Arcturus, Antares, and several others.
The first 19 stars are of magnitude 1, the other 38 of magnitude 2, and Polaris, the current north pole star, is also part of this remarkable star group. Many of them were known even to the Greeks, Romans, Arabs, or Babylonians, and they used them for navigation.
These stars were chosen due to their brightness, ease of identification, and distribution across the celestial sphere, and they are used in specific ways for navigation even now.
Sailors would often use these stars when the sun set. These celestial objects would seem to move from east to west across the sky, and they would be divided into rising stars and setting stars.
All of them would begin their path below the horizon. Sailors would determine their course by observing their movement in the same way the Sun’s movement was analyzed.
They would measure the height of these bright stars and thus tracked their progress. Constellations were also essential for sailors since their visibility changed along with the seasons. While some constellations weren’t visible anymore, others would shine and take their place due to Earth’s movement.
Thus, many had to familiarize themselves with the constellations of stars, get accustomed to when they were visible, at what times of the year, and in what hemispheres. Based on their location in the night sky, people would pin-point at what direction they were heading.
Probably the most famous navigation star is the north pole star, Polaris. This star was always used as an accurate north indicator. It is worth mentioning that the north pole star isn’t always the same, as different stars get to have this title once every hundreds of years as they move closer to the north celestial pole.
How stars create elements
It’s a bit awkward to think that explosions ultimately lead to the creation of life, celestial objects, and much more, at least, when we talk about supernovas.
The first stars which appeared in our Universe were massive and huge. However, this resulted in a short lifespan. In the last stages of a star’s life, it begins to create different elements in its core.
Through the process of nuclear fusion, stars fuse hydrogen atoms into helium, and then helium into beryllium, and so on, all the way up to iron.
Thus, every element is created until iron, after which the star explodes and swirls all these elements into space. The leftover material will eventually lead to the creation of other stars, planets, and, ultimately, living beings.
As a famous astronomer, Carl Sagan, stated: “The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars. We are made of star-stuff.”
It isn’t 100% known if every element is created within a star’s core, as certain elements disappear quickly. However, we can’t currently disprove this as well.
Ancient beliefs about stars
Many cultures throughout the ages incorporated stars in their mythologies and religions, since they attributed great significance to them. The Babylonians might just be the first culture who divided the sky into regions, and they kept track and interpreted the celestial bodies’ positions.
They placed great mystical values into the stars and used them to warn their supreme leader of possible catastrophic events that might unfold.
The ancient Greeks are famous through Ptolemy’s 2nd century Almagest and his depiction of the 48 Greek constellations. Some of them we still use today, the most notable being the zodiac constellations.
Every constellation of stars was associated with a myth and continues to be so to this day. For example, Ursa Major’s constellation is related to princess Callisto’s legend and the goddess Artemis.
Zeus seduces the young princess, and she later becomes pregnant. Artemis punishes Callisto since she broke her vow of chastity and transforms her into a she-bear.
As the years go by, Callisto wonders the forests in her new form and stumbles across her son, now a fully grown hunter, named Arcas. A battle ensues between the two of them, but Zeus intervenes to stop the tragedy.
Zeus hurls them both into the heavens where Callisto becomes Ursa Major, and her son, either Ursa Minor or Bootes, which was known to the Greeks as the Bear-Watcher.
When it comes to the Egyptians, they associated the star Sirius and the three stars which form Orion’s Belt as the location from where their gods came from and created humanity.
They even simulated Orion’s Belt’s three stars by creating Giza’s pyramids and pointed towards the asterism’s direction.
Even more pyramids and temples were discovered in Mexico, which point towards Orion’s Belt. As we can see, cultures worldwide have countless associations within their religion, myths, and tales, with the stars that are visible to the naked eye.
Scientific breakthroughs from studying the skies
Studying the sky has progressively revealed a greater understanding of our place in the Universe and how things work. Here are some scientific breakthroughs which shaped our view forever:
The Galilean Moons
After the telescope was invented in 1608, the first most outstanding achievement was the discovery of Jupiter’s moons by famous astronomer Galileo Galilei in 1609.
Galileo enhanced the power of the then crude telescopes, and was able to study Earth’s Moon, and discovered the four major satellites of Jupiter, namely Callisto, Ganymede, Io, and Europa.
This resulted in undeniable evidence that not everything revolves around the Earth, as was then strongly believed. When Galileo observed Venus, he witnessed that it had phases just like our Moon, which could only be explained if Venus orbited the Sun and not our Earth.
Finally, he pointed his telescope and observed the Milky Way stars, which were only considered bands of light and nothing else before this.
The First Galaxy
Galileo’s discoveries echoed through the ages and paved the way for new astronomers to seek the wonders of the sky. A new name which we are quite familiar with even to this day is that of Edwin Hubble.
Hubble can be credited with discovering the first galaxy, besides our own, namely, the Andromeda Galaxy. Before Hubble set his eyes upon this celestial object, it was, for a long time, considered to be merely nebulae.
It is interesting to note that the Andromeda Galaxy is the only one visible to the naked eye. Hubble extensively studied Andromeda, and in 1923, he concluded that it was indeed a galaxy and not nebulae.
He continued his observations of the sky, found numerous other galaxies, and even devised his own set of identification rules for them, known today as the Hubble Sequence.
With Edwin Hubble’s discoveries, our consciousness about the Universe expanded forever, and we will always be mesmerized by the sheer size of it.
Galileo proved that there are countless stars out there, and not everything revolves around the Earth and Hubble proved that our Milky Way galaxy isn’t the only one out there.
Since there are countless stars and galaxies, and new planets were discovered in our Solar System, such as Uranus in 1781, Neptune in 1846, and Pluto in 1930, along with the other dwarf planets, a natural question arose in the scientific community, are there any other planets out there?
Like stars and galaxies, planets seem to be endless in the Universe, and every planet discovered outside our Solar System is termed an “exoplanet.”
The first identification of an exoplanet occurred in 1992 when astronomers discovered several of them orbiting the pulsar designated as PSR B1257+12.
Many such exoplanets were discovered orbiting unstable stars or stars that were very different from our Sun, and astronomers then focused on finding sun-like stars with exoplanets orbiting around them.
Over 4,000 exoplanets have already been discovered, and even new types of planets, such as super-Earths, which are terrestrial planets like our Earth, yet several times bigger and more massive.
Stars are the universe’s quintessential objects.
In fact, they’re so useful and important to humanity that we can’t discuss navigation, spirituality, and even our own bodies without them.
Of course, it’s anybody’s guess what role they will play to humans in the future. Whether we travel among them, harness their energy, or simply continue observing, they’ll surely remain useful and significant.
By the way, observing them may be simpler than you think. With even a basic telescope, you can see galaxies (like these ones) for yourself.
That’s just one of the reasons that stargazing is such a rewarding hobby!