Accretion disc
Our survey of the sky is uncovering the secrets of how planets are born
Look in the Bible for a description of how planets are formed, and you can search all day in vain. It simply isn't there. In fact, the very concept of planets and planetary orbits isn't there.
What the Bible myth describes is a childlike guess at the formation of the universe by people who thought the entire universe was the small part of Earth they lived and herded their goats on. So, they described it as a small, flat place, floating in the sea, with a dome over it (because that's what the sky looked like to them).
Stuck to that dome were the sun and moon as lamps, and what we now know are planets, stars and far-off galaxies, they thought were lights stuck to the underside of the dome. They even guessed that there must be pillars holding up the ground and that the stars could be shaken loose from the dome by earthquakes, when they would fall to Earth and could be stamped on by a goat, albeit a big goat!
Don't believe me? Find a Bible and read Genesis 1: 1-18 and Daniel 8:10. Nowhere will you find the words planet, orbit or accretion disc.
What you get is exactly what you might expect if you brought up a child to believe in magic and magic spirits but kept them away from any sources of information about science, geography, geology or cosmology, then, at about the age of 10, asked them to describe the universe and make up a story about how it was made. What you would get is what you get if you use a creationist form of deductive logic - you just look at it and describe what you think you see.
You get the result of ignorant intuition, which is about as far removed from what is really there and how it came to be the way it is as its possible to be.
We know this because we can compare the results of that method in the Bible with the results of scientific investigation and the scientific method used to describe how planets are really formed as part of the process of forming suns and planetary systems within galaxies which are themselves a tiny part of a vast universe consisting of trillions of galaxies, each with trillions of suns and probably several trillion planets in orbits around those suns, almost none of which is visible to someone standing on the surface of Earth and 'just looking'.
The following article by Christian Ginski, a Lecturer of astronomy at the University of Galway, Ireland described what we now know of hos planets are formed and just how many there might well be in the cosmos. His article is reprinted under a Creative Commons license, reformatted for stylistic consistency:
Our survey of the sky is uncovering the secrets of how planets are born
Discs giving birth to new planets, seen by the Very Large Telescope.
Christian Ginski, University of Galway
When we look out to the stars, it is typically not a yearning for the distant depths of outer space that drives us. When we are looking out there, we are truly looking back at ourselves. We try to understand our place in the unimaginable vastness of the universe. ESO/C. Ginski, A. Garufi, P.-G. Valegård et al.
One of the most burning questions that drives us is how unique we are. Did life only emerge here on Earth or is our galaxy teaming with it?
The very first step in finding out is to understand how special the Earth really is – and, by extension, our entire Solar System. This requires knowledge about how solar systems actually form. And that’s exactly what my colleagues and I have started to uncover with a new series of studies of star-forming regions.
In the past decades, astronomers have spotted more than 5,000 planets around distant stars – so called exoplanets. We now know that planets are so abundant that you can look up to almost any star in the night sky and be near certain that planets are circling around it. But what do these planets look like?
The first planet that was discovered around a star similar to the Sun came as a shock to us. It was a so-called hot Jupiter, a massive gas giant that orbits its parent star on such a tight orbit that the length of a year is only four days. This is a truly alien world with no equal in our own solar system.
From this first groundbreaking discovery, astronomers have gone on and found tightly packed systems of super-Earths, rocky planets several times as massive as the Earth, as well as awesome gas giants in century-long orbits around their parent star. Of the many planetary systems that we have found, none equals our own solar system. In fact most of them are quite different.
To understand how all of these different systems come to be, we have to turn to the very beginning. And that’s majestic discs of dust and gas that surround the youngest stars. These are the nurseries which will eventually bring forth new planetary systems.
These discs are enormous objects, up to several hundred times as extended as the distance between the Earth and the Sun. Yet in the sky they appear tiny. This is because even the nearest ones, which are practically in our galactic backyard, are between 600 and 1,600 light years away.
That is a tiny distance when you consider that the Milky Way galaxy has a diameter of more than 100,000 light years, but it still means that light, the fastest thing in the universe, takes up to 1,600 years to reach us from there.
The typical size of one of these planetary nurseries, as seen from the Earth, would be an angle of 1 “arc-second” on sky, which is equivalent to a 3,600th part of a degree. To put it in perspective, it is like trying to observe a person standing on top of the Eiffel Tower from 500km away in the Dutch capital of Amsterdam.
New findings
Using the European Southern Observatory’s “Very Large Telescope”, the VLT, and the Sphere extreme adaptive optics camera, we have now started to survey nearby young stars.
Our team, consisting of scientists from more than ten countries was able to observe more than 80 of these young stars in amazing detail – with our findings published in a series of papers in the journal Astronomy and Astrophysics.
All the images were taken in near infrared light, invisible to the human eye. They show the light from the distant young stars as it is reflected from the tiny dust particles in the discs. This dust is much like sand on the beach and will eventually clump together to form new planets.
What we found was an astonishing diversity of shape and form of these planetary nurseries. Some of them have huge ring systems, others large spiral arms. Some of them are smooth and calm, and yet others are caught in the middle of a storm as dust and gas from the surrounding star-forming clouds rains down on them.
While we expected some of this diversity, our survey shows for the first time that this holds true even within the same star-forming regions. So even planetary systems that form within the same neighbourhood might look quite different from one another.
Planet-forming discs within the gas-rich cloud of Chamaeleon I, roughly 600 light-years from Earth.
Ginski et, al 2024, CC BY-SA
Unlike the Sun, most stars in our galaxy have companions, with two or more stars orbiting a shared centre of mass. When looking at the constellation of Orion, we found that stars in groups of two or more were less likely to have large planet-forming discs than lone stars. This is a useful thing to know when hunting for exo-planets.
Another interesting finding was how uneven the discs in this region were, suggesting they may host massive planets that warp the discs.
The next step in our research will be to connect specific planets to their nurseries, to understand how the different systems might have formed in detail. We also want to zoom in even closer in the innermost regions of these discs in which terrestrial planets like our own Earth might already be forming.
For this, we will use the next generation of telescopes spearheaded by the “Extremely Large Telescope” of the European Southern Observatory that is right now under construction in the Chilean Atacama desert.
There are many questions to answer. But thanks to our survey we now know that the very first step on the long way for life to emerge is an utterly beautiful one.
Christian Ginski, Lecturer of astronomy, University of Galway
This article is republished from The Conversation under a Creative Commons license. Read the original article.
- “The SPHERE view of the Chamaeleon I star-forming region: The full census of planet-forming disks with GTO and DESTINYS programs” (https://www.aanda.org/10.1051/0004-6361/202244005)
- “The SPHERE view of the Taurus star-forming region: The full census of planet-forming disks with GTO and DESTINYS programs” (https://www.aanda.org/10.1051/0004-6361/202347586)
- “Disk Evolution Study Through Imaging of Nearby Young Stars (DESTINYS): The SPHERE view of the Orion star-forming region” (https://www.aanda.org/10.1051/0004-6361/202347452)
And this, of course, is how we can tell the Bible is nothing more than a collection of early stories and origin myths made up by ignorant people from the fearful infancy of our species, which only a credulous fool or someone of equal ignorance and childlike naivety of the authors would believe is a science textbook.
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