We Are Made of Star Stuff

We are “star stuff”. Discuss in detail our connections to the stars as established by modern astronomy. Modern astronomy has allowed us to understand how the universe functions and also provides the answers to some of the big questions. Questions like the origin of the universe and origin of life itself. It tells us that stars are the cosmic furnaces where all most all the building blocks of life and planets were synthesized. Lighter, basic and abundant elements like hydrogen and helium were formed during the Big Bang.

During Big Bang, space expansion cooled the early energy dominated universe and a lot of energy transformed into matter. These basic elements were then able to create the early stars and also the stars of today. Inside of these stars lighter elements fused to release large quantities of energy and in the process of doing that converted hydrogen and helium into heavier elementary particles. Such elements would be deposited in the core of the star and are spewed out into surrounding interstellar space when the star dies an explosive death.

These newly synthesized heavy elements are essential for life to begin and evolve. 1 Hydrogen, helium and a little bit of lithium were made in the Big Bang. Hydrogen, the most abundant element accounted for around 75% of the matter, followed by helium at 25%. 2 Large quantity of these primordial gas formed clouds and such clouds were then condensed by local gravity to form the very first stars that lit up the dark skies of early universe. 3 As the baby stars contracted, temperature in the core rose to extreme level triggering nuclear fusion/hydrogen fusion.

Nuclear fusion is a process in which two or more atoms fuse to synthesize heavier atom and this process of fusing releases large quantities of energy. 4 All the ingredients/elements needed to make the earth and all life forms on earth were created in the cores of stars. 5 These ingredients are then released out of the core of star into the surrounding when the giant star dies an explosive death known as the supernovae. This phenomenon occurs only to stars that are very big. Elements of up to iron can be made in a star and heavier than iron elements are produced in the supernovae. At least six of these essential elements compose life on earth and they are carbon, hydrogen, oxygen, nitrogen, sulphur and phosphorous. 8 Almost all life forms on earth are carbon based. This applies to the smallest living organisms (with exception of the new Inner core of a star7 discovery of arsenic based bacteria) to the biggest – the blue whale and all the living plants. They all have the same basic building blocks in their DNA. 9 Those building blocks are the essential elements.

All of the rocky and metallic materials that made up our planet, the iron that runs in our blood, the calcium in our teeth and bones10, oxygen atoms that form water after combining with hydrogen, and, nitrogen and oxygen atoms that make up most of the atmosphere of earth are all products of stars billions of years ago. 11 As you can see in the picture above all of the heavier elements (above H and He) and including helium are made by the stars. The elements shown on the cross-section of the picture form heavier elements, they make up all the elements we discovered so far; the elements on the periodic table.

Stars begin its life mostly made out of hydrogen and helium. The breakdown of hydrogen and helium in our sun is seventy percent and twenty eight when it started its life. 12 The building of heavier elements begins with hydrogen. Hydrogen is taken four at a time to form a single atom of helium. This process goes on for ninety percent of a stars’ life. When a star runs out of hydrogen, it starts fusing helium atoms to stay alive (producing energy to fight its own immense gravity from causing itself to collapse). Three atoms of helium are fused in the process of nuclear fusion to form an atom of carbon.

As the process of fusing moves to next heavier atoms the duration of fusion process of newer atom becomes a lot shorter because for fusing atoms higher than hydrogen the number of available atoms for fusing is far fewer than the number atoms available when the star was fusing hydrogen for example. Next in line is oxygen. Adding one more helium to the carbon makes oxygen. Nitrogen is also made in the stars. 12 Without oxygen life as we know cannot survive. This process goes onto making silicon and iron. Nuclear fusion stops at iron because temperatures in star don’t reach high enough to fuse iron.

So how do the elements heavier than iron form? The answer to this question lies in the size of the star. Only big stars (much bigger that our sun) are capable of producing a supernovae. Only such a catastrophic explosion can break the boundary set by iron and produce heavier atoms to fill the rest of the periodic table of elements. From the dusts and particles leftover of dead stars combined together to form asteroids and comets. Asteroids clumped together can form planet core. So life on earth basically began with the basic material that was available.

These material/large molecules essential for the formation of living cells are proteins, carbohydrates (sugar), fats, and nucleic acids. It’s been found that meteorites contains essential stuff like amino acids (proteins made of amino acid), sugars, fatty acids (building block of fats), and bases for nucleic acids. For instance, the Murchison meteorite that crashed in Australia in 1969 is found to contain chains of fatty acids, different types of sugars, all five nucleic acid bases, and more than 70 kinds of amino acids (life forms use only 20 amino acids). 3 “We are star stuff “in the unforgettable words of Dr. Carl Sagan. The atoms that made up our bodies are created in the innards of stars that died many aeons ago. The planet we live on is made up materials like iron, silicon and carbon, etc are all forged in the nature’s grandest factory we know as stars. The air we breathe to stay alive is a product of stars. Stars also nourish life. The sun ray helps plants with photosynthesis; helps them break down carbon dioxide into organic compounds (sugars). Plants are a major source of food for humans and other creatures.

Over the past few centuries (mainly 1900-2000) astronomy has made many eye opening discoveries; about the origin of the whole universe, our fate, and that we human are not the centre of the universe. It encourages humility in us and makes us better understand our connections the cosmos. References 1. Carl Sagan (No Date). Cosmos-We are Star Stuff Available: http://www. youtube. com/watch? v=0UR2L_4ic6Y&feature=related 2. Lawrence Krauss (3-27-2009). Life, the Universe and Nothing lecture Available: http://www. youtube. com/watch? =rdvWrI_oQjY [2011-04-04] video start at 51:11-52:16minutes 3. Dr. Tony Phillips (7-18-2000). X-ray Star Stuff [online] Available: http://science. nasa. gov/science-news/science-at-nasa/2000/ast18jul_1m/ [2011-04-04] 4. Wikipedia-Nuclear Fusion (no date). [online] Available: http://en. wikipedia. org/wiki/Nuclear_fusion [2011-04-04] 5. Sam Neill (presenter) (no date). Space with Sam Neill Available: http://www. youtube. com/watch? v=0zU1F6liZKo [2011-04-04] 6. =3 7. Mike S (12-7-2010). Science & Religion #8: We are all made of stars online] Available: http://www. wheatandtares. org/2010/12/07/science-religion-8-we-are-all-made-of-stars/ [2011-04-04] 8. Jason Palmer (12-2-2010). Arsenic-loving bacteria may help in hunt for alien life [online] Available: http://www. bbc. co. uk/news/science-environment-11886943 [2011-04-04] 9. Dan Solomon (12-2-2010). NASA Announces Arsenic Based Life Forms- But Are They Going To Kill Us? [online] Available: http://www. asylum. com/2010/12/02/nasa-announcement-aliens-arsenic/ [2011-04-04] 10. Korintherne (7-7-2006).

Reasons & Facts: Cosmic Connection [online] Available: http://curezone. com/blogs/fm. asp? i=982845 [2011-04-04] 11. Dayanara (MA) (No Date). We are star stuff… [online] Available: http://www. free-daily-motivational-self-improvement. com/we-are-star-stuff. html [2011-04-04] 12. Neil Tyson (presenter) (No Date). Elements: Forged in Stars Available: http://www. youtube. com/watch? v=uKqvjEE0wFg [2011-04-04] 13. Leslie Mullen (9-5-2005). Building Life from Star-Stuff [online] Available: http://www. astrobio. net/exclusive/1702/building-life-from-star-stuff [2011