Artist rendering of colliding neutron stars. Credit: Robin Dienel/Carnegie Institution for Science
In the beginning, the universe created three elements: hydrogen, helium, and lithium. There isn’t much you can do with these simple elements, other than to let gravity collapse them into stars, galaxies, and black holes. But stars have the power of alchemy. Within their hearts, they can fuse these elements into new ones. Carbon, nitrogen, oxygen, and others, all up to the heavy element of iron. When these first stars exploded, they scattered the new elements across the cosmos, creating planets, new stars, and even us.
Satellite data shows that air pollution over European cities has dropped during coronavirus lockdowns. Image Credit: contains modified Copernicus Sentinel data (2019-20), processed by KNMI/ESA
The pandemic caused by the novel coronavirus is creating all kinds of chaos for human society. But for the dear old Earth, and the humans and creatures that breathe its air, it’s a bit of a reprieve. Mirroring what happened in China during lock-down, Europe is now seeing the same drop in air pollution.
Artist's impression of a red giant star. If the star is in a binary pair, what happens to its sibling? Credit:NASA/ Walt Feimer
We’ve all heard this one: when you drink a glass of water, that water has already been through a bunch of other people’s digestive tracts. Maybe Attila the Hun’s or Vlad the Impaler’s; maybe even a Tyrannosaurus Rex’s.
Well, the same thing is true of stars and matter. All the matter we see around us here on Earth, even our own bodies, has gone through at least one cycle of stellar birth and death, maybe more. But which type of star?
That’s what a team of researchers at ETH Zurich (Ecole polytechnique federale de Zurich) wanted to know.
A team of European researchers, using data from the X-shooter instrument on ESO’s Very Large Telescope, has found signatures of strontium formed in a neutron-star merger. This artist’s impression shows two tiny but very dense neutron stars at the point at which they merge and explode as a kilonova. In the foreground, we see a representation of freshly created strontium. Image Credit: ESO/L. Calçada/M. Kornmesser
Astronomers have spotted Strontium in the aftermath of a collision between two neutron stars. This is the first time a heavy element has ever been identified in a kilonova, the explosive aftermath of these types of collisions. The discovery plugs a hole in our understanding of how heavy elements form.
Accroding to new research, the Milky Way may still bear the marks of "ancient impacts". Credit: NASA/Serge Brunier
Despite all we know about the formation and evolution of the Universe, the very early days are still kind of mysterious. With our knowledge of physics we can shed some light on the nature of the earliest stars, even though they’re almost certainly long gone.
Now a new discovery is confirming what scientists think they know about the early Universe, by shedding light on a star that’s still shining.
For the first time, NASA's Spitzer Space Telescope has detected little spheres of carbon, called buckyballs, in a galaxy beyond our Milky Way galaxy. The space balls were detected in a dying star, called a planetary nebula, within the nearby galaxy, the Small Magellanic Cloud. What's more, huge quantities were found -- the equivalent in mass to 15 of our moons.
An infrared photo of the Small Magellanic Cloud taken by Spitzer is shown here in this artist's illustration, with two callouts. The middle callout shows a magnified view of an example of a planetary nebula, and the right callout shows an even further magnified depiction of buckyballs, which consist of 60 carbon atoms arranged like soccer balls.
In July 2010, astronomers reported using Spitzer to find the first confirmed proof of buckyballs. Since then, Spitzer has detected the molecules again in our own galaxy -- as well as in the Small Magellanic Cloud. Image Credit:
NASA/JPL-Caltech
Iron is one of the most abundant elements in the Universe, along with lighter elements like hydrogen, oxygen, and carbon. Out in interstellar space, there should be abundant quantities of iron in its gaseous form. So why, when astrophysicist look out into space, do they see so little of it?
This true-color image of Titan, taken by the Cassini spacecraft, shows the moon's thick, hazy atmosphere. Credit: NASA
Titan is a mysterious, strange place for human eyes. It’s a frigid world, with seas of liquid hydrocarbons, and a structure made up of layers of water, different kinds of ice, and a core of hydrous silicates. It may even have cryovolcanoes. Adding to the odd nature of Saturn’s largest moon is the presence of exotic crystals on the shores of its hydrocarbon lakes.
For the first time, NASA's Spitzer Space Telescope has detected little spheres of carbon, called buckyballs, in a galaxy beyond our Milky Way galaxy. The space balls were detected in a dying star, called a planetary nebula, within the nearby galaxy, the Small Magellanic Cloud. What's more, huge quantities were found -- the equivalent in mass to 15 of our moons.
An infrared photo of the Small Magellanic Cloud taken by Spitzer is shown here in this artist's illustration, with two callouts. The middle callout shows a magnified view of an example of a planetary nebula, and the right callout shows an even further magnified depiction of buckyballs, which consist of 60 carbon atoms arranged like soccer balls.
In July 2010, astronomers reported using Spitzer to find the first confirmed proof of buckyballs. Since then, Spitzer has detected the molecules again in our own galaxy -- as well as in the Small Magellanic Cloud. Image Credit:
NASA/JPL-Caltech
Scientists working with the Hubble Space Telescope have found a very complex molecule out there in space. Called Buckyballs, after renowned thinker Buckminster Fuller, they are a molecular arrangement of 60 carbon atoms (C60) in the rough shape of a soccer ball. Though it’s not the first time these exotic molecules have been spotted in space, it is the first time that Buckyball ions have been found.
Image of planetary nebula NGC 7027 with illustration of helium hydride molecules. In this planetary nebula, SOFIA detected helium hydride, a combination of helium (red) and hydrogen (blue), which was the first type of molecule to ever form in the early universe. This is the first time helium hydride has been found in the modern universe.
Credits: NASA/ESA/Hubble Processing: Judy Schmidt
It takes a rich and diverse set of complex molecules for things like stars, galaxies, planets and lifeforms like us to exist. But before humans and all the complex molecules we’re made of could exist, there had to be that first primordial molecule that started a long chain of chemical events that led to everything you see around you today.
Though it’s been long theorized to exist, the lack of observational evidence for that molecule was problematic for scientists. Now they’ve found it and those scientists can rest easy. Their predictive theory wins!
Water Molecules. Image Credit: National Science Foundation
For millennia, scientists have pondered the mystery of life – namely, what goes into making it? According to most ancient cultures, life and all existence was made up of the basic elements of nature – i.e. Earth, Air, Wind, Water, and Fire. However, in time, many philosophers began to put forth the notion that all things were composed of tiny, indivisible things that could neither be created nor destroyed (i.e. particles).
However, this was a largely philosophical notion, and it was not until the emergence of atomic theory and modern chemistry that scientists began to postulate that particles, when taken in combination, produced the basic building blocks of all things. Molecules, they called them, taken from the Latin “moles” (which means “mass” or “barrier”). But used in the context of modern particle theory, the term refers to small units of mass.
Definition:
By its classical definition, a molecule is the smallest particle of a substance that retains the chemical and physical properties of that substance. They are composed of two or more atoms, a group of like or different atoms held together by chemical forces.
Artist’s impression of simple and complex organic (carbon-containing) molecules that have been found in space. Credit: IAC/NASA/NOAO/ESA/Hubble Helix Nebula Team/M. Meixner/STScI/T.A. Rector/NRAO
It may consist of atoms of a single chemical element, as with oxygen (O2), or of different elements, as with water (H2O). As components of matter, molecules are common in organic substances (and therefore biochemistry) and are what allow for life-giving elements, like liquid water and breathable atmospheres.
Types of Bonds:
Molecules are held together by one of two types of bonds – covalent bonds or ionic bonds. A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms. And the bond they form, which is the result of a stable balance of attractive and repulsive forces between atoms, is known as covalent bonding.
Ionic bonding, by contrast, is a type of chemical bond that involves the electrostatic attraction between oppositely charged ions. The ions involved in this kind of bond are atoms that have lost one or more electrons (called cations), and those that have gained one or more electrons (called anions). In contrast to covalence, this transfer is termed electrovalance.
In the simplest of forms, covelant bonds take place between a metal atom (as the cation) and a nonmetal atom (the anion), leading to compounds like Sodium Chloride (NaCl) or Iron Oxide (Fe²O³) – aka. salt and rust. However, more complex arrangements can be made too, such as ammonium (NH4+) or hydrocarbons like methane (CH4) and ethane (H³CCH³).
Diagram of a water molecule, which is made up of two hydrogen atoms and one oxygen atom. Credit: britannica.com
History of Study
Historically, molecular theory and atomic theory are intertwined. The first recorded mention of matter being made up of “discreet units” began in ancient India where practitioners of Jainism espoused the notion that all things were composed of small indivisible elements that combined to form more complex objects.
In ancient Greece, philosophers Leucippus and Democritus coined the term “atomos” when referring to the “smallest indivisible parts of matter”, from which we derive the modern term atom.
Then in 1661, naturalist Robert Boyle argued in a treatise on chemistry – titled “The Sceptical Chymist“- that matter was composed of various combinations of “corpuscules”, rather than earth, air, wind, water and fire. However. these observations were confined to the field of philosophy.
It was not until the late 18th and early 19th century when Antoine Lavoisier’s Law of Conservation of Mass and Dalton’s Law of Multiple Proportions brought atoms and molecules into the field of hard science. The former proposed that elements are basic substances that cannot be broken down further while the latter proposed that each element consists of a single, unique type, of atom and that these can join together to form chemical compounds.
Various atoms and molecules as depicted in John Dalton’s A New System of Chemical Philosophy (1808). Credit: Public Domain
A further boon came in 1865 when Johann Josef Loschmidt measured the size of the molecules that make up air, thus giving a sense of scale to molecules. The invention of the Scanning Tunneling Microscope (STM) in 1981 allowed for atoms and molecules to be observed directly for the first time as well.
Today, our concept of molecules is being refined further thanks to ongoing research in the fields of quantum physics, organic chemistry and biochemistry. And when it comes to the search for life on other worlds, an understanding of what organic molecules need in order to emerge from the combination of chemical building blocks, is essential.
