Astronomy

As humans exert greater pressure on natural processes, understanding the intricate workings of our Earth system is increasingly vital for effective action on mitigation and adaption strategies. ESA’s Earth Explorer missions yield a wealth of astonishing findings, serving as the bedrock of scientific research in this field. Now, four new concepts have been selected to undergo assessment study, one of which is destined to be the twelfth in this family of world-leading satellite missions.

For the chief leader of the SETI Institute, established to search for and understand life beyond Earth, there's a need to step back and cuddle up to a cup of cosmic reality.

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Mixotrophs, which have characteristics of both animals and plants, could help blunt the effects of marine heat waves on ocean ecosystems

SpaceX launched another batch of its Starlink internet satellites from Florida's Space Coast this evening (April 17), and landed its rocket on a ship at sea.

Volcano detectives use artificial intelligence to sleuth out ancient secrets in Alaska. 

The tale of how the "backfire effect" ultimately, itself, backfired, and what scientists can learn from being wrong

Universe Today has recently had the privilege of investigating a myriad of scientific disciplines, including impact craters, planetary surfaces, exoplanets, astrobiology, solar physics, comets, planetary atmospheres, planetary geophysics, cosmochemistry, meteorites, radio astronomy, and extremophiles, and how these multidisciplinary fields can help both scientists and space fans better understand how they relate to potentially finding life beyond Earth, along with other exciting facets. Here, we will examine the incredible field of organic chemistry with Dr. Andro Rios, who is an Assistant Professor in Organic Chemistry at San José State University, regarding why scientists study organic chemistry, the benefits and challenges, finding life beyond Earth, and potential paths for upcoming students. So, why is it so important to study organic chemistry?

“Organic chemistry is a fascinating and powerful discipline that is directly connected to nearly everything we interact with on a daily basis,” Dr. Rios tells Universe Today. “This can range from what gives our favorite foods the flavors we love, to the medicines we take to help alleviate our pain. Organic chemistry is also the basis of describing the known chemistry that makes up the biology on this planet (called biochemistry) and can possibly provide the clues to what extraterrestrial life might be based on as well, should we find evidence of it in the upcoming years.”

While its name implies a scientific field of complicated science, the field of organic chemistry essentially involves the study of organic compounds, also known as carbon-based life, which comprises all known lifeforms on the Earth. This involves studying the various properties, classifications, and reactions that comprise carbon-based life, which helps scientists understand their structural formulas and behaviors. This, in turn, enables overlap with other disciplines, including the aforementioned biochemistry, but also includes materials science, polymer chemistry, and medicinal chemistry, as well. Therefore, given its broad range of scientific potential, what are some of the benefits and challenges of studying organic chemistry?

“Organic chemistry has played a vital role in transforming the human experience on this planet by improving our health and longevity,” Dr. Rios tells Universe Today. “All of us, or nearly all of us, have known either family members, friends or even ourselves who have fallen severely ill or battled some chronic disease. The development of new medicines, both directly and indirectly through the tools of organic chemistry to fight these ailments has been one of the most beneficial contributions of this field to society.”

Dr. Rios continues, “Learning organic chemistry in the classroom often presents a challenge because it seems so different from the general chemistry courses that most students have learned to that point. The reason for this is because organic chemistry introduces new terminology, and its focus is heavily tied to the 3-dimensional structure and composition of molecules that is not considered in general chemistry courses. The good news is that organic chemistry provides the perfect bridge from general chemistry to biochemistry/molecular biology which also often focuses on the structures and shapes of molecules (biomolecules).”

The field of organic chemistry was unofficially born in 1807 by the Swedish chemist, Jöns Jacob Berzelius, after he coined the term when describing the origins of living, biological compounds discovered throughout nature. However, this theory was disproven in 1828 by the German scientist, Friedrich Wöhler, who discovered that organic matter could be created within a laboratory setting. It took another 33 years until the German chemist, Friedrich August Kekulé von Stradonitz, officially defined organic chemistry in 1861 as a subfield of chemistry involving carbon compounds. Fast forward more than 160 years later to the present day, and the applications of organic chemistry has expanded beyond the realm of the living and can be found in almost every scientific, industrial, commercial, and medical field throughout the world, including genetics, pharmaceuticals, food, and transportation.

As noted, the very basis of organic chemistry involves the study of carbon-based life, which is the primary characteristic of life on our small, blue world. The reason is because the structure of carbon can form millions of compounds due to their valence electrons that allow it to bond with other elements, specifically hydrogen and oxygen, but can also bond with phosphorus, nitrogen, and sulfur (commonly referred to as CHNOPS).

While carbon-based life is the most common form of life on Earth, the potential for silicon-based life has grabbed the attention of scientists throughout the world due to their similar bonding characteristics as carbon. However, certain attributes, including how it shares electrons (known as electropositivity), prevent it from being able to form lifelike attributes. Therefore, if carbon-based life is currently the primary characteristic of all life on Earth, what can organic chemistry teach us about finding life beyond Earth?

“Life on Earth is highly selective in its utility of organic compounds, both big and small, which is an outcome of biological evolution on this planet,” Dr. Rios tells Universe Today. “But over the years detailed studies on the properties (reactivity, function, preservation, etc) of these molecules and polymers have revealed to us that there is nothing inherently ‘special’ about those biochemicals compared to those that aren’t associated with life (called abiotic chemistry).”

Dr. Rios continues, “What we have learned, however, is that there are trends, or patterns in the selectivity of molecules used by life that might be helpful in informing us not only how life emerged on this planet, but in the search for life elsewhere. This suggests that when we go looking for life in other worlds, we shouldn’t necessarily expect to find the same biochemical make-up we see in our terrestrial biology. Rather, we should be keeping a lookout for any patterns or trends in the chemical make-up of alien environments that are distinct from what we might consider typical abiotic chemistry.”

As noted, the science of organic chemistry is responsible for myriad of applications throughout the world, which are accomplished through the creation of new compounds. One of the most well-known applications for organic chemistry is the pharmaceutical industry and the development of new drugs and treatments, including aspirin which is one of the most well-known drugs throughout the world. Additionally, organic chemistry is responsible for everyday products, including biofuels, biodegradable plastics, agriculture, and environmental purposes. Therefore, with the wide range of applications for organic chemistry, including the potential to find life beyond Earth, what is the most exciting aspect of organic chemistry that Dr. Rios has studied during his career?

“For me, it was when I was in graduate school when I made the realization that I could apply the knowledge and tools of organic chemistry that I was studying in the lab, to questions that were relevant to astrobiology,” Dr. Rios tells Universe Today. “I am particularly interested in questions surrounding prebiotic chemistry, chemical evolution and the origin of life. The primary area that captivates my interest within the origin of life field is metabolic chemistry —exploring the origins of metabolism. This field, known as protometabolic chemistry, has been gaining momentum in recent years. Our community has been uncovering that small prebiotic molecules have the ability, under a wide range of conditions, to initiate simple reaction networks that can lead to more complex molecules over time. These results are exciting because they are potentially helping us understand the origin of one of biology’s most complex processes.”

The individuals who study organic chemistry are aptly called organic chemists who spend time designing and creating new organic compounds for a variety of purposes. This frequently involves examining the myriad of structural drawings of organic compounds and learning how each one functions individually and adding or subtracting new elements to create new compounds. Like most scientific disciplines that Universe Today has examined throughout this series, organic chemistry is successful through the constant collaboration with other fields with the goal of gaining greater insight into life and the world around us, including beyond Earth. Therefore, what advice would Dr. Rios give to upcoming students who wish to pursue studying organic chemistry?

Dr. Rios tells Universe Today, “Organic chemistry is a discipline that fundamentally interacts with so many other fields of STEM; biology, medicine, synthetic biology, bioengineering, chemical engineering, ecology, etc. Taking the time to devote a portion of your education in learning the language of this discipline will be one of the most important intellectual investments you will make in your STEM related career.”

How will organic chemistry help us better understand our place in the cosmos in the coming years and decades? Only time will tell, and this is why we science!

As always, keep doing science & keep looking up!

The post Organic Chemistry: Why study it? What can it teach us about finding life beyond Earth? appeared first on Universe Today.

We know little about how embryonic development in animals evolved from single-celled ancestors, but simple organisms with a multicellular life stage offer intriguing clues

We know little about how embryonic development in animals evolved from single-celled ancestors, but simple organisms with a multicellular life stage offer intriguing clues

Jupiter aligns with distant Uranus before it exits the evening sky as a bright supernova flares in the southern galaxy NGC 3621.

The post Jupiter Meets Uranus in Twilight; Supernova Erupts in Nearby Spiral Galaxy appeared first on Sky & Telescope.

Start at the upper left above and you can follow the progress of

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A serendipitous lab accident revealed that hibernating bumblebee queens can make it through days of flooding, revealing that they are less vulnerable to extreme weather than previously thought

A serendipitous lab accident revealed that hibernating bumblebee queens can make it through days of flooding, revealing that they are less vulnerable to extreme weather than previously thought

The 2024 solar eclipse, as seen from Indianapolis, connected strangers across a famous racetrack.

A study suggests the ice giants Uranus and Neptune aren't quite as watery as previously thought. They may also contain huge amounts of frozen methane, potentially solving the puzzle of how they formed.

The unexplained mass of a remarkably massive galaxy suggests that dark matter interacts with itself, according to new observations by the James Webb Space Telescope.

The Milky Way is ancient and massive, a collection of hundreds of billions of stars, some dating back to the Universe’s early days. During its long life, it’s grown to these epic proportions through mergers with other, smaller galaxies. These mergers punctuate our galaxy’s history, and its story is written in the streams of stars left behind as evidence after a merger.

And it’s still happening today.

The Milky Way is currently digesting smaller galaxies that have come too close. The Large and Small Magellanic Clouds feel the effects as the Milky Way’s powerful gravity distorts them and siphons a stream of gas and stars from them to our galaxy. A similar thing is happening to the Sagittarius Dwarf Spheroidal Galaxy and globular clusters like Omega Centauri.

There’s a long list of these stellar streams in the Milky Way, though the original galaxies that spawned them are long gone, absorbed by the Milky Way. But the streams still tell the tale of ancient mergers and absorptions. They hold kinematic and chemical clues to the galaxies and clusters they spawned in.

As astronomers get better tools to find and study these streams, they’re realizing the streams could tell them more than just the history of mergers. They’re like strings of pearls, and their shapes and other properties show how gravity has shaped them. But they also reveal something else important: how dark matter has shaped them.

Since dark matter is so mysterious, any chance to learn something about it is a priority. As researchers examine the stellar streams, they’re finding signs of disturbances in them—including missing members—that aren’t explained by the Milky Way’s mass. They suspect that dark matter is the cause.

“If we find a pearl necklace with a few scattered pearls nearby, we can deduce that something may have come along and broken the string.”

Soon, astronomers will have an enormously powerful tool to study these streams and dark matter’s role in disturbing them: the Vera Rubin Observatory (VRO).

Astronomers have different methods of studying dark matter. Weak gravitational lensing is one of them, and it maps dark matter on the large scale of galaxy clusters. But stellar streams are at the opposite end of the scale. By mapping them and their irregularities and disturbances, astronomers can study dark matter at a much smaller scale.

This image shows the core of the Sagittarius Dwarf Spheroidal Galaxy and its stellar streams as it’s absorbed by the Milky Way. Image Credit: David Law/UCLA

The Rubin Observatory will complete its Legacy Survey of Space and Time (LSST) in a ten-year period. Alongside its time-domain astronomy objectives, the LSST will also study dark matter. The LSST Dark Energy Science Collaboration is aimed at dark matter and will use Rubin’s power to advance the study of dark energy and dark matter like nothing before it. “LSST will go much further than any of its predecessors in its ability to measure the growth of structure and will provide a stringent test of theories of modi?ed-gravity,” their website explains.

As we get closer and closer to the observatory’s planned first light in January 2025, the growing excitement is palpable.

“I’m really excited about using stellar streams to learn about dark matter,” said Nora Shipp, a postdoctoral fellow at Carnegie Mellon University and co-convener of the Dark Matter Working Group in the Rubin Observatory/LSST Dark Energy Science Collaboration. “With Rubin Observatory we’ll be able to use stellar streams to figure out how dark matter is distributed in our galaxy from the largest scales down to very small scales.”

Astronomers have ample evidence that a halo of dark matter envelops the Milky Way. Other galaxies are the same. These dark matter halos extend beyond a galaxy’s visible disk and are considered basic units in the Universe’s large-scale structure. These haloes may also contain sub-haloes, clumps of dark matter bound by gravity.

This image shows a simulated Milky Way-size CDM halo. The six circles show sub-haloes enlarged in separate boxes. Sub-haloes are also visible, and the bottom row shows several generations of sub-subhaloes contained within subhalo f. Image Credit: Zavala and Frenk 2019

These clumps are what astronomers think are leaving their marks on stellar streams. The dark matter clumps create kinks and gaps in the streams. The VRO has the power to see these irregularities on a small scale and over a ten-year span. “By observing stellar streams, we’ll be able to take indirect measurements of the Milky Way’s dark matter clumps down to masses lower than ever before, giving us really good constraints on the particle properties of dark matter,” said Shipp.

The Lambda Cold Dark Matter (Lambda CDM) model is the standard model of Big Bang Cosmology. One of the Lambda CDM’s key predictions says that many sub-galactic dark matter substructures should exist. Astronomers want to test that prediction by observing these structures’ effect on stellar streams. The VRO will help them do that and will also help them find more of them and build a larger data set.

Stellar streams are difficult to detect. Their kinematics give them away, but sometimes, there are only a few dozen stars in the streams. This obscures them among the Milky Way’s myriad stars. But the VRO will change that.

The VRO will detect streams at much further distances. On the outskirts of the Milky Way, the streams have interacted with less matter, making them strong candidates for studying the effect of dark matter in isolation.

“Stellar streams are like strings of pearls, whose stars trace the path of the system’s orbit and have a shared history,” said Jaclyn Jensen, a PhD candidate at the University of Victoria. Jensen plans to use Rubin/LSST data for her research on the progenitors of stellar streams and their role in forming the Milky Way. “Using properties of these stars, we can determine information about their origins and what kind of interactions the stream may have experienced. If we find a pearl necklace with a few scattered pearls nearby, we can deduce that something may have come along and broken the string.”

The VRO’s powerful digital camera and its system of filters make this possible. Its ultraviolet filter, in particular, will help make more streams visible. Astronomers can distinguish stellar streams from all other stars by examining the blue-ultraviolet light at the end of the visible spectrum. They’ll have thousands upon thousands of images to work with.

Rubin Observatory at twilight in May 2022. Among the observatory’s many endeavours is the study of dark matter. Credit: Rubin Obs/NSF/AURA

In fact, the VRO will unleash a deluge of astronomical data that scientists and institutions have been preparing to handle. AI and machine learning will play a foundational role in managing all that data, which should contribute to finding even more stellar streams.

“Right now it’s a labor-intensive process to pick out potential streams by eye—Rubin’s large volume of data presents an exciting opportunity to think of new, more automated ways to identify streams.”

Astronomers are still finding more stellar streams. Earlier this month, a paper in The Astrophysical Journal presented the discovery of another one. Researchers found it in Gaia’s Data Release 3. It’s likely associated with the merger of the Sequoia dwarf galaxy.

It seems certain that astronomers will keep finding more stellar streams. Their value as tracers of the Milky Way’s history is considerable. But if scientists can use them to understand the distribution of dark matter on a small scale, they’ll get more than they bargained for.

The post The Milky Way’s History is Written in Streams of Stars appeared first on Universe Today.