We hear it all the time: Fusion is the future; it’s how the sun creates energy. But, how does it work? At its core, fusion generates energy by converting four hydrogen atoms (protons) into 1 helium atom with two neutrons (Helium-4 ). On the surface, it is hard to see how any energy is created from this process. We know that one proton and one neutron have about 1 AMU of mass, and those savvy with their laws of physics know that matter and energy cannot be created or destroyed—So how does this process seem to “generate” energy?
In reality, 1 helium atom is a tiny bit (0.047E-27 kg) less massive than 4 protons. This “missing mass is not gone, but released from the reaction as energy. Einstein taught us that mass is equivalent to energy (E = mc^2) at a fundamental level, so this is where the energy from fusion comes from. Because c^2 is a very large constant, ~9E16, a tiny amount of mass is converted to a large amount of energy. This is how the sun produces the massive amount of energy that we see radiating on us everyday. It is also why fusion has been very hard to replicate here on earth; the temperatures and pressures present in the core of the sun and required for fusion are so intense that they are very difficult to create here on Earth. But, that does not stop us from trying.
Mars has a fascinating geology that is very comparable to Earth in many ways and also shows its very dynamic history. A well known geological feature on Mars is Olympus Mons, the largest volcano in the solar system, which stands at a height of approximately 16 miles and spans 374 miles in diameter. To compare, the largest volcano on Earth is Mauna Loa which is 6.3 mi high and the volume of Olympus Mons is almost 100 times larger than that of Mauna Loa. Because Mars lacks plate tectonics, its crust remains stationary and the lava continues to pile up in one place into one very large volcano.
Another very cool feature of Mars’ geology is Valles Marineris, a massive canyon system. This system runs along the Martian equator and is 2500 mi long and reaches depths of up to 4 mi. This dwarfs the Grand Canyon in Arizona which is only 500 miles long and about 1 mile deep. To put this in perspective, Valles Marineris is as long as the United States and spans about ⅕ the entire distance around Mars. Valles Marineris formed from the cracking of the Martin crust as the Tharsis region uplifted and the planet cooled. It was widened by erosional forces, and potentially formed by water channels that have been found on the eastern flanks of the rift.
Mars’ surface also shows signs of ancient rivers and lakes which is evidenced by dried-up river valleys, and lake beds. This means that Mars once had a climate that could support liquid water and potentially life. As you can see, Mars’ geology is super fascinating and really helps to unravel the history of the planet. One thing’s for sure, future astronauts will have some pretty spectacular places to check out on Mars!
In the history of life on Earth, ozone has played an incredibly important role. For much of the early history of life, the atmosphere contained little oxygen, slowly being replaced by carbon dioxide through photosynthesis. It wasn’t until a critical mass of this CO2 was replaced that animal life could venture onto land. This is due, in large part, to the role of ozone. As oxygen began to fill up the atmosphere, it made its way into the stratosphere. There it encountered ultraviolet radiation, where it underwent a chemical reaction involving a catalyst molecule, and turned into ozone. This is how ozone forms, and it plays an integral role in moderating the greenhouse effect to maintain global temperatures, as well as absorbing ultraviolet light from the sun. Without significant protection from ultraviolet light, animal life on land would have been completely different and much harsher, if it were possible at all.
As we have learned, the cause of seasons is the directness of sunlight a particular region of the Earth receives. What you may not know is that the sun is not the only source that heats up the Earth. The Earth actually internally generates its own heat through radioactive decay. In the Earth’s core and mantle, elements like potassium, uranium, and thorium decay from unstable to stable isotopes. When an unstable nucleus decays, it releases energy in the form of heat as it achieves its more stable configuration. The heat this decay contributes to the atmosphere is 0.05 watts per square meter, while the heat from solar radiation is about 341.3 watts per square meter. This heat from decay is fractional compared to the heat from the sun, but it plays an important role in geological processes. Plate tectonics and volcanic activity are all driven by mantle convection, which is significantly impacted by the Earth’s internal heat.
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As we know, the Earth’s resources are finite. There are only so many materials and metals that we can extract from Earth before it runs out. To help combat this problem, a new solution was envisioned, asteroid mining. What asteroid mining would do is collect precious metals from asteroids near Earth. Some of these include platinum and other minerals.
An important aspect to this is the cost. The cost to send the infrastructure to the asteroid would be around 2.6 billion USD. The infrastructure itself would have a steep cost, which would cost hundreds of millions if not billions to develop. Would this cost be worth it? Well according to a case study, there could be 25-50 billion dollars’ worth of platinum on platinum rich asteroids. Although this may seem worth it, at any point during the flight the shuttle could fail and all that money that was invested is lost. So, only time will tell if asteroid mining could be a viable option.
Throughout history, many civilizations have been fascinated by the stars in the night sky. But the question is why. Why have many civilizations been fascinated by stars? What makes the night sky so attractive to humans? Why did they ascribe meaning to tiny dots that shone brightly, and seemed so far away? I present the case that asking questions led to humans to the night sky.
I think that imaginations and understanding the why was developed as a survival habit. The human that mistook a tiger for a tree branch probably survived longer than the human who didn’t do that. In that one in a million chance, the tiger could be lurking behind the tree and the one who was cautious and avoided that danger survived longer. However, it requires some imagination for a human to mistake that the tree branch looks like a tiger. It required the human brain to notice that the configuration of the tree branches had a close resemblance to a tigers legs or face. The ability to abstract, generalize, and recognize patterns was sent down the reproductive chain. The minute that imagination took root, asking the question why followed. The result of imagination is intuitively answers the question why in a specific scenario. Obviously, it wouldn’t take too long for a human to ask such a question. The minute the human asks why, the existential crisis begins. The hungry need to provide meaning to the world around them began to take over their entire lives. The dawn of consciousness put humans in a perpetual state of despair derived from the unknown around them. Just when one begins to know the world around them, they learn that they truly don’t know anything. So, the minute the first question was asked, the second one followed. The minute the second one was asked, the third one followed, and so on and so forth. It now wouldn’t be much of a surprise for a kid one day laying on his back, staring up at the sky, wondering why there are so many dots that are white and why the night sky is black. He probably wonders why the Moon is white and the sky is blue. So, the necessity to answer what those tiny dots across the sky are. He spends his entire time learning about stories of creation, subconsciously identifying patterns (the skill his ancestors passed down) that will allow him to solve this question. One day, he will grow up, and add to the collection of stories that his people talk around him. And that’s how human’s fascination with stars began and has continued for millennia.
Credit: News Week. A picture showing the Milky Way Galaxy at night.
We know that the Sun is extremely hot. Its surface temperature is 5,500 K. Temperature is a measurement of energy. So, we know that the Sun possesses huge amounts of energy. Where does that energy come from? How does the Sun create that much energy?
Credit: Gravity Warp Drive website. This image shows how the Sun generates energy.
Through a process called nuclear fusion, the Sun manages to create enough energy to keep itself from collapsing onto itself. Specifically, the Sun follows the cycle known as the proton-proton chain.
We have two branches above. Since they are exactly the same, we shall look at one of the branches. We start off with two protons with high kinetic energy. Due to their high kinetic energy, they were able to overcome the repulsive force (like charges repel) and smash into each other. In the process, a positron, a neutrino and a proton-neutron combo are created. The positron is anti-electron: it acts just like an electron, but with a positive charge instead. The positron finds an electron, and they annihilate each other, creating energy through the form of two gamma rays (electromagnetic radiation). The neutrino is created to preserve momentum. They are created from the decay of a proton into a neutron, which is how we have a proton-neutron combo. Next, the proton-neutron combo and a proton smash into each other releasing energy in the form of a gamma ray, and producing a helium isotope, containing two protons and one neutron. In total, three gamma rays of energy were produced. The same thing occurs in the other branch. It produces a positron, neutrino, a gamma ray, and a helium isotope, containing two protons and one neutron. The positron finds an electron, they annihilate each other, and produce two gamma rays of energy. So, in total three gamma rays of energy were produced from the other branch. The two helium isotopes smash into each other creating two individual protons, and another helium isotope, containing two protons and two neutrons. Overall, including both branches, six gamma rays of energy were produced. It may not seem like a lot. However, with the huge hydrogen supply, the Sun can smash a lot of hydrogen together creating enough outward radiation pressure to balance the inward gravitational force. The Sun consumes 620 million metric tons of hydrogen every second and produces 616 million metric tons of helium. So it creates an energy equivalent to 4 million metric tons, using E = mc^2.
The insane amount of energy the Sun creates helps keep itself alive, keep us alive, and every being on planet Earth. Without nuclear fusion, we just can’t survive.
Isn’t it bonkers to think that we first sent human beings to the Moon in 1969? That’s 54 years ago! In that time, we have made such large strides in technology. Finally, there are plans to go back soon!
NASA is working hard on its Artemis campaign. This campaign aims to send astronauts back to the moon to create history. Christina Koch will be the first woman ever on the moon and Victor Glover will be the first person of color to ever step foot on the moon. There have been many delays to this campaign however. The renewed agenda is to launch Artemis II, a maned mission around the Moon, in September of 2025. One year later in September of 2026, Artemis III will be launched with the intention of landing astronauts on the moon. NASA stated that they established that time frame to ensure lessons from Artemis II can be incorporated into the engineering of Artemis III.
These are exciting times to be alive! We have not sent anyone to the moon in most of our lifetimes. I believe this campaign will inspire a whole new generation of astrophysics, astronauts, and astronomers. I hope that this is only the beginning!
Aboard Voyager 1 and 2 there sits a golden record. This golden record contains anything NASA thinks is important to understanding humanity. The record contains both photos and images. The golden record fascinates me so much because of what they chose to put on it. First, they needed a way to communicate how to play the record. The did this with the part in the top left of the face of the record. The top right shows how the pictures are supposed to be created. Pictures include basic math, biology, and information about our solar system. Beyond the science stuff there are also photos of what life on Earth is like. Photos of cars, planes, sports and more. I encourage everyone to look it up and see the photos for yourself. There are also sounds including music but also everyday sounds like rain and dogs.
There is often a lot of confusion when we talk about weather versus climate, and the impact both have on our planet. Many people who deny climate change/global warming do so because they are confused between weather and climate. I had a teacher in high school who told my class that climate change wasn’t real, because the past few years had been abnormally cold in Tennessee, where we live. My teacher was mistaking climate with weather. Thankfully, he didn’t teach environmental science or astronomy.
Weather refers to the combination of winds, temperature, clouds, and pressure that make days hotter, cooler, clearer, cloudier, calmer and stormier than others. Weather is what we feel when we go outside, and it is easy to comprehend by human standards. Climate is large scale, and is difficult to determine based on personal experience. Climate is the average of weather over many many years, frequently around 30 years. We cannot experience changes in climate, as they occur gradually over decades, centuries, and millennia (Bennett et al., pg. 280).
Understanding the differences between weather and climate is vital when discussing environmental issues and the changes that are occurring on our planet. This intersection between environmental science and astronomy is necessary to fully understand and address human impact on the Earth.
