Coronal Mass Ejections are ejections of solar wind and plasma from our Sun’s corona. The blast from a Coronal Mass Ejection (CME), carries about a billion tons of material away from the sun at speeds ranging from 250 km/s to almost 3000 km/s. (NOAA) If they are directed toward Earth when they are ejected from the sun’s upper atmosphere, the fastest traveling CMEs can reach Earth in the matter of hours (15-18hrs) and the slowest take a matter of days. CMEs and solar flares are similar but don’t always happen at the same time, and scientists don’t entirely understand how they relate.
Important aspects of analyzing CMEs include size, direction, and speed. Knowing these can determine the likeliness of a CME affecting Earth and are determined from satellite imaging. CMEs contain radiation (specifically particle radiation that consists of protons and electrons) and are accompanied by geomagnetic storms. Both can have effects on satellites, spacecraft, and astronauts. Large CMEs can even interact with Earth’s magnetosphere, which would send some of the particle radiation into our upper atmosphere, causing dramatic auroras. (UCAR)
Binary stars were stars orbiting each other, and they might eventually collide due to the stellar mass loss or gravitational radiation which caused the decay of orbits. Stellar collisions could be amazing and rare, which happened once every 10000 years in our globular clusters. It was very likely, from scientists’ approximation, that a binary star system called KIC 9832227 would merge and explode in 2022. The mergence and collision would create the brightest light in the night. And the phenomenon would be visible with naked eyes, which could be spectacular! This phenomenon was predicted by Prof. Lawrence Molnar from Calvin College, who found that the period of variations in the binary stars was growing shorter in 2013 and made the prediction.
Different elements were occupied in different planets within the solar system. Mercury, Venus, Earth, and Mars were terrestrial planets made of rocks, which were composed of diverse metal elements including magnesium and aluminum. Specifically, mercury obtained a thin exosphere of oxygen, sodium, hydrogen, helium, and potassium. Venus consisted of an iron core and a carbon-dioxide atmosphere. Our planet — Earth — was mostly (90%) made of silicon, iron, oxygen, and magnesium, which was similar to the composition of Mars as well.
Jupiter and Saturn were gas giants, which mostly contained helium, hydrogen, and water. Simultaneously, Uranus and Neptune were ice giants, possessing water, methane, and ammonia fluid. In these two ice giant planets, it rained diamonds due to the separation of elements made of polystyrene, resulting in carbon dioxide atoms. Carbon was converted into diamonds at extremely high pressure within two planets.
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The Chicxulub Impact happened approximately 66 million years ago, defining the end of the Cretaceous Period and the beginning of the Paleocene, as well as the end of the Mesozoic Era and the beginning of the Cenozoic Era. This impact not only managed to eradicate the dinosaurs as the dominant lifeform on the planet but also managed to kill off 50 percent of all biodiversity.
Triceratops, one of my favorite dinosaurs, and an unfortunate victim to the mass extinction event at the end of the Cretaceous period. Credit to Fossil Facts and Finds.
This impact was caused by an asteroid that was approximately 10 kilometers wide and hit the Earth at 30 kilometers per second, producing 3*10^23 joules of force. The impact was so large that it kicked up debris across the entire world, producing ash clouds that blocked the sun for years before the emissions of CO2 put the world into a massive temperature spike.
Impact Crater at the Yucatan Peninsula in Mexico, credit to Wikipedia
It is theorized that this asteroid originated from the from the asteroid belt, although from where is up to debate. Some suggested but discredited theories on where it originated from were from the Baptistina group of asteroids in the asteroid belt or from the remnants of a comet. The most modern theory of the asteroid originating from the main asteroid belt was determined from simulations, probability, and high deposits of chromium and platinum isotopes at the impact crater.
The idea that the dinosaurs went extinct by an asteroid hitting them is a relatively new idea. In Disney’s Fantasia, it shows the dinosaurs dying off by heat wave, exhaustion, and climate change. This was the common theory until this impact crater was discovered. Initially found by Walter Alverez and his father Luis Walter Alverez, the high levels of iridium in the clay in the late 1970s. An oiling company hired Glen Penfield and Antonio Carmago as geologists to scout the area, where they noticed the ridge present near the town of Chicxulub extended into the ocean creating a circle. Further research in the area revealed pink granite and other igneous rock that only form deep inside the Earth, brought up to the surface.
Despite being the most recent mass extinction event, as well as being one of the most sudden and impactful (literally), the Earth’s natural forces of erosion, plant growth, and oceans had covered up one of the larger craters on its surface. There was even a town in the center of the crater without anyone realizing it. It was so well hidden that it took until 1991 for a paper to be published declaring it to be an impact crater. Unlike other planets like Mars and Mercury, Earth’s changing atmosphere and lifeforms can erode and erase crater impacts with little evidence left.
An image of Proxima Centauri taken by the Hubble Space Telescope (Wikipedia)
The closest star to our solar system is one named Proxima Centauri. Proxima Centauri is a relatively small star, as it is a red dwarf star with about 12.5% the mass of the Sun and only about 0.17% as bright as the Sun. Proxima Centauri resides about 4.25 light years away from Earth, and is part of a three-star system with Alpha Centauri A and Alpha Centauri B. A fun fact about Proxima Centauri is that it is a flare star, meaning it changes in brightness every once in a while due to activity of its magnetic field. In 2016, for example, it became 68 times brighter than normal because of a “super flare.” Proxima Centauri also has three known planets orbiting the star, one of which might be a super-Earth residing in the habitable zone of the star where liquid water can exist on the planet’s surface under normal temperature and pressure.
One of Cassini’s most famous images of Saturn (NASA)
The story of the Cassini spacecraft is one of scientific discovery and self sacrifice. Cassini was launched in 1997 and spent 20 years in space, focusing on the planet Saturn, its moons, and its rings, before the spacecraft’s intentional demise in 2017. Through Cassini, we were able to land a probe on Titan, Saturn’s largest moon, and discover seven new moons of Saturn. Cassini also made several flybys of and gained valuable insight into Enceladus, a moon which has a massive subglacial ocean and which has been labeled as one of the most likely places of extraterrestrial life in the solar system. In 2017, Cassini’s “grand finale” was one that both advanced scientific research on Saturn and preserved scientific principles. The spacecraft performed several close flybys of the planet’s rings before finally plunging itself into the atmosphere of Saturn, sending images and data back to Earth up until it burned up in the atmosphere, concluding its scientific mission. This was done in order to prevent any microbes that hitchhiked on the spacecraft from Earth from contaminating Saturn’s moons if it accidentally crashed into one after running out of fuel.
Cassini’s final image before burning up in Saturn’s Atmosphere (NASA)
Over the decades, there have been many hypotheses made about how our Moon was formed. There are many possibilities that we can rule out simply due to the facts that we know about the Universe. Firstly, we know that the Moon was not captured by the Earth’s gravity because the Earth is too small to have enough force to catch such a large celestial body. We also know that the Earth and the Moon could not have formed at the same time because if they had then they would have formed to be roughly the same in composition and density. The leading theory that scientists have devised is that the Moon was formed by the aftermath of another planet colliding with the Earth. This is called the “Giant Impact Hypothesis.” This collision sent particles careening away from the Earth, which began to orbit and eventually collided together to form the Moon that we know today. Another idea that supports this is that a large collision might also be the reason for the Earth’s tilted axis.
A Helpful Visual of the Impact Hypothesis
This theory has a lot of substantial evidence to support it. It is completely plausible that another planet, which would have probably been roughly the size of Mars, could have hit the Earth with enough force to send a large portion of the Earth’s outer shell into space in large pieces of debris. That debris would not have gotten far before it was ultimately restrained by the force of the Earth’s gravity, so it would have formed a ring around the planet. The debris caught in that ring would have slowly collided together over the span of several orbits. Eventually, it would have formed a spherical object and remained in that orbit. This is what astronomers believe to have happened to form the Moon, but there is unfortunately no way to be absolutely certain of it, which is why it remains a theory.
A short video can also be found here to help you to better visualize what this collision and formation would look like.
A new study by Nature Astronomy has tapped an estimate for the greenhouse gas emissions of the astronomy industry. Unfortunately, despite the fact that the global astronomy industry is much smaller than many other industries, its emissions are strikingly large. The number estimated by this study is a staggering 20 million tonnes of CO2 annually. Putting this into context, astronomical researcher Jürgen Knödlseder of France’s IRAP notes in an interview with NPR that this level is on par with the annual emissions of Croatia, Bulgaria or Estonia’s national emissions over a full calendar year. While it is important to note that there is a tremendously long list of industries which pollute more heavily, the astronomy industry should feel a need to correct this because they have large per-capita emissions and, more importantly, it is an important authority on reporting on climate change. For an industry tasked with communicating the urgency of Climate Change to the citizens of Earth, large levels of greenhouse gas emissions may strike the public as hypocritical. Some astronomers have even proposed slowing down the production of new telescopes until the processes become more efficient, or at the very least become primarily powered by renewable energy sources. While not all in the industry will feel comfortable making such a dramatic move, this study should stress to those that love looking out from Earth that we have an urgent, time-sensitive problem right here at home.
While stars are powered by nuclear fusion, nuclear reactors here on Earth have yet to make that leap. Fission is our only readily available source of nuclear power, but it is significantly less lucrative than its counterpart. The difference is the process, which combines two isotopes of hydrogen to trigger an energy release instead of splitting atoms, like in fusion. However, this process requires massive pressure (like in the cores of stars) that is hard to replicate on Earth. To make up for it, advanced facilities like the JET Laboratory use ridiculously hot plasma suspended in a magnetic field, the temperature of which is roughly ten times that of the cores of stars. This excessive heat allows for the process to take place and has been proven to work on small scales. A snapshot of one of these reactions is included below.
At this scale, fusion does not produce a remarkable amount of energy, but it shows more ambitious products have merit. This test in particular, which happened in early 2022, was used as a benchmark to justify support for a ITER, a facility under construction meant to be the next step in fusion exploration.
New findings by the AKARI space telescope, coupled with surface modeling at the Earth-Life Science Institute (ELSI) at Tokyo Institute of Technology present new evidence that the asteroid matter which composes Earth was located much further out in the solar system than initially thought. Their study involved computer modeling to develop reflective spectra of hypothetical materials believed to exist in the primitive outer belt of the solar system. The researchers placed heavy evidence on studying ammonia-bearing clays found on Earth. According to the researchers at Tokyo Institute of Technology, this is interesting because this material can only stabilize and form in conditions that are water-rich and at a very low temperature, akin the the conditions found in the outermost asteroid belts of our solar system. Thus, these researchers propose that the various mineral materials which now compose earth formed in outer orbits of our current solar system, before the mixture was brought closer to the center of the solar system, by mixing processes. Their theory will be tested when their spacecraft, Hayabusa 2, returns samples: if the samples contain ammoniated salts and minerals, it will be strong evidence to put our cosmic history in perspective according to this theory.
