Comparing the Atmospheres of Mercury, Venus, Earth, and Mars

Posted on February 27, 2023 by Melanie Marszal

We may not think much about the presence of Earth’s atmosphere in our day-to-day lives, but it has an immense impact on us. Earth’s atmosphere contains the oxygen we need to breathe, protects us from many of the Sun’s harmful ultraviolet (UV) rays, helps stabilize the Earth’s temperature, and is responsible for weather patterns. If the composition or thickness of our atmosphere were any different, we would likely not survive.

Mercury, Venus, and Mars are the other terrestrial planets in our solar system, meaning they have rocky surfaces resembling Earth. However, one of the reasons they end up seeming so distinct from Earth is their differing atmospheres.

The first aspect of each atmosphere that differs is the chemical composition. You may know that Earth is composed of 78% nitrogen and 21% oxygen (and 1% argon). Mercury has an even higher composition of oxygen than Earth, with oxygen comprising 42% of its atmosphere. The other elements present in Mercury’s atmosphere include sodium, hydrogen, and helium. On the other hand, the atmospheres of Venus and Mars are comprised almost entirely of carbon dioxide, with it making up 96% and 95% of their atmospheres, respectively. Nitrogen is also present in these 2 atmospheres.

The other extremely important way each of these atmospheres differ is in thickness. Earth’s atmosphere is thick enough to keep the temperature somewhat regulated and to keep out harmful UV rays. On the other hand, Mercury has virtually no atmosphere, which causes major temperature variability. The reason Mercury has so little atmosphere may be that since it is so close to the Sun, particles in the atmosphere are frequently heated enough for them to escape the planet’s gravitational pull, leaving the atmosphere. Solar winds likely also contribute. Mars has a relatively thin atmosphere as well, but not as thin as that of Mercury. Venus is on the other side of the spectrum, with an incredibly thick atmosphere, which traps heat.

Another difference between atmospheres is clouds. On Earth, we often see white clouds of water vapor form (a.k.a. clouds). On Venus, clouds of sulfuric acid often form. Thin clouds of water and carbon dioxide form on Mars.

The four terrestrial planets in our solar system: Mercury, Venus, Earth, and Mars (image from Wikipedia)
Posted in Class, Terrestrials | Tagged , , , | Comments Off on Comparing the Atmospheres of Mercury, Venus, Earth, and Mars

Solar Flares and the Carrington Event

Posted on February 26, 2023 by sydneyastr2110

We heard a little bit about the Carrington Event in class, and I wanted to know more about it. A solar flare is essentially a burst of energy on the Sun which sends electrified gas and subatomic particles toward Earth.

In 1859, there was an abnormally large solar flare caused two geomagnetic storms known as the Carrington Event. The name is from the last name of an astronomer, Richard Carrington, who observed the event through his telescope. While observing the Sun, he noticed intense, white light bursting from the sunspots.

A few hours later, the world experienced telegraph communication failures. Basically, extremely powerful of currents were traveling through the wires. According to writer Christopher Klein, “the atmosphere was so charged… that they [telegraph operators] could unplug their batteries and still transmit messages,” (Klein). Accounts from the time mention the incredible bright red sky caused by the event. You can check out a more in-depth description of the event here.

This event was certainly unusual in size as it was “twice as big as any other solar storm in the last 500 years,” (Klein).

This was over 160 years ago, so why do we care? On January 5, 2023, there was an X1.2 solar flare. The X is representative of a classification for the most intense flares. While this was intense, the 1.2 indicates that it was nowhere close to the size of the Carrington Event. The classification and images are available from NASA. The image below is from NASA and shows the solar flare on the left side of the Sun.

Image Credit: NASA/GSFC/SDO

Could an event like the Carrington Event happen again? Yes, absolutely. A study in 2020 from the University of Warwick and the British Antarctic Survey determined, “that on average there is a 0.7% chance of a Carrington class storm per year.” If you want to know more about the results of this study, check it out here. This type of storm could be detrimental to modern infrastructure as it would impact power grids and satellites with estimated losses of $1 trillion to $2 trillion (Klein).

Posted in Historical, Observables, Sun | Tagged , , , | Comments Off on Solar Flares and the Carrington Event

The Coolest Telescope

Posted on February 15, 2023 by Liam Prescott

The James Webb telescope, unveiled on December 25 2021, is by far the coolest telescope. Webb has the power to view infrared light rays from exoplanets that are potentially habitable. Also the innovative technological achievement can better observe our own solar system and the first galaxies that were formed 13.5 billion years ago. It has a 6.5 meter mirror that is the largest NASA has ever built, and this allows it to view more further objects in greater detail and accuracy. The telescope is designed for space and is 60 times larger than previous space telescopes too.

MoreInfoandpicsource
,
,
,
,
,
,
,
Posted in Instruments | Tagged , , , | Comments Off on The Coolest Telescope

Evidence for Understanding

Posted on February 13, 2023 by dougkyles422111

I want to talk about an aspect of light that doesn’t make the most sense to me, and that is how we receive it. Thinking about sight abstractly, we cannot really comprehend at all times what we are seeing are particles of light. To us, our visual environment is our reality. Learning about how the reality around us is really just electrical signals being received by our brain from light-sensitive particles is a concept that is hard to wrap one’s head around. This is part of chapter 6 that was most interesting to me. 

Even further, light can be considered energy- as small as on the electron level. Receiving light can be broken down as photons giving ionization energy to electrons within the atoms within the cells of our eyes. The understanding the previous chapter on light and energy provides allows one to go so deep into the idea of the reality of our world that the knowledge is in my opinion unbelievable. This is what I’d like to discuss. While I don’t believe there’s enough information or evidence for me to doubt the science behind chapters 5 and 6, I find that subconsciously I question how we know so much about things that cannot exactly be observed. Coupled with chapter 3 on historical astronomers I wonder if we have possibly a system that is outdated and will be changed soon with time. The following article is one I read that helped slightly with my understanding of how we know what we know about the atom.

Posted in Class, Light | Tagged , | Comments Off on Evidence for Understanding

Blog 2 – Tides: my thoughts from the anime Avatar: the Last Airbender

Posted on February 13, 2023 by niqretnuh

One of my favorite poetic interpretations of tides comes from the anime “Avatar–the last airbender”. In the episode “The Siege of the North”, the root of the mysterious power of “water-bending” is explained to stem from the moon, and the power of tides. The goddesses “tui (推)” and “la (拉)” (“push” and “pull”) directs the motion of the tides, symbolizing the  “yin-yang” balance behind everything in life. Born and raised in a coastal city, watching the bright, white moon rise over the horizon always reminds me of this beautiful and philosophical episode.

In astronomy, we learned that tides result from the gravitational force from the moon. The differences in the force received from the two opposite sides of the Earth causes its shape to deform, causing tides to occur. However, unlike portrayed in the anime, tidal forces do not disappear in day time – in fact, the sun’s gravitational difference, although very limited compared to that of the moon, still contributes to tidal phenomena on the Earth. 

Although not entirely scientifically accurate, the anime still sparks a lot of discussions over the moon tides, and the philosophical meaning we can derive from this phenomenon. In my childhood, this episode in Avatar provided me with endless imagination over this mysterious, powerful phenomenon.

Posted in Class | Tagged , , , | Comments Off on Blog 2 – Tides: my thoughts from the anime Avatar: the Last Airbender

The Wave-Particle Duality of Light

Posted on February 13, 2023 by jackdoyle25

In common perception, most things in our universe fall into two fundamental categories: energy and matter. Energy could be electricity, heat, sound waves, or kinetic motion. Matter is generally a descriptor of things made up from atoms, such as planets or stars or humans ourselves. However, looking at these on a more fundamental level, the lines between energy and matter are blurred. Take kinetic energy, which is stored in the matter of the object which is in motion, or stars, which are full of constantly occurring chemical reactions to create energy. The so-called “fundamental” distinction between matter and energy is, in fact, a flawed idea.

Nowhere is the ambiguity of this distinction more significant than in the nature of light itself. Our previous examples involve intersections between what we think of as energy and matter. Light, however, can present itself as both. To be more specific, light can behave as a wave or as a particle.

An example of an experiment which provides evidence for the wave-particle duality of light.

Particles of light are called photons, each of which can be observed as their own individual particle and contain energy. Waves of light are inseparable from the concept of photons, as photons have their own wavelengths and frequencies, which are the defining properties of waves.

The idea that light can be both a wave and a particle at the same time is conceptually unwieldy, but it is necessary to our understanding of how light works. This understanding allows us to reframe the distinctions between matter and energy. Light is an example of a particle acting as energy, and of a wave acting as matter. The destruction of such a simple dichotomy confounds logic, and in doing so, opens up a world of possibilities. This principle of wave-particle duality is crucial to one of the most fascinating fields of modern scientific study: the theory of quantum mechanics.

Posted in Light, Physics | Tagged , | Comments Off on The Wave-Particle Duality of Light

The Tools of Discovery

Posted on February 13, 2023 by dromalley

For my second blog post, I’ve decided to provide an overview of a few of the most advanced telescopes both on and around the world which have allowed astronomers to peer into the distant mysteries of our universe and uncover more about its nature. First, we will examine some of the most advance ground based telescopes.

Several of the Very Large Array‘s telescopes

First completed in 1980, the Very Large Array is the largest terrestrial telescope array on the planet, with each of its three arms measuring 21 kilometers at full extension. The VLA consists of 27 individual dishes each 25 meters across, providing a total of more than 13,000 square meters of collecting area. The VLA takes observations in the radio range, providing astronomers with deep views into the cosmos.

The Gran Telescopio Canarias in Spain

The largest single optical telescope on Earth, those which observe in the visible range, however, is the Gran Telescopio Canarias in Spain which observed its first light in 2007. This telescope is 10.4 meters across and provides astronomers with their clearest views of the sky in the visible light range.

The Hubble Space Telescope

Moving into orbit, we come to probably the most famous telescope in the history of astronomy: the Hubble Space Telescope. Launched in 1990, its first few years were troubled as a defect in the mirror restricted scientists to observing less taxing objects. However after this was corrected in 1993, Hubble went on to make many important discoveries, especially in helping researchers understand the history and origin of the universe. Hubble has taken many famous photos, including the “pillars of creation” and the Hubble deep field, an incredibly detailed photo of an unremarkable section of night sky which may include as many as 10,000 galaxies.

The Hubble deep field

Finally, we have the newest and most technologically advanced telescope ever created: the James Webb Space Telescope, or JWST. the JWST was launched in 2021 and has a diameter of 6.5 meters, giving it about 6 times more collecting area than Hubble. The JWST’s observations are focused on the near-infrared as opposed to Hubble’s visible light and near-ultraviolet capacities, providing astronomers with a different perspective on many objects and taking our most detailed measurements of other star systems to date. As the JWST’s mission has just begun, there is much work for it still to do, and it will surely have many great contributions to astronomy in the future.

An illustration of the James Webb Space Telescope
Posted in Historical | Tagged , , , , , | Comments Off on The Tools of Discovery

Blog Post 2: Celestial Navigation

Posted on February 12, 2023 by Myles7235

In order to navigate the vast seas when traveling in today’s time, we can easily use modern technology to pinpoint exactly where we are in the ocean. A prime example of this type of technology would be GPS systems. However, GPS systems haven’t been around forever. Celestial navigation is the art of determining both the location and orientation of one’s position based on stellar bodies. A prime example of a stellar body used for celestial navigation is the North Star, Polaris. People often mistake its importance to be connected to its brightness, but in actuality there are many other stars that are as bright or even brighter than Polaris. The real reason that Polaris is important is that it is always positioned above the Earth’s North Pole. There are a common set of steps to help people locate Polaris. You can find more information about celestial navigation here.

First, you scan through the constellations until you locate Ursa Major. You can look for the big dipper, which is in ursa major. Next, you locate the 4 stars that create the spoon-like pattern of the big dipper and the 3 stars that create the handle. Follow a line towards the little dipper from the 2 stars in the spoon-like pattern that are furthest away from the handle and you’ll find the North Star! You can check out a visual of this process here.

Posted in Class, Instruments | Tagged , , , , | Comments Off on Blog Post 2: Celestial Navigation

Sextants – Then and Now

Posted on February 12, 2023 by 7smessier45

Humans have navigated the open ocean for thousands of years; among the first to do so were the aboriginal Australians and Polynesian seafarers about 50,000 years ago. More recently–but still a few hundred years ago–celestial navigation by Western cultures relied on a navigator’s understanding of the stars (and other heavenly bodies, including the sun), the current (assumed) position of the vessel, and tools like a sextant and an accurate clock. A sextant was a tool that enabled seafarers to determine their latitude and longitude using the angle (as measured by a sextant’s graduated radial arm) between a celestial body and the horizon. From there, the navigator would record the angle and the time of day to cross reference with tables, called “almanacs,” published by either a Navy or a reputable navigation source. Using these two pieces of information, the navigators of the 18th century could determine their position within a few hundred meters. 

Old Sextant

In the 1970s, with the launching of military GPS satellites, the use of and training with sextants largely disappeared. However, in our era of cyber attacks and fears about technology security, the US Navy began reviving its usage of the historical tool. Nowadays, the US Navy–and other branches of the military that rely on accurate measures of position without landmarks–require at least some of their offices to be proficient with the tool.  

QMSM Rodgers using Sextant

I find it incredible that no matter how advanced we think we are as a society, we always fall back on our fundamental tools at some point or another. It’s incredible to think that even with our technological advancements, we still rely on and honor our ancestors’ techniques through our use of the heavens to navigate. 

Posted in Class, Historical, Stars | Tagged , , , , | Comments Off on Sextants – Then and Now

Powered and Unpowered Gravity Assists

Posted on February 12, 2023 by Trevor Pillow
A visualization of the Voyager 1 using Jupiter’s gravitational well to reach Saturn

The farthest planets in the solar system are so distant, it is infeasible to reach them using only rockets. The delta-v, or change in velocity, required to propel a spacecraft to a gas giant like Saturn is far too impractical for today’s rockets to achieve. The main problem is that a spacecraft needs tons of fuel to reach a planet, but to get that fuel into orbit, the spacecraft needs even more fuel. The costs of such a rocket escalate until it is too expensive to even attempt to build.

However, by using our understanding of physics to our advantage, we can efficiently generate delta-v using gravity wells. An object with a significant mass, such as a planet, will develop a field of gravitational influence. Objects within this influence are attracted to the planet, while the planet is equally attracted to the object. We can take advantage of this in order to achieve higher speeds using little to no extra fuel.

If a spacecraft approaches a planet in the same direction that the planet is travelling, the spacecraft will increase its orbital velocity relative to the sun. Approaching a planet from the opposite direction that a planet is travelling will decrease a spacecraft’s orbital velocity around the sun. This maneuver is known as an unpowered gravity assist. By increasing a spacecraft’s orbital velocity, the spacecraft will be able to expand its orbit to reach further planets in the solar system. By decreasing a spacecraft’s orbital velocity, the spacecraft will shrink its orbit around the sun.

We can use this knowledge to travel not only to the furthest extents of our solar system, but also to deep within the sun’s gravitational influence. The most efficient way to get a close orbit around the sun is to first travel to Jupiter, and then perform a powered flyby. Changing a spacecraft’s velocity from within a deep gravity well is more efficient, and therefore allows the spacecraft to get closer to the sun than it otherwise would be able to. So, we can launch a spacecraft into Jupiter’s orbit and perform a burn at a much greater efficiency than we can achieve near Earth. It seems counterintuitive that the best way to reach the sun is to first approach Jupiter, but studying the orbital mechanics that allow us to efficiently travel through space have given me a greater understanding into the effects of gravity.

Posted in Sun | Tagged , , , , , | Comments Off on Powered and Unpowered Gravity Assists