If you look for an image of Jupiter in any article or textbook, you’ll likely see the famous Great Red Spot in that picture. This immense storm on Jupiter’s surface is more than double the size of Earth, and has raged on for centuries. The incredible size and duration of the Great Red Spot begs questions as to how this is the case; the storms we know on Earth last for a few weeks in the most extreme of cases. What explains this nigh-impossibly large and long-lived storm?
The storm itself is situated between two “bands” on Jupiter’s surface, which could explain its formation. These bands move in opposite directions, which may have led to the initial disequilibrium that is known to create storms. This type of formation is seen in a different way on Earth, where hurricanes form out of warm air arising from warm water. Jupiter doesn’t have liquid water oceans, but a similar disequilibrium of temperatures may have caused storms including the Great Red Spot. In fact, we know that Jupiter’s cloud layers are distinct by composition, temperature, and depth, which may play a role in storm formation.
As to the longevity of the Great Red Spot, there is no certain answer. It is possible that the storm creates enough disequilibrium in Jupiter’s troposphere to sustain itself, but this is conjecture. It’s also possible that the storm simply hasn’t run out of steam because there’s nothing on the gas giant’s surface to take that steam away.
Though we know very little for certain about the Great Red Spot, its existence and persistence raise huge questions in our understanding of Jovian planets, and in our understanding of our own weather. Determining the forces behind this titanic storm could provide breakthroughs in both Jovian and terrestrial meteorology.
Black holes have always fascinated me, so here I am, writing a second blog post about them. I recently read a sci-fi novel that involved a man-made black hole. It was incredibly massive, but only the size of a pinprick. This led me to wondering, what are the smallest black holes we’ve discovered in real life?
Just last year, as discussed in this article, astronomers identified one of the smallest black holes ever discovered moving through the Milky Way galaxy. There is some debate over how small it actually is. The team of Baltimore astronomers who made the initial discovery used Hubble observations to conclude that the black hole had a mass of approximately 7.1 times the Sun’s (or 7.1 “solar masses”). However, another team out of California concluded that the black hole could weigh between 1.6 and 4.4 solar masses. According to the article, stellar-mass black holes are typically formed from stars of solar masses of about 20. It is also unique in that it is wandering the galaxy alone: without being accompanies by any stars.
It’s unclear how large these black holes are in volume, and I’m not sure that’s something we can detect with current technology. It’s cool to imagine what a baseball-sized, or even a Moon-sized, black hole would be like!
Not much is known about the Oort Cloud, because it is simply so far away! Rather than being a disk like the asteroid and Kuiper belts, it is thought to be a spherical shell that surrounds the Solar system. The precise bounds of the cloud are not known, but it is thought to extend from about 2,000 to 100,000 AU from the Sun, taking up an incredible (over 99.99%) amount of the total volume of the Solar System. I would be interested to learn in how the density of objects varies throughout that volume.
The Oort cloud relative to the rest of the solar system, on an exponential scale. Sourced from phys.org
Oort cloud objects are incredibly distant and dim. Therefore, we haven’t observed many bodies in the cloud itself, via spacecraft or telescope: instead its existence is largely inferred. It was proposed by astronomer Jan Oort in the 1950s as a way of explaining long-period comets, which can have orbits hundreds of thousands of years long. The NASA article from which this information is sourced gives the example of comet C/2013 A1 Siding Spring, which after passing by Mars in 2014 will not return for another 740,000 years.
Unfortunately, with our current technology there isn’t much hope of visiting the Oort cloud with spacecraft. However, propulsion and aerospace technology is constantly advancing. If we progressed from traveling via (literal) horse power to landing on the Moon in under a century, I have no doubt humankind will someday send a probe to the Oort cloud! It’s exciting imagining what we could learn from it.
The photo above features the transit method of detecting extrasolar planets.
Detecting extrasolar planets is a very delicate and challenging task for scientists. The distances between stars and relative sizes of stars compared to planets make it extremely hard to pick them out. Stars are also typically a billion times brighter than planets. There are a number of different methods that have been tried to detect extrasolar planets. Direct imaging is one method used to capture images of the planet using a telescope as it orbits its host star. This method is largely unsuccessful because the light from the planet is often overwhelmed by the much brighter light from the star. This is mainly useful for larger planets. Often times, scientist are forced to infer a planet’s existence by observing gravitational anomalies. Almost all of what we know about extrasolar planets comes as a result of indirect methods either by detecting gravitational or brightness effects on the host star. The next method, the astrometric method, requires measuring the motion of a star caused by the gravitational pull of an orbiting planet. This is useful but often hard to measure because of the very slight effects of a planet’s gravity on the star. Another method is the Doppler Method which involves measuring a red or blue doppler shift on light emitted by a star after being affected by the pull of gravity from a planet. Lastly, the Transit Method also requires a great deal of precision by carefully monitoring the brightness of a star system over an extended period to detect a potential eclipse or transit of a planet. Like other methods, this one has its weaknesses including not being able to detect planets located far away from their host star as there isn’t enough time to see a detectable pattern in the dips in brightness with each orbital period or if the planet is especially small. Scientists typically will try to use multiple methods in order to confirm the existence of an extrasolar planet. We do not know for certain the properties of these extrasolar planets or even if they fall into the terrestrial and jovian categories we have in our solar system. As the powerful James Webb telescope begins operations, we should be able to answer more questions about other planets in the future.
Although NASA approved the mission in 2001, the New Horizons mission officially entered the public conscience when the craft was launched on January 19th, 2006. The speedy spacecraft performed its flybys of Pluto and its largest moon Charon in mid-2015. Several instruments onboard allowed scientists–including Principal Investigator Alan Stern–to gather valuable data that transformed our conception of the Pluto system and the Kuiper Belt. (I have highlighted some of the most important discoveries and a photo from the primary mission in the next section!) New Horizons has completed its primary mission of exploring Pluto and is conducting an “extended mission.” The extended mission has included the most distant flybys of any spacecraft and led to the discovery of a highly unusual Kuiper Belt object that consists of two conjoined bodies and has since been named Arrokoth. As of this post, NASA has extended the New Horizons mission a second time to enable it to explore more of the Kuiper Belt and potentially beyond; the mission clock reads seventeen years, three months, and four days.
As my political science friends and I like to say, NASA is one of–if not–the best US government agencies because it consistently over-delivers while remaining under budget. So please, give NASA some support (if you can) and read on to learn more about Pluto and the discoveries of the New Horizons team!
Pluto is about half the size of the United States and has five known moons. Charon–the largest of its moons–is about half the size of the “dwarf planet,” and since the two bodies are tidally locked, the moon completes one full orbit of Pluto in the same time it takes the “dwarf planet” to complete one revolution on its axis–153 hours. It takes Pluto 248 years to travel around the sun on its highly elliptical orbit, which takes it from just above 49 astronomical units at its furthest point from the sun to 39 AU at its closest point.
One consequence of this unusual orbit that was informed by discoveries from the New Horizons mission is that at its near point, Pluto’s surface sublimates–going directly from solid to gas (e.g., dry ice)–causing the atmosphere to thicken. (The atmosphere thins as the dwarf planet moves away from the sun, and the gasses return to solid form.) The New Horizons mission also upended scientific conceptions of Pluto when it relayed data that revealed persistent geological activity on the “dwarf planet.” Of the features on Pluto’s surface, the mission discovered–including mountains, valleys, and plains–the evidence of craters and filled craters is particularly striking and provides the best evidence for the aforementioned geological activity.
Should Pluto Be a Planet?
This is a divisive question not just online but in scientific circles as well. Personally, I agree with several prominent (planetary) scientists who argue for Pluto’s reclassification as a planet. Because while the current “dwarf planet” only fulfills two of the International Astronomical Union’s criteria for a planet, it could be argued that several planets in our solar system have not cleared their orbital planes; incidentally, this is the criterion Pluto fails to meet and has been used as justification for its second-class status. Do you think Pluto should be a planet? Or do you think that Pluto deserves to be considered a “dwarf planet?”
The Sun provides us the most necessary elements for life, and is the reason why we can see whatever surrounds us. The objects reflect sunlight and as those light reaches our eyes, we pick up the signals and “see” the objects. What would the world look like if the sun were to magically disappear?
Solar eclipses happen when the Sun, the Earth, and the moon are aligned with each other. Since the orbits of the moon, Earth, and Sun do not fall on the same plane, these astronomical bodies only meet each other at specific times. A total solar eclipse only happens once in about 18 months, and only at specific points.
In the areas that are completely blocked by the moon’s shadow, a total solar eclipse happens on the Earth. If the Earth is located where the moon only blocks the center of the sun, while the periphery of the sun is exposed, we have an annular solar eclipse. In the case where the moon only blocks a part of the sun, we see a partial solar eclipse.
So, where should you go if you want to see the next total solar eclipse, which is going to happen on Apr. 8, 2024? If you are in the US, you would likely want to be around the belt that day “100%” in the image below. For Vanderbilt Students, we would be able to see this eclipse if we simply drive as far north as Louisville, Kentucky – which is about 3 and a half hours away by car.
The James Webb Space Telescope is by far the most intricate piece of technology we have ever sent into space. The engineering process for the JWST took nearly 30 years to build with Randy Kimble (who had worked on its predecessor – the Hubble Space Telescope) and had a cost of $10 billion.
The components of the the JWST are as follows:
Near-Infrared Camera (NIRCam): this is the primary imager of the JWST that covers an infrared wavelength from 0.6 to 5 microns. This allows the telescope to detect light from the earliest galaxies and stars, young stars in the Milky Way, and Kuiper Belt objects.
Near-Infrared Spectrograph (NIRSpec) : this is the instrument used to gather the light collected from the NIRCam into a spectrum. This spectra gathered allows us to know the physical properties like temperature, mass, and chemical composition of deep space objects.
Mid-Infrared Instrument (MIRI) : this is both a camera and spectrograph that detects light in the “mid-infrared” region of the electromagnetic spectrum in which the wavelengths are longer than our eyes can see. This has a wavelength range of 5 to 28 microns which allows it to see the redshift of distant galaxies and newly forming stars amongst much more!
Fine Guidance Sensor (FGS): this is the instrument that allows for the JWST to take the beautiful high quality images we see as it sends them to us. It also allows for scientists to further discover things like exoplanets and their transit spectroscopy.
Using all of these instruments, on Tuesday, July 12, 2022, we received JWST’s first full color image of the Carina Nebula (left).
This is so significant because it showed the extreme amount of progress given that this image (right) is of the same nebula but taken from the Hubble Telescope in 2008.
The amount of detail present in the JWST photo compared to the Hubble Telescope catapulted astrophotography light years ahead (HA!) of what it used to be.
The Carina Nebula contains the stellar nursery (that is so cute) NGC 3324 – the region in which new stars are formed. The peaks of this region are nearly 7 light years high, and the types of stars created in these regions are usually O- and B- type stars as they are formed by cosmic recycling. The nebula is about 7,500 light years away and coupled with the superior technology of the JWST, will shed light on how stars are formed and evolution of galactic clouds!
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For my “any astronomy” blog posts, I like to somewhat link them to my personal life. Last time, I shared my hometown planetarium, the Adler Planetarium. This time, I wanted to focus on this week’s astronomy-related event as my birthday is this Thursday. I found this amazing website called This Week’s Sky at a Glance. Almost like a weather forecast, it shares what telescope users should expect to see when they look in the sky.
For those who have yet to do any observing this semester, I think this could be a helpful tool to see what could potentially be seen the day you observe. To my fellow Aries, our constellation will have been visible tonight. Additionally, throughout the week we shall see Mercury and Venus, with brief and faint appearances from Mars and Saturn.
The key sky news for my birthday, April 13th, is the visibility of the star Kochab or Beta Ursae Minoris, which will appear at the right of Polaris. According to Star Facts (2022), Kochab is the second brightest star in the Ursa Minor and apart of the Little Dipper. At this point in the year, most of the Little Dipper is not visible but it would be wonderful to see a component of it.
As corny as it may sound, there will be many stars visible from Nashville on April 13th. I encourage you all, to find some time to discover a day whose night sky intrigues you!
Pluto, a dwarf planet farther out than Neptune in the Kuiper Belt, was once thought to be the ninth planet of our solar system. However, the discovery of Pluto’s moon, Charon, led to the revision of calculations on Pluto’s mass, and the redefinition of planets finally “kicked” Pluto out of the solar system planets since it is not massive enough to clear its surrounding asteroids’ orbits. After that, Pluto was assumed to be an uninteresting dwarf planet because it is thought to be too small and far from the sun to have any geological activities that are of interest to us.
However, this notion was completely changed after the New Horizon mission launched in 2006. On Earth, it is exceedingly difficult to identify specific features on Pluto since it is so far from us, and in light of the newly discovered Kuiper Belt, scientists wanted an opportunity to take a close look at these outer astronomical bodies in our solar system. In this attempt to uncover the mysteries of Pluto and the Kuiper asteroid belt, New Horizons mission was selected; it was launched in 2006 and remained inactive until it got to the proximity of Pluto in 2015.
The information uncovered by this mission was shocking to many. Pluto showed much evidence for geological activities – the lack of craters on its surfaces, the ice volcanoes, mountains made of ice, and the biggest grand canyon in our solar system. How Pluto gains its internal heat for these activities when so far from a heat source and so small in mass it is still a myth to us today. However, the New Horizons mission has really opened our eyes to a metaphoric “new horizon”.
Artist’s conception of Ganymede and Jupiter. Image by NASA
Although by visible light and upon first glance Ganymede might seem like an unassuming satellite, further inspection and deeper exploration demonstrates that this view is both tired and untrue.
Simply by size alone, Ganymede is a headliner. As the largest moon in our solar system, it exceeds in size Earth’s moon (obviously), but it’s also larger than both Pluto and Mercury–bodies which either have been, or are currently classified as planets. Though Ganymede doesn’t meet the three criteria to be classified as a planet (thanks, Jupiter), the size of this satellite is quite remarkable.
Beyond the matter of size, Ganymede is an anomaly within our system, in that it is the only moon known to have a magnetic field of its own.
Hubble image of Ganymede, with its auroral belts colorized in blue. Image by NASA/ESA
As demonstrated in the image above, the Hubble Space Telescope captured auroral belts on Ganymede, and what’s more, it noted that the aurorae are “rocking” back and forth to a degree that supports the conclusion that a massive salt-water ocean lies beneath the surface of the moon. This ocean, which is estimated to be ten times deeper than Earth’s oceans and contain more water than the entire surface of the Earth, was an exciting discovery in the search for life-sustaining worlds and life beyond Earth. According to NASA, a previously created model supports the idea that it would be possible for primitive life to develop in this ocean.
