What is Oumuamua?

Oumuamua is one of the most important celestial discoveries of a generation and is the first interstellar object to be observed in our own solar system, following its official discovery at the Haleakala Observatory, Hawaii, on 19 October, 2017. Scientists aren’t really sure where Oumuamua came from or what it’s made of, there’s also been lengthy debate about whether it’s actually an asteroid or a comet.

At first, Oumuamua was classified as a comet, but further observations revealed no other hallmarks associated with being a comet. Following its passing of the sun at an incredible 87.3 kilometers per second, it was reclassified as an asteroid. It was later reclassified once again as during further observations and was found to be slightly but steadily accelerating, which is, of course, more typically the behaviour of a comet.

Oumuamua was spotted around 33,000,000 km away from the Earth, which is about 85 times as far away as the Moon. It was observed to be anywhere between 100 and 1,000 meters long, with both its width and thickness pinpointed at somewhere between 35 and 167 metres. It’s fair to say that in terms of celestial objects, Oumuamua is pretty small. This led scientists to believe that Oumuamua could in fact be a fragment of a disintegrated rogue comet, that is, a comet that isn’t bound to a single location by a gravitational pull.

One of the Solar System’s Biggest Mysteries

There is absolutely zero chance that Oumuamua originated in our solar system, it’s moving so fast in relation to the sun that it’s got to have began its journey incomprehensibly far away. What this also means is that there’s no chance it will be ensnared in a solar orbit, and will eventually leave our solar system and carry on with its journey to the depths of interstellar space. When you consider the amount of time that it’s been travelling to have built up such tremendous speed, it’s time in our vicinity is a tiny fraction of it’s existence.

Renowned Harvard astrophysicist Avi Loeb went as far as suggesting that Oumuamua could be an alien space ship that’s searching our solar system for signs of life. He hypothesized that it’s neither an asteroid or a comet, but is in fact a light sail. A light sail is a form of spacecraft that is powered solely by radiation pressure.

Similar technology is being employed by the Breakthrough Starshot project. The Starshot project is many years from completion which would have suggested, if it were a spacecraft, that it was from a highly advanced society. Loeb’s ideas were roundly dismissed by his peers who unequivocally stated that Oumuamua is made of organic matter and has not been constructed by any living being.

What’s in a Name?

Oumuamua means “a messenger from afar arriving first” in Hawaiian. It was given this name due to being discovered by scientists based in Hawaii and also for the pertinent symbolism associated with it. For some, Oumuamua symbolizes a messenger sent from a distant realm to reach out and make contact with humanity.

While Oumuamua may be the first of its kind, scientists and astrology fans throughout the world are hoping it’s not the last. The next time we have a visitor from so far away, let’s hope it sticks around for a little while so we get to learn a bit more about it.

Alpha Centauri

What is Alpha Centauri?

Alpha Centauri is the closest star and planetary system to our solar system. Despite being the closest, it’s still an incredible 4.37 light years, or 43.7 trillion kilometers away. It’s regarded as a special system to scientists, not only because it’s the closest to us in terms of distance, but because it’s one of an extremely small number of places throughout the entirety of the Milky Way galaxy that has the potential to provide the conditions that are essential to supporting terrestrial life.

To the naked eye, Alpha Centauri looks like a single star that’s glowing brightly in the sky, when it is in fact three. Alpha Centauri A and its smaller counterpart, Alpha Centauri B, are the two biggest stars in the entirety of the Centaurus constellation. Each has a similar mass to the Earth’s sun, and they orbit one another at a similar distance to Uranus and our sun.

The third star, Alpha Centauri C, is the nearest star to Earth that lies outside of our solar system. Centauri C is much smaller than it’s two neighbors and is only around 12 percent of the mass of our sun, which equates to it being around 50 percent larger than Jupiter.

Where is Alpha Centauri?

Alpha Centauri is part of the Centaurus constellation which itself lies approximately 1.34 parsecs or 4.37 light years from Earth. The Centaurus constellation is one of the largest constellations visible in the night sky and has been observed for hundreds, if not thousands, of years.

As the name would suggest, the constellation represents the centaur, the human / horse hybrid that was an almost ever-present figure in Greek mythology. The are a number of different opinions on which individual centaur the constellation is named after, but the general consensus is that it’s Chiron, the mentor of Hercules.

The Discovery of Alpha Centauri

Alpha Centauri was mentioned as early as the 2nd-century in the star catalog of Ptolemy, The Almagest. English explorer Robert Hues bought Alpha Centauri to the attention of European stargazers in 1592 when he noted its existence in his Tractatus de Globe. It’s pretty safe to say that countless others would have noticed the star system during the years between those noted instances, but their records have more than likely been lost to the ages.

In 1689, Jean Richaud first noticed that there were more stars in the system and thus Alpha Centauri was then known to be a binary star – a star system that consists of a number of stars that all orbit the same point in space. Over 80 percents of stars we see in the night sky are estimated to be binary stars.

The approximate orbit paths were calculated in 1926 by William Stephen Finsen. His work paved the way for today’s measurements that are accurate enough for visual observers to determine the positions of other stars in the system to almost precise measurements.

During the summer of 2012, scientists at the La Silla Observatory in Chile reported the discovery of a planet orbiting Alpha Centauri B. The planet is slightly larger than Earth and is an important milestone in astrological history, as it was the first discovery of a planet in our neighboring star system of Alpha Centauri. It’s also the smallest exoplanet to ever have been discovered that is in orbit around a star that’s similar to our sun.

The Future of Alpha Centauri

When the relevant technology exists, it’s likely that Alpha Centauri will be the first destination of an unmanned or manned interstellar space exploration mission. Unfortunately, due to the limitations of technology at the present, crossing the vast distance between our sun and Alpha Centauri would take several thousands of years.

However, new forms of technology are in development that could reduce the travel time from millennia to a matter of decades. This revolutionary nuclear pulse propulsion or laser light sail technology is in development as part of the Breakthrough Starshot program and could dramatically increase humanity’s ability to travel through space. Early missions to Alpha Centauri are likely to be solely for reconnaissance and to deepen our knowledge of planets that exist in the system.

In January 2017, Breakthrough Initiatives began a collaboration with the European Organisation for Astronomical Research in the Southern Hemisphere to search for habitable planets in the Alpha Centauri system. Who knows, maybe a few thousand years from now, humans will have colonized the system in something reminiscent of a science fiction movie.

Alpha Centauri in Popular Culture

Alpha Centauri has played a massive role in works of fiction for decades. It’s featured in countless TV shows, films, and books. The following list are some of the most notable examples.

Film and Television:

Avatar: James Cameron’s blockbuster, Avatar, was set on a fictional habitable moon known as Pandora. Pandora orbited the also fictional gas giant Polyphemus, which in turn orbited Alpha Centauri A.

Lost in Space: Both the TV series and later film adaption of Lost in Space, feature an ill-fated trip to a known habitable planet of Alpha Centauri.

Star Trek: Alpha Centauri has featured in various episodes of Star Trek over the years, from The Original Series, to Deep Space Nine.


Centauri Dawn: This book is the first in a trilogy by Michael Ely that’s based on the 1999 computer game Sid Meier’s Alpha Centauri, and features people attempting to settle on a habitable planet in the system.

Marvel Comics’ Transformers Series: Cybertron, the home planet of the Transformers robots, originally orbited Alpha Centauri. This is before it was thrown out of orbit and sent hurtling through interstellar space.


Phobos is one of the most interesting and thought-provoking discoveries in our Solar system. The largest of the two moons of Mars, this tiny dark-colored body has sparked mystery, intrigue and wild speculation around the scientific community.

Facts and Oddities About Phobos

  • Small Size. Phobos is very tiny, especially compared to its host planet Mars. The diameter of Phobos is only about 14 miles, which means a trip all the way around the moon’s surface would only total about 150 miles.
  • Close Orbit. Phobos orbits very close to Mars. In fact, it is the closest moon orbit in the Solar system at only 3,700 miles from the planet’s surface. For a point of reference, the Earths moon is almost 240,000 miles away.
  • Fast Orbit. Since Phobos travels so close to Mars, it must move very fast to maintain a stable orbit. That high rate of speed causes Phobos to circle Mars three times every day.
  • Decaying Structure. One of the oddities that has caused great discussion among astronomers is the decaying pattern of this moon’s travel. The orbit of Phobos is falling slowly toward the planet, losing altitude at the rate of over half an inch every year. Marks on the surface of Phobos could indicate the weakening of its internal structure, which may eventually break up from the increasing gravitational attraction as it gets closer to Mars.
  • Low Gravity. Phobos is a very low-density moon, and therefore has significantly lower gravity than normal for its size. A 150-pound person on Earth would weigh only around two ounces on Phobos.

How Phobos Was Discovered

Phobos, along with the other, smaller moon Deimos were discovered by American astronomer Asaph Hall in 1877. Many had attempted to locate the moons of Mars, but the ability to see them was often lost in the bright reflection of the planet. Finally, Hall found Deimos and then Phobos in its close orbit to the planet.

Phobos, which means “fear” and Deimos, which means “terror”, were Greek gods and sons of Ares, a god of war and servant of the Roman war god Mars.

Recent Exploration

Mariner 9 was the first satellite placed in orbit over Mars, where it transmitted the first close images of Phobos in 1971. The Viking probes also passed Phobos beginning in 1977 and provided more stunning imagery of the tiny moon. NASA’s Mars rovers Spirit, Opportunity and Curiosity have provided images of the moons as seen from the surface of the planet. Several other excursions have also sent images and further data over the years, and numerous future explorations for Mars and its moons are currently being discussed.

Observation and Speculation

Since the gravity on Phobos is so low, scientists have speculated that it might be used as a landing point for spacecraft prior to exploring the planet itself. The close proximity to the planet’s surface would make exploration easy, and allow for data collection all around the planet due to the fast-moving trajectory of the moon.

During the mid-1900’s, some far-reaching astronomers speculated that due to some irregularities in its structure and the decay of its orbit, Phobos might actually be a hollow, artificial satellite built by Martians and launched above the planet. Scientists from around the world considered this possibility for some time, until the theory was finally discarded.

Hercules-Corona Borealis Great Wall

The Hercules-Corona Borealis Great Wall is the biggest entity in the universe. The object is also named the Great GRB wall. It’s a galactic superstructure that is held together with gravity. It’s estimated to be about 10 billion light-years away, so it’s only been existence about 4 billion years after the Big Bang. For comparison, 10 billion light-years away are 10% of the diameter of the known universe.

The structure contains many billions of galaxies and an estimated 19 Gamma-Ray Bursts.

The Discovery of the Hercules-Corona Borealis Great Wall

In 2013, the Hercules-Corona Borealis Great Wall was discovered by a team of American and Hungarian scientists, led by I. Horvath, Zs. Bagoly, and J. Hakkila. The team was searching for Gamma-Ray bursts. The scientific community has been mapping Gamma-ray Bursts since 1997. Gamma-Ray Bursts are very rare, occurring only once every couple million years.

A Perplexing Discovery

The discovery has caused some confusion in the scientific community. The Hercules-Corona Borealis Great Wall contradicts Albert Einstein’s theory, called the cosmological principle that outlined the limit to the universe being 1.2 billion light-years. The Hercules-Corona Borealis Great Wall is eight times the limit that Albert Einstein proposed for the universe. As a result, the discovery has been dubbed ‘so big it shouldn’t exist.’

In fact, to this day, it’s discovery is sometimes debated, but the discovery team stands behind their claims. While critics wonder, since the structure is so far away if the team made a mistake.

As the structure is so distant, it’s particularly difficult to map it to the full extent or know much about it. However, scientists believe that this structure can give us more details on the universe as a whole.

More Theories Disproven

The structure has caused more than one disruption in the scientific community. As the Hercules-Corona Borealis Great Wall is 10 billion light-years away, it means we see the structure 10 billion years ago. However, the universe is thought to be only 13.8 billion years old. The discovery of this structure seems to imply that the universe is older than we thought. It would take more than the 13.8 billion years for something as large as the Hercules-Corona Borealis Great Wall to form.

One of the scientists who discovered the structure, Istvan Horvath, says he is unsure how the structure could have possibly formed in that amounts of time. This remains a mystery that still needs to be solved.

The Meaning Behind the Name

The team of astronomers that discovered the Hercules-Corona Borealis Great Wall was looking for Gamma-Ray Bursts (GRB) which is why the wall is often called the Great GRB Wall.

Originally, the team of scientists never bothered naming the cluster as they were so focused on proving its existence. The term ‘Hercules-Corona Borealis Great Wall’ was first used by a Filipino teenager on Wikipedia after reading about the discovery in 2013. The name was used to imply it borders the Hercules and Corona Borealis borders.

However, this isn’t quite right as it’s much larger than both of those constellations. The structure also covers from the Bootes constellation to as far as the Gemini constellation. Additionally, the celestial object is more round in shape, as a cluster of galaxies, rather than the long shape of a galaxy wall as the name implies. Still, the name stuck and was picked up later by media outlets.

The Great GRB Wall has been proposed as a new name in later papers and adopted by many in the scientific community.

The IBEX Ribbon

In 2009, NASA’s Interstellar Boundry Explorer (IBEX) was able to create the first map of energetic neutral atoms beyond the solar system. The resulting map was dominated by a large wavy feature that was soon named the IBEX ribbon by scientists. This ribbon is actually a dense stream of neutral particles that are reacting to the magnetic fields and solar winds in the region creating a ribbon pattern. The IBEX ribbon is situated about 9 billion miles from earth. The width and length of the ribbon varies on a constant basis due to the magnetic field and solar winds that move the charged ions and change the density levels.


The IBEX Ribbon was discovered by the IBEX small explorer and the pattern was picked up by a team of scientists at NASA after the initial boundary map created by IBEX. The data was verified by the Voyager 1 and Voyager 2 missions as they passed the ribbon.


The goal of the IBEX was to explore the interactions between the solar winds and interstellar medium at the outer edge of this galaxy. The unexpected discovery of the IBEX ribbon has added scientific importance to the mission. The IBEX has now been sending data about the ribbon and the surrounding solar boundary for over ten years.

The IBEX Ribbon


The original theory on the reason for the existence of the IBEX ribbon in this particular place explains that neutral atoms from beyond the boundary are brought to the area by solar winds. The magnetic fields in the area cause the neutral atoms to be stripped of their electrons and making them become charged ions. The ions are pushed towards the sun in the process causing the ribbon effect that can currently be seen. The issue with this theory is that the models developed by computers using the theory show a much narrower ribbon than can currently be seen.

The current theory adds a key element, the rapid rotation caused by the solar winds and magnetic field has created waves and vibrations in the magnetic field. This has caused the charged ions to become trapped in the region which has increased ion density and resulted in a broader ribbon.


This is a fairly new discovery and has not had any impact on culture or historical events as yet. Currently, the interest in the IBEX ribbon is purely scientific as science hopes to learn more about the boundary of our galaxy and what lies beyond the reaches of our solar system.

Students at Princeton have recently used computer models to discuss the possible origin of the IBEX ribbon. This theory uses the spatial retention model and showed that the size and shape of the ribbon can vary greatly depending on the influx of ions through the heliosphere.


The IBEX ribbon remains a source of great interest to those in the study of astronomy and physics. The ribbon was not expected to exist and we still don’t know the true origin of this phenomenon.

The ribbon has been described as a narrow region on the boundary of our solar system that is 2 to 3 times brighter than anything else in the sky. So far, about 100 papers have been published on the IBEX ribbon and there is still a large amount of data to go through and more to discover.

There are no free photos of the IBEX ribbon currently available as it is not possible to photograph but rather is looked at via computer models and images. This link from NASA has a computer image.


As one of the first celestial bodies discovered via telescope, Europa is one of the most important discoveries in the history of our solar system. Without its discovery in orbit around Jupiter, it’s very possible that it might have taken decades or centuries for humans to discover some of the mysteries about the solar system, instead of finding them out as early as the 17th century.

How Was Europa Discovered?

Europa was first discovered on January 8, 1610, when noted astronomer Galileo Galilei noted four celestial bodies orbiting Jupiter through his telescope. Prior to the discovery of Europa and the other three Galilean moons, it was believed that the earth was at the center of the universe, and all celestial bodies revolved around the earth.

However, Galileo’s discovery proved that the geocentric model had to be false, because the four Galilean moons could not revolve around Jupiter if the earth were indeed at the center of the universe. The presence of these celestial bodies proved that other planets had their own gravitational pull, leading to the acceptance of the heliocentric model of the sun at the center of the universe.

Where Does Europa’s Name Come From?

In Greek mythology, Europa was a Phoenician princess who was abducted by Zeus and taken to the island of Crete. She would eventually become the first queen of Crete as well as one of Zeus’ many brides. As the Romans named the five planets visible with the naked eye after the gods of Roman mythology, Europa made sense as a name for a moon of Jupiter, which was the Roman name for Zeus.

What Is Europa’s Surface Like?

Europa is the smallest of the Galilean moons, and like the earth’s moon, it’s a cold and dark place. The temperature never rises above 260 degrees below zero on the Fahrenheit scale at Europa’s equator, and temperatures can be 100 degrees colder at its poles. As such, Europa is an ice-covered body, which makes it one of the most reflective objects in the solar system. The presence of ice on Europa makes it one of the rare bodies in the solar system where water exists in some form.

Is Life Possible On Europa?

In a word, no. Europa does possess some of the qualities that are necessary for life, such as water. However. Europa’s surface temperature is far too cold for humans to successfully live there without massive technological advances beyond current capabilities. Even if technology were to come far enough to make its surface more hospitable to humans, only part of Europa would ever see any light. The moon is tidally landlocked, so the same part of Europa always faces Jupiter at all times.

What Missions Have Seen Europa?

Europa was first examined up close in 1973 and 1974, during the fly-bys of Pioneer 10 and Pioneer 11. These would be the best images of Europa until 1995, when the Galileo probe went into orbit around Jupiter on an eight-year mission, taking several photos of the moon as well as the other Galilean moons.

As of 2019, two future explorations are planned of Europa’s surface. If all goes as planned, the Europa Clipper is set to make several fly-bys of the Galilean moon while in orbit around Jupiter, beginning in 2023. The Europa Lander plans to go even further, as it would launch in 2025 with the aim of landing on Europa.

With these missions in the pipeline, it’s clear that scientists believe Europa still has several new mysteries waiting to be unlocked, and the newest missions might greatly expand our knowledge of this body.

Orion Nebula: A Star is Born

Orion Nebula

Gaze into the night sky during the winter months, and you’ll spot a blur in the well-known constellation of Orion. It may look like a smudge in the sky, but this dynamic, turbulent cloud of gas and dust—known as the Orion Nebula—gives birth to stars more than eight times the mass of the sun.

Features of the Orion Nebula

Orion Nebula Cluster

The Orion Nebula, also called Messier 42 or M42, is a busy star-forming region only 1,500 light-years away from Earth. To locate the nebula, look beneath the three bright stars that form Orion’s belt. It is a hazy patch midway down Orion’s sword.

This enormous cloud of gas and dust is about 25 lights years wide. It consists primarily of hydrogen, with some helium, oxygen, carbon, and nitrogen. Star formation begins as gravity pulls together bits of dust and gas, creating a clump. As the clump grows, its gravity gets stronger. Eventually, the mass collapses at the center. If enough thermal energy is created, nuclear fusion results and the earliest stage of star formation begins the protostar.

There are about 1,000 stars in the Orion Nebula. Most are younger than 1 million years old, with some as young as 30,000 years. About 700 stars are in different stages of formation.

The nebula gives off a greenish hue, with red and blue-violet regions. Its glow comes from a cluster of its four brightest stars. Forming a trapezoid shape, this star cluster is the heart of the nebula and is called the Trapezium.

Discovery of the Orion Nebula

The nebula was discovered in 1610 by Nicolas-Claude Fabri de Peiresc, who made notes of the nebula in his personal records. The first published observations of the Orion Nebula were made by Swiss astronomer Johann Baptist Cysatus in 1618. Charles Messier added the nebula to his catalog of astronomical objects in 1769.

Recent Research

The Orion Nebula’s proximity to Earth makes it the subject of many studies. Here are some recent findings:

Young Stars May Stop Other Stars from Forming

The stars at the heart of the Orion Nebula create stellar winds that interact with surrounding clouds and create shockwaves. A new discovery suggests that these winds may affect star formation by blowing away the materials needed to produce new stars.

The Nebula Has More Than Stars

The Hubble Space Telescope has discovered protoplanetary disks in the nebula—signs of the earliest stages of solar system formation. Three large planets were also found.

It also identified the largest known population of brown dwarfs mixed in with new stars. Brown dwarfs are intermediate-sized celestial objects, between a star and a planet in size. Unable to generate enough heat to ignite nuclear fusion, they eventually fade away.

A Possible Black Hole

Astronomers often wondered why stars in the Orion Nebula move at a rapid speed. A team of astrophysicists suggests there may be a black hole in the middle of the Trapezium. They created a model showing that as the star cluster drives gas outwards, it propels some stars out of the cluster. Others were driven into the center of the cluster, colliding with a massive star. The star imploded into a black hole with a mass about 200 times larger than the sun.

Additional Reading

Thanks to the Orion Nebula’s proximity to Earth, this dynamic and ever-changing stellar nursery provides us with continual discoveries about the star and planetary formation. Here are additional stories of interest:

Take a Breathtaking Trip Through the Orion Nebula in NASA’s New Video

The Dragon in Orion’s Nebula

Crab Nebula

Crab Nebula

If you’ve ever taken a close look at the Taurus constellation with a telescope, you might have seen a bright, crab-like mass in the constellation, looking much bigger than the typical star. If so, you’ve taken a glance at the Crab Nebula, which astronomers have known about for centuries but have only recently begun to learn about. The Crab Nebula is neither the largest nor the closest nebula that astronomers have spotted, but it is only one of four supernovae that have occurred in the Milky Way over the past millennium, making it an important part of the galaxy.

Who Discovered the Crab Nebula and How Was it Named?

Crab Nebula Supernova

The Earl of Rosse, William Parsons, recreated the nebula in 1840 after looking through a telescope and noting that his observation of the nebula resembled that of a crab. However, Parsons was not the first to discover the nebula. That honor went to John Bevis, an amateur astronomer who found the object in the sky in 1731 and thought it resembled a cloudy blob.

In truth, both of them were likely right with their observation of the nebula. Because the Crab Nebula sits 6,523 light-years away from the earth, the Nebula that we see is actually how the Nebula looked centuries ago. In fact, the Nebula dates all the way back to the year 1054 A.D., when Chinese astronomers noticed a supernova in the Taurus constellation.

Why Can We See the Crab Nebula?

Despite the long distance away from our planet, the Crab Nebula is visible with a telescope because of how massive the nebula is and how bright it shines. From end to end, the nebula is roughly 11 light-years wide, substantially larger than the sun. In turn, the nebula is roughly 75,000 times brighter than the sun, making it possible to see it with a telescope or binoculars, despite it being almost 25,000 times as far away from the earth as Neptune.

How Was the Nebula Connected to the Supernova?

Although the star that created the Crab Nebula exploded in 1054, astronomers were able to figure out the nebula was expanding over time in the 1900s. Through their observations, they were able to track moving particles and noticed that the nebula had grown and changed shape since the first observations of the event. Based on this, scientists were able to trace the nebula’s origins back to the observation of the Chinese based on continued observations of the nebula, further increasing their understanding of the event.

What Sits at the Center of the Nebula?

Crab Nebula

When a star goes supernova, one of two outcomes can happen. The Crab Nebula took the path of becoming a neutron star, otherwise known as a pulsar. The pulsar is a densely packed object that contains most of the neutrons that formed from the supernova, sucked in to the center of the nebula by its immense gravity. The radiation from the pulsar is what gives the Crab Nebula its brilliant appearance and allows us to see it through a telescope.

Will We Ever See It Up Close?

It’s highly improbable. The Crab Nebula’s position of over 6,000 lightyears away means that humans would be millennia away from even beginning to approach the nebula and observing it up close. Science might find a way to observe it in a closer manner tens of thousands of years from now, but current generations will have to be satisfied with long-distance images from the Hubble Telescope.


Named for the Roman God of the sea, Neptune is a bright blue, ice giant planet. It is the eighth planet from the sun, and it sometimes switches places with Pluto, making it even farther away. Although it’s the third most massive planet in our solar system, Neptune is the smallest of the ice giants, and its size and distance from Earth make it impossible to see without a telescope.

Galileo first spotted Neptune in 1613, but he dismissed it as a mere star. The planet’s existence was later predicted after the discovery of Uranus, making it the first planet hypothesized by mathematicians; the prediction was made because Uranus’ orbit contradicted Newtonian law, thus suggesting that another planet must be nearby.

In 1846, Neptune was finally designated a planet after being observed by astronomers Johan Galle and Heinrich Louis d’Arrest. Galle wanted to call the planet Janus. However, Urbain Le Verrier, who had previously predicted Neptune’s location and existence, was responsible for the official name.

Composition and Chaotic Winds

Neptune’s thick atmosphere is made up of helium, hydrogen, and methane. Its winds easily reach speeds of 1,200 to 1,500 miles per hour, making them the fastest winds in the solar system. While the outmost layer is particularly cold, Neptune’s pressure and temperature increases near its core. Currently, scientists don’t believe Neptune’s environment is conducive to Earth-based life.

Neptune is encircled by several dark, thin rings named Adams, Arago, Lassell, Le Verrier, and Galle. A small white cloud called the Scooter (believed to be plumes from the lower atmosphere) also circles Neptune every 16 hours. Like Earth, Neptune likely experiences seasons. However, it takes 165 Earth years to orbit the Sun, meaning that each of its seasons lasts four decades.

Voyager 2 and Great Dark Spots

The Hubble Space Telescope has observed Neptune for several years, but only one space probe has ventured to the planet: Voyager 2. Voyager 2 took photos of Neptune in 1989, and its thanks to these photos that we learned more about Neptune’s moon, Triton; Triton was first discovered in 1846 by William Lassell, about two weeks after Neptune itself was discovered. Thirteen other moons, all named after lesser sea nymphs and gods, also surround Neptune. However, with its nitrogen ice, Triton is by far the most famous. Triton is also known for its retrograde orbit, meaning that its rotation is opposite Neptune’s.

Neptune is famous for its “Great Dark Spot,” which was also first seen in Voyager 2 photos. This spot was giant, and the entire Earth could easily fit inside. But in 1994, to the surprise of scientists, the Dark Spot suddenly disappeared. Even more surprising, a scattering of new dark spots have shown up since. Scientists believe that the constantly disappearing and newly appearing dark spots are due to Neptune’s rapidly changing atmosphere.

Popular Culture

Neptune has been referenced in various works of fiction, including Futurama and the Cthulu Mythos. In western astrology, Neptune is associated with Pisces, spiritualism, and creativity. While we still have a lot to learn about Neptune, it’s already established itself as an important part of our culture and science.

Additional Resources:


As one of the five planets that can be seen with the naked eye, Jupiter’s existence has been well-known since ancient times. However, the largest planet in the solar system provided perhaps the most important discovery in astronomical history in 1610 A.D., when Galileo Galilei first discovered four of the moons that orbit Jupiter. These marked the first discovery of any celestial bodies orbiting another celestial body, as up to that point, it was believed that the earth was at the center of the universe in accordance with Ptolemy’s theory.

However, Galileo’s discovery gave credence to the idea that Nicolas Copernicus’ theory that the sun was actually at the center of the universe, as Jupiter’s four moons (later named Io, Europa, Ganymede and Callisto) did not appear to orbit the earth in any way, shape or form — and, as Galileo reasoned, if those moons didn’t orbit the earth, the planet itself likely didn’t orbit the earth either. Without Galileo’s work in relation to Jupiter, it’s likely that the geocentric model of the universe would have lasted for decades longer, as opposed to gradually fading into the background with new research.

Facts About Jupiter

Jupiter takes its name from the Roman king of the gods, most likely because Jupiter is by far the largest planet in the solar system. Jupiter’s size is truly immense as far as celestial bodies go, as the planet is 11 times the size of the earth and 2.5 times bigger than the other seven true planets in the solar system. In terms of volume, the size difference is even more pronounced, as it would take well over 1,000 earths to match the volume of Jupiter.

Because of its size, Jupiter is the fourth-brightest object in the sky, trailing only the sun, the moon and the planet Venus, which is over 200 million miles closer to the earth than Jupiter when it’s at its closest point and Venus is at its furthest point. By contrast, Mars can be as close as 10 times as close to the earth as Jupiter, but the size difference means that Mars cannot match Jupiter in terms of visibility and brightness.

Discoveries Related to Jupiter

Jupiter has been the subject of several important discoveries since Galileo first discovered the Galilean moons in the 17th century. One of the most important was Robert Hooke’s initial discovery of the Great Red Spot, an anti-cyclonic high pressure system on the planet’s surface. Hooke made his discovery in 1665, and the spot has been monitored consistently since 1830. Astronomers haven’t yet figured out how the spot has sustained itself for so many years, and they might not get a chance to discover the answer. The spot has been shrinking for several years now, and activities on the planet suggest that the spot could be in danger of breaking apart in the not-too-distant future.

Other discoveries of Jupiter include the planet’s ring system, which was discovered by complete accident when the Voyager 1 spacecraft flew by the planet in 1979 and noticed a faint set of rings around Jupiter that nobody had ever seen before. The rings are so faint that they are impossible to see with the naked eye and can only be seen when the sun reflects light off of them, making them very difficult to see with a telescope. Jupiter’s rings were the third planet’s rings to be discovered, after Saturn’s very visible rings and Uranus’ faint rings. Jupiter’s rings are composed of dust coming off of its moons, and the rings can only sustain themselves through more dust coming off of the planet’s many moons.

One of the more recent discoveries concerning Jupiter has been the sheer number of celestial bodies orbiting the planet. For years, astronomers had thought that Jupiter’s moons totaled 16, which would still be the most of any planet in the solar system. However, discoveries from more recent probes of the planet have shown that Jupiter boasts 63 moons, and more could still be discovered.

Jupiter added 11 moons in 2002 alone, and the next seven years saw an additional 22 moons added to its total. Its four most famous moons remain the four original moons that Galileo discovered, and the Galilean moons have made their way into pop culture, with one example being in the Harry Potter universe, where Harry’s astronomy class required him to identify which of Jupiter’s moons was covered in ice, with the answer being Europa.

Probes of Jupiter

As one of the four outer planets and one of the two gas giants along with Saturn, Jupiter does not have a surface that allows for a spacecraft to land there. Because of that, all exploration of the planet must be done either via telescopes or by sending a probe to either conduct a fly-by or to orbit the planet. As of 2019, seven spacecrafts have flown past Jupiter, and the Galileo and Juno shuttles have gone into orbit around the planet. The Juno shuttle entered Jupiter’s orbit in 2016, and is scheduled to orbit the planet until 2021, with two other probes of Jupiter’s moons scheduled to launch in 2022 and beyond.

Of these probes, arguably the most successful was the Galileo probe, which built on the efforts of Voyager 1’s fly-by by examining the rings around the planet, determining that Europa’s ice-covered surface actually has more water than the entire surface of the earth and taking images of the volcanoes on Io. Galileo was also the first successful probe of the atmosphere of Jupiter, giving us some of the first semblances of concrete information about what the surface of the planet is really like.

It’s too early to tell what the Juno probe will discover, but with three more years planned on its mission, it’s likely that scientists will soon have plenty of secrets to examine about Jupiter that will lead to the questions of the future.