Tag: astronomy

Moons are enchanting, and why they may not be, as these celestial bodies have always fascinated humans, especially the scientific community.

Our Earth has one, and even 50 years after landing the first man on the moon, scientists still have a thousand questions about our moon yet to be answered (the dark side particularly).

So what about the moons revolving around other planets in our solar system? Do they intrigue the scientific community too?

Yes, they do, and today we will get to know about Jupiter’s fascinating moons that have been baffling scientists for decades.

Excited? Get on board.

How Many Moons Does Jupiter Have?

According to NASA, Jupiter has 80 moons, out of which 57 have official names given by the IAU or the International Astronomical Union.

These celestial bodies combine to create a satellite system, called the Jovian system. However, scientists are monitoring the planet closely, and we can expect more moons around this gas giant.

Although Jupiter has several unique moons, scientists are especially intrigued by the four giants (Galilean satellites), namely Ganymede, Io, Callisto, and Europa.

 Why? These moons are massive, and scientists would have considered them planets if they orbited around our sun. Simon Marius and Galileo Galilei were the first astronomers to discover them in 1610.

Let us learn more about these massive Jupiter moons.

• Ganymede – The Largest Moon

Ganymede holds the record of being the largest moon present in our solar system. In fact, Ganymede is so massive that it has an independent magnetic field with regions where you can experience northern lights.

Besides having a magnetic field, scientists have also found evidence of oxygen in Ganymede’s atmosphere. However, the oxygen layer is fragile and may not support life.

Ganymede has several terrains that appear after faulting or water release. There are also dark terrains on this moon that may indicate or depict the moon’s crust. Furthermore, these dark regions have multiple craters covered with ice.

Ganymede has a crisscrossed surface that features a collection of new and older terrain. This unique surface structure gives Ganymede its distinctive look and makes it stand out from the rest of the cluster.

• Callisto – The Ugly Duckling

Callisto is the 2^nd largest moon of Jupiter and has the most craters in the entire solar system. This heavily cratered look helped it bag the title ‘ugly duckling’ in the scientific community.

However, there is more than meets the eye, as studies suggest that Callisto may have a salty ocean beneath its surface. In short, there can be life beneath the icy crust of this massive moon, which is why scientists keep a constant eye on this Jupiter moon.

So how wide is the salty ocean? According to estimates, Callisto may be hiding in a massive ocean below its icy surface. Furthermore, studies also indicate that the ocean may reside around 250 kilometers or 155 miles beneath the surface.

Other estimates also suggest that Callisto may have metal and rock mixed with ice, which translates the possibility of supporting living organisms in the salty ocean.

If these estimates come true, we can expect a fleet of controlled satellites heading toward Callisto soon.

• Io – EYE oh

Besides having ice-dominated moons, Jupiter also has a moon with the most volcanic activity in our solar system. Meet the third largest moon of Jupiter, Io, featuring a combination of three different celestial bodies in one.

Io or ‘EYE oh’ is similar to our Earth’s moon and shares a significant similarity. Io orbits Jupiter tidally, meaning Io only faces Jupiter from one side during its orbit.

However, Io has an elliptical orbit, which is the primary reason Io experiences many volcanic activities. The tidal force of the planet puts enormous gravitational effects on Io, causing its surface to erupt throughout its orbit.

In short, there are hundreds of lava fountains and volcanoes that are active on Io that can shoot lava miles high from the surface. You can compare this gravitational pull with Earth’s moon as both run on identical principles.

However, our moon’s gravitational effect is significantly less than Jupiter’s Io and does not harm our planet.

Besides volcanic activity, Io also alters Jupiter’s atmosphere and causes lightning storms in the upper atmosphere. This phenomenon is often experienced when Io is above Jupiter’s magnetic field, transforming the moon into a generator generating electricity.

So is life possible on Io? Although life can thrive in most inhospitable places, scientists believe that the extremity of Io’s atmosphere is not ideal for supporting life.

• Europa

Europa is a fascinating moon in the cluster of Jupiter’s moons, as it may have a watery ocean beneath the icy crust. Scientists had their fascination growing after the Voyager craft provided clues that a massive ocean might be hiding below the surface.

Furthermore, Europa’s icy crust is not as thick as other moons and may have an ocean up to 100 miles deep. If these calculations and estimates are accurate, Europa may be holding more water than Earth, which will undoubtedly allow life to prosper on the moon.

However, Europa is 5.2 AU (Astronomical Units) away from the sun, meaning that the sun’s energy is probably against the odds. So without a significant energy source, life on this celestial body can be a bit challenging.

On the other hand, the Galileo craft witnessed convection on the moon’s surface, including domes and pits. In short, some heat sources can be beneath the surface, which may help life to exist on Europa.

Although humans have a long way to go before we can set foot on this possible exoplanet, we can collect water samples from space and determine whether alien life exists on the moon.

NASA is planning a crucial mission to this moon called the Europa Clipper to conduct a detailed survey of this possible exoplanet.

Final Thought

Jupiter’s moons have different characteristics and have been intriguing researchers for decades. 

Thankfully, modern techniques and advanced equipment have helped the scientific community to understand these moons better, and soon we may have operated spacecraft heading that way.

When anything makes an appearance as bright and dramatic as the Hale-Bopp comet, it forever stays in mind, even if it happened only once in a lifetime. It isn’t surprising why Hale-Bopp is one of the most watched comets. If you don’t already know what comet Hale-Bopp is, here are the facts about this brightest comet that will blow your mind.

What Is Hale-Bopp?

Hale-Bopp is a comet that falls under the category of long-period comets. Compared with short-period comets, these groups of comets are comparatively less predictable because of their elliptical orbits. Hale-Bopp is a bright comet with blue and white tails. 

As per a study by the Swinburne University of Technology, Hale-Bopp has an orbital duration of more than 200 years. This strikingly bright comet came closest to earth in 1997 and remained visible for 18 months. Its majestic brightness was most visible in the Northern Hemisphere. 

How Was Hale-Bopp Discovered?

The discovery of Hale-Bopp is two-fold. Both the independent discoveries were made by amateur astronomers Thomas Bopp in Arizona and Alan Hale in New Mexico. And this is where the comet earned its name. NASA had recorded this phenomenal discovery as the farthest comet to be found by amateurs when it was discovered. 

The discovery of the Hale-Bopp comet by the two astronomers took place on July 23, 1995, independently near spherical cluster M70. It was a surprising discovery because it seemed to have suddenly appeared in the spot where it hadn’t been two weeks ago. 

Alan Hale has a doctorate in astronomy. When he trained his telescope to the M70 area, he was amazed to see a foreign dot that hadn’t been there a couple of weeks ago when he looked. Hale believed that the object was a comet when he discovered its movement after checking back after some hours. 

Incidentally, Thomas Bopp also discovered the same comet, and both men reported their findings to the International Astronomical Union’s Central Bureau for Astronomical Telegrams. 

The newly-identified comet was named C/1995 O1 and intrigued every astronomer with its bright emission even at a great distance. As a long-period comet, it’s hard for astronomers to predict Hale-Bopp, which is essentially just a ball of dust and ice. 

The Origin Of Hale-Bopp Comet

It isn’t quite clear how Hale-Bopp originated. But most research concluded that Hale-Bopp has its origin in the Oort Cloud, like other long-period comets. 

Oort Cloud is a globular collection of ice particles whose position lies at an approximate distance of 2000 to 1000000 Astronomical Units (AU) from the sun.

An Astronomical Unit is a unit used to measure the distance between the sun and the earth. One AU equals 150 million kilometers which is the estimated distance between the earth and the sun. 

Because of the distant position of the Oort Cloud from the sun, the objects in it are prone to gravitational turmoil. So, even the slightest forces can unhinge the objects in the Oort Cloud and send them to an elliptical orbit that revolves around the sun. 

Hale-Bopp: The Comet That Leaves An Impression

Every time something as remarkable as the appearance of Hale-Bopp happens, the tabloids get full. Hale-Bopp incited the interests of the public, and it was apparent on both the internet and in newspapers. 

It wasn’t long before some professionalism was put into the survey. Using the Hubble Space Telescope, NASA reported that Hale-Bopp is a gigantic comet with a diameter that spans 30-50 km. 

There aren’t many other significant comets that have garnered the same attention and views as Hale-Bopp. The comet features an absolute magnitude of -1 which means that it is one of the brightest heavenly bodies to orbit the inner solar system. 

In comparison, the luminosity of Halley’s comet is nothing compared to the brightness of the Hale-Bopp comet. Speculating the brightness from the same distance, the latter is 1000 times more luminous than Halley’s comet. 

Hale-Bopp And The Heaven’s Gate Cult Tragedy

The appearance of Hale-Bopp is revolutionary. Not only did it create mass fascination in space and heavenly bodies, but it is also linked with a tragic incident related to the Heaven’s Gate cult. This refers to the mass suicide of 39 members of the cult in San Diego as the comet passed across the earth. 

Heaven’s Gate was a religious cult led by Marshall Applewhite. The cult members follow the belief that their bodies are like vessels that could be abandoned for a higher purpose of the soul and spirit. The tragedy was doomed to happen when the cult started believing that Hale-Bopp didn’t appear alone. They believed that the comet was followed by an alien spacecraft. 

NASA reports that March 22, 1997, is the day when Hale-Bopp came the closest to earth. The mass suicide happened around the time when the comet was closest. But how did it happen? The short answer is poison. 

Marshall Applewhite, along with 38 other members, 17 men, and 21 women, took their own lives believing that the appearance of the comet was a cosmic sign calling them to leave their bodies behind so that their souls could embark on the ghost alien spacecraft for a new life. 

The incident took place in San Diego, and the dead bodies wearing matching clothes were found in bunk beds in a mansion. The members consumed a deadly mixture of vodka and Phenobarbital to die and prepare their souls to be transported to what they believed Hale-Bopp is bringing along with it.

Will We See Hale-Bopp In The Skies Again?

Not likely. At least not in our time. The latest appearance of Hale-Bopp on earth’s sky was in 1997. Before that, it appeared once about 4200 years ago. So this means that it will be thousands of years until the comet makes another appearance. 

According to estimates, this comet isn’t set to return to earth’s sphere until 4385. This large active comet has an approximate diameter of 40 km with a speed of 1.2 billion miles in four years. 

A good number of amateur astronauts have discovered foreign objects in space. But with more and more spacecraft and satellites emerging, such as the Solar and Heliospheric Observatory (SOHO), the detection of unfamiliar objects has become relatively more relaxed.