Eclipse Newsletter

ECLIPSE NEWSLETTER

The Eclipse Newsletter is dedicated to increasing the knowledge of Astronomy, Astrophysics, Cosmology and related subjects.

VOLUME 3 - NUMBER 4 JULY – AUGUST 2019

PLEASE SEND ALL PHOTOS, QUESTIONS AND REQUST FOR ARTICLES TO [email protected]

ALL PREVIOUS ISSUES OF ECLIPSE CAN BE FOUND AT

mountcuba.org

SPECIAL NOTE.

LOTS OF NEW AND EXCITING THINGS HAPPENING AT MOUNT CUBA ASTRONOMICAL OBSERVATORY. PLEASE VISIT THEIR SITE. YOU MAY EVEN FIND A MEMBERSHIP WOULD BE A GOOD IDEA.

CONTENTS:

SOMBRERO GALAXY – M104 DO GALAXIES COLLIDE AND WHAT HAPPENS IF THEY DO? Milky Way Versus Andromeda As Seen from Earth

WHAT IS THE LIFECYCLE OF A STAR? PART 4.

ARE WE MADE OF STAR DUST?

SOME FAMIOUS PHOTOS FROM HUBBLE.

GET RICH QUICK? PSYCHE 16.

METEOR SHOWERS FOR JULY AND AUGUST.

THOSE INTERESTING METEOR.

SATURN’S MOON ENCELADUS COULD SUPPORT LIFE.

If you see text in green, my hope is you will do some research. I will continue to use hyperlinks. Just swipe, right click, open hyperlink.

Hyperlinks are in Blue.

THE SOMBERO GALAXY – M104

Why does the Sombrero Galaxy look like a hat? Reasons include the Sombrero's unusually large and extended central bulge of stars, and dark prominent dust lanes that appear in a disk that we see nearly edge-on. Billions of old stars cause the diffuse glow of the extended central bulge. Close inspection of the bulge in the above photograph shows many points of light that are actually globular clusters.

The spectacular dust rings harbor many younger and brighter stars, and show intricate details astronomers don't yet fully understand. The very center of the Sombrero is thought to house a large black hole. Fifty million-year-old light from the Sombrero Galaxy can be seen with a small telescope towards the constellation of Virgo.

Sombrero Galaxy Profile

Constellation: Virgo

Also known as: Messier Object 104, M104 or NGC 4594

Type: Spiral Galaxy

Diameter: 50,000 light years

Distance: 29 light years

Mass: 800 billion M☉ Number of Stars: 100+ billion

Interesting facts. One of the minor characters from the Superman comics is “Vartox.” He describes himself as coming from the planet Valeron in the “Sombrero Hat” Galaxy. The 1960’s television show “The Outer Limits” included a picture of the Sombrero Galaxy at the end of each show in its credits. Both the Milky Way and Sombrero Galaxies have globular clusters that are believed to be between 10 and 13 billion years old. The Sombrero Galaxy has up to 2,000 globular clusters at its core, which is around 10 times that of the Milky Way Galaxy. Using both the Hubble Space Telescope and the Spitzer Space Telescope, NASA has been studying the Sombrero Galaxy in both visible and infrared light. Until 1912, astronomers thought that the Sombrero Galaxy was a spiral nebula inside the Milky Way. Vesto Slipher, an American astronomer worked at the Lowell Observatory and proved that the Sombrero was a galaxy outside of the Milky Way. Slipher’s studies also proved that the Sombrero Galaxy was moving away from the Milky Way Galaxy and this was the first recognition of the expansion of the universe.

There are over 7 billion people on Earth. Researchers have estimated that the Sombrero Galaxy contains a minimum of 100 stars for each person on Earth. The “broad rim” of the hat shape is where the Sombrero has its dust lane that is made up of dust and hydrogen gas. The Sombrero dust lane contains almost all of the galaxy’s molecular cold gas and is thought to be the main site where its stars are created. Unlike some galaxies, researchers think that there aren’t many stars that form inside the Sombrero Galaxy’s nucleus. The Sombrero Galaxy is different in that it has characteristics of both elliptical and spiral galaxies in its appearance. Scientists speculated that the appearance of the Sombrero Galaxy looked like a spiral galaxy was swallowed by an elliptical galaxy. This would be impossible as it would destroy the spiral galaxy. Scientists now speculate that the shape of the Sombrero Galaxy is a large elliptical galaxy is due to 9 million years ago when a large elliptical galaxy accumulated a lot of gas clouds that flattened out to form the shape of a spiral galaxy.

DO GALAXIES COLLIDE AND WHAT HAPPENS IF THEY DO?

This illustration shows the merging of the Milky Way and the Andromeda Galaxies.

We don't want to scare you, but our own Milky Way is on a collision course with Andromeda, the closest spiral galaxy to our own. At some point during the next few billion years, our galaxy and Andromeda – which also happen to be the two largest galaxies in the Local Group – are going to come together, and with catastrophic consequences.

Stars will be thrown out of the galaxy; others will be destroyed as they crash into the merging supermassive black holes. And the delicate spiral structure of both galaxies will be destroyed as they become a single, giant, elliptical galaxy. But as cataclysmic as this sounds, this sort of process is actually a natural part of galactic evolution.

Astronomers have known about this impending collision for some time. This is based on the direction and speed of our galaxy and Andromeda's. But more importantly, when astronomers look out into the universe, they see galaxy collisions happening on a regular basis.

Gravitational Collisions:

Galaxies are held together by mutual gravity and orbit around a common center. Interactions between galaxies is quite common, especially between giant and satellite galaxies. This is often the result of a galaxies drifting too close to one another, to the point where the gravity of the satellite galaxy will attract one of the giant galaxy's primary spiral arms.

In other cases, the path of the satellite galaxy may cause it to intersect with the giant galaxy. Collisions may lead to mergers, assuming that neither galaxy has enough momentum to keep going after the collision has taken place. If one of the colliding galaxies is much larger than the other, it will remain largely intact and retain its shape, while the smaller galaxy will be stripped apart and become part of the larger galaxy.

Such collisions are relatively common, and Andromeda is believed to have collided with at least one other galaxy in the past. Several dwarf galaxies (such as the Sagittarius Dwarf Spheroidal Galaxy) are currently colliding with the Milky Way and merging with it.

However, the word collision is a bit of a misnomer, since the extremely tenuous distribution of matter in galaxies means that actual collisions between stars or planets is extremely unlikely.

Andromeda–Milky Way Collision:

In 1929, Edwin Hubble revealed observational evidence which showed that distant galaxies were moving away from the Milky Way. This led him to create Hubble's Law, which states that a galaxy's distance and velocity can be determined by measuring its redshift – i.e. a phenomena where an object's light is shifted toward the red end of the spectrum when it is moving away.

However, spectrographic measurements performed on the light coming from Andromeda showed that its light was shifted towards the blue end of the spectrum (aka. blueshift). This indicated that unlike most galaxies that have been observed since the early 20th century, Andromeda is moving towards us.

In 2012, researchers determined that a collision between the Milky Way and the Andromeda Galaxy was sure to happen, based on Hubble data that tracked the motions of Andromeda from 2002 to 2010. Based on measurements of its blueshift, it is estimated that Andromeda is approaching our galaxy at a rate of about 110 km/second (68 mi/s).

At this rate, it will likely collide with the Milky Way in around 4 billion years. These studies also suggest that M33, the Triangulum Galaxy – the third largest and brightest galaxy of the Local Group – will participate in this event as well. In all likelihood, it will end up in orbit around the Milky Way and Andromeda, then collide with the merger remnant at a later date.

Consequences: In a galaxy collision, large galaxies absorb smaller galaxies entirely, tearing them apart and incorporating their stars. But when the galaxies are similar in size – like the Milky Way and Andromeda – the close encounter destroys the spiral structure entirely. The two groups of stars eventually become a giant elliptical galaxy with no discernible spiral structure.

Such interactions can also trigger a small amount of star formation. When the galaxies collide, it causes vast clouds of hydrogen to collect and become compressed, which can trigger a series of gravitational collapses. A galaxy collision also causes a galaxy to age prematurely, since much of its gas is converted into stars.

After this period of rampant star formation, galaxies run out of fuel. The youngest hottest stars detonate as supernovae, and all that's left are the older, cooler red stars with much longer lives. This is why giant elliptical galaxies, the results of galaxy collisions, have so many old red stars and very little active star formation.

Despite the Andromeda Galaxy containing about 1 trillion stars and the Milky Way containing about 300 billion, the chance of even two stars colliding is negligible because of the huge distances between them. However, both galaxies contain central supermassive black holes, which will converge near the center of the newly-formed galaxy.

This black hole merger will cause orbital energy to be transferred to stars, which will be moved to higher orbits over the course of millions of years. When the two black holes come within a light year of one another, they will emit gravitational waves that will radiate further orbital energy, until they merge completely.

Gas taken up by the combined black hole could create a luminous quasar or an active nucleus to form at the center of the galaxy. And last, the effects of a black hole merger

7 could also kick stars out of the larger galaxy, resulting in hypervelocity rogue stars that could even carry their planets with them.

Today, it is understood that galactic collisions are a common feature in our universe. Astronomy now frequently simulate them on computers, which realistically simulate the physics involved – including gravitational forces, gas dissipation phenomena, star formation, and feedback.

LIFE CYCLE OF A STAR. PART 4 ASHES TO ASHES DUST TO DUST.

For the benefit of those new to the Eclipse Newsletter. let’s have a review before we get to the final phase.

Stars such as the sun are large balls of plasma that inevitably fill the space around them with light and heat. Stars come in a variety of masses, and mass determines how hot the star will burn and how it will die. Heavy stars turn into supernovae, neutron stars and black holes whereas average stars like the sun end life as a white dwarf surrounded by a disappearing planetary nebula. All stars, however, follow roughly the same basic seven- stage life cycle, starting as a gas cloud and ending as a star remnant.

A Giant Gas Cloud

A star begins life as a large cloud of gas. The temperature inside the cloud is low enough for molecules to form. Some of the molecules, such as hydrogen, light up and allow astronomers to see them in space. The Orion Cloud Complex in the Orion system serves as a nearby example of a star in this stage of life.

A Protostar Is a Baby Star

As the gas particles in the molecular cloud run into each other, heat energy is created, which allows a warm clump of molecules to form in the gas cloud. This clump is referred to as a Protostar. Since Protostars are warmer than other material in the molecule cloud, these formations can be seen with infrared vision. Depending on the size of the molecule cloud, several Protostars can form into one cloud.

The T-Tauri Phase

In the next stage, T-Tauri stage, a young star begins to produce strong winds, which push away the surrounding gas and molecules. This allows the forming star to become visible for the first time. Scientists can spot a star in the T-Tauri stage without the help infrared or radio waves.

Main Sequence Stars

Eventually, the young star reaches hydrostatic equilibrium, in which its gravity compression is balanced by its outward pressure, giving it a solid shape. The star then becomes a main sequence star. It will spend 90 percent of its life in this stage, fusing hydrogen molecules and forming helium in its core. The sun of our solar system is currently in its main sequence phase.

Expansion into Red Giant

Once all of the hydrogen in the star's core is converted to helium, the core collapses on itself, causing the star to expand. As it expands, it first becomes a sub-giant star, then a red giant. Red giants have cooler surfaces than main sequence stars; and because of this, they will appear red rather than yellow. If the star is massive enough, it can become large enough to be classified as a supergiant.

Fusion of Heavier Elements

As it expands, the star begins fusing helium molecules in its core, and the energy of this reaction prevents the core from collapsing. Once helium fusion ends, the core shrinks, and the star begins fusing carbon. This process repeats until iron begins appearing in the core. Iron fusion absorbs energy, so the presence of iron causes the core to collapse. If the star is massive enough, the implosion creates a supernova. Smaller stars like the sun

contract peacefully into white dwarfs while their outer shells radiate away as planetary nebulae.

Supernovae and Planetary Nebulae

A supernova explosion is one of the brightest events in the universe. Most of the star's material is blown into the space, but the core implodes rapidly into a neutron star or a singularity known a s a black hole. Less massive stars don't explode like this. Their cores contract into tiny, hot stars called white dwarfs while the outer material drifts away. Stars smaller than the sun don't have enough mass to burn with anything but a red glow during their main sequence. These red dwarves, which are difficult to spot but which may be the most common stars out there, can burn for trillions of years. Astronomers suspect that some red dwarves have been in their main sequence since shortly after the Big Bang

In the May – June issue, I left off with the following.

In the end, we are left with an old Solar System, where little is left of the inner planets. It is likely that anything within the orbit of the Earth will have been swallowed by the Sun as it expanded through the red giant phase. Although the future white dwarf Solar System will seem very alien to present day, some things won’t change. Jupiter’s orbit might have receded with the drop in solar mass, it will remain a planetary heavyweight, causing disruption in asteroid orbits. Using known asteroid data, the motion of these chunks of rocks are allowed to evolve, and over millions of years, they may get thrown out of the Solar System, or more interestingly, pushed closer to the white dwarf. Once the whole system has settled down, resonances in the asteroid belt will become amplified; Kirkwood Gaps (caused by gravitational resonance with Jupiter) will widen, and according to Deus simulations, the edges of these gaps will become perturbed even more, making more asteroids available to be tidally disrupted and shredded to dust. Remember? Ashes to ashes? Dust to dust?

Let’s try to put it all together in one statement. A supernova is the death of a massive star.

Stars exist on a delicate balance between their gravity trying to crush them and the radiative force from the fusion in the core trying to expand apart. When a star fuses all the hydrogen in its core, it will start to fuse helium, then beryllium, and so on and so on until it starts to fuse iron. Iron fusion actually removes energy from the surroundings, meaning the outward pressure of the core ceases. Gravity takes over, pulling the outer layers of the star in.

At this point, temperatures and pressure in the core spike to incredible levels, causing a massive shock wave to blast the outer layers of the star into space at near light speed. The temperatures and pressures are so great that every natural element is forged and subsequently scattered in the explosion.

As for the core, its fate depends on the size of the star. Some cores collapse into neutron stars, very dense bodies made entirely of neutrons. The biggest stars' cores get compressed

even further, crushing matter into one mind-boggling point: a singularity, the heart of a black hole.

Supernova create some of the weirdest objects in the universe, but they seed the next generation of stars. The outer layers that get ejected in the supernova form a nebula, the cradle of stars and planets. They also scatter the heavier elements necessary for life into the universe. You, me, and every living thing on Earth per our existence to supernova.

SO, ARE WE MADE OF STAR DUST?

Many of the more common elements were made through nuclear fusion in the cores of stars, but many of the rarer elements were not. Because nuclear fusion reactions that make elements heavier than iron require more energy than they give off, such reactions do not occur under stable conditions in typical stars. On the other hand, supernovae are not stable, so they can make these heavy elements beyond iron.

In addition to making elements, supernovae scatter the elements that are made by both the star and supernova out into the interstellar medium. These are the elements that make up stars, planets and everything on Earth, including our bodies.

TWO FAMOUS PHOTOS FROM HUBBLE

THE PILLARS OF CREATION

THE BUTTERFLY NEBULA

GET RICH QUICK? NASA headed towards giant golden asteroid that could make everyone on Earth a billionaire. NASA is eyeing up a nearby asteroid that contains enough gold to make everyone on Earth a billionaire.

Psyche 16 is nestled between the orbits of Mars and Jupiter and is made of solid metal.

As well as gold, the mysterious object is loaded with heaps of platinum, iron and nickel.

That means if we carried it back to Earth, it would destroy commodity prices and cause the world's economy – worth $75.5 trillion – to collapse.

We've known about Psyche 16 for a while, but its potential to cause havoc on Earth was recently touched upon by a veteran miner.

Scott Moore, who heads up Euro Sun Mining, said the sheer amount of gold in the asteroid threatens to throw the gold industry into chaos.

"The 'Titans of Gold' now control hundreds of the best-producing properties around the world," he told Oil Price.

"But the 4-5 million ounces of gold they bring to the market every year pales in comparison to the conquests available in space."

Nasa is launching a mission to probe the asteroid in summer 2022. Dubbed the Discovery Mission, it will arrive at Psyche 16 around 2026.

But bringing back an asteroid of this value could completely wipe out our global economy.

Fortunately, the space agency is taking the trip for scientific purposes and isn't planning on conducting any mining.

It reckons 16 Psyche is a survivor of violent hit-and-run collisions between planets which were common when the solar system was forming.

That means it could tell us how Earth’s core and the cores of the other terrestrial planets were formed.

Two space mining companies – backed by big name celebs – are gearing up for a gold rush after asteroid ownership was made legal in 2015.

Deep Space Industries and Planetary Resources each have their eyes on the 2011 UW158 asteroid which is twice the size of the Tower of London and worth up to $5.7 trillion.

METEOR SHOWERS FOR JULY AND AUGUST.

Delta Aquarids Meteor Shower (July 28) Of all astronomical events, meteor showers are the closest to home: We spot meteors as they burn up in Earth’s upper atmosphere less than 100 miles above the ground. At the same time, the Delta Aquarid meteor shower is made up of visitors from the outer solar system, specks of dust and gravel associated with comets Marsden and Kracht. (The meteors are unrelated to the star Delta Aquarii.) The meteor shower takes place each year when Earth’s orbit intersects the orbit of the comets. The shower is spread over several nights, but peaks on the night of the 28th (actually after midnight, on the early morning of the 29th). Best seen in dark skies; expect to see about 20 meteor flashes an hour.

Perseids Meteor Shower (August 12) Unlike the fairly subtle Delta Aquarids, the Perseids are among the most dramatic meteor showers. They can be seen over a week or so, peaking on the night of the 12th. As Sea and Sky notes, the Perseid shower can produce about 60 meteors an hour — an average of one every minute or so — and is also known for bright meteors. A nearly full moon will tend to drown out the fainter meteors, but the bright ones should still put on a good show. THOSE INTERESTING METEORS.

When you look up at the night sky from a dark location, what do you see? On average, you can expect to see perhaps seven meteors per hour and considerably more during a meteor shower. What you’re actually witnessing is the fiery descent of a small particle through the Earth’s atmosphere. Most meteors simply burn up in the atmosphere, but some survive to strike the Earth as meteorites. By finding these space rocks and analyzing their composition, we’ve learned a great deal about the origins of the Earth and the evolution of the solar system.

Meteor Facts: What’s in a Name?

The terms meteor, meteorite, meteoroid, micrometeoroid and asteroid all refer to space rocks in one form or another. What’s the difference between them? Meteoroids and micrometeoroids refer to the vast number of relatively small rocks and particles in orbit around the sun. If a meteoroid encounters the Earth’s atmosphere and vaporizes, the visible trail we see in the sky is referred to as a meteor. They are sometimes called falling stars or shooting stars, though they aren’t stars at all. Sometimes a meteor survives its fiery descent and strikes the ground. Meteors that have hit Earth are referred to as meteorites. There are also fireballs and bolides, which refer to very bright meteors that often explode as they descend.

What’s the difference between meteoroids and asteroids? It’s largely a matter of size but not all that well-defined. According to the American Meteor Society, the vast majority of meteoroids range in size from small pebbles down to a grain of sand. Micrometeoroids are dust-sized particles. The largest meteoroids are those space rocks up to one meter or perhaps several meters in size. Anything larger is generally considered an asteroid. Asteroids can be as large as hundreds of kilometers in diameter. The largest, such as Ceres at about 952 km (592 miles) in diameter, are considered dwarf planets.

Meteor’s and the Earth’s Origins Most meteorites appear to come from large asteroids that broke up, or never completely formed, billions of years ago. Studying them helps scientists understand the processes taking place deep inside the Earth. Although the center of the Earth has never been directly seen or examined, meteorite studies have enabled us to determine that the Earth’s core is composed mostly of nickel and iron metal. This is true for the other planets as well. When the Earth was in the process of being formed and still molten, the metals sank to the center while the lighter materials formed the mantle and rocky crust on the exterior.

Evolution of the Solar System The scientific study of meteors that have hit Earth, or meteorites, is crucial to the understanding of the solar system’s history and origin. Researchers have determined the age of certain ancient meteorite materials and have used that to establish the age of the solar system to be almost 4.6 billion years. The study of these primitive meteorites has yielded clues to the conditions present during planetary formation, as well as the composition and proportion of elements present in the entire solar system. This kind of information supports the process of mission planning for asteroid visits and will ultimately help identify the resources necessary to enable human spacefaring into the solar system.

What Have We Learned? According to National Geographic, approximately 50 tons of space debris falls onto the Earth’s surface every day. The vast majority of these particles are dust-sized micrometeorites. Occasionally, meteorites as large as boulders strike the Earth and a few impressive examples have survived the impact event and have been found intact. The largest of these is the Hoba meteorite in Namibia, discovered in 1920. This 54,000 kilogram-monster is too large to move. Other large meteorites are mostly destroyed on impact, leaving behind huge craters such as the Barringer Meteorite Crater near Winslow, Arizona. Here’s a case where the distinction between asteroids and meteorites is somewhat blurred. The object that created the Barringer Meteorite Crater about 50,000 years ago was a nickel-iron meteorite about 50 meters across that massed about 270,000 metric tons. This huge rock is clearly large enough to be considered an asteroid but is still commonly referred to as a meteorite. Of course, there have been actual asteroid strikes in the distant past, such as the 10 kilometer, more than 6 miles in diameter, asteroid that formed the Chicxulub Crater in Yucatan, Mexico. Chicxulub is one of the largest impact craters ever discovered on the Earth. That violent event is believed to have triggered the extinction of the dinosaurs and other animal and plant life some 65 million years ago.

SATURN’S MOON ENCELADUS COULD SUPPORT LIFE.

With its global ocean, unique chemistry and internal heat, Enceladus has become a promising lead in our search for worlds where life could exist.

Speaking with Live Science, Neveu said he was surprised when the Cassini spacecraft had discovered an ocean on Enceladus, given its size. "It's a very tiny moon and, in general, you expect tiny things to not be very active [but rather] like a dead block of rock and ice," he told the news outlet. Fifty simulations were created using data from the Cassini spacecraft, which intentionally plunged itself into Saturn's atmosphere in September 2017. However, there was some guesswork that led Neveu and co-author Alyssa Rhoden to estimate the age of Enceladus' ocean, which was based on a single simulation, one that best replicated the conditions seen on the celestial satellite, Live Science added. Additional research is needed to make the simulation faster and get a more precise date for the exact age of Enceladus' ocean.

Neveu's study was published in April in the scientific journal, Nature Astronomy.

The prospect for life on Enceladus has been raised before, including by NASA in 2017. The space agency found the presence of hydrogen in its atmosphere, something Linda Spilker, Cassini project scientist at NASA’s Jet Propulsion Laboratory, said at the time could be meaningful. "It could be a potential source for energy from any microbes," Spilker said at the time. "We now know that Enceladus has almost all of the ingredients you would need for life here on Earth."

In the 2017 announcement, Thomas Zurbuchen, associate administrator for NASA's Science Mission Directorate, said these findings were the closest the space agency had come at the time "to identifying a place with some of the ingredients needed for a habitable environment,” adding that NASA's missions "are getting us closer to answering whether we are indeed alone or not.” Complex organic molecules were discovered on Enceladus in 2018, which scientists said are the "building blocks" for life. Cassini was launched in 1997 at a total cost of $3.9 billion ($2.5 billion in pre-launch costs and $1.4 billion in post-launch) and spent 13 years circling, studying and taking data of Saturn and its moons, including Titan, Saturn's largest moon, which may also be home to extraterrestrial life.

BE SURE TO CHECK OUT THE PUBLIC NIGHTS, FAMILY NIGHTS AND EVENTS AT mountcuba.org FOR STAR PARTIES, CHECK THE HOME PAGE OF THE DAS FOUND ON THE mountcuba.org WEB SITE.