Not the Ordinary “All You Need to Know About Meteors”

The word ‘meteor’ is derived from the Greek language and is translated to mean ‘suspended in the air’.  But what exactly are they?

Astronomy defines a meteor as a meteoroid that enters planet Earth’s atmosphere. These meteors can be composed of a combination of rock and various metals. Have you ever chanced upon a shooting star? Yup, that’s a meteor for you right there!

Wait! Now what’s a Meteoroid? It’s a small body of rock wandering in outer space. Now back to the meteors.

Did you know that the Earth’s atmosphere is penetrated by millions of meteors every day?

We bet you didn’t. Just like you might not know the most fascinating facts about meteors that we’re about to list down for you.

When we say small, we mean that a meteor can range in size anywhere between being as small as a grain of sand and as big as a baseball. If they’re less than 2mm in diameter they’re called a micrometeorite. Normally, most meteors range around the size of an average pebble, a baseball is as big as they get. If they grow bigger than 10m in diameter, they’re outcast as an asteroid!

It is believed that the extinction of dinosaurs was caused by an 8-mile meteor that hit the Earth and caused a dust cloud that altered the climate dinosaurs were conditioned for. Well if that’s true, we know who’s to blame for the fact that we don’t have dinosaurs anymore!

Astronomers believe that every year there are around 500 meteorites that manage to reach the surface of the Earth. However, out of these hardly five or six are recovered for the scientists to study. Why? That’s because most meteors drop in the ocean – can’t blame them for the Earth’s surface being composed of 71% water. What happens to the rest of them? They burn up in the atmosphere of our planet!

When they burn, some meteors burn brighter than the norm – they are called fireballs. Fireballs give off different hues when they burn, depending on their metallic composition. You can consider yourself lucky if you can spot a fireball, because they usually occur during daytime (where the sun blinds their sighting) or over the ocean.

Ever heard about a meteor shower? It’s a short time frame where millions of meteors appear on the sky. Meteor showers occur as an aftermath of a broken comet. There are two that occur every year. The Geminids can be witnessed in December, and the Perseids can be seen in August. Keep a look out for when they might be occurring this year around.

Oh, and before you even think about it, if you ever come across one, it’s absolutely illegal to trade a meteorite in South Africa. Don’t say we didn’t warn you!

By the way, did you know that a study conducted in 1985 declared that a human being is bound to be hit by a meteorite once in every 180 years? The first and only known victim of a meteorite hit was Ann Hodges of Alabama. The meteorite hit her in her home back in 1954. Guess we’ll have to wait around till the year 2134 to find out how true the 1985 study was.

But then again, will the world still exist by then? Who knows!

Earth – Third Rock from the Sun

Located nearly 93 million miles, or 1 Astronomical Unit (AU) away from the Sun, the planet Earth is the largest of the terrestrial planets—or the four rocky planets closest to the Sun in our solar system. (The rest are gas giants).

Earth is the only planet in our solar system that is not named after Greek and Roman gods and goddesses. The name Earth is at least 1,000 years old and is an English/German word that simply means ground.

It takes roughly 24 hours for the Earth to complete a full rotation, but that is gradually slowing. This deceleration is almost imperceptible, but has the effect of lengthening our days. It is happening so slowly, though, that it could be 140 million years before the length of a day increases to 25 hours.

The first photo of Earth from space was taken on October 24, 1946, by a V-2 test rocket launched from New Mexico. From there, we turned our attention to the closest body in our solar system: the Moon.

While the Moon, Earth’s only natural satellite, is only the fifth largest in our solar system, in terms of percentage of the size of the body it orbits, the Moon is the largest satellite of any planet in our solar system.

Astronomers hypothesize that the Moon was formed 4.5 billion years ago, not long after Earth, from the debris left over after a giant impact between Earth and a Mars-sized body.

The first unmanned spacecraft to reach the Moon was one from the Soviet Union’s Luna program in 1959, and the first manned lunar landing being Apollo 11 in 1969. The last manned spacecraft was Apollo 17 in 1972, and since then, the Moon has only been visited by unmanned spacecraft.

NASA started to plan to resume manned missions for the construction of a lunar base by 2024, but the program was cancelled in favor of a manned asteroid landing by 2025 and a manned Mars orbit by 2035.

Using Gravitational Waves to Understand the Origins of Supermassive Black Holes

Supermassive Black HoleA computer simulation of the Universe could help identify the origins of supermassive black holes. The research, led by scientists at Durham University’s Institute for Computational Cosmology in the United Kingdom, was presented at the Royal Astronomical Society’s National Astronomy Meeting.

Gravitational Simulations

The researchers ran cosmological simulations to predict the rate at which gravitational waves caused by collisions between supermassive black holes might be detected. The first black holes were formed 13 billion years ago and capturing these gravitational waves could provide clues about what caused these monster black holes and where they formed.

“By combining the detection of gravitational waves with simulations we could ultimately work out when and how the first seeds of supermassive black holes formed,” lead author Jaime Salcido, a PhD student, said in a statement.

Detecting gravitational Signals in Space

The study combined simulations from a project aiming to create a realistic representation of the known Universe inside a computer, with a model to calculate gravitational wave signals. Scientists are working on the Evolved Laser Interferometer Space Antenna (eLISA) detector, which is expected to detect gravitational waves caused by collisions between supermassive black holes. The instrument will be launched into space in 2034. eLISA could help pinpoint the mechanism that created these massive black holes and when they first formed.

“Black holes are fundamental to galaxy formation and are thought to sit at the center of most galaxies, including our very own Milky Way,” said co-author Professor Richard Bower. “Discovering how they came to be where they are is one of the unsolved problems of cosmology and astronomy.”

There are currently ground-based instruments that work similar to eLISA, but eLISA will be in space and at least 250,000 times larger than ground-based detectors. As such, eLISA should be able to detect lower frequency gravitational waves.

Gravitational waves were first predicted by Albert Einstein 100 years ago. They are concentric ripples caused by events in the universe that squeeze and stretch the fabric of space time. Most gravitational waves cannot be detected because they are weak.

“Understanding more about gravitational waves means that we can study the universe in an entirely different way,” Salcido said.

What are Neutrinos?

Neutrinos are everywhere. They are found everywhere in our galaxy, in our sun, and they are even passing through our bodies at this very moment. So what are they? A lot is still unknown about neutrinos. What we do know is that they are fundamental particles that were formed in the first second of our universe 15 billion years ago, preceding even atoms. They are subatomic particles produced by the decay of radioactive elements.

Neutrinos are constantly being created in the nuclear reactions of stars, just like our sun. They are also created in nuclear reactions right here on our planet. They have an undetermined mass or no mass, travel at almost the speed of light, and are unaffected by magnetic fields. These three things allow neutrinos to meet the basic requirements for astronomy.

There are three types of neutrinos, each type is called a “flavor.” Each neutrino’s flavor type corresponds with a charged particle from which it gets its name. The types of neutrinos are electron neutrino, muon neutrino, and tau neutrino.

The name neutrino was first coined by Enrico Fermi in 1933 as a word play on neutrone, the Italian name of the neutron. Neutrino means “little neutral one.” Their low mass and neutral charge interests scientists because it means neutrinos can be used to probe environments that other radiation cannot penetrate. The rest mass of the neutrino is an important test of cosmological and astrophysical theories. This little particle can be a major focus of study in astrophysical communications.

In November 2012, American scientists used a particle accelerator to send a coherent neutrino message through 780 feet of rock. This marked the first use of neutrinos for communication. Future research may permit binary neutrino messages to be sent through immense distances and through the densest materials.  

What if the Earth Stopped Rotating?

Even though this is impossible, it’s still fun to think about! If the Earth stopped rotating, it would be terrible for everything that is on the surface of our planet!

The Earth rotates on its axis, moving us through space at about 1000 miles an hour for someone standing on the equator. In seconds that’s about .3 miles a second, which doesn’t seem so bad. If the Earth stopped, momentum would keep us moving at that same speed until friction slowed us down. The results would be catastrophic!

Our atmosphere is also moving at a similar speed with us. If everything suddenly stopped, it would be like an epic simultaneous hurricane on almost every part of the planet. The closer to the North and South poles however, the less damage it would cause. If you were standing on the North pole you’d hardly feel the Earth stop.

With the Earth stopped, a day would last 365 days. It would take a full year for the Earth to fully orbit the sun and bring back the Earth to the same location in the sky. Each year would consist of one long day and one long night. That means we would have 6 months of day and 6 months of night.

Our tilt gives us our seasons. A stationary planet would have no tilt. Without that tilt, there would be no seasons. It would be summer all the time. Plants and animals would inevitably die. Since our Earth turns every day, the shape of our Earth is like a ball, or to get technical, an oblate spheroid. Without that tilt, the Earth would instead be a perfect sphere. Since our Earth has a bulge in the middle, the oceans are held out by the equator at 8 kilometers out. On a perfect spherical Earth, the world’s oceans would redistribute, flooding many regions of the planet. We would end up with a single continent and oceans in the North and South poles.

As the Earth stops spinning, so would the Earth’s core. Our core produces the magnetic field that protects us from radiations from space. Cosmic rays would obliterate any life remaining on the surface of the Earth and only life underground could possibly survive.

White Dwarf Stars

Whether a star morphs into a white dwarf, a neutron start or a black hole at its end of life cycle will depend upon the amount of mass that is contained in its center core, along with the mass’s proportional gravity.

As mentioned in our article, the more mass or matter that a body contains, the more gravity that is produced. This is the key, for the more mass, the more gravity and consequently, the more pressure from the gravity. It is this pressure that provides for the extreme heat that is generated and subsequently, the fusion of atoms. The types of elements that are fused is what determines if the dying star will be a dwarf, neutron or black hole. These rules of physics are universal.

Stars die when the fusion process ceases. Then, depending upon its size, it will change into one of the types mentioned above.

Our sun, which is in the category called the main sequence, is not an extraordinary star by any means, although we may feel that is not the case here on Earth, as we mortals cannot even set our eyes on this star, but the fact remains that in comparison to other stars in our Milky Way Galaxy and other galaxies, our sun is a mere pea compared to some of the giants in the universe.

With that said, the sun, when it dies will expand to become a red giant.

Thirty Meter Telescope (TMT)

In Pasadena, California, and at various locations around the world, scientists and engineers have been busy planning and designing what they hope will become the largest, most advanced, and powerful optical telescope in the world. When finished, the Thirty Meter Telescope (TMT) will allow astronomers to study objects in our own solar system as well as stars throughout our Milky Way and its nearby galaxies. The TMT will also be able to observe forming galaxies at the very edge of the observable Universe, close to the beginning of time.

The TMT will feature one of the largest mirrors of any telescope. Larger than the James Web Telescope currently under construction. Even though technology to build a mirror bigger than 8.4 meters doesn’t exist, scientists are developing a mirror for the TMT consisting of 492 smaller mirrors that together will measure at 30 meters, almost 100 feet. The diameter of the dome will be 217 feet with a total dome height of 180 feet, as tall as an eighteen story building. The TMT will also use an array of scientific instruments including a wide field optical spectrometer, infrared imaging spectrometer, infrared multi-object spectrometer, as well as six other instruments that are currently being developed.

The TMT was planned to be built atop the mountain Mauna Kea in Hawaii, making it the highest altitude telescope. Unfortunately, the project was not met without controversy. Protests and demonstrations sparked against building the TMT. Mauna Kea is thought of as a sacred mountain to native Hawaiians. On December 2nd of 2015 construction was halted as the Supreme Court of Hawaii invalidated the TMT’s building permit citing that Due Process was not allowed. Hopefully, one day the project will continue, either in Hawaii or another location. The TMT would not only give a huge boost to a state’s economy but also provide many jobs to the community.

The Sun

The SunThe Sun is a standard ‘G’ sized star, compared to the smaller stars and large supernovas in our universe. All stars in the universe are made of gas held together by its own gravity. Every planet in our solar system revolves around the Sun and is held in orbit by the speed at which is revolves against the gravitational pull of the Sun. The closer the planet is to the Sun, the more the gravitational pull the sun has on the planet, but the faster the planet will revolve around it.

The temperature at the Sun’s core is about 27 million degrees and without its light and energy, there would be no life on earth. Formed about 4.5 billion years ago, it is estimated that it has another 4.5 billion years before it destroys itself into most likely a neutron star (larger stars would morph into a black hole, due to the much larger gravitational pull they have).

All stars are fused together (called nuclear fusion) by hydrogen atoms and helium atoms due to the powerful gravitational pull in the star’s core, resulting in the enormous amount of energy that becomes our sun. The energy of this star is so powerful that it is equivalent to the explosion of over 100 billion Hiroshima bombs per second. Hard to comprehend, but true. And noted before, our sun is just a standard size star. A star the size of Betelgeuse would release even more fusion energy per second.

Comparison of Sun with gas giant planets
Comparison of Sun with the gas giant planets Jupiter, Saturn, Uranus, Neptune

The sun contains more than 99 percent of the mass of the entire solar system. It would take 1.3 million Earths to fill up the Sun. Here us a quick calculation:

The volume of the Sun is 1.412 x 1018 km3. The volume of the Earth is 1.083 x 1012 km3. So if you divide the volume of the Sun by the volume of the Earth, you get 1,300,000. The size of the Earth is insignificant compared to the Sun. It is only about the size of an average sunspot.

When we look at the Sun (not recommended), we are actually looking at it as it was nine minutes ago, because the sun is about nine light minutes away from Earth, so if the Sun exploded right now, we would still have a comforting nine minutes longer to live.

The Ringed Gas Giant: Saturn

Saturn Compared to Earth

Although all four gas giant planets have rings made of ice and rocks, Saturn has the most spectacular rings. There are seven rings in total and the largest ring is up to 200 times the planet’s diameter. However, although the rings extend thousands of miles from the planet, they are only about 30 feet thick.

One day on Saturn last 10.7 hours and it takes the planet 29 Earth years to orbit the Sun. It is the farthest planet from the Sun that can be seen with the naked eye.

Saturn is a gas giant made up of mostly hydrogen and helium and does not have a solid surface. Although Saturn cannot sustain any life, some of its 62 moons might be able to support life. Most of the moons are named after Titans in Greek mythology because Saturn itself is named after Cronus, the lord of the Titans.

Saturn’s moons are all very different. Titan is the largest of Saturn’s moons and is slightly larger than Mercury. Pan and Atlas are shaped like flying saucers. One half of Iapetus is bright like snow while the other half is dark. Enceladus as 101 geysers at the southern pole that spew water and other chemicals. And others like Prometheus and Pandora interact with the rings to keep them in their orbits.

In 1979, Pioneer 11 was the first spacecraft to reach Saturn and flew within 13,700 miles of it. In doing so, it discovered the planet’s two outermost rings. The Cassini spacecraft is currently in orbit around Saturn and has returned incredible data on the planet and its moons over the last decade of observation.

The Moon

It’s intrigued millions for centuries, worshiped by civilizations, calculated by scientists, walked by humans and the subject of hundreds of books, movies, songs and TV shows. It is the moon.

Earth's Moon
It is interesting to note that this photo was taken with nothing more than a hand held DSLR Canon camera and a 75-300 mm zoom lens

A remnant broken from Earth some four billion years ago, it orbits our planet every 27.3 days in synchronous rotation, meaning that the same side of the moon is always facing the Earth; hence the phrase ‘The  dark side of the moon’, becoming even more popular after the Pink Floyd album of the same name.

Although called ‘Earth satellite’, the orbiting body has a circumference of 10,917.0 km and a diameter of 3,475 km. It weighs 73,476,730,924,573,500 million kg in units of mass, which is 0.0123 that of Earth.

The moon is 384,400 km or approximately 250,000 miles from earth. Scientists have named just about very part of the moon. Noting one of the more famous ones, the Sea of Tranquility. Also called Mare Tranquillitatis, where astronaut Neil Armstrong first landed his Lunar Module spacecraft with the words “Tranquility base here, the Eagle has landed”, then when he climbed down the later of the Eagle, the first man on the moon stated his famous words “That’s one small step for man, one giant leap for mankind”. (See Google’s map of the Apollo 11 landing locations)

Moon Locations

Others noteworthy to mention here are Mare Imbrium / Sinus Iridium, which is the southern dark spot in the lower end of the picture.

Interesting Facts on Astronomy and the Universe