Astronomy – Page 4 – Super Facts

Astronomer

Daily writing prompt

What alternative career paths have you considered or are interested in?

So I am trying out the Daily writing prompt for the first time, answering the question “What alternative career paths have you considered or are interested in?”.

I’ve always been interested in astronomy and astrophysics, and I studied engineering physics, later electrical engineering. I did not think astronomer or astrophysicist was an easily attainable career and perhaps not very well paid either, but I think it would have been a fun job to have.

Celestron Powerseeker 70EQ

I am a bit of an amateur astronomer, and I own a basic telescope for amateurs, a Celestron Powerseeker 70EQ. It is not a great telescope, but it is good enough for observing objects such as Saturn and its rings, Jupiter and its four Galilean moons, Mars, Venus (the crescent), the moon and its craters. Those objects you can see from inside a big city like Dallas. Naturally you can do much better if you leave the city and especially if you visit a dark spot. I am a member of TAS, Texas Astronomical Society and they own a dark spot in Oklahoma. Below is a photo of my Celestron Powerseeker 70EQ standing in my garage.

Black Telescope standing in front of bicycles in a garage — Celestron Powerseeker 70EQ

What Does an Astronomer Do?

Astronomers study the universe, including galaxies, stars, planets, and other celestial objects, using telescopes and other instruments to observe and analyze them. They observe and analyze celestial objects. Depending on their specific area, astronomers have different duties.

They observe celestial objects using telescopes.
They conduct research, analyze data and test hypothesis.
They use and develop models including complex mathematical models and computer simulations to understand complex astrophysical phenomena.
They collaborate with peers, they teach, and they do mentoring and public outreach.

Types of Astronomers

Observational Astronomers use telescopes and other observational instruments to collect data from celestial objects.
Theoretical Astrophysicists use mathematical models and computer simulations to understand the physical processes in the universe. They may study stellar evolution, galaxy formation, cosmology, and black holes.
Planetary Scientists study planets, moons, and other objects within our solar system. They use data collected by space missions, telescopes, and remote sensing techniques.
Stellar Astronomers study stars, their properties, and their life cycles. They may study variable stars, binary star systems, massive stars, stellar remnants such as white dwarfs, neutron stars, or black holes.
Galaxies and Cosmology researchers study galaxies and the large-scale structures in the universe.
Radio Astronomers study celestial objects using radio waves instead of visible light. They may study radio galaxies, cosmic microwave background radiation, and the structure of the Milky Way.
Exoplanet Astronomers study and discover planets orbiting stars outside our solar system. They use techniques such as transit photometry and radial velocity measurements to detect and characterize exoplanets.

Famous Astronomers

Nicolaus Copernicus 1473–1543, discovered the heliocentric model putting the sun at the center of our solar system.
Johannes Kepler 1571–1630, revolutionized our understanding of how planets orbit the Sun. He used the Copernicus heliocentric model and very careful measurements to show that the planets moved in elliptical orbits around the sun and he came with additional laws to describe the speed of the planets in their orbits.
Galileo Galilei, 1564–1642, or Galileo di Vincenzo Bonaiuti de’ Galilei, was an Italian astronomer, physicist and engineer who greatly improved the optical telescope and discovered the four primary moons of Jupiter and the rings of Jupiter. He proved that all falling bodies fall at the same rate, regardless of mass, and developed the first pendulum clock. He got in trouble for defending Nikolai Copernicus idea.
Edmund Halley, 1656–1742, investigated and discovered many things including the nature of comets’ orbits.
Edwin Powell Hubble, United States, 1889–1953. Hubble proved that many objects previously thought to be clouds of dust and gas and classified as “nebulae” were galaxies beyond the Milky Way. He showed that these galaxies were moving away from us and each other leading to the conclusion that the universe was expanding.
Vera Rubin, 1928–2016, studied the rotation of galaxies and uncovered the discrepancy between the predicted and observed angular motion. This led to the discovery of dark matter.

What about you? What alternative career paths have you considered or are interested in?

To see the Super Facts click here

The vastness of space and the beginning of infinity

Superfact 14: The vastness of space and the beginning of infinity

The Universe is unimaginably large. Our solar system is enormous. It consists of our star, the sun, the planets including earth, dwarf planets, asteroids, comets, rocks, the Kuiper belt, the Oort cloud, and much else. It is 100,000 times wider than the distance between the sun and our earth. Yet it is just one star system among between 100 and 400 billion in our galaxy, the Milky Way.

But that is not all. According to the Nobel Prize winner in physics, Roger Penrose, our universe is just one in an eternal (infinite) series of universes, an eternal chain of Big Bangs that has always existed. See his conformal cyclic cosmology (CCC) model (and the book cycles of time).

According to Stephen Hawking, M-theory, an extension or collection of string theories, states that there are 10^500 or 10000000000000…(followed by five hundred zeros) possible multi-verses that are all equally possible. Hugh Everett’s multiverse or multi-world theory states that there are infinitely many universes.

Now try to imagine the size of it all. You can’t do that, can you?

The vastness of space and the beginning of infinity — Photo by Pixabay on Pexels.com

About The Universe

When the astrophysicist Brian Cox was asked the question “what is the one fact about the Universe that blows your mind the most?”, he answered, “One. Just the size and scale of it…”.

At first, I thought his answer was a bit boring. I mean, what about neutron stars, which essentially are giant atomic nuclei? What about the amazing mysteries surrounding black holes, and what about supermassive black holes, quasars, magnetars, the great attractor, what about the big bang, quantum physics, massless particles, the amazing general theory of relativity, dark energy, etc.

Then I tried to imagine the size and scale of the universe and I realized that he knew what he was talking about. The more you think about it, the more it blows your mind.

A picture of the Andromeda Galaxy with a bright white light near its center. The bright light is almost outshining the entire galaxy. — An illustration of the Andromeda galaxy with a supernova explosion near its center. “Elements of this image furnished by NASA” Stock Photo ID: 2495486227 by muratart.

The vastness of space and the beginning of infinity

Below is a 55 second video in which astrophysicist Brian Cox ruminates on what it means to live a finite fragile life in an infinite eternal Universe.

Our sun is a star. The sun’s diameter is 109 times larger than earth’s diameter, which means that you could fit more than one million earths inside the sun. The distance between the sun and the earth is called an astronomical unit or 1 AU. 1 AU is approximately 11.7 million times larger than earth’s diameter and 107,340 times larger than the sun’s diameter.

The solar system including all the planets, dwarf planets, asteroids, the Kuiper belt and the Oort cloud is 100,000 AU across with the sun just being a dust speck in the middle.

I mentioned that M-theory implies that there are at least 10^500 multiverses. To get an idea of how bif that number is; It is a quintillion times a quintillion times a quintillion times a quintillion times a quintillion times a quintillion times a quintillion times a quintillion times a quintillion times a quintillion times a quintillion times a quintillion times a quintillion times a quintillion times a quintillion times a quintillion times a quintillion times a quintillion times a quintillion times a quintillion times a quintillion times a quintillion times a quintillion times a quintillion a quintillion times a quintillion times a quintillion times. By the way a quintillion is a million trillion.

Below are two more videos. The first one is trying to give a perspective on the size of our solar system, our galaxy, and the Universe. It is 11 minutes and 9 seconds long. The second one is very long, half an hour, and it is a bit advanced, so I recommend it only to star nerds.

However, at 22 minutes and a bit more than 30 seconds it states the observable universe is less than a 15 millionth of the universe (which might be even bigger) which contains at least 30 quintillion galaxies.

To see the other Super Facts click here

Supermoon October 2024

“Supermoon October 2024” is not a super-fact post but some fun facts about the Moon. It is a super-moon post instead.

As many of you probably have read, we currently have a so-called supermoon (October 17 & October 18). The moon’s orbit around earth is not a perfect circle but slightly elliptical. Therefore, the moon’s distance to earth varies.

A supermoon is when a full moon occurs when the moon is at its closest point to Earth, called perigee, making it appear larger and brighter than usual. Or more correctly, the term supermoon is usually used to describe a full moon that comes within at least 90% of the perigee. Since this is a special moon event, I took out my little telescope and looked at the moon and its craters. I also took a look at Jupiter, and I saw three of the four Galilean moons.

A close up photo of the near side of the moon | Supermoon October 2024 — Photo by Pixabay on Pexels.com

Jupiter in the middle. It is a greenish speck with lines. It is surrounded by three white dots. — The green speck is Jupiter. The three little dots are three of the four Galilean Moons. I roughly saw this in my telescope an hour ago, but it is not my photo. Photo by Raoni Aldrich Dorim on Pexels.com

I thought I might as well mention a few interesting facts about the moon.

There is no dark side of the moon

This is a very common misunderstanding. The moon is always showing the same side towards us (or almost exactly the same side). When there is a full moon the backside, or far side, of the moon is dark, but that is not the case when the moon is half, or a crescent, etc. When the moon is new, the far side / backside is “full” from sunlight. If you wondered, NASA and other space agencies have photographed the far side of the moon.

On the left is the near side of the moon and on the right the far side of the moon | Supermoon October 2024 — The near side of the Moon and the far side of the Moon. Comparison between the two hemispheres of the Moon. Elements of this image were furnished by NASA. Stock Photo ID: 2157518223 by Claudio Caridi.

Below is a youTube video showing an animation composed of actual satellite photos by NASA.

A few comments about this animation. You see no stars because the sun is shining, and the earth is also quite bright. The reason you don’t easily see stars during the day is not because the sky is blue but because there is too much light to see them. The sun ruins the starry sky. In addition, stars are not easily captured by cameras when there is ambient light. And again, of course, contrary to the belief of some, the backside of the moon is not always dark.

The far side of the moon is different

As you can see in the YouTube video and the enhanced photo above, the far side looks different from the nearside and it is different in appearance and terrain. The near side of the moon has large, dark, flat-lying basins called maria. They look like oceans. The far side is a lot more rugged and covered by lots of craters. Another difference is that the far side of the moon has a much thicker crust compared to the near side.

Photo of the moon on a blue background | Supermoon October 2024 — Photo by Alex Andrews on Pexels.com

The moon is drifting away from earth at about 3.8 centimeters per year

The moon is moving away from earth due to the gravitational forces between the moon and earth, which also causes tidal bulges in the Earth’s oceans and the moon. Back in high school I took a physics test on which you had to calculate how much the moon was moving away from earth based on the size of the tidal waves on earth. I did not solve that one, but not many did. The calculation made perfect sense though and some geniuses got it.

NASA found water on the moon

In 2020, NASA announced the discovery of water on the sunlit surface of the Moon. You can read about it here.

Drop of water — Photo by Pixabay on Pexels.com

The moon was likely created by a celestial collision : The most widely accepted explanation for the existence of the moon is that the Moon was created when a planet-like object, the size of Mars slammed into Earth, soon after the solar system began forming. That was about 4.5 billion years ago.

To see the Super Facts click here

The Strange Worlds of Exoplanets

Superfact 13: The Strange Worlds of Exoplanets

Our sun is a star, and it has 8 planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune (as well as comets, asteroids, dwarf planets, etc.). The stars you see when you look up in the sky also have planets. We have identified 5,765 exoplanets (as of July 24^th, 2024) but there are billions more in our galaxy. Some exoplanets are similar to Earth, and some are very different from any of the planets in our solar system.

Exoplanets

We know that exoplanets exist, we know some of them are in the so-called habitable zone and that some of them are very strange and interesting. This is certainly important knowledge for how we view our world and the Universe and yet many people who have not paid attention to astronomy news are very surprised to hear this information.

I’ve met many people who aren’t sure about the difference between a planet and a star, so being confronted with the news about exoplanets can be dizzying. That is why I am referring to the Strange Worlds of Exo Planets as a super-fact.

Star system model. Planets in orbit Straight front of sun. Solar system consisting of planets on a black background | The Strange Worlds of Exoplanets — Our solar system. From right to left, the Sun, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. In the image the planets are lined up in a straight line and they are very close to each other. That is, of course, not realistic. Stock Photo ID: 2504532389 by ibnallahdin.

A bright star on the right and from right to left there are seven exoplanets | The Strange Worlds of Exoplanets — This is an imagined star/solar system. Notice that this solar system has seven planets, one less than our solar system. We would refer to these planets as exoplanets, if they were real. Stock Photo ID: 2466463165 by Nazarii_Neshcherenskyi

Most known exoplanets orbit stars roughly similar to the Sun but a lot of exoplanets have been seen orbiting red dwarf stars. It is estimated that there are 11 billion potentially habitable Earth-sized planets in the Milky Way. 40 billion if planets orbiting the numerous red dwarfs are included.

Blue and brown Earth like planet with rings. — An imagined Earth like exoplanet. Stock Illustration ID: 1440413666 by Dotted Yeti.

Habitable Zones

About 1 in 5 Sun-like stars have an “Earth-sized planet in the habitable zone. The definition of “habitable zone” is the distance from a star at which liquid water could exist on orbiting planets’ surfaces. Habitable zones<<Link-2>> are also known as Goldilocks’ zones, where conditions might be just right – neither too hot nor too cold – for life. The habitable zone for our solar system goes from the orbit of Venus to orbit of Mars with Earth in the middle.

It may seem strange that Venus is borderline in the habitable zone considering it’s hellish 870 degrees Fahrenheit. However, being in the habitable zone is no guarantee that the planet is habitable, and Venus got unlucky with its greenhouse gases (beginning about 2 billion years ago). Below you can watch a NASA video explaining about habitable zones.

Planets are extremely faint compared to their parent stars. For example, a Sun-like star is about billion times brighter than the reflected light from any exoplanet orbiting it. It is difficult to detect such a faint light source, and furthermore, the parent star causes a glare that tends to wash it out.

Just think about why you don’t see many stars during the day. They are still there and why you can’t see them is not because the sky is blue, but because the sun’s powerful light washes them out. Therefore, it is necessary to block the light from the parent star to reduce the glare while leaving the light from the planet detectable; doing so is a major technical challenge. All exoplanets that have been directly imaged are both large (more massive than Jupiter) and widely separated from their parent stars.

Size comparison between Earth, Jupiter, and Tres-4 | The Strange Worlds of Exoplanets — One of the largest known planets (by volume and mass) is TrES-4b Picture is from NASA.

The vast majority have been detected through indirect methods, such as the transit method. It should be noted that the official definition of the term planet used by the International Astronomical Union (IAU) (since they booted Pluto) only covers our Solar System and thus does not apply to exoplanets. My opinion : we may need another update on the definition of what a planet is as we continue making exoplanet discoveries.

Black dot on a bright star. — Exoplanet transiting in front of its star: Stock Photo ID: 2315686527 by muratart

Star surrounded by four specks that are slowly moving around the star as movie plays | The Strange Worlds of Exoplanets — One example of exoplanets that has been directly observed is the HR 8799 system. This system harbors four super-Jupiters orbiting with periods that range from decades to centuries. The footage below consists of 7 images of HR 8799 taken with the Keck Telescope over 7 years. The video was made by Jason Wang, data reduced by Christian Marois, and orbits were fit by Quinn Konopacky. Bruce Macintosh, Travis Barman, and Ben Zuckerman assisted in the observations.

Exoplanets Are Very Strange

Many of the exoplanets are very strange. Gliese 581 is about 20 light-years away from Earth and is very similar to earth, but it doesn’t rotate. The orbit of WASP-17b is the opposite of the rotation of its star (unlike our planets, and most exoplanets). Its radius is 1.9 times larger than Jupiter’s radius. In other words, its volume is 6.86 times larger than Jupiter’s and yet its mass is only half the mass of Jupiter making it a big light puff ball. Like giant cotton candy.

Gliese 436b, this planet has a core made up of ice (yes ice formed from water) that is as hot as fire. TrES-2b or Kepler-1b reflects less than 1% of the light it receives. It is darker than coal. 55 Cancri-e is believed to have an interior of diamond. In addition, the side facing its star/sun is extremely hot (1,700°C or 3,100°F).

A planet with an inside that is sparkling like a diamond. — A planet being cut in half, revealing a magnificent diamond inside. 55 Cancri e planet. The surreal world of cosmic gemstones. Stock Photo ID: 2381787311 by Dabarti CGI.

Then we also have J1407b, an exoplanet six times as massive as Jupiter and 20 times as massive as Saturn but with a ring system that outshines that of Saturn by far. J1407b is often referred to as Super Saturn.

A planet surrounded by rings that are hundreds of times wider than the planet. — The rings of Super Saturn. J1407b is an exoplanet 20 times more massive than Saturn. Stock Illustration ID: 2329821675 by Love Employee.

Determining what materials exoplanets consist of is very difficult but NASA believe they’ve found water planets. Check out this video from NASA and the illustration below.

A comparison between Earth (left) and Kepler-138 d (right). The planets are cut like apples so we can see the inside cores. Kepler-138 d has a very deep ocean. — This is an artist’s illustration showing a cross-section of the Earth (left) and the exoplanet Kepler-138 d (right). Like the Earth, this exoplanet has an interior composed of metals and rocks (brown portion), but Kepler-138 d also has a thick layer of high-pressure water in various forms: supercritical and potentially liquid water deep inside the planet and an extended water vapor envelope (shades of blue) above it. These water layers make up more than 50% of its volume, or a depth of about 1,243 miles (2,000 kilometers). The Earth, in comparison, has a negligible fraction of liquid water with an average ocean depth of less than 2.5 miles (4 kilometers).

NASA also believe they have found water vapor in a small exoplanet’s atmosphere, GJ 9827d. Check out the video below.

Below is an imagined exoplanet with mushroom like life

An astronaut is standing on the surface of an alien planet. He is surrounded by giant mushrooms and in the sky, there is a large moon or a planet. — Exoplanet with life Stock Illustration ID: 1524001694 by Dotted Yeti

So, it is estimated that there are 11 billion potentially habitable Earth-sized planets orbiting stars roughly the same size as the sun in the Milky Way. It is estimated that there are an additional 40 billion potentially habitable Earth-sized planets orbiting red dwarf stars in the Milky Way.

The NEID Spectrometer

As you can see in the comment section below, a fellow blogger and on-line friend David Lee Summers mentioned that looking at exoplanets is his “day” job! He spent the last three nights helping to take spectra of exoplanet systems with the WIYN telescope at Kitt Peak. They work with the NASA-funded NEID spectrometer.

A spectrometer is a scientific instrument that measures the distribution of light wavelengths, or the spectral components of a physical phenomenon It is amazing what you can find out from star light, the weight of exoplanets, the size of stars, the elements and substances in stars and planets. Below is the extreme-precision radial-velocity spectrograph mounted on the WIYN 3.5-meter Telescope at Kitt Peak National Observatory. That is the instrument David works with.

David wrote a blog post about his work which I will re-blog in the near future.

The blue NEID port adapter used for measuring the weight of exoplanets and more. — Image of the NEID fiber feed (Port Adaptor) mounted on the WIYN telescope obtained during commissioning of the instrument. The Port Adaptor feeds light from the telescope to the NEID instrument, which is located on another floor of the building, below the telescope. The WIYN 3.5-meter Telescope at Kitt Peak National Observatory is located near Tucson, Arizona. Click on the image to visit the NOIR lab and read about the NEID spectrograph.

Thank you so much David.

Do you believe there’s intelligent life on any of them? If you do, why haven’t we heard from them?

To see the other Super Facts click here

We are Star Dust

Superfact 10 : We Are Star Dust

The matter in our bodies and our planet was formed by fusion in the cores of distant stars and then spread across the Universe by supernova explosions. This matter was later incorporated in second and third generation stars like our sun and its planets.

What do I mean by “We are Star Dust”? Let me explain. The first stars in the Universe were made of 75% hydrogen and 25% helium and trace amounts of Lithium, just like the entire Universe at the time. There were no heavier elements that could form planets or other solid celestial bodies. These early stars tended to be large and heavier elements like carbon, oxygen, and iron were formed by fusion in the cores of these stars.

Many of the first stars, called first generation stars, ended their lives in massive supernova explosions and the dusty remains of these explosions, including the metals formed in their cores, became the building blocks of the stars we see today. These second and third generation stars have planets and other smaller solid objects orbiting them, formed from the gas and dust (star dust) left over from the supernova explosions. So, we are star dust. The atoms formed inside the first-generation stars are now within us.

The picture consists of two pie chart graphs representing stars. The left one is a first-generation star with one pie for the 75% hydrogen and one pie for the 25% helium | We are Star Dust — The first-generation stars consisted of 75% hydrogen and 25% helium and trace amounts of Lithium. A second or third generation star like our sun is still mostly hydrogen and helium but also many other elements. The rocky planets circling the sun are mainly elements heavier than hydrogen and helium. Image credit NASA, ESA, CSA, STScI.

A colorful, nebula, a remnant from a supernova explosion on the background of a black sky full of stars. — Remnants of a recent supernova W49B, 26,000 light years away. Credit: X-ray: NASA/CXC/MIT/L.Lopez et al.; Infrared: Palomar; Radio: NSF/NRAO/VLA.

For those who know astronomy this may be basic information, but I’ve met many people who are unfamiliar with this information, and they are quite often surprised and astonished. That is why I consider this information a super fact. I can add that this process, the birth and death of first-generation stars, the supernova explosions, the disbursal of the matter, which later clump together to form new stars and rocky planets as well, takes many millions of years.

Bright white star surrounded by bluish rings | We are Star Dust — This is an Illustration of a supernova. Stock Vector ID: 2109918599 by Varunyuuu.

A Refresher

For those who need a refresher of things like stars and planets and galaxies. Our sun is a star, a third-generation star. It is much bigger than our Earth. If Earth is the size of a small pea or a caper, then the sun would be the size of a beach ball. However, our sun is not a big star, and it is only one star among between 100 and 400 billion stars in our galaxy the Milky Way.

Many galaxies including our own are disc shaped or look like spirals. If you imagine a dust storm cloud in which there are a thousand dust particles per cubic foot, each representing a star. Then this dust cloud would be 100 to 400 feet thick, and a thousand feet wide and long. I can add that there are between 100 billion to 2 trillion galaxies in the visible Universe. Also, the Universe is much bigger than the visible Universe and might be infinitely large.

The milky way galaxy stretches across the night sky. — A glimpse of our milky way galaxy. Photo by Stefan Stefancik on Pexels.com

As mentioned, orbiting around our sun there are planets, dwarf planets, moons, planet rings, asteroids, comets, meteoroids, interplanetary dust, etc. The star closest to the sun is Proxima Centauri, which is 4.24 light-years away, but it is too small to be seen. The stars that are visible in the night sky tend to be large stars that are not too far away.

Here in Dallas where I live you can typically see 15 stars with the naked eye, and you cannot see the Milky Way. That’s because of the light pollution. In northern Sweden where I grew up you could see 3,000 stars, our galaxy the Milky Way, as well as the Andromeda Galaxy on a clear night with the naked eye.

In 1885 a supernova explosion was recorded in the Andromeda Galaxy. Below is a constructed photo showing how it might have looked like if we had had better equipment back then. Notice that the supernova explosion is essentially outshining the entire galaxy. We are the result of the gases and dust spread by such explosions. You can also read more here.