Lunar eclipse followed by total solar eclipse, March and April 2024

The penumbral lunar eclipse takes place on Monday, March 25, 2024.

A penumbral lunar eclipse happens when only the Earth’s outer and light shadow, called the penumbra, falls on the lunar disk. During this type of lunar eclipse, the lunar disk appears only a little darkened. During the March eclipse, about 95.6% of the Moon will be in the penumbral shadow.

The image below explains the different types of lunar eclipses:

Image source:

https://starwalk.space/en/news/penubral-lunar-eclipse-march-25-2024

The March full “worm” moon announces the coming of spring. Named for the emergence of earthworms when the ground thaws, the worm moon is considered to represent renewal and growth.

We will take the example of the city of Rio de Janeiro in Brazil, where the penumbral lunar eclipse begins on Monday, March 25, 2024, st 01:53(AM). The maximum eclipse occurs at 04:13, the eclipse ends at 06:05. The duration of this eclipse is 4 hours and 13 minutes.

The image below shows how the Moon looks like when viewed from Rio de Janeiro at about 2:00 AM, and at the time of the maximum eclipse at 4:12 AM (Moon appearance and image made with the Stellarium astronomy app)

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Historically, it is generally known or recognized that the first solar eclipse was predicted by the ancient philosopher and astronomer Thales. This eclipse most likely took place on May 28, 585 BCE.

A solar eclipse happens when the Moon comes in between the sun and the Earth. The Moon gets in the way of the Sun’s light and casts its shadow on Earth.

The following image shows the positions of planet Earth, the Moon and the Sun in the solar system at the time of the total solar eclipse on April 8, 2024 (image made with the Mobile Observatory app):

The image below shows an animation of the path of the solar eclipse:

Image source: https://en.m.wikipedia.org/wiki/File:SE2024Apr08T.gif

Taking as an example the town of Tipton, Indiana, USA, the animated image below shows three steps of the total solar eclipse. The maximum of the eclipse occurs on Monday, April 8 2024 at 15:08, the eclipse ends at 16:23. The duration of the solar eclipse is 2 hours and 32 minutes (eclipse images made with the Stellarium astronomy app):

In the image above, Zeta Piscium A is the primary component of Zeta Piscium (ζ Piscium, abbreviated Zet Psc, ζ Psc), a quintuple star system in the zodiac constellation of Pisces. Zeta Piscium A consists of a pair of A-type sub-giant stars with an angular separation of 0.15 arcseconds and visual magnitude 5.28.

The image below shows the solar eclipse taking place on April 8 in Torreon, Mexico at 11:46 (AM)

Lunar and solar eclipses come in pairs, separated by an interval of two weeks.

The March lunar eclipse is the first of the year 2024. It is followed by three more eclipses: a total solar eclipse on April 8, a partial lunar eclipse on September 18, and an annular solar eclipse on October 2.

Relevant and miscellaneous info about the Red Planet

It seems November 28 is called “Red Planet day”. I already wrote a post about Mars, but there are always additional and interesting facts and information about Mars, some of which I will present here.

The atmosphere of Mars is composed of carbon dioxide (about 95%), molecular nitrogen (2.8%), and argon (2%).It also contains trace levels of water vapor, oxygen, carbon monoxide, hydrogen, and noble gases. The atmosphere of Mars is much thinner than Earth’s. The average surface pressure is only about 610 pascals (0.088 psi) which is less than 1% of the Earth’s value. The currently thin Martian atmosphere precludes the existence of liquid water on the surface of Mars, but many studies suggest that the Martian atmosphere was thicker in the past. The Martian atmosphere is an oxidizing atmosphere. The photochemical reactions in the atmosphere tend to oxidize the organic species and turn them into carbon dioxide or carbon monoxide.

Mars has two permanent polar ice caps. During a pole’s winter, it lies in continuous darkness, chilling the surface and causing the deposition of 25–30% of the atmosphere into slabs of CO₂ ice (dry ice). The temperature and circulation on Mars vary every Martian year, as expected for any planet with an atmosphere and axial tilt.
The surface of Mars has a very low thermal inertia, meaning it heats quickly when the sun shines on it. Typical daily temperature swings, away from the polar regions, are around 100 K.

An example of a known geological feature on Mars is Olympus Mons, a large shield volcano on Mars. The volcano has a height of over 21.9 km (13.6 miles or 72,000 feet) as measured by the Mars Orbiter Laser Altimeter (MOLA). Olympus Mons is the youngest of the large volcanoes on Mars, having formed during Mars’s Hesperian Period with eruptions continuing well into the Amazonian. The volcano is located in Mars’s western hemisphere, with the center at 18°39′N 226°12′E, just off the northwestern edge of the Tharsis bulge. There is a possibility that Olympus Mons is still active.

The image below shows a colorized topographic map of the volcano Olympus Mons, together with its surrounding aureole, from the Mars Orbiter Laser Altimeter (MOLA) instrument of the Mars Global Surveyor spacecraft:

(Image source: https://en.wikipedia.org/wiki/File:Olympus_Mons_aureole_MOLA_zoom_64.jpg)

Now for some explanations of the red color of Mars. The surface of the planet Mars appears reddish from a distance because of rusty dust suspended in the atmosphere, with an omnipresent dust layer that is typically on the order of millimeters thick.. A large amount of the regolith of Mars, or its surface material, comprises iron oxide. Basically, rocks on Mars contain a lot of iron, and when they are exposed to the various atmospheric phenomena, they ‘oxidize’ and turn onto a reddish color. The surface iron on Mars became oxidized, forming iron oxide known more commonly as rust — a compound made of two iron atoms and three oxygen atoms, the chemical formula of iron (III) oxide being Fe₂O₃. The massive oxidation most likely occurred when Mars had flowing water and a thicker atmosphere.

Detailed observations of the position of Mars were made in Antiquity by Babylonian astronomers who developed arithmetic techniques to predict the future position of the planet. The late ancient philosophers and astronomers (such as Hipparchus, and then Claudius Ptolemy in his work known as the Almagest) developed a geocentric model to explain the planet’s motions, using systems and combinations of circular tracks called deferents and epicycles.

During the seventeenth century CE, Tycho Brahe measured the diurnal parallax of Mars that Johannes Kepler used to make a preliminary calculation of the relative distance to the planet. Kepler studied for years to motion and the orbit of planet Mars.
Kepler tried several oval curves for the orbit of Mars that might fit the observations, including the ellipse. He was not happy with the physical reasons for choosing any of them until he noticed that one focus of an approximating ellipse coincided with the Sun. The curve and focus made it clearer for Kepler to elaborate a physical explanation.

Kepler’s initial attempt to define the orbit of Mars as a circle was off by only eight minutes of arc, but this made him to spend six years to resolve the discrepancy. The data seemed to produce a symmetrical oviform curve inside of his predicted circle. He first tested an egg shape, then engineered a theory of an orbit which oscillates in diameter, and returned to the egg. In early 1605, he geometrically tested an ellipse, which he had previously assumed to be too simple a solution for earlier astronomers to have overlooked. He had already derived this solution trigonometrically many months earlier.
In his Astronomia Nova, published in 1609, Kepler presented a proof that Mars’ orbit is elliptical. Evidence that the other known planets’ orbits are elliptical was presented only in 1621. Kepler published his first two laws about planetary motion in 1609, having found them by analyzing the astronomical observations of Tycho Brahe.
Kepler gradually discovered that all planets orbit the Sun in elliptical orbits, with the Sun at one of the two focal points. This result became the first of Kepler’s three laws of planetary motion.

The image below depicts the orbits of the planets Mercury, Venus, Earth, and the elliptical orbit of Mars around the Sun. The date is November 28, 1613 (image made with the Starry Night astronomy software):

The first person to draw a map of Mars that displayed any terrain features was the Dutch astronomer Christiaan Huygens.

Mars comes closer to Earth more than any other planet save Venus at its nearest—56 million km is the closest distance between Mars and Earth, whereas the closest Venus comes to Earth is 40 million km. Mars comes closest to Earth every other year, around the time of its opposition, when Earth is sweeping between the sun and Mars. Extra-close oppositions of Mars happen every 15 to 17 years, when we pass between Mars and the sun around the time of its perihelion (closest point to the sun in orbit). The minimum distance between Earth and Mars has been declining over the years, and in 2003 the minimum distance was 55.76 million km, nearer than any such encounter in almost 60,000 years (circa 57,617 BCE). The record minimum distance between Earth and Mars in 2729 will stand at 55.65 million km. In the year 3818, the record will stand at 55.44 million km, and the distances will continue to decrease for about 24,000 years.

Starting in 1960, the Soviet Union launched and sent a series of probes to Mars including the first attempted flybys and hard (impact) landing. The first successful flyby of Mars was on 14–15 July 1965, by NASA’s Mariner 4. On November 14, 1971, Mariner 9 became the first space probe to orbit another planet when it entered into orbit around Mars.
The first to contact the surface were two Soviet probes: Mars 2 lander on November 27 and Mars 3 lander on December 2, 1971—Mars 2 failed during descent and Mars 3 about twenty seconds after the first Martian soft landing. Mars 6 failed during descent but did return some corrupted atmospheric data in 1974.The 1975 NASA launches of the Viking program consisted of two orbiters, each with a lander that successfully soft landed in 1976. Viking 1 remained operational for six years, Viking 2 for three. The Viking landers relayed the first color panoramas of Mars.

The image below shows the clearest image of craters of Mars taken by Mariner 4:

(Image source: https://en.wikipedia.org/wiki/File:Mariner_4_craters.gif)

In order to understand and study the gravity of Mars, its gravitational field strength g and gravitational potential U are frequently measured. Mars being a non-spherical planetary body and influenced by complex geological processes, the gravitational potential is described with spherical harmonic functions, following the conventions in geodesy, via the following formula:

Here is an explanation of the potential formula above:

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Mars will be in opposition with the Sun and in opposition to Earth on December 8, 2022. This means that Mars and the Sun will be on opposite sides of planet Earth, the two planets being the closest together in their respective orbits.

The following image shows planetary orbits, with the shining Sun in the middle of the image and with Mars in opposition to Earth, on December 8, 2022 (image made with the Mobile Observatory astronomy app):

An important event related to Mars will be evidently the first human mission to the Red Planet, which should be the outcome or result of thorough preparation and international cooperation, so that the prepared, trained and qualified crew of the first human trip to Mars will be able to travel in space, set foot and land on the Red Planet, stay there and explore for a limited period of time, and then come back safely to Earth.

Finally, the image below shows planet Mars and the orbit of one of its moons (Phobos) as seen from the surface of planet Saturn at 0°N 0°E, on November 28, 2022 (image made with the Starry Night astronomy software):

Remarks about comparing the spaceship carrying humans to Mars with a modern day Noah’s Ark

I will start with some notes about the older, ancient story of Noah and the ark, then move on to modern spaceships.

The biblical story of Noah, of the ship and of the flood was taken, inspired or borrowed from earlier stories related to older cultures and religions.

The flood could have been local, which is more plausible. Various allegorical and metaphorical elements and dramatizations were added with time, but denying the complete story of the ship and the flood is not the right approach, since the story was rooted in history.

Ancient narratives

The counterpart of Noah in the older Mesopotamian narrative, from which the Biblical flood story was taken, borrowed, or inspired, is called Utnapishtim. Utnapishtim took in the ark his wife, family, relatives, the craftsmen of his village, baby animals, and grains.

One of the metaphorical additions could have very well been the animals (or the amount or number of animals) in (or on) the ship. Noah’s counterpart or equivalent in the ancient Greek story, for example, is called Deucalion.

Deucalion and his wife Pyrrha survived the deluge unleashed by Zeus by building a chest. There are essentially no animals in this version of the flood story. Some authors added pigeons by which Deucalion tried to find out whether the waters had retired, and some later authors such as Lucian (flourished 2nd century CE) added animals that Deucalion had taken with him.

The story of the ship and the flood was explained or interpreted in relation to a decision or decree by the supreme god or deity in ancient (polytheistic) religions, and in relation to the monotheistic God in the Bible. Every ancient culture and group of people explained this story and the events related to it according to their particular social, cultural and religious environment, background, ideas and beliefs. Moreover, there is a direct relationship between the character of Noah and the supreme deity that ordered the flood in the narratives of ancient cultures and religions. This is a point or topic that I could expand on in a future article or post.

In early Antiquity an important event took place where a man built, “drove” or piloted a ship that was the first or unique of its kind and likely represented a significant technological achievement at that time. The man had the ship land on a (very) high place. This man accomplished other great things or deeds, and the story of his life and of his actions was remembered, transmitted, told, retold, interpreted and reinterpreted in various ways.

The story of the great flood and of the demise of all humans outside the ship contained dramatized or allegorical elements. I will try to present (according to my readings and analysis) a possible reasonable way to explain what happened.

The ship was unique and a technological accomplishment, it landed on a high place and the events left a big impression on the people at that time. There were possibly some local floods or one big local flood that took place. People at that time in Antiquity didn’t know about the shape of the Earth and about all its parts or regions, and they likely thought that the region or part of the planet where they lived represented the entire inhabited world, which is one of the reasons why the flood was made global and total in subsequent narratives. Some wondered or said that IF there had been really a global catastrophe or flood when the ship or ark was sailing, the only ones who would have survived would have been the people (and the other living creatures, if any) present on the ship. From the word IF to making it a reality there are only a few steps, and these steps were crossed when the story was told, retold and retransmitted generation after generation, with embellishments, metaphorical and supernatural elements gradually added to it.

In the past the ship was a boat, an Ark, and the high place where it landed was a mountain. In the future, the ship could be the first spaceship carrying humans to another planet, and the high place could be a planet such as Mars.

Modern spaceship narrative

I think a spaceship carrying humans to another planet, particularly the first ship that will carry humans in the context of the first human mission to planet Mars, will be an important event that will be remembered and interpreted in various ways in the decades and centuries following the mission. One or some of these interpretations or narratives will consider the spaceship to be somewhat similar to Noah’s ship or ark, and the leader of the first human mission or trip to Mars could be possibly viewed within these interpretations as someone similar to Noah.

Here is another related remark. It is mentioned in the Bible that Noah was about 500 years old when he had children, and about 600 years old when the flood started and he entered the ark. Taking into consideration that the ages of the first ancient patriarchs were allegorically exaggerated or extended in the early parts of the Bible, and that the real age could be found by dividing the allegorical age approximately by 10, this would mean or entail that the age of 500 can be realistically rendered as 50 approximately, and that the man named Noah in the Bible was approximately (a little more than) 60 years old when the flood began and he entered the ship. It would be interesting or relevant to know or take notice of the age of the first person who will be the leader of the first human mission to planet Mars when the speceship begins its human trip to the red planet.

There are many valid reasons that could be given to justify the human mission to Mars and the human exploration of other planets. Some of these reasons include that life could be threatened on planet Earth, that after inhabiting the entire planet humans naturally ought to go beyond Earth and explore and inhabit the Moon and other planets, and so on. However it should be taken into account that at this period of time few humans are ready or prepared to take part in a human mission to Mars, and in order to succeed, such a human mission should be the result of thorough preparation and of global and international collaboration. And the human mission to Mars is not and should not be a suicide mission. Whether a person will get on the spaceship to Mars or not depends on this person being adequately qualified, prepared and ready to do so.

In any case, let us see how future events will unfold.

Estimating the date or the year when humans will land on Mars

Let us begin with some general facts and data.

Earth is the third planet from the sun, an Earth year is approximately equal to 365.26 days.

Mars is the fourth planet from the sun, a year on Mars is approximately equal to 687 (Earth) days.

Earth moves in an orbit around the sun at an average (semi-major axis) distance of 149,598,023 km, or 92,955,902 miles, or 1 AU (astronomical unit).

Mars moves in an orbit around the sun at an average distance 227,939,200 km , or 141,634,850 miles, or 1.523679 AU.

Mars Oppositions occur when Earth passes between the Sun and planet Mars. Mars oppositions take place approximately every 2 years and 2 months, or every 779.94 Earth days. During these times of opposition, the two planets have the closest distance to each other.

Two useful or interesting dates of closest encounter and closest distance between Earth and Mars are the following ones.

The first date of closest encounter is June 27, 2033. At this date, the distance between Earth and Mars will be approximately 0.428 AU.

To visualize things better, below is an image showing the positions of Earth and Mars and of neighboring celestial bodies on January 29, 2033 (image source: 3D Solar System Simulator):

Below is an image showing the positions of Earth and Mars and of neighboring celestial bodies on June 29, 2033 (image source: 3D Solar System Simulator):

A second date of closest encounter is September 15, 2035. At this date, the distance between Earth and Mars will be approximately 0.381 AU.

The first of these two dates of closest encounter, June 27, 2033 (give or take a few days), could be realistically chosen as the time and date when a human will land on Mars.

People and humans have been planning and wanting to go and set foot on the red planet for the last few decades, some intending to go there in an unprepared and unrealistic way.

In order to ensure the success of the first human mission or trip to Mars, the mission should be the result of international cooperation, everyone taking part in the trip ought to be very well trained and prepared. All the aspects of the mission (technological, scientific, computational, financial, …) ought to be thoroughly taken into consideration, so that the human crew will be able to land on Mars, stay there for a determined short period of time, and return back safely to Earth.

The human mission or trip to Mars is not a game or a one-way voyage with uncertain or harmful results and consequences.This will be a very important event in the history of humankind, and not everyone is ready or able to make the journey to Mars .But those humans who will travel to Mars should be prepared to the maximum.

The human crew would be sent a few months earlier to Mars, so that they would land on Mars at a date approaching the date of closest Earth-Mars distance of June 2033. Hence one of the best dates for humans to set foot on Mars for the first time would be in the summer of 2033.

Among the various factors upon which the progress and success of the mission will depend, one important factor would be the readiness and sagacity of the leader of the first human mission to Mars, who will most likely be the first person to set foot on Mars, and whose decisions will be essential and vital to the suitable choice of dates, and to the successful planning, unfolding, development, and accomplishment of the first human mission to planet Mars.

What are the benefits of sending humans to Mars?

What were the benefits for early human groups and populations to travel and discover new lands, or to build rafts, boats or ships, move from seashore to seashore and inhabit different regions and continents?

What were the benefits for the explorers or navigators of the past to risk traveling across seas and oceans or to circumnavigate this planet?

Ever heard about human curiosity, human ingenuity and inventiveness, the human desire, inclination and potentiality to know, to learn, to adapt, to investigate, to discover, to transcend, to go beyond the limits, to rise above adversity, “to boldly go where no one has gone before”?

Robots, spacecrafts or space probes can help humans gather information and make new discoveries, but they are not meant to replace them.

It has been said that exploring and inhabiting Mars would turn humanity into a bi-planetary or a multi-planetary species, which I think is advantageous and important. And as Konstantin Tsiolkovsky stated: “The Earth is the cradle of humanity, but one cannot remain in the cradle forever.”
Sending humans to Mars and humans going there is a very significant event, a necessary endeavor and the logical next step in the progress and evolution of humankind.
Of course this event should be well planned, well organized and should be done the right way.

In order to make the human mission to Mars a reality, a crew of several men and women will constitute the group of people who will make the first trip to planet Mars. This trip will have to be the result of meticulous preparation, international efforts and international cooperation.

It is reasonable to assume that the nations which are capable of sending humans and astronauts to outer space by their own means, will have to and will want to play a primary role in this endeavor, but the first human trip to Mars must be a global, international and joint effort in order to succeed.

Moreover, it would be best for the leader of the first manned mission to Mars, and the first one to set foot on Mars, to rise above national allegiances and narrow interests, and to act as a representative of the entire human species.

(Free image from unsplash).

Landing people on Mars, and what is needed to go and stay there

Setting up a “colony”, or establishing a constant human presence on Mars and inhabiting the red planet would require many things.

Here are some things or points to take into consideration, and some requirements that come to mind.

Having or getting access to water (frozen or otherwise) on Mars through drilling.

Building or creating artificial Mars habitats with complex life-support systems.

Equipment for energy production and energy storage, and equipment for moving over the Martian surface.

Equipement necessary to produce food, propellant, water, energy, and breathable oxygen.

Basic utilities to deal or cope with the inhospitable Martian environment.

Establishing the necessary means of communication with Earth.

The following facts have to be taken into account:

Mars has a weaker global magnetosphere than Earth does. Combined with a thin atmosphere, this allows a significant amount of ionizing radiation to reach the Martian surface.

Mars has a surface gravity 0.38 times that of Earth. The density of its atmosphere is about 0.6% of that on Earth. Moreover, landing piloted missions on Mars would require braking and landing systems different from those used to land crewed spacecraft on the Moon or robotic missions on Mars.

That being said, we are getting ahead of ourselves.

The first human mission to planet Mars will not and should not be a one-way trip or a suicide mission. As a result of meticulous preparation and global cooperation, a crew or “team” of thoroughly trained, qualified and prepared astronauts will go to Mars, most likely in the first years of the third decade of this century. They will land on Mars, stay there and explore for a limited period of time (possibly a few weeks), and then come back safely to Earth.

At this time, few people are prepared or ready to go to Mars. Sending many or lots of humans to Mars around 2050 is an unrealistic project. Such ill-considered, incautious, precipitate ideas or plans will very likely end or result in failure, tragedy, disaster, and people getting killed.

A number of years or a few decades after the first human mission to Mars, when the time is right, there will be a second exploratory mission, and a third one if necessary. These successive missions could gradually and properly pave the way for a more permanent human presence on Mars.

It is also to be noted that the existing formal educational system (which needs to be reformed) with its structure and requirements doesn’t prepare people or make them better candidates to travel to Mars or to another planet. If a person for example entered the university at the age of 18 or higher and obtained a higher education diploma or degree, such as a master’s degree or a science PhD, this might be useful for going to the Moon or traveling in the vicinity of planet Earth, but it does not qualify the aforesaid person to be able or be ready to go or to travel to Mars.

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I will add some remarks on using the words colony and colonize.

According to the Shorter OED, a colony is “ A settlement in a new country; a body of settlers forming a community fully or partly subject to the mother state; the territory of such settlers”.

Another dictionary definition of the word colony is “A group of people living in colony, comprising the original settlers and their descendants and successors”.

Yet another definition is “a group of people of a particular nationality, race or ethnicity living in a foreign place“.

The word or verb (to) colonize means “to establish a colony”, or “send settlers to a place and establish control over it”, or “settle and establish control over the indigenous people of a place”.

There are no humans or indigenous people present or living on planet Mars.

I often prefer to use the expression “human exploration” instead of the word “colonize” or “colonization” in relation to Mars, as the term “colonize” includes meanings or historical connotations involving aggressiveness, brutality, and the subjugation of others. But since there are no existing humans or intelligent life forms on Mars, I guess the word “colonize” could be used as well.

At any rate, the first one or two human missions to Mars ought to be dedicated to exploration instead of “colonization”, in the sense that it is early and premature for the first humans who will set foot on Mars to start building habitations or “colonies” and to stay for a long time on the red planet.

The Laplace nebular theory or hypothesis

The Laplace nebular theory is sometimes called the Kant-Laplace nebular hypothesis. It is essentially a theory attempting to explain the origin of the Solar system, and suggesting that the solar system was formed from dust and gas orbiting the Sun.

Immanuel Kant developed and published his theory and his cosmological ideas in 1755, in his book entitled Universal Natural History and Theory of the Heavens, using mostly qualitative descriptions and explanations. Kant suggested a nebular hypothesis in which solar systems are the result of nebulae (interstellar clouds of dust) that coalesce into accretion disks and form suns and their planets.

Pierre-Simon Laplace independently developed a nebular theory, and expounded his model in more scientific and detailed terms in 1796, in the popular work Exposition du système du monde, where he discussed and exposited his work in astronomy and celestial Mechanics.

Laplace suggested that the Sun originally had an extended hot atmosphere throughout the volume of the Solar System, with the existence of a contracting and cooling protosolar cloud—the protosolar nebula. As this cloud cooled and progressively contracted under the effects of gravity, it flattened and spun more rapidly, throwing off a series of gaseous rings of material; and according to him, the planets condensed from this material.

(Image source: https://www.amazon.com/Exposition-syst%C3%A8me-French-Pierre-Simon-Laplace/dp/3967877280)

Laplace’s nebular theory or model was widely accepted in the 19th century, but it encountered some difficulties and was criticized, one main problem involving angular momentum distribution between the Sun and planets.

Scientists sought to modify or replace Laplace’s theory during the 20th century. As an example, at the start of the 20th century, James Jeans analyzed the physics of rotating bodies and deduced that Laplace’s theory that the solar system formed from a single cloud of gas was incorrect; he proposed instead that the planets condensed from material drawn out of the sun by a hypothetical catastrophic near-collision with a passing star. Such a theory is not accepted today. At the end of the 20th century, Andrew Prentice formulated a “Modern Laplacian Theory” where each planet accretes within a discrete circumsolar gas ring. Prentice has used his unorthodox model to make some accurate predictions about the solar system.

The widely accepted modern variant of the nebular theory is the solar nebular disk model (SNDM) or solar nebular model. It provided explanations for a variety of properties of the Solar System, including the nearly circular and coplanar orbits of the planets, and their motion in the same direction as the Sun’s rotation.

Concerning the first human mission to planet Mars

Some elements of this post are taken or inspired from answers I wrote on the Quora question-and-answer website.

The first human mission to Mars will be a unique and significant event in the history of humanity, and the humans who will be selected or chosen to participate in this trip should represent the diversity and totality of humankind, but at the same time they should be extremely well picked. Sending humans to Mars or humans going there is a very significant event, a necessary endeavor and the logical next step in the progress and evolution of humankind.

In order to ensure the success of the first human mission or trip to Mars, the mission should be the result of international cooperation and collaboration. Everyone taking part in the trip ought to be very well trained and prepared. All the aspects of the mission (technological, scientific, computational, financial,…) ought to be thoroughly taken into consideration, so that the human crew will be able to land on Mars, stay there for a determined (short) period of time, and return back safely to Earth.

Among the various factors upon which the progress and success of the mission will depend, one important factor would be the readiness, sagacity and skills of the leader of the first human mission to Mars, who will most likely be the first human to set foot on Mars, and whose decisions will be essential and vital to the suitable choice of dates, and to the successful planning, unfolding, development, and accomplishment of the first human mission to planet Mars.

The humans who will go to Mars are not on a one way tip or on a suicide mission. They have to be properly and effectively trained and prepared for the trip, and everything should be well done and organized so that they return safely to Earth.

I think the number of persons who will take part in the first mission to Mars will be more than four, possibly between six and eight. Anyway this number is open to discussion and can be debated.

Here are a number of general criteria and considerations that I think should be taken into account for choosing these people:

• The humans or astronauts who will go to Mars ought to be representative of the diversity of humankind and of the entire human species.
• They ought to be chosen from all the major inhabited continents:
  Asia , North and South America , Africa , Europe , Australia (or Oceania) .
• Men and women ought to be represented, and the mission crew might include a married couple.
• The major human skin colors ought to be represented : black (and/or people with dark skin or complexion), white and yellow.
• The first trip/mission to Mars should be the result of international cooperation, however it is to be expected that nations which are capable of sending humans and astronauts to outer space by their own means, will have to and will want to play a primary role.
• At the risk of disappointing a number of people, I think that at this time (this century or the next decades ) not many people are ready, qualified or prepared to go to Mars. The trip to Mars is not a game or a one way trip.

Moreover, I think the existing formal educational system, with its structure and requirements, doesn’t prepare people or make them better candidates to travel to Mars or to another planet. Having a higher education diploma or degree does not necessarily mean one will be able or ready to go or to travel to Mars.

I have already written several posts expressing my opinion about the existing educational system, and the need to change or reform this system. 

As a related topic and example, NASA was recently accepting astronaut applications, with one of the requirements being the possession of a master’s degree. I think a degree or diploma from the existing educational system may be useful or helpful for human missions to the near outer space (in the vicinity of planet Earth) and to the Moon, but such degrees or diplomas (obtained in the framework of the current education system) will not be at all useful for humans who will take part in the human mission to Mars.

I also think that those who follow the current system with its age requirements are not prepared to go to Mars or to another planet. For example, I don’t think the students or persons who go to college or who enter the university at (or above) the age of 18 or 20, and who succeed and earn a master’s degree or a PhD, have the readiness or the capabilities to participate in the human mission(s) to Mars. 

As an additional note, I read in the past a comic book where students on another planet finished their university studies or became engineers at the age of fifteen or fourteen. If the right changes or reforms are implemented, I think this is the direction in which the existing educational system will evolve. Kids and adolescents should be given more and more the opportunity to use and benefit from new, efficient and beneficial educational methods, to accelerate their education and to follow their own stages of development, and to finish their secondary studies as well as their university or college studies at a younger age.

In any case, the right choices and decisions will be hopefully and necessarily made, and everything will become clearer and will be settled when the time is ready for humans to go to Mars, which will most likely take place in the early thirties of this century.

Images of Jupiter and Saturn and some related info

After a close look  at planet  Mars in a previous post , here are images and info related to Jupiter and Saturn.

Jupiter is the biggest planet in the solar system , fifth from the Sun between Mars and Saturn.It
was named after the Roman king of the gods.

This first image of Jupiter shows the planet with the (multicolored) ring system surrounding it.The Grest Red Spot is also visible (image made with Universe Sandbox).

The faint diffuse ring system  of Jupiter was  identified by the Voyager 1 spacecraft in 1979.The
ring system consists mostly of dust particles , and comprises three main parts: the halo closest to
Jupiter, the main ring ,and the gossamer ring outside the main ring.

The Great Red Spot (GRS) of Jupiter is a huge high pressure anti-cyclonic storm , similar to a big
hurricane.Three planets each having the same size of the Earth could comfortably fit in it.
The image below gives a detailed view of the GRS and its surroundings (made with Starry Night).

Next is a picture of Saturn with its ( multicolored ) system of rings .Planet Earth is shown to the right of Saturn. Image made with Universe Sandbox.

Saturn is the second largest planet in the solar system after Jupiter.
Saturn has bright rings made of lots of small particles having sizes from a centimeter to a few
meters to more than a kilometer.The particles of the rings are composed mainly of aggregated
water ice pieces and some rocks.The rings extend away from Saturn and have a very large
diameter ,but they are very thin and have a thickness of less than one kilometer.Galileo first
observed the rings in 1610 ,but he thought they were large moons on both sides of planet Saturn.
A few decades later in 1655 Christian Huygens explained that Saturn was in fact surrounded by
rings.These rings were divided into many sections by astronomers and scientists.The D ring is
closest to Saturn ,the F, G ,E rings and the Phoebe ring are the outermost rings .

The final image below is of Saturn and its rings in March 2015 (made with Starry Night and a touch of Photoshop;the lighting is an added effect).

The rings of Saturn lie within the Roche limit.Inside this borderline distance (approximately 2.44
Saturn radii ) a celestial body or moon disintegrates due to the stronger tidal forces of Saturn and
rings are formed  , while outside it a body or disk of orbiting material is expected to accrete and
coalesce.

A general formula for calculating the Roche limit is:

The Roche limit varies for rigid bodies and for fluid satellites.

Additional reference work related to this post and the Roche limit :
Planets, Stars and Stellar Systems , Volume 3:Solar and Stellar Planetary Systems ( edited by Terry D. Oswalt ,
Linda M. French and Paul Kalas).

Images of planet Mars and related input

It was by studying the orbit of planet Mars and the obesrvational data collected by Tycho Brahe that
Johannes Kepler was able to formulate his laws of planetary motion in the early 1600s ,
concluding that the orbits of the planets are ellipses, with the Sun at one focus of the ellipse.
The Martian atmosphere is very thin , composed mainly of carbon dioxide (between 95% and
96%) ,and  contains nitrogen , oxygen ,argon and traces of water vapor.
Mars appears to have a red or red-orange color.Its surface , rocks and soil contain dust composed
mainly of iron which reacted with oxygen , giving iron oxide or rust.This red colored dust has been
carried by storms into the atmosphere and has covered most of the Martian surface and  landscape.

The following images of Mars were made with Redshift and Starry Night.

We begin with an image of Mars from a position behind the moon Deimos.The date for the image is February 2015.

Phobos and Deimos were discovered in 1877 by Asaph Hall.Both have irregular shapes.Phobos (with a diameter of 22.2 km across or 13.8 miles) is larger than Deimos (with a diameter of 12.6 km or 7.8 miles) and is closest to Mars.

Next is an image of Mars showing also Phobos , Deimos and some planets of the solar system.

The third image features Phobos and Mars with Planum Boreum , the North polar cap of Mars , consisting mostly of water ice.

Below is a detailed image of Planum Boreum and its surroundings , including Vastitas Borealis , the largest lowland region of Mars.

 

Click here to view an enlarged and more detailed image of Planum Boreum.

Here is a simple way to find the surface gravity g for Mars.The same equation used to determine
the value of g on Earth’s surface can also be used to determine the acceleration of gravity or
surface gravity on the surface of other planets.
We equate the force of gravity at the surface of a planet,or the force on an object in a gravitational
field F=mg (also called weight) with the force of gravity between objects in space given by the
Universal Law of gravitation .
Hence:

The value of g obtained here may be very slightly different from values cited in textbooks because
we used specific  and more detailed or accurate values of the constants.
The ratio of the surface gravity of Mars compared to Earth is 3.72761/9.80665 or 0.38011,which
means the surface gravity of Mars is about 38% that of Earth.

Mars is close to Earth and the fourth planet from the Sun , and it has become famous in the past
decades or years  because people and humans have been planning and wanting to go and set foot on the
red planet , some people intending to go there in an unprepared  and unrealistic way.
I think it must be taken into account that a manned mission to Mars and the first mission/trip ( or even trips) to
Mars should be undertaken as part of an international enterprise with international cooperation and an international crew , consisting of people very well prepared ,well trained ,well versed in science ,engineering , technology , astronautics and aviation (preferably having pilot skills) , and having planned everything to the tiniest detail in order
for the crew to go land on Mars , stay there for a short determined period of time , conduct
experiments , establish a base for future trips , and come back to Earth safely.
Not to offend anyone ,but this is not a game or a one-way voyage with uncertain or harmful results and consequences.This will be a very important event in the history of humankind , and not everyone is ready,
prepared or able to make the journey to Mars .