Uranus

It is the seventh planet from the sun in our solar system and has the third-largest diameter. It’s windy and very cold. Uranus is surrounded by 27 small moons and 13 faint rings. It rotates at a unique angle of nearly 90-degrees, making it look like its spinning on its side while orbiting, unlike other planets.

Who Discovered Uranus?

The planet Uranus was discovered on March 13th, 1781 by British astronomer William Herchel, even though he initially he thought he had seen a comet or a star. It was two years later that the object was universally accepted as a new planet especially after astronomer Johann Elert Bode personally observed it. The discovery of the planet ‘Uranus’ was accidental, as Herchel was carrying out a survey of all of the magnitude 8 stars using his telescope when he noticed a faint object as it moved across the fixed stars.

Ironically, Uranus was discovered on several previous occasions, but it was often mistaken as a star. In 1690, Jon Flamsteed had observed Uranus and cataloged it as 34 Tauri. Flamsteed went on to observe Uranus six more times. Between 1750 and 1771, French astronomer, Pierre Lemonnier observed Uranus 12 times total, including four sequential nights.

The Name ‘Uranus’

Herchel initially tried unsuccessfully to name the new planet Georgium Sidus after King George III of England. However, it was Johann Bode’s choice of the name ‘Uranus’ that was ultimately chosen. Uranus is a Greek name for the god of the sky and in Greek mythology, one of the earliest gods was sometimes known as “Father Sky’ and considered to be the son and husband of Mother Earth or Gaia.

Known Expeditions

In 1977, astronomers discovered rings around Uranus but not as sophisticated ones as those surrounding Saturn. They were using NASA Voyager 2 when they discovered Uranus was the second ringed planet.

We got our closest look at Uranus with the Voyager 2 space probe. It was within 50,600 miles (or 81,500 km) of the Uranus’s cloud tops on January 24, 1986. Thousands of scientific records and images of the moons, atmosphere, interior, rings, and magnetic environment around Uranus were radioed by Voyager 2 on its way to Neptune.

Physical Characteristics of Uranus

Uranus is over four times larger than Earth, and it’s primarily composed of various ices and gases. The atmosphere consists of 83% hydrogen, 15% helium, 2% methane, and traces of acetylene. The interior of Uranus is richer with heavy elements, and it’s highly likely there is the presence of compounds like oxygen, nitrogen, and carbon in addition to rocky materials. Unlike Jupiter and Saturn, Uranus is not covered mostly by hydrogen. It’s similar to these two planets, but it lacks their hydrogen fluid metallic envelope. Uranus has 27 moons that are known, which are named after the works of William Shakespeare and Alexander Pope.

Culture Associated With Uranus

In astrology, Uranus is referred to as the ruling planet of Aquarius. The electric blue color that’s associated with the sign is due to Uranus being a cyan hue. It’s also associated with electricity. An interesting fact is that the chemical uranium was named by the German chemist Martin Klaproth, who was inspired by the discovery of the planet Uranus.

The Potential for Life

The environment of Uranus is not conducive to organisms and cannot support life as we know it. The materials, temperatures, and pressures on Uranus are too volatile and extreme for living organisms to adapt and survive.

Mysteries and Wonders of the Sun

In 1543, Nicolaus Copernicus sparked the Scientific Revolution with his proposal that the Sun is the center of our solar system. It took some time for his theory to be accepted, but scientists know now, more than ever, how critical the Sun is to our survival on Earth.

The universe is filled with billions of stars, but the Sun is our energy and life source. It gives us light and warmth, day and night, and changing seasons. It has inspired awe in humans for centuries, and is culturally and spiritually significant to many civilizations and cultures.

How the Sun was Created

Structure of Sun

More than 4.5 billion years ago, a giant cloud of dust and gas called a nebula collapsed. Gravity drew most of the dust and gas into the center, creating a giant mass that became the Sun. The remaining dust and gas spread out to form the rest of the solar system: planets, dwarf planets, moons, comets and asteroids.

The Sun measures 864,000 miles wide and is 100 times larger than Earth. Its mass accounts for 99.8% of the solar system, and its gravitational pull keeps the planets in orbit.

The yellow dwarf star is made up of hydrogen, helium and plasma. It is structured as follows:

  • core
  • radiative zone
  • convective zone
  • photosphere (the surface)
  • chromosphere
  • corona

By mass, hydrogen makes up 71% of the gases in the sun. As nuclear fusion converts hydrogen to helium, energy is generated and carried by photons from the star’s core to the surface. It takes about 170,000 years for a photon to reach the surface, but once it is released from the Sun, it takes about 8 minutes to reach Earth.

This energy creates incredible heat. The Sun is 27 million degrees Farenheit at its core. Its surface temperature is 10,000 degrees Farenheit and the corona is more than 1 million degrees Farenheit.

It’s estimated that the Sun has enough hydrogen to burn for another 5 billion years. It will then turn into a red giant, which is a dying star. It will begin burning helium and expand to more than 100 times its size. At this point, it will likely engulf Mercury and Venus, and possibly Earth.

Studying the Sun

Our Earth And The Sun

Scientists have much to learn about the Sun and its behavior. Here are four important research missions:

Solar and Heliospheric Observatory (SOHO): NASA and the European Space Agency launched this observatory in 1995 to study the structure and dynamics of the Sun. Previous solar laboratories orbited Earth, but SOHO orbits the Sun for an uninterrupted sightline. This project captured the first images ever of the Sun’s convection zone, provided precise measurements of the Sun’s temperature structure, and measured the acceleration of the slow and fast solar wind.

Solar Dynamics Observatory (SDO): NASA launched this observatory in 2010 to study the solar atmosphere. Its mission is to understand solar variations that affect life on Earth. This includes studying the structure of the Sun’s magnetic field and how this energy is released in the form of solar wind and energetic particles.

Parker Solar Probe: This groundbreaking probe launched in 2018. Its seven-year mission will take it closer to the Sun’s surface than any previous spacecraft. Built to survive temperatures of up to 2,500 degrees Farenheit, it will fly into the low solar corona and eventually be as close as 3.8 million miles to the Sun’s surface. By comparison, Helios 2 was 26.55 million miles from the surface of the Sun in 1976.

Polarimeter to Unify the Corona and Heliosphere (PUNCH): NASA is launching a new mission in 2022. PUNCH will consist of four separate spacecraft studying the Sun’s outer layers and their influence on the planets. It is hoped this knowledge will help scientists to predict solar events.

Religious and Cultural Significance of the Sun

For centuries, humans have been awed by the presence of the Sun in the heavens. The ancient Romans and Greeks believed the Sun was a god driving his chariot across the sky. Ancient Egyptians named their Sun god Ra, while the Greeks worshipped Helios.

The Aztecs believed that their Sun god, Huitzilopochtli, needed nourishment to stave off darkness. Warriors who died—or were sacrificed—gave the Sun its energy and were later reincarnated as hummingbirds.

The Sun Dance has traditionally been an important ritual to the Plains Indians of North America. This ceremony was prohibited by governments after colonization, but remains significant to many Indigenous peoples today.

Surya, the Hindu sun deity, is considered the source of eternal life and is honored by temples and shrines throughout India. Surya Namaskar, or “sun salutation,” is a sequence of poses meant to honor the sun. It is widely practiced in yoga.

A number of ancient cultures created stone formations based on the Sun’s movement. One of the most famous is Stonehenge in Wiltshire, England. Dating to about 2500 BC, the stones of this prehistoric structure were carefully arranged so that at the summer solstice, light shines into the center of the ring. Thousands of people journey to Stonehenge each year to take part in solstice celebrations.

Recently, the film Sunshine (2007), directed by Danny Boyle, imagines a world where the Sun is dying and the survival of humankind is at risk. The story is set in 2057 and follows a group of astronauts trying to use a nuclear weapon to ignite the star.

Many musicians have written songs about the sun, particularly the Beatles, who released Here Comes the Sun (1969), Good Day Sunshine (1966) and I’ll Follow the Sun (1964). Other themed songs include Seasons in the Sun (1974) by Terry Jacks, Black Hole Sun (1994) by Soundgarden and Blister in the Sun (1983) by Violent Femmes.

Additional reading:

Preparing for Discovery with NASA’s Parker Solar Probe

First Image from Inside the Sun’s Atmosphere

The Enigmatic Moon

super moon

Enchanting, luminous, magical, and mysterious are all words that are often used to describe the Moon. This silvery celestial body has long captured the attention of the human mind. After centuries of staring up at our closest heavenly neighbor, people still know so little about it. From its first discovery to the moment humanity set foot on its strange and distant surface and through the present, the Moon has fascinated us. Keep reading to learn all you will ever need to know about this enigmatic entity.

Just the Basics

The Enigmatic Moon

While it may still seem mysterious to most, there is a lot that scientists have learned about our Moon over the years. Some of these stats are verifiable fact and others are mere theory, however, they all represent the best information humans have about this celestial enigma.

Formation

While it is impossible to know for sure, the majority of scientists agree that the Moon was formed after a Mars-sized object crashed into the Earth in its infancy. The resulting debris from both Earth and the colliding object then melded together as a molten mass to form the Moon. Centuries of cooling turned the magma pools into the Mares that can be seen today.

Size & Distance

The Moon is the fifth largest moon in our solar system. Yet it is still quite small when compared to the Earth. In fact, the Moon has a radius of roughly 1,080 miles (1738 km) which makes it less than one third the size of the Earth. For reference, imagine that the Earth is a basketball, the Moon would be a softball.

Also, although there are nights when it may seem like you could reach up and touch the Moon, it is actually 238,855 miles (384,400 km) from the Earth. That means that you could fit 30 Moon-size bodies between the Earth and it.

Studies have shown that the Moon is slowly moving away from the Earth. In fact, scientists estimate that each year it travels another inch away.

Rotation

The Moon not only orbits the Earth but also spins on its own axis. This rotation on its axis takes around 27 days, although it appears from here to be 29 days. This is roughly the same amount of time it takes the Moon to orbit Earth. What all of this means is that people on Earth are only able to see one side of the Moon, ever. That side is called the near side and by default makes the other side the far side. Some refer to this far side as the dark side although that is a misnomer as both sides receive the same amount of sunlight.

Gravity

While it is a commonly held belief that the Moon has no gravity, that is not true. Anything with mass has a gravity of some sort and while the gravity on the Moon is nowhere near that on Earth, it is still present. Since the Moon’s mass is so much less than the Earth’s, its gravity is as well. In fact, the Moon’s gravity is roughly 83.3 percent of Earth’s. That is why humans weight so much less there.

Moon Phases

There are seven phases the Moon goes through during its 27-day rotation. These are:

Phases of Moon
  • New Moon: appears to be missing from the night sky
  • Crescent Moon: appears like a small sliver of light
  • First Quarter: Appears that 25 percent of the Moon is visible
  • Waxing Gibbous: half the Moon is clearly visible
  • Full Moon: The entire circle of the Moon can be seen.
  • Waning Gibbous: Again, only half the Moon is apparent
  • Last Quarter: The last 25 percent of the Moon is visible
  • Crescent Moon: same as above on the opposite side

For a large part of human history, these facts were unknown. All people knew of the Moon in early days was what they observed and what they were told. That is until the Moon was truly discovered.

Discovering the Moon

It is hard to imagine that there was a time in human history when the Moon was undiscovered. It has always been there lighting up the night sky and driving imaginations to run wild. In fact, all ancient civilizations incorporated this cosmic curiosity into their traditions, religions, and everyday life. However, humanity eventually pulled itself out of the mire of superstition and myth and into the age of science. That is where the study of the Moon really got interesting.

The Moon as a God

Many ancient peoples saw this giver of light as a deity to be worshipped and appeased. Those who lived near the water likely recognized the correlation between the Moon and the tides. Those people inland likely witnessed the animal behavior that seemed to be triggered by certain phases of the moon. All of them had to be amazed by the fact that while the only other body in the sky, the Sun, disappears completely, the Moon is omnipresent. All of this gave ample “evidence” that this entity was indeed a god.

As time passed, our world grew smaller with the advent of science. Increasingly more of our world was explained each day and the facets of nature that once fascinated and astounded us became old hat. It was in this golden age of discovery that the Moon was finally “discovered” for the satellite that it is. Yet, even this landmark discovery is shrouded in mystery.

The Mystery of Who Saw It First

Ask any science teacher who discovered the Moon and they will likely tell you it was Galileo Galilei, the Italian astronomer. After all, he not only saw and drew the Moon, but also four of Jupiter’s moons and several planets. However, it is well known that these drawings date to early 1610 and that is where the problem starts.

A recently discovered sketch of the Moon clearly denotes the line between the near side and the dark side as well as the three main Mares (seas) and other prominent features that were also noted by Galileo. The problem is that this newly found sketch is dated 26 July 1609!

That is roughly six months before Galileo’s drawing of the Moon.

So, who is this mysterious artist who may steal Galileo’s thunder? The sketch came from the notes of English Astronomer Thomas Harriot. His sketch, based on observations made through a telescope, is now believed by many to be the first official discovery of the Moon.

So, who discovered the Moon? It depends on who you ask. However, all empirical evidence points to Thomas Harriot.

How the Moon Got Its Name

It may seem odd that our one natural orbiting satellite — the Moon — has no name while those of all the other planets (109 total) bear the names of Greek and Roman heroes, gods, and other entities. (Except Uranus, whose moons are named after Shakespearian characters. However, at the time that the Moon was first seen, it was the only one that anybody knew about. Until Galileo’s 1610 discovery of four of Jupiter’s moons, nobody knew there would be more than one.

The word “moon” is believed to come from the ancient Greek name for the celestial body, Mene. The Greeks also called it Selene, which was their moon deity. The Romans called it Luna after their own moon goddess. A name which has led to many moon-based words such as lunar and lunatic.

Yet, the name Moon stuck even after we learned that it was not alone in the night sky. Why? Many believe it is because this name is universal to every culture without a specific claim to it from one. Others chalk it up to pure laziness. Whatever the reason, the Moon may be one of many, but it is still one of a kind.

Cultural Significance of the Moon

As previously discussed, nearly every culture had some sort of position of honor for the Moon within its traditions and beliefs. The Chinese still celebrate the Moon Festival on the 15th day of the 8th month of the lunar calendar. The Moon impacts several areas of the Hindu religion as well. Representing several deities and a number of other important concepts and values. Even Western Christianity has Moon-centered traditions. Easter is celebrated on the first Sunday after the first full moon following the vernal equinox. The Moon is also a central figure in many Pagan religions.

To the Moon

The Space Race of the late-1950s through the mid-1970s saw the world’s two great superpowers, the U.S.S.R. (now Russia) and the U.S.A. racing to be the first to the Moon. What this meant exactly, nobody was quite sure, but eventually, it led to human beings walking on the Moon.

It took several failed and successful attempts, on both sides, to make the Moon landing a reality. Take a look back through the years to see how close the U.S.S.R. came to beating the U.S. to the Moon. These successful missions are historically important as they all set the stage for what came after, the first human on the Moon.

  • September 1959: Soviet Luna 2 was the first space shuttle to crash land on the Moon.
  • October 1959: Luna 3 captured the first images of the far side of the Moon in a flyby mission.
  • July 1964: The U.S. launched its first successful impactor mission with the Ranger 7 space shuttle.
  • March 1965: The U.S. sends Ranger 9 for a third impactor mission to the Moon.
  • July 1965: The Zond 3 is sent up by Russia to do a flyby.
  • January 1966: The Russian Luna 9 module is the first successful controlled landing on the Moon.
  • March 1966: Luna 10 orbits
  • October 1966: Luna 12 orbits
  • November 1966: The first U.S. shuttle to successfully orbit the Moon launched, Lunar Orbiter 2.
  • September 1968: USSR Zond 5 mission is the first to land on the Moon containing live animals.
  • December 1968: The Apollo 8 orbits the Moon with the first shuttle crewed by humans.
  • May 1969: Apollo 10
Astronaut on Lunar Moon Landing Machine

The next date on the list is July 16, 1969. The day that Apollo 11 was launched. Four days later on July 20, 1969, a man set foot on the Moon for the first time in history. When the Apollo 11 shuttle landed on the Moon and the door opened, the whole world held their breath. A televised event, people gathered around their televisions to watch grainy images of Neil Armstrong climbing weightlessly down that ladder and taking those first tentative steps for mankind. It was a moment that forever changed the landscape of the human experience.

Six more manned missions followed from November 1969 through December 1972 with all but the Apollo 13 mission in April of 1970 successfully landing people on the surface of the Moon. Soon, other countries joined the exploration of space. Japan, the People’s Republic of China, and India all developed successful space programs. The European Space Agency and a company in Luxembourg also succeeded in launching expeditions to the Moon. Israel has tried, but at the time of this writing, no successful space missions could be found.

Moon Culture

The Moon figures prominently in American culture as well as those of others around the world. Movies, television programs, songs, and even automotive manufacturers (think Mitsubishi Eclipse, moon roofs, etc.) tie themselves to the Moon. Even common phrases take the Moon into consideration.

  • Once in a Blue Moon: A Blue Moon is the second full Moon of the month.
  • Moonstruck: A phrase meaning dazzled or bewitched.
  • Lunatic: A word created from the erroneous idea that the Moon could cause insanity.
  • The Man in the Moon: A trick of the markings on the Moon’s surface that makes it appear to have a face. Many different cultures had myths to explain who this “man” was.

There is Sailor Moon, a Japanese cartoon from the late twentieth century. Moonlighting is a word that means working a second job, usually at night. It was also a popular television show starring Bruce Willis and Cybill Shephard in the late 80s. Bad Moon Rising was a popular song by the band Creedence Clearwater Revival.

Truly, the Moon is as big a part of our daily lives as it is the night sky.

Wrapping It Up

While the Moon is something few of us will ever reach, it is not out of the question. Humanity once looked at the Moon as a god, to be feared and worshiped. Today, it continues to capture the imaginations of many and inspire poetry and prose alike.

Venus

Here’s What You Need to Know About the Planet Venus

Venus is the second plant in our solar system. Its name comes from the Roman deity ‘Venus’: the goddess of love and beauty. The Romans likely considered her one of the most beautiful goddesses in the pantheon because Venus is the brightest of the five planets that ancient astronomers knew about.

Ancient astronomers thought that Venus was two different stars, Lucifer (morning star) and Vesper (evening star) visible at sunrise and sunset respectively. But further observations of the planet in the space age revealed a hellish environment.Observing the planet up close was extremely difficult, though,because the environment quickly destroys spacecraft.

10 basic facts about Venus

Space Station

Here are 10 important facts about Venus.1. Venus is about the same size as earth. If Venus and Earth were the size of nickel, the sun would be the size of a standard font door.2. Venus is about 108 million kilometers (67 million miles) away from the sun.3. Venus spins backwards, so the sun rises in the east and sets in the west on Venus and one day on the planet is equal to 243 days on Earth.4. Venus’s landscape is mainly vast plains that feature extensive ridged plateaus and high volcanic mountains.5. Venus has no moons and rings.6. Venus’s surface temperature is about 465 degrees Celsius (900 degrees Fahrenheit), a temperature high enough to melt lead.7. Venus has been explored by more than 40 spacecraft.8. Venus has been explored by more than 40 spacecraft.9. Venus’s hellish temperatures and acidic clouds make it inhabitable.10. Venus rotates slowly but has hurricane force winds that blows clouds all the way around planet in five days.

Who discovered Venus?

Venus is easy to see with your naked eye. It’s the second most visible celestial non-star object in the sky, the first being the moon. So, as humans, we’ve always been aware of the planet since we looked up at the sky. Besides Venus, you can also see Mercury, mar, Jupiter and Saturn with the naked eye.

However, ancient astronomers had no knowledge of Venus beyond being a shiny object they saw in the morning and evening sky. This was until Copernicus came up with his theory of a heliocentric solar system in which the sun is at the center and planets orbit it. This was when astronomers recognized Earth and Venus as planets.

In 1610, Galileo used his telescope to observe Venus and realized that it went through phases like the moon, thereby confirming Copernicus’ theory. These phases matched Copernicus’ predictions and showed that Venus is a planet that orbits the sun, and not Earth. This theory become more evident in December 4, 1639, when Venus transited across the sun’s surface. Venus’s most recent transit was in 2012 and the next one will be in 2117.

Does Venus have special relevance in any culture?

Venus has featured considerable in human culture; more specifically, in religion and myth. Many writers and poets have also sought inspiration from the planet. In classical Greek mythology, Venus was called Lucifer, fabled son of Cephalusand Aurora and bearer of the morning torch.

Sumerians in ancient Mesopotamia associated Venus with the goddess Inanna, later known as Ishtar by the Babylonians and Akkadians. She was the goddess of love and war and presided over birth and death. Ancient Canaanites personified Venus as the god Attar, a masculine variation of Ishtar. The planet often represents the goddess Anahita in Persian mythology. In Islamic tradition, Venus is called Zohrah and is associated with a “beautiful woman.”

Pop culture references to Venus

In pop culture, the term Venus evokes thoughts of femininity. Among the most famous examples of this is the iconic relationship guide titled “Men are from Mars, Women are from Venus.” In the context of the solar system, Venus was a popular setting for many science fiction writers in the 20th century. Before we learned about what lay beneath the furtive cloud cover of the planet, these writers imagined it as being a more habitable planet.

Here are books based on ideas writers had before we learnt the true nature of the planet.• Achille Eyraud’s Voyage to Venus (1865)• Garrett P. Serviss’ A Columbus of Space (1909)• Frederik Pohl and C.M. Kornbluth’s The Space Merchants (1953)• S. M. Stirling’s The Sky People (2006)• Stephen King’s short story “The Cursed Expedition”

The following are stories based on updated ideas after space exploration revealed the nature of the planet’s surface.• Stanisław Lem’s book Astronauci (The Astronauts) (1951)• Felix Thijssen’s Dutch novel “Pion” (1979)• Ben Bova’s novel Venus (2000) from his “Grand Tour” series• Geoffrey A. Landis’s “The Sultan of the Clouds” (2010)• James S. A. Corey’s Caliban’s War (2012)

Classic movies about Venus include• Queen of Outer Space (1958)• 20 Million Miles to Earth (1957)• Abbott and Costello Go to Mars (1953)• Stranger from Venus (1954)• Voyage to the Planet of Prehistoric Women (1968)

Venus has served as the backdrop in video games such as Destiny, Battlezone and Transhuman Space.

Space-related expeditions to Venus

The United States, European Space Agency, Soviet Union and Japanese Aerospace Exploration Agency sent more than 20 spacecraft in total to Venus. In 1962, NASA’s Mariner 2 came within 34,760 km (21,600 miles) of the planet. The Soviet Union’s Venera 7 made the first landing to Venus and Venera 9 was the first to return with photos of the planet’s surface.NASA’s Megallen was the first Venusian orbiter and it used radar to generate maps of 98 percent of the Venusian surface, showing details of features as small as 100 meters (330 feet) across.

The Venus Express from the European Space Agency orbited Venus for eight years with numerous equipment and confirmed the presence of lightning on the planet. Japan’s Akatsuki set out for Venus in 2010 but went hurling into space after a pivotal orbit-insertion burn killed the main engine. However, Japan’s next craft successfully entered Venus’ orbit in 2015 and spotted an additional “gravity wave” in the planet’s atmosphere in 2017.

In recent years, the Russian Academy of Sciences’ Space Research Institute and NASA have discussed about a joint Venera-D mission to Venus that would launch around the year 2020.

Pluto

The mysterious and elusive Pluto is such a tiny member of the Solar system, yet it has been making notable headlines for nearly 100 years. First identified in 1930, it was soon named and classified as the ninth planet in the system. But with the passing of time, advanced technology and the discovery of many other objects at the far reaches of the system caused Pluto’s status to be downgraded to a dwarf planet, amidst significant scientific community controversy and public outcry. Recent images and data from spacecraft have opened new avenues of understanding about Pluto, and have revealed many surprising truths about it and its moons.

Just The Facts

Some basic information about Pluto:

Pluto_characteristics

Size

Pluto is only about 1,400 miles in diameter. That’s about 2/3 the size of the Earth’s moon, or roughly equivalent to the half the width of the United States. It’s about 1/30th the mass of Mercury, the smallest planet in the Solar system.

Location

Pluto resides in what is called the Kuiper Belt, or the Trans-Neptunian area just outside the orbit of the planet Neptune. Dark and cold, this band contains a number of smaller objects plus several other dwarf planet candidates.

Moons

Pluto_Charon

Though small in dimension, Pluto retains five moons of its own. The largest, Charon, is about half the size of Pluto and the two orbit each other much like a double planet. The other moons are much smaller and are named Nix, Hydra, Kerberos and Styx.

Environment

The terrain of Pluto includes ice plains, highlands, mountains and craters. There is an atmosphere consisting of nitrogen, methane and carbon monoxide. Being about 40 times farther from the sun than Earth, temperatures remain nearly 400 degrees below zero Fahrenheit.

Status

Originally Pluto was designated as the ninth planet of the Solar system, but after other similar objects were discovered in the same Trans-Neptunian region, it was reduced to dwarf planet status.

History and Discovery

Pluto was discovered in 1930 by a young astronomer named Clyde Tombaugh. Tombaugh was working at the Lowell Observatory, named after the noted astronomer Percival Lowell. Tombaugh believed, as Lowell also had previously, that there was evidence of a mysterious planet appearing in constellation maps beyond Neptune. In February of 1930, he found his proof and the object was positively identified as a planet.

Venetia Burney, a young girl from Oxford, England, suggested to her grandfather that the new planet be given the name Pluto, a mythological figure. He contacted the observatory with the suggestion, and it was officially accepted.

Modern Discoveries

Little else was known about the planet until the discovery of Pluto’s largest moon, Charon, in 1978. Charon surprisingly turned out to be about half the size of Pluto, and the two actually orbit each other very similar to a double planet. Technology continued to improve for long-range observations, and the other four moons were eventually discovered beginning in 2005. They were given the names Nix, Hydra, Kerberos and Styx, which are also names of mythological figures.

About this time other bodies were being discovered in the Trans-Neptunian region, and at least one gave indications of being larger than Pluto. This caused increased discussions among the scientific community about how to define a planet, resulting in Pluto being reduced in classification from a planet to the newly termed “dwarf planet” designation.

Recent Exploration

Only one spacecraft has ever visited the Pluto system. In 2015 the NASA spacecraft New Horizons passed through the system and provided a series of astounding close-up photographs of Pluto and its moons. These images, coupled with other expansive collections of data from the craft, have given the scientific community a wealth of new information to analyze and interpret regarding Pluto and its system. Although tiny and seemingly insignificant, Pluto continues to surprise everyone with its elaborate structure, associated atmosphere and its various orbiting bodies.

Trivia and Oddities

  • Very Small. Pluto is extremely small. Its diameter is roughly half the width of the United States or about 1/40th of the size of the smallest planet in the Solar system.
  • Glacier. There is a large glacier on Pluto that is about the size of the states Texas and Oklahoma put together.
  • Extreme Cold. Pluto exists beyond all eight planets of the Solar system, approximately 40 times farther from the sun than the earth. The temperatures on Pluto remain at nearly -400F.
  • Blue Skies. In spite of the extreme environmental conditions, Pluto actually has an atmosphere consisting of nitrogen, methane and carbon monoxide. This combination of gasses gives the skies a blue tint and a hazy appearance.
  • Disney Character. Pluto was discovered and named early in 1930. Later that year, Disney introduced a new character in their cartoons, Mickey’s dog Pluto. Many have speculated that Disney released the character to ride the wave of public enthusiasm over the new planet, but nothing official was ever established.
  • Many Moons. Even though Pluto is so small, it surprisingly turned out to have five moons in orbit around it. The largest is nearly half its size and creates a unique dual-orbit phenomenon.
  • Roman God Name. Pluto was named after a Roman god by an 11-year-old girl in 1930. Pluto is the god of the underworld in Roman mythology.
  • Slow Days. The orbit of Pluto around the sun is much slower than Earth’s. In fact, it takes almost 250 Earth years for one year to pass on Pluto. Each day is slow as well. One day on Pluto takes about 6 days on Earth.
  • Distant Sun. Pluto is so far from the sun that it takes light about 4 and a half hours to make the journey to reach it. For comparison, light travels from the sun to the Earth in just over eight minutes.

Mercury

As the closest planet to the sun in the solar system, you might expect that Mercury would be the hottest planet in the solar system. But much like the desert on our earth, Mercury actually doesn’t maintain heat all that well. When the sun shines directly on it, Mercury is indeed a very hot place to be, as the temperature can top 800 degrees Fahrenheit, well above the melting point of several metals. But at night, the temperatures can drop to -279 degrees Fahrenheit, which is almost cold enough to turn oxygen to liquid.

Why doesn’t heat stay in place on Mercury? It’s because it’s the only planet in the solar system that doesn’t have a real atmosphere above its surface. While Venus has a thick, cloudy atmosphere, Mercury offers only the slightest exosphere, which does next to nothing to block the sun’s rays from its surface. This results in Mercury’s surface temperature heating up rapidly during the day, while cooling quickly when the sun’s rays disappear for the day.

History and Facts About Mercury

Mercury Facts

Like the rest of the five planets that can be seen with the naked eye, Mercury’s existence has been known to astronomers and the general public alike for centuries. The planet received its name in ancient times from Roman mythology, and Mercury’s name comes from the Roman messenger of the gods, who was known for his speed, symbolized by his winged sandals. Other instances in popular culture include books by C.S. Lewis, Ray Bradbury and the Bill Watterson comic Calvin and Hobbes.

The speed of the Roman god was likely the reason for Mercury’s name, as the planet is by far the fastest of all of the eight planets in its orbit around the sun. One complete revolution for Mercury takes a mere 88 days, and one earth year is the equivalent of just over four years on Mercury.

Ironically, while Mercury spins around the sun very rapidly, it is incredibly slow in spinning on its own axis. One complete rotation on Mercury takes 59 days, meaning that a year is long enough to sustain only a day and a half’s time on the planet. Given how long a day takes and how cold the planet gets at night, it’s hardly a surprise that life has never been found on Mercury.

Virtual Image of Mercury

At its closest point to the sun, Mercury is a mere 36 million miles away from the sun, which makes it impossible for the planet to sustain a moon in its orbit. In fact, nothing but dust orbits Mercury, in part because of its smaller size as well as its distance from the sun. Mercury is only about one-third the size of the earth and is even smaller than the moons that orbit some of the gas giants, making it unable to sustain the gravitational pull that is required for a celestial body to orbit the planet. Even if Mercury was a greater size, the gravitational pull of the sun would make it virtually impossible for anything to orbit Mercury instead of the sun.

Discoveries Related to Mercury

Mercury’s recorded history dates all the way back to 265 B.C., when Timocharis made the first observation of the planet in the night sky. Since that time, little new information has been discovered about the closest planet to our sun. In fact, Mercury took longer to see than planets that were further away because of just how close it is to the sun, as the planet can only be seen in the twilight of the sun.

As one of the four inner planets, it is technically possible for a spaceship to land on Mercury’s solid surface, but none has attempted it to date, likely because the conditions on the planet are too harsh for a spacecraft to survive on the planet’s surface for long. The only real informationwe have about the planet’s surface comes from one fly-by of the planet during the 1970s by Mariner 10 and one orbit of the planet by the Messenger probe, which entered Mercury’s orbit in 2011.

Why Is Mercury Hard to Explore?

sunset

The challenges that come from exploring Mercury have to do with the planet’s proximity to our sun. While it does have a surface that makes landing technically possible, unlike that of Jupiter or Saturn, the gravitational pull of the sun makes it very difficult for a probe to reach the speed and structure that it needs to get close to Mercury without being swallowed up by the sun’s gravitational pull. Another major difficulty with exploring Mercury comes from the solar radiation that comes from being so close to the sun’s rays.

Being just 35 million miles from the sun requires the surface of a spacecraft to be strong enough to withstand the solar radiation, which is four times that of the radiation that is present on earth. With little atmosphere available to protect a spacecraft from the sun’s rays, it has proven beyond the abilities of modern science to break through the challenges of exploring Mercury and finally provide a complete picture of what the existence is like on the closest planet to the sun. Only the Messenger probe has made a successful entry into Mercury’s orbit, a process that took six years from launch date.

The Future of Mercury

However, this hasn’t meant that scientists have stopped trying in their efforts to explore the sun’s nearest planet. The BepiColombo mission is scheduled to arrive in the planet’s gravitational pull in 2025, and it aims to build off the work that was first started by Mariner 10 and Messenger to give us a greater picture of Mercury’s surface, movement and other secrets about the planet’s existence.

Whatever the results are of the new mission, it’s likely that scientists will keep trying to build a better spacecraft in accordance with advancing technologies until they’re able to find the answers regarding Mercury’s existence that allow them to ask new questions about the fastest revolving planet in the solar system.

Exploring Mars: Then and Now

Humans have always been fascinated by Mars, from the notion that life may have existed on the planet to the possibility that we could one day set foot there.

This unique planet is Earth’s second-closest neighbor, after Venus. It is 35.8 million miles away, but Mars is the planet most similar to Earth. It is solid and rocky, with familiar surface features such as canyons, valleys, mountains, and volcanoes. There is evidence that water—important for sustaining life—existed on Mars as recently as one billion years ago.

Quick Facts About Mars

  • Mars is the fourth planet from the sun.
  • Its average temperature is a chilly -81 degrees Fahrenheit.
  • Mars takes 24 hours and 37 minutes to rotate on its axis, making its day slightly longer than an Earth day.
  • It takes 687 Earth days for Mars to orbit the sun.
  • Measuring 4,220 miles in diameter, Mars is about half the size of Earth. Only Mercury is smaller.
  • Gravity on Mars is 38% of Earth’s, which means a 20-pound weight on Earth weighs only 7.6 pounds on Mars.

Early Discoveries

Mars

Mars is one of the five brightest planets in the night sky and has been visible to the naked eye for thousands of years. Its reddish-orange appearance comes from particles of iron oxide or rust on its surface and in its atmosphere.

Ancient civilizations could see Mars glowing red in the sky, and associated the planet with the blood of a battle. The Romans named Mars after their god of war. The planet’s two moons are named for the horses that pulled the chariot of Ares, the Greek god of war: Phobos means “fear” and Deimos means “terror.”

Many early scientists contributed to the body of knowledge relating to Mars. These include:

1610: Italian astronomer Galileo Galilei made the first observation of Mars through a telescope.

1659: Dutch astronomer Christiaan Huygens prepared the first map of Mars showing features of its terrain.

1781: British astronomer William Herschel calculated the axial tilt of Mars to be similar to Earth, and concluded that Mars experiences distinct seasons.

1877: American astronomer Asaph Hall discovered that Mars has two moons and calculated their orbits.

Recent Exploration of Mars

Relatively speaking, Mars is one of the easiest places in the solar system to reach from Earth, and space organizations from around the world continue to send orbiters, landers, and rovers to collect data and enhance scientific understanding.

The first flyby of Mars was completed in 1965 when the Soviet Union’s Mariner 4 probe traveled 5,900 miles from the surface of Mars. It transmitted 21 images of the planet.

Eight unmanned spacecraft have landed on Mars. The first was Mars 2, a probe launched by the Soviet Union. It crashed on the impact on November 27, 1971, but was the first manmade artifact to touch the planet’s surface. Its twin spacecraft, Mars 3, landed on December 2, 1971. Although its rover was damaged, Mars 3 began sending the first picture from Mars before transmission ceased.

In 1976, the United States successfully landed two probes. Viking 1 and Viking 2 sent the first color pictures from Mars, as well as scientific data related to temperature and pressure change.

The first remote-controlled rover to roam Mars landed in 1997 as part of NASA’s Mars Pathfinder mission. Other rovers followed, including Spirit and Opportunity, which landed on opposite sides of the planet in 2004. Data provided by Curiosity, which landed in 2012, has led scientists to conclude that water once flowed in an ancient streambed on Mars, the planet had the proper chemistry to support life, and radiation on Mars could pose a health risk to humans.

Future Missions

Life on Mars

NASA operates a comprehensive Mars Exploration Program that is seeking signs of life on the planet, exploring habitability and preparing for human exploration. Other countries are also planning missions in the near future. Orbiters and rovers expected to launch in 2020 include the Hope Mars Mission from the United Arab Emirates, ExoMars 2020 from Europe and Russia, and the Mars Global Remote Sensing Orbiter and Small Rover from China, which aims to collect a soil sample and return it to Earth.

In the private sector, Elon Musk, the CEO of Tesla, is ambitiously planning to send manned missions to Mars with the possibility of establishing a settlement in our lifetime.

Mars in Popular Culture

While researchers continue to gather scientific evidence about Mars, writers, filmmakers, and other artists have created fictional worlds. As early as 1897, H.G. Wells wrote his famous novel War of the Worlds. His story of Martians invading Earth was later dramatized on a radio broadcast by Orson Welles in 1938.

Ray Bradbury published a collection of stories in 1950 called The Martian Chronicles, imagining a world where humans colonized Mars. Even John Gray’s 1992 self-help book, Men are from Mars, Women are from Venus uses the planet as a metaphor for differences and misunderstandings.

Animator Chuck Jones created the Looney Tunes character Marvin the Martian in 1948, a comedic villain that wore armor similar to the Roman god Mars. Popular live-action movies involving the red planet include Total Recall (1990) with Arnold Schwarzenegger, which was remade with Colin Farrell in 2012; Mars Attacks (1996) with Jack Nicholson and Glenn Close; Mission to Mars (2000) directed by Brian De Palma; and The Martian (2015) starring Matt Damon and based on the book by Andy Weir. The iconic David Bowie sang about Life on Mars? in 1971.

Additional reading:

Make Mars Habitable Again: Scientists Unveil New Plan to Allow Life on the Red Planet

This Material Could Make Parts of Mars Habitable for Humans, Study Says

Earth

Earth is the planet we all live on and call our home. But how much do you know about Earth, it’s history and all the amazing facts about it? Our planet is truly a remarkable celestial object that gives us life and allows us to thrive. The earth is massive in its size and complicated in its processes. We have yet to fully understand everything about our planet and the way it functions, but we know a lot. And the facts that we do know are fascinating!

Everything Earth! Size, Shape, Composition

The Earth is the third planet from the sun and the only, to date, astronomical object to harbor life. It’s the fifth-largest planet in the solar system. The shape of the Earth is often pictured as a circular globe, but to be more exact, is an oblate spheroidal. The Earth bulges around the equator and flattens at the North and South poles, due to it’s rotating nature.

Astronomical background. 3D render.

Like all planets, the Earth rotates around the sun, with one complete orbit taking 365.2564 days, which accounts for our calendar year. However, the Earth’s rotation is very gradually slowing down, at a rate of about 17 milliseconds per hundred years. This is causing our days to lengthen, but it’ll be another 140 million years before the average day lengthens to 25 hours.

The Earth is the densest planet in the solar system and is made up of mostly silicon, oxygen, and iron. Approximately 70% of the planet is covered in water, but only 3% of that water is fresh while the rest is salted.

Seasons, Daytime & Night Explained

Our planet wouldn’t be what it is today without our Seasons and the cyclical shift between day and night. The Earth is able to have it’s four seasons because the Earth is tilted 23.4 degrees on its axis (the imaginary straight line from the South Pole to the North Pole). This tilts allows different parts of the globe to be positioned towards or away from the sun at different times of the year.

Additionally, the Earth travels around the sun at a rate of approximately 30 kilometers per second. While the planet is orbiting, it also spins on its axis. So, as Earth rotates, the side facing the sun receives daylight, and the other side is dark.

When Was Earth Created?

The Earth is estimated by scientists to be 4.54 billion years old, with an error range of 50 million years. Scientists were able to determine the approximate date of the planet by examining the Earth’s every-changing crust and the rocks in neighboring planets such as the moon and landed meteorites.

For comparison, our solar system (which is contained in the Milky Way galaxy) is thought to be 13.2 billion years old, and the universe is estimated to be 13.8 billion years. In comparison, our planet is quite young!

Who Named the Earth?

The Earth is the only planet in our solar system not named after a Greek or Roman deity. All the other planets (Mercury, Venus, Mars, Jupiter, and Saturn) were named in ancient periods because they were visible to the naked eye. Later on, when Uranus was discovered (March 13, 1781) and Neptune (September 23, 1846), the tradition of naming planets after Greek or Roman gods was upheld.

So, who named the Earth? The quick answer is that it’s unknown. The word ‘Earth’ is derived from both German and English words ‘erde’ and ‘eor(th)e/ertha’ respectively, which mean ground. The association with ground or soil is because the Earth was named before people understood it’s a planet, and they simply focused on the ground they walk on. However, it’s still unclear who christened our planet with its name.

The History of the Earth

The Earth originated as a large cloud of the nebula (a type of gas) that collapsed into itself because of its size. Over a hundred thousand years after the collapse, the Sun formed at the center of a protoplanetary disc, with the nebula gas swirling around it. Gases and other materials around the disc started to clump together in certain spots and constant collisions between these bodies formed planetesimals (miniature planets).

The ice planets, Uranus and Neptune, and the gas giants, Jupiter and Saturn, formed much quicker than the four terrestrial planets: Venus, Mars, Mercury, and Earth.

Earth

When a body of material the size of Mars slammed into the Earth, a portion of the surface was liquified and ejected as molten debris into space. This ejection of material would eventually form the Moon.

At some point, as the Earth was cooling from the formation of the Moon, comets or asteroids slammed into the Earth, carrying large amounts of water or ice. This brought large sources of water vapor to Earth, which would eventually form our oceans with the assistance of volcanic activity.

The Earth’s atmosphere remained toxic for a long time, with large amounts of nitrogen, sulfur, and carbon monoxide (due to the volcanic activity) and little oxygen. Tiny portions of the landmasses would emerge but would be swallowed up by lava quickly. It would take another half a million years before tiny landmasses would begin to form permanently. The oldest rocks found on Earth have been traced back to this point in time, are now in Australia, dating back to 4.4 billion years ago.

Although the Earth still had little oxygen present, there was life on Earth. Evidence has been found of certain biological activity that was able to live in the water with certain levels of carbon. Many attribute the presence of water on Earth as why life was first created on the planet.

The Earth we know today would never have been possible without high levels of oxygen in the atmosphere. Due to the frequent volcanic activity, there were high amounts of carbon in the air. You need plant life to create oxygen and absorb carbon monoxide. Eventually, miniature organisms of bacteria were able to form using the oxygen in the water and the light from the sun. This was an early version of photosynthesis.

As the frequency of photosynthesis increased, more oxygen was released into the atmosphere. Existing life forms on the planet that we’re unable to ingest the new, higher amounts of oxygen perished. This period was known as the Great Oxygenation Event.

Next, the rise of oxygen removed significant portions of the methane in the atmosphere. The removal of methane and the increase in oxygen lowered the temperature of the Earth, causing the Ice Age.

Glacier Perito Moreno National Park in Argentina, Patagonia

After the Ice Age, life thrived again in plant organisms. Eventually, larger organisms such as mammals, insects, reptiles, and humans inhabited the planet. The evolution of life was only possible due to the unique conditions on Earth of the right temperature, atmosphere, and resources.

The Human Timeline & Earth

Humans are primates, and we have been genetically traced back to having a close relationship with another primate species, the apes. The human primate species was able to evolve to gain the characteristics and attributes that define the human species today.

Six Million Years Ago: The first readily accepted link to human beings has been linked back to a primate group based in Africa called Ardipithecus. This is the group responsible for beginning to walk upright. Walking upright freed up our hands, giving us the ability to use our hands for weaponry, toolmaking, and addressing other survival needs.

Four Million – Two Million Years Ago: The next group, the Australopithecus group, could walk upright but also began to climb trees. This allowed humans to hunt and gather more efficiently. People could pick fruits and climbed trees to escape danger, predators, and scan the landscape for water and resource.

Three Million – One Million Years Ago: The Paranthropus group is known for adapting larger teeth, which allowed humans to have a wider diet, and become stronger.

Two Million – 200,000 Years Ago: Scientists estimate that the Homo group appeared on our planet approximately two million years ago. This group includes the evolution into the Homo Sapiens, which is our species, about 200,000 and 300,000 years ago. The Homo group is characterized by larger brains and greater tool-making ability, which allowed us to explore outside of Africa. We managed to survive against the climate change conditions of the time and began exploring the entire world.

Scientists have mapped out that the journey taken by this species started with the first explorers using the Bab-al-Mandab Strait to explore Eurasia, and then to India. As little as 50,000 years ago, humans explored Australia and southeast Asia. Explorations into the Middle East allowed people to further go to Europe and Asia. It’s estimated, 20,000 years ago, people used a land bridge that been formed by glaciation, to cross over to North America.

Evolution of mankind towards a world hyper-connected and led by social networks.

Leaving Our Planet

Unlike what you see at the movies, Earth has never experienced some form of alien-life takeover. Instead, quite the opposite is true. Humans have always had a fascination with the universe and have attempted (and succeeded) into venturing into outer space many times!

Spaceship launch at night, landscape with colorful smoke clouds and galaxy background. The elements of this image furnished by NASA.

The First Space Exploration

The first human exploration into space was conducted by the Soviet Union. On Oct 4, 1957, the Soviet Union sent the first artificial satellite, named Sputnik 1, into space. Just a short four years later, Russia would send Yuri Gagarin to become the first human to orbit the Earth in spaceship Vostok 1, on April 12, 1961. His entire trip lasted 108 minutes.

The United States wasn’t going to be left behind and quickly launched its efforts into space exploration. On January 31, 1958, just one year after the Sputnik 1 launched into space, America sent Explorer 1 as the first U.S. satellite to orbit the moon. And, one year after Yuri went into space, America sent John Glenn into space on February 20, 1962, making him the first American to orbit the Earth.

The Future of the Earth

Earth’s long-term future is directly tied to the Sun. Many aspects need to be regarded when considering the future of the earth including the chemistry at the Earth’s surface, the gravitational interactions with the other planets and objects in the Solar System, resources, and the Earth’s atmosphere. The living organisms that inhabit the Earth can only live in a particular set of circumstances. If the Earth was to drastically increase or decrease in temperature, it can cause resources to die. As a result, the living organisms dependent on those organisms would also perish.

Additionally, if the Earth’s proximity to the Sun was to change, this could have drastic impacts on the Earth’s climate. Lastly, if the Earth’s atmosphere was to change too significantly, it could result in the current inhabitants of Earth being unable to live on the planet anymore (as what happened with the Great Oxygenation Event).

Eventually, the Earth will die. The Sun is a star, and all stars eventually die. As the Earth is so dependent on the Sun, when the Sun dies it, will cause our planet to perish. However, the timeline for this is expected to be quite long, it’s estimated this wouldn’t happen for another seven to eight billion years.

A large Meteor burning and glowing as it hits the earth’s atmosphere. 3D illustration.

Before then, there are other possible threats to the planet we call home. There is a threat of a volcanic apocalypse, an asteroid threat, the core freezing over, or a Gamma-ray burst. These are events that are either random or very difficult to predict, so it’s about the same as worrying about getting hit by a car. It could happen, but it’s mostly out of your control!