• The solar system consists of our star, the Sun, eight planets, dozens of moons, a multitude of comets, asteroids, and space rocks, along with several dwarf planets such as Pluto. Everything is bound to the Sun by gravity.
• The Solar System was formed 4.6 billion years ago from a cloud of gas and dust called the solar nebula. A shockwave from a nearby supernova (a massive star) explosion likely initiated the process. The Sun formed in the center, and the planets formed around it.
• The solar system is part of the Milky Way. There are at least between 250 to 500 billion stars in our Milky Way galaxy—possibly even more. That’s at least 30 times more stars in the Milky Way than there are people on Earth.
• The Solar System has eight planets—Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune—followed by the dwarf planet Pluto.
• Earth is only a small part of the Solar System. Although Earth is significant, within the solar system, it is relatively small. It would take 1.3 million planets the size of Earth to fill up the Sun. Earth is much smaller than planets like Jupiter and Saturn.
• The Sun is 93 million miles from Earth—that’s the same as taking 1000 trips to Australia! Despite its considerable distance, light from the Sun only takes 8 minutes to travel to Earth.
• All planets and the Sun in the Solar System are shaped like spheres. In the past, people believed the Earth was flat, but now, with satellite pictures, we can prove that it is a sphere. Similarly, all planets and the Sun are spherical.
• Planets in our Solar System have different temperatures. Venus is the hottest planet with an average temperature of 460°C, while Uranus is the coldest with an average temperature of -220°C. In comparison, Earth’s average temperature is 15°C.
• There are 181 moons in the Solar System, and scientists are continually discovering more. Additionally, there are 552,894 asteroids and 3,083 comets in the Solar System.
• Neptune was the last planet to be discovered in the solar system. On the night of September 23, 1846, astronomers identified Neptune through a telescope.
• We can observe some of the Solar System from Earth. For example, we have all seen the Sun and our Moon. Venus is also visible, making it the brightest object in the night sky after the Moon.
• The Sun is the largest and most powerful object in our Solar System, providing us with light, heat, and energy. It is the source of all life on Earth.
• Many ancient civilizations considered the Sun to be a deity. As the essential source for growing food and sustaining life on Earth, it was logical for people to perceive it as a God.
The surface temperature of the Sun is 5,505 °C. While we know the Sun is hot, its exact temperature is an astonishing 5,505°C.
• The Sun’s light reaches the Earth in eight minutes, a phenomenon known as the speed of light.
• Occasionally, spots on the Sun erupt and interfere with our mobile phone signals. These eruptions can disrupt satellites, affecting the functionality of phones, GPS systems, and televisions.
• All the planets in our Solar System orbit the Sun, meaning they revolve around it. Earth takes 365 days to complete one orbit, defining a year.
• The Sun is composed mainly of Hydrogen and Helium. Approximately 74% of the Sun is made up of Hydrogen, while 24% is Helium.
• Eclipses, where the Sun disappears in the day, are caused by events in the Solar System. They occur when the Moon is positioned between the Sun and Earth.
• The Sun is the center of the Solar System, with all other planets orbiting around it. About 1 million Earths could fit inside the Sun. Despite appearing unique due to our proximity, it is an average-sized star compared to others.
• Life on Earth wouldn’t exist without the Sun. Additionally, the Sun influences seasons, ocean currents, weather, and climates on our planet.
• Mercury is the closest planet to the Sun and the smallest planet in our Solar System. It is the first planet in the Solar System and is named after the Roman Messenger God.
• It is a Rocky Planet with a solid surface covered with craters, resembling the moon.
• Mercury’s year is only 88 Earth days due to its close proximity to the Sun, resulting in short orbits. This means if you lived on Mercury, you’d celebrate New Year’s every 3 months.
• A day on Mercury takes 59 Earth days. Because Mercury spins so slowly, it takes 59 Earth days to complete a full rotation.
• Mercury is the second hottest planet in the Solar System, even though it is the closest to the Sun. Venus, with a temperature of 471°C, is hotter than Mercury, which reaches 430°C during the day and drops to -180°C at night.
• Mercury has been visited by two spacecraft – Mariner 10 and MESSENGER. NASA’s Mariner 10 was the first spacecraft sent to study Mercury. MESSENGER, a NASA robotic space probe, orbited the planet between 2011 and 2015, studying its chemical composition, geology, and magnetic field.
• Mercury has a very low surface gravity, attributed to its lack of atmosphere, which means there is no wind or weather.
• Mercury’s surface has ice on it, despite its proximity to the Sun. Some parts of Mercury receive very little direct sunlight, and certain craters remain in constant darkness.
• Venus is the second closest planet to the Sun and is sometimes referred to as Earth’s twin due to its similar size, mass, gravity, and composition.
• It is the hottest planet in the Solar System, even surpassing Mercury. Venus reaches a scorching temperature of 471°C—hot enough to melt lead. Additionally, Venus has crushing air pressure at its surface, more than 90 times that of Earth, akin to the pressure encountered a mile below the ocean on Earth.
• Venus is the only planet in our Solar System that rotates clockwise on its axis, contrary to the anti-clockwise rotation of most other planets.
• A day on Venus lasts 243 Earth days, making it the longest rotation of any planet in the Solar System. This means a day on Venus is equivalent to 243 Earth days.
• Despite having a longer day, a year on Venus is shorter than a year on Earth. It takes Venus 224.7 Earth days to complete an orbit around the Sun, resulting in a year lasting 224.7 Earth days. Interestingly, a day on Venus is longer than a year on Venus.
• Venus is visible at night and is the third brightest natural object in the night sky after the Moon and the Sun.
• Venus is named after a Roman God, as the Romans believed that gods and goddesses were in charge of everything on Earth.
• Venus was first observed through a telescope in 1610, with the astronomer Galileo Galilei being the first person to study Venus through this instrument.
• Earth is an incredible planet with diverse ecosystems, geology, and a rich history.
• It is the third closest planet to the Sun, positioned just right to maintain the perfect temperature for life.
• Earth is the only planet in our Solar System known to contain life. Scientists have extensively searched our Solar System and others for planets with conditions suitable for life, like plants and animals.
• Earth is 4.543 billion years old, while humans have only been around for about 300,000 years.
• About 71 percent of Earth’s surface is covered by water, and the oceans hold approximately 96.5 percent of all Earth’s water.
• Earth rotates at around 1000 miles an hour, yet we don’t feel the spinning due to gravity keeping us close to the surface.
• It is the 5th smallest planet in the solar system; a million Earths could fit inside the Sun.
• Earth isn’t perfectly round; it bulges around the equator by an extra 0.3 percent due to its rotation about its axis.
• Days on Earth are getting longer, increasing by about 1.7 milliseconds every century due to the moon slowing down Earth’s rotation through the tides.
• Earth used to look very different. About 250 million years ago, the continents formed a supercontinent called Pangaea, which later broke apart to form the continents we know today.
• Earth’s atmosphere is composed of gases, including nitrogen, oxygen, argon, and carbon dioxide. Without these gases, life as we know it wouldn’t be possible.
• Mars has captivated human fascination for centuries, and our understanding of the Red Planet has significantly advanced in recent years. Positioned between Earth and Jupiter, it is the fourth planet from the Sun in our Solar System.
• The red color of Mars is due to its surface containing iron. Rocks on the Martian surface oxidize when exposed to the atmosphere, resulting in a reddish hue, similar to how an old bike left in the rain turns red when it rusts.
• Mars experiences 4 seasons like Earth and shares other similarities, such as weak gravity that cannot effectively retain its atmosphere. The planet features polar ice caps, volcanoes, canyons, and weather.
• A year on Mars is longer than a year on Earth, taking 687 Earth days to complete one orbit around the Sun.
• Living on Mars would require a spacesuit as the thin atmosphere is mostly composed of carbon dioxide, argon, nitrogen, and a small amount of oxygen and water vapor. Mars has almost no oxygen, making it unsuitable for human survival.
• Mars is about half the size of Earth, ranking as the second smallest planet in the solar system after Mercury, with a diameter of 6,791 kilometers.
• Mars can get extremely cold because it is farther away from the Sun than Earth. While temperatures at Mars’ equator can reach 20°C, they can plummet to as low as -140°C at its poles.
• Mars boasts the highest mountain in our Solar System, Olympus Mons, a volcano about three times the height of Mount Everest, the tallest mountain on Earth.
• Named after the Roman God of war, Mars derives its title from its red surface, resembling the color of blood.
• Space scientists use robots to explore Mars. On November 27, 1971, the Mars 2 lander crash-landed due to an onboard computer malfunction, becoming the first man-made object to reach the surface of Mars despite the crash.
• This gas giant is the sixth planet from the sun and the second-largest in the Solar System. Its iconic rings are one of the most recognizable features in the night sky.
• Perhaps the most beautiful planet in our solar system, Saturn is a gas giant with a spectacular ring system, featuring many extreme physical features and atmospheric conditions.
• Standing on Saturn is impossible as it is a gas giant without a solid surface. Its surface is mainly composed of Helium, the same gas found in birthday balloons.
• Saturn’s rings are enormous, extending the same distance as from Earth to the moon. Composed of bits of ice, dust, and rock, the rings are not solid, with some particles smaller than a grain of sand and others taller than skyscrapers.
• Winds around the equator of Saturn can reach speeds of 1,800 kilometers per hour, making it very windy. In comparison, the fastest ever recorded wind on Earth was 407 kilometers per hour.
• Saturn has more moons than any other planet in the Solar System, with 82 confirmed moons, and likely more yet to be discovered.
• The largest moon of Saturn, named Titan, is bigger than Mercury.
• Saturn is named after the Roman god Saturnus and was known to the Greeks as Cronus.
• A day on Saturn lasts only 10.7 hours, and a year is equivalent to 29 Earth years. This means Saturn completes one orbit around the Sun every 29 Earth years.
• Jupiter is the largest and biggest planet in our solar system, captivating with its size and numerous moons, making it one of the most fascinating planets in our solar system.
• As a Gas Giant, Jupiter is predominantly composed of hydrogen and helium gases.
• Positioned as the 5th planet from the Sun, Jupiter boasts a radius of 69,911 km, more than twice the size of all the other planets combined.
• Jupiter possesses a powerful magnetic field, causing you to weigh two and a half times as much as you would on Earth. It hosts many moons, with four of them surpassing Pluto in size.
• Although Jupiter has rings, they are too faint to be clearly visible. Saturn and Uranus are not the only planets with rings; Jupiter has them too, but they are challenging to observe.
• Jupiter has 80 known moons, and there may be even more. Fifty-seven moons have received official names from the International Astronomical Union (IAU), while another 23 await official names.
• A day on Jupiter is incredibly fast, completing one rotation in just 10 hours.
• Jupiter’s year is equivalent to 11.8 Earth years, taking that long to orbit the Sun.
• Clouds on Jupiter contribute to powerful storms and lightning strikes. The storms generate bright and dense clouds, adding to Jupiter’s captivating appearance.
• Named after a Roman God, Jupiter was considered a sky-god overseeing all aspects of life.
• Jupiter is visible in the night sky and ranks as the third brightest object in the Solar System, following Venus and the Moon. With a telescope or binoculars, one might even observe small specks of light orbiting Jupiter—these are its Galilean Moons.
• Uranus is the seventh planet from the Sun and the third-largest in the Solar System. As one of the four ice giant planets, it stands out with its unique blue-green color, attributed to its methane-rich atmosphere.
• It was the first planet discovered with a telescope in 1781 by astronomer William Herschel. Initially, Herschel thought it was either a comet or a star.
• Uranus is an ice giant, composed of dense “icy” materials, primarily water, methane, and ammonia, situated above a small rocky core.
• Uranus features 13 rings, with two sets displaying distinct colors—the inner rings are dark and grey, while the outer rings are blue and red.
• The discoverer of Uranus, William Herschel, unsuccessfully attempted to name it Georgium Sidus after King George III. Instead, the planet was named Uranus.
• The diameter of Uranus is such that 63 Earths could fit inside it, measuring 25,362 km.
• Unlike other planets named after Greek Gods of the sky, Uranus is the only planet not named after such a deity.
• Uranus has 27 known moons, and interestingly, these moons are named after characters from Shakespearean plays.
• Forming about 4.5 billion years ago, Uranus likely originated closer to the Sun before moving to its current position in the outer solar system around 4 billion years ago.
• A day on Uranus takes about 17 hours, representing the time it takes for Uranus to complete one rotation on its axis. In Uranian time, a complete orbit around the Sun (a year) takes about 84 Earth years, resulting in just one birthday in a human’s entire lifetime on Uranus.
• Neptune is the eighth planet from the Sun and the most distant planet in our Solar System. This beautiful blue planet is named after the Roman god of the sea.
• A large planet, Neptune is nearly four times the size of Earth and more than 30 times as far from the Sun as Earth, located at a distance of 4.4738 billion kilometers.
• Neptune’s blue color is due to methane, the same gas that makes up some of our trumps (referring to flatulence). The type of methane on Neptune gives it its distinct blue hue.
• As an ‘Ice Giant,’ Neptune is composed of dense “icy” materials, primarily water, methane, and ammonia, situated above a small rocky core.
• Neptune boasts at least 5 rings and four additional ring arcs, clumps of dust and rocks likely formed by the gravity of nearby moons.
• A year on Neptune is equivalent to 164.81 Earth years due to its considerable distance from the Sun, making it take a long time to complete its orbit. Living on Neptune, you would never reach your birthday, as it takes 164 Earth years to equal 1 Earth year.
• Neptune has 14 known moons, with its largest moon, Triton, discovered on October 10, 1846, by William Lassell, just 17 days after the discovery of the planet by Galle.
• No humans have set foot on Neptune. Voyager 2 is the only spacecraft to have visited Neptune, and no humans were on board. No spacecraft has orbited this distant planet for in-depth research due to the extreme distance, making it challenging to build a spacecraft for such a journey and extended observation.
• Pluto was first discovered in 1930 and is the most famous dwarf planet in the Solar System. In August 2006, the International Astronomical Union (IAU) downgraded Pluto’s status from a planet to a “dwarf planet.”
• Pluto lies in the Kuiper Belt, a donut-shaped region of icy bodies beyond the orbit of Neptune, where Pluto can be found.
• Sometimes Pluto is closer to the Sun than Neptune due to its elliptical orbit.
• Pluto is smaller than Earth’s Moon, with a radius of 1,188.3 km.
• There are white mountains on Pluto, making it the only place other than Earth in our solar system with white-peaked mountains. However, these white caps are not made of snow but rather methane frost.
• A day on Pluto lasts 153 hours or about 6 Earth days, as it takes Pluto about 6 Earth days to complete one rotation on its axis.
• A year on Pluto is 248 Earth years, with Pluto taking 248 Earth years to orbit the Sun.
• Pluto has 5 moons, with the largest being Charon. Pluto and Charon are so big that they orbit each other like a double planet.
• Pluto’s extremely cold temperatures make it necessary to wear a big coat if one were to visit. Being very far from the Sun, Pluto experiences temperatures ranging from -228 to -238°C, too cold for human habitation.