Stars form in large clouds of gas and dust called molecular clouds. Molecular clouds range from 1,000 to 10 million times the mass of the Sun and can span as much as hundreds of light-years. Molecular clouds are cold which causes gas to clump, creating high-density pockets. Some of these clumps can collide with each other or collect more matter, strengthening their gravitational force as their mass grows. Eventually, gravity causes some of these clumps to collapse. When this happens, friction causes the material to heat up, which eventually leads to the development of a protostar – a baby star. Batches of stars that have recently formed from molecular clouds are often called stellar clusters, and molecular clouds full of stellar clusters are called stellar nurseries. At first, most of the protostar’s energy comes from heat released by its initial collapse. After millions of years, immense pressures and temperatures in the star’s core squeeze the nuclei of hydrogen atoms together to form helium, a process called nuclear fusion. Nuclear fusion releases energy, which heats the star and prevents it from further collapsing under the force of gravity. A star’s gas provides its fuel, and its mass determines how rapidly it runs through its supply, with lower-mass stars burning longer, dimmer, and cooler than very massive stars. More massive stars must burn fuel at a higher rate to generate the energy that keeps them from collapsing under their own weight. Some low-mass stars will shine for trillions of years – longer than the universe has currently existed – while some massive stars will live for only a few million years. At the beginning of the end of a star’s life, its core runs out of hydrogen to convert into helium. The energy produced by fusion creates pressure inside the star that balances gravity’s tendency to pull matter together, so the core starts to collapse. But squeezing the core also increases its temperature and pressure, making the star slowly puff up. However, the details of the late stages of the star’s death depend strongly on its mass. A low-mass star atmosphere will keep expanding until it becomes a subgiant or giant star while fusion converts helium into carbon in the core. (This will be the fate of our Sun, in several billion years.) Some giants become unstable and pulsate, periodically inflating and ejecting some of their atmospheres. Eventually, all the star’s outer layers blow away, creating an expanding cloud of dust and gas called a planetary nebula. stars go into multiple different categories on their color; their colors are different temperatures. Red stars, like Antares, is around 3,000 k, being the coldest stars. Then it goes to orange stars, like Aldebaran, they are around 4,000 k. Then its yellow stars, like our sun, which are 6,000 k. Then blueish-white stars like Sirius that are 10,000 k. Then it’s the blue stars, the hottest stars, like the famous Rigel star, which range from 25,000 – 30,000 k. I would like to take a moment to talk about how the temperature reference "k" is, the kelvin, symbol K, is the SI unit of thermodynamic temperature; its magnitude is set by fixing the numerical value of the Boltzmann constant to be equal to exactly 1.380649 × 10-23. Many people like to look at stars in the night and use constellations, which are sort of like pictures and connecting dots, majority of the time the constellations are based off history, religion, and personal beliefs, constellations are what brought zodiacs into say. People wonder sometimes "why do stars glow?" According to an article named https://stardate.org/, "Stars produce their energy through nuclear fusion. For most stars, this process is dominated by a process called the “proton-proton chain,” a sequence of events that transforms four hydrogen atoms into one helium atom. The proton-proton chain reaction fuels most stars and provides them with the energy required to support their enormous masses for most of their lifetimes; indeed, it is the source of our own Sun’s power." This is a trusted website that talks specifically about space and gives a logical reason behind it. After a star dies, it explodes, spreading multiple millions of little stars around. In the year 1994, in Los Angeles, along with a few other places, there was a giant power outage where all the lights, electronics, buildings, all power shut off, people started freaking out because when they looked up, some people claimed that they “thought the sky was falling", multiple people called the fire department, other called cops, everyone was called. What was originally thought of as the world ending, was actually people seeing the full night sky covered in stars that were now fully visible without light pollution in the way.
The moon is mostly made of iron; other metals found on the moon are magnesium, aluminum, silicon, titanium, gold, silver, and mercury. It is Earth's only natural satellite and the only extraterrestrial body that humans have visited. Gravity on the moon is one-sixth of Earth's gravity, allowing astronauts to take giant leaps on its surface. The moon lacks an atmosphere, but spacecraft have found water ice at both poles, deposited from impacting comets. In our solar system, there are a total of 146 moons. With a radius of about 1,080 miles (1,740 kilometers), the Moon is less than a third of the width of Earth. If Earth were the size of a nickel, the Moon would be about as big as a coffee bean. The Moon is an average of 238,855 miles (384,400 kilometers) away. That means 30 Earth-sized planets could fit between Earth and the Moon. The Moon is slowly moving away from Earth, getting about an inch farther away each year. The Moon is rotating at the same rate that it revolves around Earth (called synchronous rotation), so the same hemisphere faces Earth all the time. Some people call the far side – the hemisphere we never see from Earth – the "dark side", but that's misleading. As the Moon orbits Earth, different parts are in sunlight or darkness at different times. The changing illumination is why, from our perspective, the Moon goes through phases. During a "full moon," the hemisphere of the Moon we can see from Earth is fully illuminated by the Sun. And a "new moon" occurs when the far side of the Moon has full sunlight, and the side facing us is having its night. The Moon makes a complete orbit around Earth in 27 Earth days and rotates or spins at that same rate, or in that same amount of time. Because Earth is moving as well – rotating on its axis as it orbits the Sun – from our perspective, the Moon appears to orbit us every 29 days. With too sparse an atmosphere to impede impacts, a steady rain of asteroids, meteoroids, and comets strikes the surface of the Moon, leaving numerous craters behind. Tycho Crater is more than 52 miles (85 kilometers) wide. Over billions of years, these impacts have grounded up the surface of the Moon into fragments ranging from huge boulders to powder. Nearly the entire Moon is covered by a rubble pile of charcoal-gray, powdery dust, and rocky debris called the lunar regolith. Beneath is a region of fractured bedrock referred to as the megaregolith. The light areas of the Moon are known as the highlands. The dark features, called maria (Latin for seas), are impact basins that were filled with lava between 4.2 and 1.2 billion years ago. These light and dark areas represent rocks of different compositions and ages, which provide evidence for how the early crust may have crystallized from a lunar magma ocean. The craters themselves, which have been preserved for billions of years, provide an impact of history on the Moon and other bodies in the inner solar system. If you looked in the right places on the Moon, you would find pieces of equipment, American flags, and even a camera left behind by astronauts. While you were there, you'd notice that the gravity on the surface of the Moon is one-sixth of Earth's, which is why in footage of moonwalks, astronauts appear to almost bounce across the surface. The temperature on the Moon reaches about 260 degrees Fahrenheit (127 degrees Celsius) when in full Sun, but in darkness, the temperatures plummet to about -280 degrees Fahrenheit (-173 degrees Celsius).
There are millions of different planets I could talk about in this, but since we don’t have all the time in the world, I'll talk about the ones in our solar system specifically. We will start off with Mercury, the one closest to the sun. Mercury is one of the five classical planets visible with the naked eye and is named after the swift-footed Roman messenger god. It is not known exactly when the planet was first discovered - although it was first observed through telescopes in the seventeenth century by astronomers Galileo Galilei and Thomas Harriot. It is a very small planet, only slightly larger than the earth's moon, One year on Mercury is only 88 days on earth. Mercury's surface temperatures are both extremely hot and cold. Because the planet is so close to the Sun, day temperatures can reach highs of 800°F (430°C). Without an atmosphere to retain that heat at night, temperatures can dip as low as -290°F (-180°C).
Venus, the second planet from the sun, is the hottest and brightest planet in the solar system. The scorching terrestrial (rocky) type planet is named after the Roman goddess of love and beauty and is the only solar system planet named after a female when following the International Astronomical Union designation of names that the astronomy community uses as a convention.
Earth is the third planet from the Sun and the only astronomical object known to harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all of Earth's water is contained in its global ocean, covering 70.8%of Earth's crust. The remaining 29.2% of Earth's crust is land, most of which is located in the form of continental landmasses within Earth's land hemisphere. Most of Earth's land is somewhat humid and covered by vegetation, while large sheets of ice at Earths polar deserts retain more water than Earth's groundwater, lakes, rivers and atmospheric water combined. Earth's crust consists of slowly moving tectonic plates, which interact to produce mountain ranges, volcanoes, and earthquakes. Earth has a liquid outer core that generates a magnetosphere capable of deflecting most of the destructive solar winds and cosmic radiation.
Mars is a cold desert world. The average temperature on Mars is minus 85 degrees Fahrenheit – way below freezing. It is half the size of Earth. Mars is sometimes called the Red Planet. It's red because of rusty iron in the ground. Like Earth, Mars has seasons, polar ice caps, volcanoes, canyons, and weather. It has a very thin atmosphere made mostly of carbon dioxide, nitrogen, and argon. People would not be able to breathe the air on Mars. There are signs of ancient floods on Mars, but now water mostly exists in icy dirt and thin clouds. On some Martian hillsides, there is evidence of liquid salty water in the ground. Scientists want to know if Mars may have had living things in the past. They also want to know if Mars could support life now or in the future.
Next would be Jupiter, Jupiter is a world of extremes. It's the largest planet in our solar system. If Jupiter was a hollow shell, 1,000 Earths could fit inside. Jupiter also is the oldest planet, forming from the dust and gases left over from the Sun's formation 4.5 billion years ago. But it has the shortest day in the solar system, taking only 10.5 hours to spin around once on its axis. Jupiter's signature stripes and swirls are actually cold, windy clouds of ammonia and water, floating in an atmosphere of hydrogen and helium. The dark orange stripes are called belts, while the lighter bands are called zones, and they flow east and west in opposite directions. Jupiter’s iconic Great Red Spot is a giant storm bigger than Earth that has raged for hundreds of years.
Now for my favorite planet, Saturn is the sixth planet from the Sun and the second largest planet in our solar system. Adorned with a dazzling system of icy rings, Saturn is unique among the planets. It is not the only planet to have rings, but none are as spectacular or as complex as Saturn's. It's 96% hydrogen, 3% helium, and 1% other gases. 1 year on Saturn is the equivalent of 29 years on earth. Saturn's gravity is 1.08 times the gravity as earth, average temperature of about -285 degrees F.
Uranus is a very cold and windy world. The ice giant is surrounded by 13 faint rings and 28 small moons. Uranus rotates at a nearly 90-degree angle from the plane of its orbit. This unique tilt makes Uranus appear to spin sideways, orbiting the Sun like a rolling ball. Uranus was the first planet found with the aid of a telescope. It was discovered in 1781 by astronomer William Herschel, although he originally thought it was either a comet or a star. It was two years later that the object was universally accepted as a new planet, in part because of observations by astronomer Johann Elert Bode.
Dark, cold and whipped by supersonic winds, giant Neptune is the eighth and most distant major planet orbiting our Sun. More than 30 times as far from the Sun as Earth, Neptune is not visible to the naked eye. In 2011, Neptune completed its first 165-year orbit since its discovery. The planet’s rich blue color comes from methane in its atmosphere, which absorbs red wavelengths of light, but allows blue ones to be reflected into space. Neptune was the first planet located through mathematical calculations. Using predictions sent to him by French astronomer Urbain Le Verrier, based on disturbances in the orbit of Uranus, German astronomer Johann Galle was the first to observe the planet in 1846. The planet is named after the Roman god of the sea, as suggested by Le Verrier.
There are also two well-known dwarf planets I won't go into too much detail about; their names are Pluto and Ceres.
comets are leftovers from the dawn of our solar system around 4.6 billion years ago and consist mostly of ice coated with dark organic material. They have been referred to as "dirty snowballs." They may yield important clues about the formation of our solar system. Comets may have brought water and organic compounds, the building blocks of life, to the early Earth and other parts of the solar system. Each comet has a tiny frozen part, called a nucleus, often no larger than a few kilometers across. The nucleus contains icy chunks, frozen gases with bits of embedded dust. A comet warms up as it nears the Sun and develops an atmosphere, or coma. The Sun's heat causes the comet's ice to change to gases, so the coma gets larger. The coma may extend hundreds of thousands of kilometers. The pressure of sunlight and high-speed solar particles (solar wind) can blow the coma dust and gas away from the Sun, sometimes forming a long, bright tail. Comets have two tails―a dust tail and an ion (gas) tail. Comet sizes vary significantly, from small nuclei under 1 kilometer in diameter to exceptionally large ones over 100 kilometers wide
Most asteroids can be found orbiting our Sun between Mars and Jupiter within the main asteroid belt. Asteroids range in size from Vesta – the largest asteroid at about 329 miles (530 kilometers) in diameter – to bodies that are less than 33 feet (10 meters) across. The total mass of all the asteroids combined is less than that of Earth's Moon. The current known number of asteroids, or minor planets, is 1,364,189, according to the International Astronomical Union's Minor Planet Center. The number of Near-Earth Objects, or NEOs, is more than 35,000. NEOs are comets and asteroids that have been nudged into Earth's neighborhood by the gravity of nearby planets. About 99% of NEOs are asteroids. Their closest approach to the Sun is less than 1.3 times Earth's distance from the Sun.
Asteroids, sometimes called minor planets, are rocky, airless remnants left over from the early formation of our solar system about 4.6 billion years ago.
Most asteroids can be found orbiting the Sun between Mars and Jupiter within the main asteroid belt. Asteroids range in size from Vesta – the largest at about 329 miles (530 kilometers) in diameter – to bodies that are less than 33 feet (10 meters) across. The total mass of all the asteroids combined is less than that of Earth's Moon.
Black holes are some of the strangest and most fascinating objects in the universe. They're extremely dense, with gravitational forces so strong, that nothing, not even lights, can escape once it crosses the boundary known as the event horizon.
The Milky Way could contain over 100 million black holes, though detecting these gluttonous beasts is very difficult. At the heart of the Milky Way lies a supermassive black hole — Sagittarius A*. The colossal structure is about 4 million times the mass of the sun and lies approximately 26,000 light-years away from Earth, according to a statement from NASA.
The first image of a black hole was captured in 2019 by the Event Horizon Telescope (EHT) collaboration. The striking photo of the black hole at the center of the M87 galaxy 55 million light-years from Earth thrilled scientists around the world.
Black holes are expected to form via two distinct channels. According to the first pathway, they are stellar corpses, so they form when massive stars die. Stars whose birth masses are above roughly 8 to 10 times mass of our sun, when they exhaust all their fuel — their hydrogen — they explode and die leaving behind a very compact dense object, a black hole. The resulting black hole that is left behind is referred to as a stellar mass black hole and its mass is of the order of a few times the mass of the sun.
Not all stars leave behind black holes, stars with lower birth masses leave behind a neutron star or a white dwarf. Another way that black holes form is from the direct collapse of gas, a process that is expected to result in more massive black holes with a mass ranging from 1000 times the mass of the sun up to even 100,000 times the mass of the sun. This channel circumvents the formation of the traditional star, and is believed to operate in the early universe and produce more massive black hole seeds.
Black holes were predicted as an exact mathematical solution to Einstein's equations. Einstein's equations describe the shape of space around matter. The theory of general relativity connects the geometry or shape of shape to the detailed distribution of matter.
The black hole solution was found was by Karl Schwarzschild in 1915, and these regions — black holes — were found to distort space extremally and generate a puncture in the fabric of spacetime. It was unclear at the time if these corresponded to real objects in the universe. Over time, as other end products of stellar death were detected, namely, neutron stars seen as pulsars it became clear that black holes were real and ought to exist. The first detected black hole was Cygnus-X1.
Black holes do not die per se, but they are theoretically predicted to eventually slowly evaporate over extremely long time scales.
supermassive black hole (SMBH), a black hole more than one hundred thousand times the mass of the Sun. Nearly every large galaxy has a supermassive black hole at its centre. Active galactic nuclei, such as Seyfert galaxies and quasars, are powered by supermassive black holes. The largest supermassive black hole is in the galaxy cluster Abell 1201 and has a mass thirty billion times that of the Sun. Sagittarius A*, the supermassive black hole at the centre of the Milky Way Galaxy, has a mass four million times that of the Sun.
Many people claim that the idea didn’t start until the early 90's. However did you know the first genuine UFO sighting was in 1665. the website https://www.smb.museum/ by Kunstbibliothek says "In April 1665, six fishermen witnessed an unexplained celestial phenomenon – an aerial battle in the skies above the Baltic Sea near Stralsund. As evening broke, a dark-grey disk appeared high above the city centre. A UFO in 1665 is the first exhibition of its kind to focus on this historical UFO sighting. With reference to contemporaneous visual and textual sources, the exhibition reconstructs the way this event was portrayed in the media and exposes certain paradigms and communications strategies that are still used today to determine how we report on “unexplained aerial phenomena” (UAPs)." This is a trusted website, giving valid evidence.
“If you ask me, do I believe there’s life in a universe that is so vast that it’s hard for me to comprehend how big it is. My personal answer is yes,” Nelson said at a news conference. His own scientists put the likelihood of life on another Earth-like planet at “at least a trillion.”
https://www.nasa.gov/ talks about the idea as well, NASA hosted a media briefing at 10 a.m. EDT on Thursday, Sept. 14, at the agency’s headquarters in Washington to discuss the findings from an unidentified anomalous phenomena (UAP) independent study team it commissioned in 2022, this is trusted because it’s a certified website by NASA.
MULTIPLE ASTRONOMERS HAVE CONFIRMED THAT THEY WERE NOT ALONE ON EXPEDITIONS AND THAT THEY ENCOUNTRERED ALIENS BUT WERNT ALLOWED TO SHARE AT THE TIME.
