Space & Astronomy Wiki – the closest star to Earth –
Worshiped by every recorded human culture, the Sun – or Sol as the Romans called it – contains over 99.8 percent of the mass in the solar system, and is over a thousand times as massive.
Composed of 7.8 percent helium (He) and 92.1 percent hydrogen (H2) along with 0.1 percent oxygen and other elements, Sol looks solid in photographs, but its surface is a sea of hot 5,500 Celsius (10,000 degrees Fahrenheit) gas.
Called ‘Helios’ by the Greeks, the Sun is a stellar type G star called a main-sequence star but will change into a brighter, bigger and cooler red dwarf star around 5 billion years after its birth.
With a diameter over 100 times that of Earth at 1.4 million km (840,000 miles), the Sun is a common medium-sized yellow star you could fit over a million piles of earth inside.
Sitting at a distance of 149.6 million km (93 million miles) from our planet or 1 astronomical unit (AU), a distance which is used as a common measuring stick by astronomers viewing the solar system, the Sun transforms over 600 million tons of hydrogen into 596 tons of helium every second through nuclear fusion.
Dominating the gravity pool of the solar system, the mass of the Sun warps spacetime, which determines the orbits of the planets, and governs the movements of all mass bodies within the boundaries of the system.
Space & Astronomy Wiki – the planets in the solar system –
At an average distance of 0.72 AU from Sol, Venus is the second planet from the Sun, closest sister planet to Earth in size and mass, and the third densest planet in the solar system at an average density of 5.24 g/cm3.
The second-brightest object in the night sky, with the Moon being the brightest, at between magnitude -3.8 and -4.6, Venus was first recorded by Babylonian astronomers in the 17th century BC and is named after the Roman Goddess of Love and Beauty.
Called both the Evening Star and Morningstar, Venus is the second largest terrestrial planet in the solar system and the hottest planet with an average surface temperature of 462 degrees Celsius.
Composed of a crust, molten mantle, and core, the surface of Venus is totally obscured by dense clouds of carbon dioxide that trap heat very effectively, producing a runaway greenhouse effect.
Rotating very slowly on its axis, Venus rotates in the opposite direction to the other planets in the solar system, creating extremely long days and nights, and a west to east movement of the Sun across the sky.
Looking at the surface of Venus you see mountains, valleys, craters, and even evidence of previous volcanic activity. This is deceiving, though, because the geology of the surface of this planet is very different than that of Earth.
We’ll talk more about the surface geology, atmosphere and life history of Venus in future articles.
The portion of the sky the Hubble Space Telescope is currently looking at is full of planets both big and small
Astronomy News – One of the greatest things about being an astronomer is the excitement of mystery and wonder you feel every time you discover something you never even suspected. This must have been the feeling running through the minds of astronomers looking at the data provided by the Hubble Space Telescope indicating the presence of planets around distant stars. The rush of adrenalin as they went over the data they had worked and waited for must have been truly euphoric.
What kind of planets would they find? Smaller rocky worlds like Earth, larger gas planets like Jupiter, or some unusual planet never before dreamed of. All of their hard work and dedication to the task-at-hand is about to open a door of discovery to worlds of wonder. Worlds with environments unlike anything we have experienced on Earth, where life we could never envision might have evolved. This is why astronomers spend countless days, weeks, months and ultimately lives studying the sky above our heads.
Astronomers see a sky full of planets
The small portion of the sky being studied by astronomers using the Hubble Space Telescope is full of planets. Some appear to be of a similar rocky composition to our home planet while others appear to be totally inhospitable to Earth-type life. Planets like Earth are thought to be mainly composed of rocky material, which is denser and thus heavier than the materials making up gas planets. The planets being found orbiting stars in the portion of the sky being surveyed by Hubble are helping to rewrite planet formation theory and other areas of astronomical study. Astronomers are finding planets of types they were expecting to find, and a few they weren’t expecting to see.
The first planets found by the Hubble Space Telescope were large gas giants, like Jupiter and Saturn, but more recent finds have included planets similar in size and possible composition to Earth. Astronomers want to study Earth-like planets in an effort to uncover more secrets concerning the birth of our own solar system and the planet, which could give us clues to the development and evolution of Earth-like life in our universe. More recent developments even include the first direct imaging of a planet orbiting a distant star.
The truly amazing part is Hubble is only surveying a portion of the sky with around 100,000 suns and we’re finding more and more planets as astronomers continue to refine their planet finding techniques and instruments. Once we extrapolate and calculate the number of possible planets, using the available data so far gathered, we find the number of possible planets to be beyond count.
Astronomers will use the James Webb Space Telescope to journey to the beginning of space and time
During the 2013 human space odyssey, astronomers explored a portion of the night sky with the Hubble Space Telescope and exclaimed. It’s full of planets! In the years ahead during the human journey to the beginning of space and time, we expect astronomers to discover undreamed-of worlds, revolving around suns we humans can’t even conceive of. Especially once the James Webb Space Telescope comes online we should expect to visit undreamed of planets.
Best to buckle your seatbelt and prepare for the ride of your life! The human journey to the beginning of space and time is about to take off to planets beyond imagination. In the months and years ahead we expect to visit worlds with environments we would find inhospitable at best. Worlds where human survival would be doubtful and any life we found would be unusual beyond imagination.
Click this link to watch a YouTube video on weird planets in the universe.
The heliosphere is interacting with the galaxy more than we thought
The human journey to the beginning of space and time continues
Astronomy News – Mankind is preparing to journey to the outer solar system in the decades ahead and part of the preparation is using NASA’s Interstellar Boundary Explorer, or IBEX, spacecraft to take a look at conditions on the edge of the solar system to get an idea of the environment humans and the spacecraft we send to the edge of the solar system will have to withstand to survive. NASA’s Interstellar Boundary Explorer has just finished producing a new set of maps of the dynamic conditions that exist near the boundary between the local interstellar medium of the galaxy and our own heliosphere. The Interstellar Boundary Explorer spacecraft creates sky maps of the outer solar system by counting and measuring particles astronomers call energetic neutral atoms that are created near the interstellar boundary region in collisions between charged particles emanating from Sol and star-dust between the stars. These collisions send energetic neutral atoms towards Sol at velocities ranging from 100,000 to 2.4 million miles per hour.
Astronomers looking at the edge of the solar system using the Interstellar Boundary Explorer recently announced that their views of the edge of the solar system over a six month period have revealed the outer solar system is a lot more dynamic than scientists first thought. That interaction between the solar wind and the interstellar medium on the other side of the interstellar boundary region are constantly changing as we move through space and time. The first map produced indicates an unpredicted bright ribbon of energetic neutral atoms emanating toward Sol from the edge of the solar system. A bright ribbon that currently has scientists studying the heliosphere scratching their heads in a confused manner because this scenario doesn’t fit any of the preconceived models they had created of the conditions and environment near the outer solar system.
The energy of the sun affects all life on Earth in ways we don’t even imagine
Humans have worshipped Sol for thousands of years
The original source of energy for all life on Earth, Sol has always ruled the lives and minds of human beings in many ways. The ruler of the daytime sky in ancient times and still today, Sol was worshipped by ancient humans of many cultures, and will always be a major force in the life of every human being on Earth. The Sumerians worshiped Utu as their sun god over two thousand years ago and modern humans worship the sun in their own way. We send spacecraft toward Sol, to study the lifecycle and physical and chemical characteristics of our sun, and determine everything we can about the sun.
Astronomy News – Hinode (Solar-B) is one spacecraft humans have sent out toward Sol in an attempt to delve deeper into the mysteries of the sun. A highly sophisticated observational satellite equipped with three solar telescopes, Hinode has recently revealed that the solar corona isn’t quite as static as solar scientists were first thinking. Hinode has surprised solar scientists of late with views of complex structures in the solar chromosphere, solar scientists use to think were static, but now believe to be dynamic structures flowing in time. This is making solar scientists rethink some of the previous ideas they had about the heating mechanisms and dynamics of the active solar corona.
Astronomers study the Sun continuously in an attempt to understand its mysteries
What questions will solar scientists working with Hinode try to answer next? They’ll be looking into why a hot corona exists above a cooler atmosphere? The origins and driving forces behind solar flares and the Sol’s magnetic field? The changes that the release of solar energy in its many forms has on interplanetary space in our solar system and life on Earth? The answers to these questions could be a key to eventually answering many of the questions the first stargazers and all humans have been asking for thousands of years. Solar scientists are also interested in knowing how magnetic changes near Sol’s surface effect the heliosphere, the outer atmosphere of Sol that extends beyond Pluto, and how severe changes in the heliosphere can cause satellites to malfunction and electrical blackouts on Earth.
You could fly around forever and never hit a thing
Astronomy News – Considering the volume of bodies circling in the solar system one might think that collisions between bodies in the solar system is commonplace, but in fact collisions between bodies circling in the solar system are relatively uncommon. This is what makes a recent report by NASA of a possible collision of one of their spacecraft with a meteorite a highlight of sorts, or at least something relatively unusual. NASA reported a possible collision between a meteorite and part of the sensitive instrumentation on board their THEMIS-B spacecraft, which is one of the two ARTEMIS spacecraft, at 0605 UT on October 14. Apparently, the flight dynamics data collected on THEMIS-B indicated that it might have been struck by a meteorite, which likely means the meteorite made a slight change in the flight path of the spacecraft. According to NASA, everything is still a go with THEMIS-B’s insertion into Lissajous orbit, and up coming simultaneous measurements of particles and the electric and magnetic fields in two different locations, using both ARTEMIS spacecraft. This will provide astronomers with the first three-dimensional look at how energetic particle acceleration happens near the Moon’s orbit, in the solar wind, and in the distant magnetosphere.
Deep Impact approaches comet Hartley 2 and will arrive at its nearest location on November 4
Astronomy News – NASA’s EPOXI mission is currently on a journey to comet Hartley 2 and Deep Impact as this mission is more commonly referred too will arrive at its nearest spot to this icy world on November 4. NASA was using imagers on Deep Impact during the days between September 9-17 to get a view of comet Hartley 2 before the spacecraft arrives on location and the things they saw has NASA’s comet scientists shaking their heads. Apparently, comet scientists observed the characteristic increase in the release of cyanide associated with comets as they travel through the inner solar system, by a factor of five or six times during this observation period in September. What they didn’t see was the expected increase in dust emissions due to this fivefold increase in the release of cyanide, which is something new according to comet scientists, who are now busy trying to figure out what they actually saw.
Comets could hold the keys to understanding the beginnings of life on Earth
Why would the difference be so important to comet scientists as Deep Impact approaches comet Hartley 2? Scientists hate unknown parameters being suddenly thrown into their well-calculated plans and this discovery certainly could affect the mission in ways we’ll possibly never hear about. Where did the dust go? The dust obviously didn’t go anywhere and is still close to comet Hartley 2, which could affect the quality of the view observers will get of Hartley 2. This will especially be true for observers on Earth, who now that they know about this fact can certainly take this fact into consideration. Otherwise, this fact is going to skew your observations and your interpretation of what you’re actually seeing when trying to view comet Hartley 2 from Earth. Certainly, this isn’t likely to seriously affect the mission as a whole, and Deep Impact will surely get some spectacular pictures of comet Hartley 2 as it approaches and recedes from the sun.
We’ll never know if we don’t go out there and study them
The interesting thing about comets releasing significant amounts of cyanide is that cyanide is a carbon-based molecule that certainly could have been brought to Earth on comets like Hartley 2 billions of years in the past. Comets haven’t changed since this time and have been hitting the Earth and releasing cyanide since this time, which brings up interesting questions that NASA is hoping the EPOXI mission and follow up missions to other comets is going to answer in the years ahead.
The Earth is moving at several different velocities at this very moment
The Earth’s orbit around Sol and other things
All motion is relative according to Einstein’s theories of space and time
Astronomy answers and questions – The Earth beneath you and the night sky above you are both moving relative to each other and you, and the universe around you. The Earth not only spins counterclockwise on its axis but also orbits Sol about once every 365 spins on its axis, give or take a few minutes, in a counterclockwise direction. Speeding through space and time at an impressive 100,000 km/hr (60,000 miles/hr), around 100 times faster than a speeding bullet, faster than the launch speed for any known spacecraft and certainly faster than Superman, the Earth’s orbit isn’t a perfect circle. In fact, the distance of the Earth to Sol during its transit differs significantly at different times, due to this non-circular orbit, but on average the distance between Earth and Sol is about 150 million kilometers (93 million miles). This distance astronomers call an astronomical unit or AU, and this unit is used by astronomers as a measuring stick of sorts, only on a bigger scale than the mile or kilometer.
Up and down has no meaning
The axis of the Earth during its orbit is also tilted about 23 1/2 degrees from the line perpendicular to the flat plane traced out by the Earth’s orbit around Sol. This flat plane astronomers call the ecliptic plane and in reality, this axis tilt has no meaning in Einstein’s spacetime and is only useful in relation to the ecliptic plane. In Einstein’s universe, the notion of tilt by itself has no meaning in spacetime, where up and down are related to away from the center of the Earth (or any body with mass) and toward the center of mass, respectively.
The Earth’s axis also continues to point in the same general direction throughout Earth’s orbit of Sol. This direction is toward Polaris, often called the North Star by travelers and navigators, and lies within 1 degree of the north celestial pole, which makes it useful for navigating on the surface of Earth. This direction closely marks the direction of due north in the night sky and the altitude of Polaris is nearly equal to the latitude of an observer on the surface of Earth. Navigators and star gazers have used these facts for thousands of years to determine direction and location on the Earth’s surface and travel from one destination to another.
The changing position of Earth during the 365 days it takes the Earth to complete one orbit also results in the night sky above your head changing nightly. Sol appears to move against a background of distant stars in the 88 constellations in the Milky Way above you. The 12 constellations along the ecliptic plane star gazers refer to as the constellations of the Zodiac, but a thirteenth constellation, Ophiuchus lies partially on the ecliptic plane, as well.
Earth’s movements help create seasons
The combination of the rotation of the Earth on its tilted axis and orbit around Sol also helps create the seasons we experience on Spaceshipearth1. In future articles, we’ll talk about the seasons of Earth, the meaning this has for life on Earth, and how this relates to the study of the movements of the exo-planets humans have, so far, viewed during the human “Journey to the Beginning of Space and Time”.
Astronomy questions and answers – The Earth is constantly in motion relative to everything around it and rotates on its axis once every day and orbits Sol once per year. The Earth’s axis is defined as an imaginary line connecting the North and South poles and passing through the center of the planet. The Earth rotates west to east, viewers above the North Pole will see the Earth move counterclockwise from their view, and this is why to star gazers the Sun and stars appear to rise in the east and set in the west every day.
Looking upward at the night sky you don’t actually feel the relative motion of the Earth beneath you, despite this you’re rotating at about 1000 km/hr, depending on where you’re situated on the Earth. Standing in the exact center of the North Pole, your relative speed of rotation is much less than if you were standing on the equator, and the closer you’re to the equator, the faster the Earth beneath you is moving. Standing on the equator the Earth beneath you is rotating at about 1,670 km/hr, move half-way to the North or South Pole, and the speed of rotation of the Earth decreases significantly to about 1,275 km/hr, and once you are standing on the exact North or the South Pole the Earth isn’t rotating. The rotation of the Earth on its axis has consequences for the planet and all life existing on the spaceshipearth1. The daily rotation of the Earth on its axis creates the night and day cycle we all rely on, and this motion combined with the spaceship earth’s orbit around Sol produces the seasonal cycles we all experience during life on Earth. We’ll talk about the Earth’s daily cycle and what this means for life on Earth in future articles.
Everything on your “Journey to the Beginning of Space and Time” is moving relative to everything else in the universe
The solar system is moving through the Milky Way
Astronomy questions and answers – Staring upward at the night sky above you get the notion you’re stationary in the universe, but nothing could be further from the truth. The Earth beneath you is spinning on its axis at 1000 km/hr, orbiting Sol at 100,000 km/hr, the Milky Way Galaxy at 800,000 km/hr while the solar system is moving relative to the local stars at 70,000 km/hr. In fact, the universe around us could be moving through a relative space and time of some unknown kind unimaginable to the human consciousness, and we would have no way of detecting this relative motion. We are all travelers in a sense on spaceshipearth1, which is the only habitable planet we know of for humankind that exists in the universe.
The Milky Way is moving through the universe
Everything appears to be moving relative to everything else we view as we look outward into space and time, which makes traveling through space and time a hazardous activity at the best of times. The universe you’ll experience on your “Journey to the Beginning of Space and Time” isn’t the universe you experience on Earth. The relative motions of everything in the universe mean we’ll need to explain a few things to you about the way things work in the universe. In future articles, we’ll talk about the Earth’s rotation and orbit around Sol, and how this affects the planet, we’ll explain the Earth’s motion in the Milky Way Galaxy, and the motion of our solar system in relation to the nearby stars in the night sky. This will give you a base upon which to stand as we take you further out into the cosmos to explain the relative universe you’ll experience during your journey. Toward this goal, we’ll explain the meaning of Einstein’s General and Special Relativity for your trip and the way you’ll experience things during your journey.