Are you curious about this universe? How extensive is the universe? And where is our position in this universe? There are still many questions that will come out of our heads. This universe still holds most of the mystery for us, it takes a long time to express it. But we are on a journey full of twists to uncover the great mystery.
the content of the universe
The universe is really wide, it takes a big imagination to imagine it, everything around us is part of the universe. The Earth we live in, the stars we see every night, the Moon and the Sun that always accompany us every day, all parts of the universe.
Observable universe logarithmic illustration..wikimedia
If all the stars that looked like bright spots in the night were also part of the universe, of course, our universe is unbelievably great. And so it is.
Until now, science has not been able to answer the exact size of the universe. What we know about the information, only the universe we can observe. That too was great. Moreover, the universe expands. The distance between galaxies is getting bigger or often we call those galaxies away from us.
Does that mean we are the center of the universe? Not really. So, on a large scale, the contents of the universe will look the same everywhere and in all directions. On this large scale, the smallest objects are galaxies in the universe.
Why is that? According to the cosmological principle, the universe is homogeneous and isotropy and the observer is not in a special position in the universe. Homogeneous gives meaning wherever the observer is in the universe he will observe the same thing. While isotropy means in any direction the observer sees it will see the same thing. Thus there is no special place in the universe.
Galaxies that exist in the universe we can call also a giant super star cluster. Inside there are billions of stars that move around the center of the galaxy. Of the approximately 2 trillion galaxies, there is the Milky Way, the galaxy where the Sun is located. The Milky Way consists of hundreds of billions of stars. The magnitude of the Milky Way is known as 100 000 light years.
Around the Milky Way, there are other large and small galaxies. The distance is not close, but because the mass of the galaxy is very large then the force of gravity is also great. Therefore the Milky Way along with other nearby galaxies interact and form a common group-the same as the center of their mass. This group we call Local Groups and consists of about 54 galaxies. Groups of such galaxies are also formed in other galaxies outside of the Local Groups.
Well, the Sun is a source of light for the Earth is one of the billions of stars in the Milky Way. Every star can have a planet that surrounds itself. These planets are formed from the rest of the gas and dust that form stars.
If every star has one planet then that means there are hundreds of billions of planets that also inhabit the Milky Way and there are more in other galaxies. Indeed, not all stars have planets. But, there are many stars that have more than one planet, like in the Solar System. As of November 23, 2016, 3541 planets and 4706 planet planets have been discovered by Wahana Kepler.
As the name suggests, the Solar System is a planetary system that is "centered" on the Sun. These planets are formed from the rest of the gas and dust that make up the Sun. The Solar System consists of planets, dwarf planets, asteroids, comets, satellites that all circulate around the central point of mass that is super close to the Sun. Or in other words, all these objects move around the Sun.
Among the planets, there is Earth, the planet that is home to humans. This one planet is unique because it has a life. Until now, astronomers have not found another planet that has a life like on Earth. The planet, also known as the blue planet, can have life because there is liquid water. The Earth's location in the sun's livable zone is ideal. Warm temperatures allow the water to remain liquid and the evolution of life can work. And though the Earth is big for our size, humans, in the universe, the Earth is not even visible at all, because the galaxy just looks like a scattered node filling the space and time of our expanding universe.
a colorful universe
The universe never ceases to make the inhabitants of this planet called Earth to be amazed. And for that, we also have to thank the spies in the sky. Not just one indeed, and each tells his or her own style in the same or different wavelengths.
This time, the story comes from the Hubble Telescope revealing a story in a universe showing the universe evolving through the Ultraviolet Coverage of the Hubble Ultra Deep Field (UVUDF) project.
Surveys conducted by Hubble is started from the curiosity of astronomers. Just like all the research was done by scientists. Starting from curiosity to reveal the secret of the object being studied.
During this time astronomers already know and have information about the formation of stars that occur in nearby galaxies. Such information can be obtained from observations of UV (ultraviolet) telescopes such as the Galex Observatory operating from 2003-2013. Hubble's own telescope made observations in near-infrared and visual wavelengths. With this ability, astronomers can get a chance to study the birth of stars in distant galaxies. How can? Hubble shows distant galaxies that are still primitive because, indeed, the light takes a very long time to reach us.
But at the distance of 5 and 10 billion years from us, the period when most stars in the universe are born, the data to understand the conditions of the time is still very less. The very massive and hot stars of the time radiated their light in ultraviolet wavelengths. These massive and hot young stars are often ignored as targets of direct observation and leave a gap in the cosmic linearity for human understanding.
The addition of ultra-violet data in Hubble Ultra Deep Field that uses a 3-wide-field camera on the Hubble Telescope gives observers the opportunity to make direct observations into the area of star formation that has been unobserved. The data generated by Hubble's observations became important information for astronomers to understand the formation of stars.
Observations on ultraviolet wavelengths provide an opportunity to look directly at the galaxies that are forming stars and also the locations where stars are formed. From here astronomers will be able to understand how galaxies like the Milky Way can grow from a small collection of hot stars into a galaxy with massive structures like today.
In the latest snapshots taken by Hubble, the area has been previously studied by astronomers from images generated by Hubble Ultra Deep Field from 2004 - 2009. But with the addition of ultra-violet light, the combination of all observations produces images that reveal more stories in the area. The new image combines all the colors that Hubble can observe from ultraviolet rays to near-infrared light.
As a result, the image taken in the Fornax Race area shows 10,000 galaxies that are several hundred million years old after the Big Bang. That is, Hubble brings people back to the past to see the journey of the universe and assemble it into a whole cosmic lifeline.
And the journey to look into the past has not been completed because in the future there will be James Webb Space Telescope (JWST) who will also see with the eyes of the ultraviolet to uncover more mysteries in the past.
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