Category Astronomy

What does we are all stardust mean?

The human body is made up of four fundamental elements: carbon, hydrogen, oxygen and nitrogen (also called the CHON or HONC elements). So are rocks, plants, animals, water and air. Do you know where these elements came from? The STARS. Yes, even the calcium in your bone and iron in your blood came from the distant stars. In fact, every atom in your body was forged in the centre of stars years ago. Read on to know how…

When the universe began 13 or 14 billion years ago, with the Big Bang, the only elements that existed were hydrogen, helium and a small amount of lithium. Over time, gravity increasingly pulled gas molecules towards each other and eventually gave birth to the first generation of stars. These stars were much greater than our Sun in size and temperature. The nuclear fusion within those stars then produced heavier elements, including carbon, oxygen, and nitrogen. When the stars exploded in supernova at the end of their life-cycle, the elements were shot into the far-flung reaches of the universe. Those stellar explosions continued, making new stars and planets. As more, massive stars exploded heavier elements continued to be created. Stars and elements are still being born this way, even as you read this.

As far as our galaxy, Milky Way, is concerned, stars had generated most elements now present on Earth about 5 billion years ago. Within the next billion years, the first signs of life on Earth appeared. No one is exactly sure how life formed on the planet. But one thing is clear like Carl Sagan said. “The cosmos is also within us, we’re made of star stuff.

 

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NASA lifts off cargo spacecraft named after Kalpana Chawla to International Space Station

A commercial cargo spacecraft bound for the International Space Station (ISS) has been named after NASA astronaut, Kalpana Chawla, the first India-born woman to enter space. Northrop Grumman, an American aerospace and defence technology company, announced that its next Cygnus capsule will be named the “S.S. Kalpana Chawla”, in memory of the mission specialist who died with her six crewmates aboard the space shuttle Columbia in 2003. “Chawla’s final research conducted onboard Columbia helped us understand astronaut health and safety during spaceflight. Northrop Grumman is proud to celebrate the life of Kalpana Chawla and her dream of flying through the air and in space,” the company said.

Born in Haryana, India, Chawla moved to the United States to earn her master’s and doctorate degrees in aerospace engineering from the University of Texas in 1984 and the University of Colorado in 1988, respectively.

She then began her career at NASA, conducting research in fluid dynamics at the Ames Research Center in California. After becoming a naturalized US citizen, Chawla applied for and became a NASA astronaut as a member of “The Flying Escargot,” NASA`s 15th class of trainees.

 

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How did scientists estimate Sun’s age?

The Sun’s age

Scientists say our Sun is four-and-a-half billion years old but how did they estimate its age?

To predict the age of the Sun, scientists looked at the age of the whole solar system because it all came together around the same time.

To find out the solar system’s age, scientists looked for the oldest things they could find. And, Moon rocks, meteorites and Earth rocks worked perfectly well for this. Scientists extensively studied these objects, and after much research came to the conclusion that each of the objects were approximately four and- A-half billion years old, and hence, the Sun is likely to be of the same age.

How long will it shine?

Now that we know how old the Sun is, how much longer will it shine upon us?

Scientists believe that stars such as our Sun usually burn for about nine or 10 billion years. This means our Sun is halfway through its life and will last for another five billion years at least.

Once five billion years are up, the Sun will become a red giant. The Sun will become bigger and cooler at the same time and it will be a lot different than the Sun we know today. As a red giant our Sun will become 2,000 times brighter than it is now. Wonder what would happen to our solar system at that time – will there be new life?

 

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If fire needs oxygen, where does the sun get oxygen if there’s no oxygen in space?

Indeed, this was a scientific problem for hundreds of years: if Sun consisted of oxygen, it would run out of fuel in a few hundred years. So what’s the deal?

But wait, nowadays we know more. What other objects glow like the Sun, even without oxygen?

This example of a lamp bulb shows that not all objects that shed light need oxygen to do so. Of course, for light bulb that gas is typically some inert gas (see e.g. Which gas is typically used in light bulb?).

In fact, the light bulb doesn’t use up the gas. Instead, it uses an electric wire, i.e. a resistor, heated up by the electricity flowing through it. The wire heats up, in turn heating up the gas.

The Sun is a bit similar to a light bulb. From early spectroscopic studies in the 1800s, we know that it consists of gas, mostly hydrogen and helium. The latter was actually first discovered on Sun giving the element its name from Helios, Greek name for Sun.

Nowadays we also know that this gas is heated up not by directly burning its chemical constituents, but by a special phenomenon that is the reverse of what’s happening in nuclear power plants: nuclear fusion.

While in nuclear power plants uranium splits up and by doing so releases energy (nuclear fission), in nuclear fusion the hydrogen atoms combine to form helium or even more massive particles. In case of light particles like hydrogen this again releases large amounts of energy.

The energy released speeds up the particles in the Sun’s core and in turn these super-heated particles slowly bounce around and raise to Sun’s surface. There, the temperature of the hydrogen-helium gas is 5500 degrees Celsius or near 10 000 degrees Fahrenheit.

A gas this hot will glow literally like the Sun, finally releasing the heated energy to the universe and, consequentially, to us.

Sun continually loses a tiny portion of its mass to keep shining, combining hydrogen to helium in its fusion forge, its core. From observing other stars like it, we know it has enough nuclear fuel to shine for another few billions of years.

 

Credit : Quora

Picture Credit : Google

What is analemma?

This is what the sun looks like when you take a picture a week, for a year, always at the same time of the day, and in the same place.

Due to the 23.5° inclination of earth’s axis and the ellipticity of its orbit, the height of the sun is not the same every day, and the combined effects is what the image shows.

The height of the points corresponds to the declination of the sun on that date, while the horizontal coordinate indicates the deviation of the solar position with respect to the average time (shown by clocks).

The inclination of the figure depends on the latitude in which it is observed and on the time.

If earth’s orbit were a perfect circle and its axis were perpendicular to the orbit, the sun would be in the same spot every day and the analemma would be a point. With a circular orbit but an inclined axis, the two parts of the analemma would be symmetrical. If the axis were not inclined but the orbit were elliptical, the analemma would instead be a segment.

On other planets the analemma has a different shape, on Mars for example, it looks like a drop.

 

Credit : Quora

Picture Credit : Google

What are some cool facts about the Universe?

Here are 17 coolest facts about the Universe.

1. Time concept is within the Universe. Time doesn’t exist, clock does. Time is just an illusion. If you think time is constant throughout the Universe then you’re probably wrong. It varies according to gravity and speed.

2. Universe wasn’t forever. It originated from a singularity.

3. According to NO BOUNDARY THEORY, no one has created the universe and no one directs are fate. Why? Since, everything needs time to be exited in, but time is within the Universe. Where and when would the creator live in?

4. The biggest black hole in the observable universe is TON 618.

5. The biggest star in the observable universe is UY SCUTY.

6. Black holes are actually not holes, they are collapsed and dead stars which leave a residue in the form of black holes whose gravity and mass is much more than the star itself and infinite density.

7. Spacetime tells matter how to move, matter tells spacetime how to curve.

8. There are more stars in a galaxy than the grains of sand on earth but there are more atoms in a grain of sand than the number of stars in a galaxy.

9. The sun has enough heat to enlighten the atmosphere for about 4 billion years from today.

10. If you leave earth at the age of 15 with the speed of light and return after 5 years, you’ll find all your friends are 65 y/o now. This is due to time dilation. Remember point 1? Time is an illusion.

11. In a way, we represent energy. And also energy can neither be created nor be destroyed. The energy we have within us is as old as the universe is i.e. 13.4 billion years old. Sounds like holy shit!

12. Whenever you look up in the sky, you see into the past in an encrypted way.

13. As the universe keeps expanding, in the beginning of the universe, it is said to have a size smaller than a proton.

14. If universe was forever, there would have been no life. Because all the stars in the universe are continuously heating up the universe. In this way, even sun would do the same work and the planets like earth would have no life due to extreme heat.

15. The light of sun you observe is the light sun radiated 8.20 minutes ago.

16. If there is an intelligent life other than us then they must be very very far away from us otherwise they would have visited us by now.

17. The most dangerous thing we can find on any other planet would be humans.

Adding some more:

18. There is no sound in space. Space is unbelievably silent. Sound has no medium to travel in space. Space travelers use technology to communicate in the space.

19. 700 million light years away from Earth, there is böotes void, one of the largest known voids of the observable universe with a diameter of 300 million light years and has approximately 50–60 galaxies only!

20. A year on Venus is 224 Earth days i.e. time of revolution and a day on Venus i.e. time of rotation is 243 Earth days. A year on Venus is longer than its day.

21. Don’t cry in space, your years won’t fall.

22. Imagine if alien females go through menstrual cycle, where would their blood flow on zero gravity?

25. When you look at the person in front of you, you look 0.0003 nanoseconds in the past.

26. If Andromeda galaxy was visible to us with naked eyes, it’d seem to be 6 times bigger than the moon.

27. A spacesuit costs US$ 12 million.

28. The observable universe, 93 billion light years, it just made of 103 folds of a paper. Seems unbelievable because it is impossible to fold a paper more than 8 times but this is proven by scientists. If you had a paper large enough that you can fold it as many times you want then the entire observable universe would fit in 103 folds!

29. Carl Sagan’s Cosmic Calendar. The 13.7 billion year lifetime of the universe mapped onto a single year. At this scale the Big Bang takes place on January 1 at midnight, the current time is December 31 at midnight, with Beyoncé in it. Each second is 434 years.

30. If you look outside from a black hole, you could look at the entire universe just as the size of your T.V.

 

Credit : Quora

Picture Credit : Google