WILL THE EARTH BE SWALLOWED UP BY SUN ONE DAY ?

In about 5 billion years when hydrogen  in the sun's core has been exhausted,the sun will swell up and become a red giant.Astronomers are not entirely sure just how large will the sun eventually become,but it is likely that in the phase of development the sun will only consume the inner planets Mercury and Venus.However if Earth is spared total annihilation-life on earth will no longer be possible.A gigantic and hostile Sun will shine 2300 times its current intensity and will cause the earth's crust to melt into an  ocean of lava.Don't worry none of us will be alive for 5 billion years......

WILL THE UNIVERSE KEEP ON EXPANDING FOREVER ?

In theory there are three possibilities as to what may happen to the universe in the future.The expansion of cosmos could be held back by gravity, come to a complete standstill and then go to reverse.The universe would then collapse causing BIG CRUNCH.The second possibility is that expansion could slow down but continue,which in fact would take an infinite time to come to a standstill.The third possibility is that  expansion will accelerate over time.Until 15 years ago astronomers were convinced that one of the first two scenarios

was likely.Then they made an unexpected discovery that stellar explosions in very distant galaxies proved that expansion in fact was increasing.Researchers don't yet know why this should be the case,but it seems that expansion is driven by a mysterious 'dark energy' that fills our cosmos.

                                         

                                           EDWIN HUBBLE(1899- 1953)PROVED THAT THE UNIVERSE CONTAINED OTHER GALAXIES THAN MILKY WAY.HIS OBSERVATIONS WERE DECISIVE IN PROVING THAT SPACE WAS EXPANDING                                                         

                                                               
 




AS IS HAPPENING WITH THESE SPIRAL GALAXIES, THE MILKY WAY AND THE ANDROMEDA GALAXY WILL COLLIDE IN TIME IN THE DISTANT FUTURE.

GALACTIC BLACK HOLES

Most of the galaxies are thought to have a black hole at its center-collapsed stars with such a strong gravitational field that even light cannot escape from them, which is why they cannot be seen directly.Galaxies have large black holes that pull in a constant stream of dust and star fragments.There is probably a relatively small black hole just 100000 times the mass of the sun - at the center of our galaxy.Scientists are able to detect black holes because their colossal gravity draws in surrounding matter which, as it descends into black hole becomes very hot and begins to glow , thereby revealing  the black holes' position.

QUASARS

 

  Quasars are the super bright cores of galaxies that are otherwise invisible.They are the brightest objects in the Universe,giving off thousand of times of more light than normal galaxy.The luminosity is thought to be generated by super massive black holes at the center of the Quasars.These black holes are many billion times the mass of the Sun.Six thousand quasars have been discovered from the universe.Some are thought to be formed from the collisions between neighbouring galaxies.

            

Asteroids are the rocky bodies that orbit the sun mainly between Mars and Jupiter. Although most of the asteroids pose no threat to the Earth, 2000 large asteroids closely approach earth's orbit . They are known as NEOs:  Near Earth Objects.

                                                                          


 NOTABLE ASTEROIDS

Name                                                      Claim to fame

1. Ceres,Pallas,Vesta,Hygiea              Known as the 'BIG FOUR'
2. Ceres                                             Largest known 940 km wide, discovered by Giuseppi Piazzi
3. Spock                                            Named after the Star Trek Character
4. Ida                                                 Has its own moon
5. 323 Brucia                                     First to be captured by photography
6. Gaspra                                           First photographed by probe           

Fragments of rock up to  1m wide are called meteoroids.When they enter earth's atmosphere they burn up,producing showers of light called meteors or 'shooting stars'.

By convention asteroids are named after  their discoverer , comets are named after their discoverer but meteorites are named after their landing site.
Meteorites  give scientists unique opportunity to study fragments of the solar system.A meteorites from mars, found in Antarctica in 1984, bore shapes resembling microscopic fossils.

Comets are made of ice and dust.In the orbit in the outer reaches of the solar system they are dark and cold, but when they approach the sun they heat up and start glowing tails if dust and gas blowing away from sun.

Comets originate at the edge of the solar system and have large elliptical orbits.Comets gas tails can reach100 million km long and always point away from sun.

“The recently discovered object, known as comet ISON, is due to fly within 1.2 million miles (1.9 million km) from the center of the sun on Nov. 28, 2013 said astronomer Donald Yeomans, head of NASA’s Near Earth Object Program at the Jet Propulsion Laboratory in Pasadena, Calif.”

"ONE SMALL STEP FOR MAN, ONE GIANT  LEAP FOR MANKIND."

These words by Neil Armstrong will tell you what i am going to talk about.

yes that's THE MOON -

I have some interesting facts for you:-

1-The Moon was formed around 4.5 billion years ago ,that's really near earth's age!

2-It was formed when an asteroid hit young earth throwing rocky debris into space that gradually coalesced.

3-It is made of same chemical elements as earth but in different proportions-calcium,lava,fragments of rocks

    and surface ice which was recently found in the south pole of the moon.

4-As its rotation period and earth's rotation period is same (29 days), we see only one side of the moon from earth

5-It does not emit light of its own but reflects sun's light.

6-It is the home to numerous form of landscapes that include volcanoes,hills,craters,plains etc.

7-There have been more than 12 successful moon missions.

8-The bright light of the full moon nearest the autumn equinox in September gave northern hemisphere farmers extra time to bring in  the harvest , hence it known as HARVEST MOON! 

Hello Everyone !!!!!!!!!

Welcome to the the world of space and universe.

I Anish Singla will tell you about interesting facts about space and universe.