Gravity

Gravity is a force that attracts every object that has mass towards every other object that has mass towards every other object. Mass is the amount of matter an object, or body contains. The amount of gravitational pull between two bodies depends on the mass of the two bodies and the distance between them. The greater the masses the greater the force. The further the distance between them, the smaller the force. The amount of gravitational pull between bodies is very massive, such as a planet.
This is called the Law of Universal Gravitation. It was first written by the English scientist Sir Isaac Newton (1642-1727). This law of gravity explains how the gravitational pull between bodies causes the planets to orbit the sun. A body has a gravitational field around it. Any other object in the field experiences a pull from the body, which pulls the object towards it.

Unsolved Mysteries

For centuries, people have been puzzled and fascinated by mysterious places, creatures, and events. Why have ships and planes vanished without a trace when crossing Bermuda Triangle? Are some houses really haunted by ghosts? Does the Abominable Snowmen actually exist? What secrets are held by a black hole? Read on my future posts to know about some of these facts.

Halley

Halley’s Comet zooms by Earth regularly, and so it has a chance a tiny one of colliding with our planet. During a flyby, the famous chunk of ice is easy to spot, even without a telescope. For example, there are reports from 240 B.C., when ancient Chinese stargazers saw it without any problem.
Here’s a timeline that shows some of the world changing events that happened between Halley’s visits. As you will see, Halley doesn’t appear at exactly even intervals. By computing the averages time between visits what year would you except the comet to turn up next?
1338- Hundred Years war starts between England and France on 1301 Visit.
1405- Chinese Sailors explore the Indian Ocean on 1378 Visit.
1492- Columbus sets sail to find a route to Asia through the Pacific.
on 1456 visit.
1910- World War I begins on 1910 visit.
1986- First Official U.S. observation of Martin Luther king Jr. Day, in honor of slain civil rights leader, space shuttle Challenger explodes

Meteor Master

Hero who could spot and stop Doomsday Meteor would be Carolyn Shoemaker. Since 1983, she has discovered more than 800 asteroids and 32 comets, some of which cross Earth’s orbit. Mrs. Shoemaker is already a hero in the eyes of world astronomers. Working with her husband, Gene, and David Levy, she discovered Comet Shoemaker-Levy 9.
Jupiter’s gravity had grabbed the comet and forced it to orbit the gas giant instead of the Sun. The powerful gravity ripped the comet into 21 pieces, all of which slammed into Jupiter in 1994. The spectacular crash gave astronomers an exciting glimpse at the chemistry of Jupiter’s mysterious atmosphere.

Stick Man

It’s a map of galaxies! In 1986, astronomer Margaret Geller led a team of researchers to pinpoint the location of more than 1,000 nearby galaxies. The map shows that galaxies are not evenly spaced in the universe, but grouped together in narrow bands with large spaces or voids between them. Geller nicknamed the image the “Stick Man” because it resembled a stick figure with arms outstretched.

Andromeda

The closest major galaxy to Earth, the spiral-shaped AndromedaGalaxy is the most distant object visible to the naked eye. It lies about 2.5 million light-years from Earth and contains over 200 billion stars.

Hang Ten

The circle of sky is divided into 360 degrees. The “hang ten” sign shows about a 20-degree distance when holding your hand out at arm’s length. This is roughly the length of the Big Dipper. A closed fist measures about 10 degrees, and one finger equals one degree. At night, identify a major constellation, like Orion or Ursa Major.

Betelgeuse

As a red supergiant, Betelgeuse boasts a distinctive orange color that stands out against the mostly blue stars of Orion. Its brightness varies over a period of about seven years and is unpredictable, sometimes changing in just few weeks.

Orion

Orion is one of the most easily recognized constellations with its distinctive “belt” of three bright stars. The Greeks saw the star as a hunter, but Native Americans saw a group of running deer. Syrian astronomers believed the stars formed a giant called AI Jabbar. In the northern hemisphere, you cannot see Orion in June. However, you can see it in Chile in June.

Astrology

All of the planets in our solar system orbit the sun in a band of the sky known as the Ecliptic. Ancient astronomers divided the stars in the ecliptic in to 12 constellations. Most of these constellations are named for animals or mythological creatures, so Greeks gave this band of stars the name Zodiac, meaning “Circle of animals.” The zodiac is used in astrology, the belief that the planets’ positions can influence the future. Astrology is not the same thing as astronomy, the scientific study of the universe. Astrology has no scientific basis at all.

Nebula

A nebula is an enormous cloud of gas atoms and tiny particles. Nebulae are the birth place of new stars and some dying stars leave nebula as wreckage. The smallest nebula is much larger than the solar system and the largest are hundreds of light years across. Some nebula is bright while others are dark. The brightness could be due to their atoms getting affected by the energy given out by neighboring stars. Dark nebulae appear as black starless areas, since they are absorbing light from stars beyond

Big Dipper

The Big Dipper- a star group appeared in the sky in early March, 10.30 p.m., but by 3.30 a.m. It’s moved far to the west. The stars don’t really move, of course, but the earth is constantly on the go. Imagine the sky as the inside of a great hollow sphere, with the stars as fixed points on the sphere. Picture the earth as the center of that sphere.
Where you are on the earth and how the earth is moving determines which parts of the inside of the sphere you see. As the Earth revolves on its axis, the stars and constellations appear to revolve in the sky around a point directly over the axis. The earth not only revolves on its axis, but it also changes position as it orbits the Sun.
So in late September the Big Dipper will appear low in the sky. And in March of next year, it will appear to be in the same place it was this march.

Polaris

Also called the Pole Star and the North star, Polaris sits almost exactly over the North Pole. Polaris has long been important to navigators because of its position. It is located at the tip of the handle of the Little Dipper (Part of Ursa Minor)

Images of Binary star

BInary Star

A Binary star or a double star is a pair of stars that revolve around each other and are held together by gravity. The closer a pair of stars are, the faster they revolve. Some Binary stars are almost touching and go around each other in a few hours, while others, which are separated by hundreds of times the diameter of the solar system, may take a million years to orbit each other. About a quarter of all known stars belong to binary systems. Most of these, particularly the close pairs, must have been born together. In most cases, one star is large, cool and reddish while the other star is small and white hot.

Images of Neutron Star

Neutron Star

A neutron star is the smallest and densest kind of star. An atom has electrons in its orbits and solid protons and neutrons form the centre or nucleus, which takes a small portion of the atom. As long as a star shines, the power of its radiation holds all the parts of atoms apart. But when the star begins to die, the gravity in the star makes the outer layer collapse inwards with such force that the centre is crushed to solid neutrons because the electrons and protons are forced together to make neutrons. A neutron star is one of the strangest objects in the universe. It becomes a million times heavier than lead. A pinhead size of a neutron star would weigh as much as a multi stored building.

Images of Sirius

Sirius

Sirius is the brightest star in the sky. It is at a distance of 9.5 light years from the Earth. It is also known as the Dog Star because it lies in the constellation of Canis Major, the Greater Dog. Sirius is actually a binary star and it is made of two stars that orbit around each other. Only the brighter of the two can be seen with the naked eye. Sirius was important in ancient Egypt before the calendars were developed. The appearance of Sirius coincided with the annual flooding of river Nile.

Images of Proxima Centauri

Proxima Centauri

Proxima Centauri is the closest known star in the Solar System and is about 10,000 times dimmer than the Sun. It is about 4.3 light years away and is visible with binoculars. It is the faintest member of a triple star system called Alpha Centauri present in the constellation of Centaurus. The other two stars form a brilliant double star when viewed through a small astronomical telescope. They are each about as bright as the Sun and take 80 years to orbit each other. The Proxima Centauri flares up every now and then and appears brighter than normal for just a few minutes. It takes about a million years to orbit the bright stars.

Images of Horsehead Nebula