1. Halley’s Comet is named after English astronomer Edmond Halley who first determined its period of orbit. It was the first comet to be recognized as having a periodic orbit.
2. It is known as a periodic comet (or short term comet) because the time it takes to orbit the Sun is less than 200 years.Halley’s Comet is the most well known comet.
3. Records of humans observing Halley’s Comet go back thousands of years, with appearances noted by Babylonian, Chinese and European star gazers.
4. It can be seen with the naked eye from Earth every 75 to 76 years. It last appeared in the inner Solar System in 1986 and will return again sometime in 2061
5. The tail and fuzzy glow you see around Halley’s Comet is known as a coma. The coma over Halley’s Comet can stretch up to 100,000 km across
1. Most galaxies have a black hole at the center. Ours is no exception. The center of our galaxy is called SAGITTARIUS A, and it houses a black hole with a mass of 40,000 Suns that is 14 million miles across
2. Milky way galaxy contains of more than 200 billions stars.
3. Diameter of our galaxy is approximately 100,000 light years. The largest neighboring galaxy to Milky Way is Andromeda galaxy.
4. The oldest star in Milky way galaxy is 13.2 billion years old which is known as HE 1523. it is almost as old as the Universe itself.
5. The Milky Way belongs to group of barred spiral galaxies, which means that it is a spiral galaxy with a bar-shaped structure that consists of billions of stars.
1. On January 1, 1801, Giuseppe Piazzi discovered the first asteroid. He named this asteroid CERES, after the Sicilian Goddess of grain. Ceres is also the largest asteroid to have been discovered so far.2. According astronomers, asteroids are debris left behind by the Big Bang that could not come together to form another planet because of the effect of Jupiter's gravitational pull.
3. Asteroids have been hitting the Earth since millions of years. However, due to the friction with Earth's atmosphere most of the asteroids get burnt. The asteroids that enter the Earth' s atmosphere are called METEORS while the ones that get burnt and appear as shooting stars are called METEORITES.
4. The Chicxulub impact crater created by asteroid is thought to be 65 million years old. It is also thought to be the source of the climate changes that led to the extinction of all of the dinosaurs.
5. Most asteroids are covered in dust. This dust is called REGOLITH. It is result of constant collisions in space.
1. Mercury completes a trip around the Sun every 88 days, speeding through space at nearly 50 km per second, faster than any other planet.
2. Unlike Uranus, Neptune, and Pluto, which were discovered in the last few hundred years, ancient peoples have known about Mercury for thousands of years.
3. Mercury is so small that it has too little gravity to hold an atmosphere like Earth or Venus.
4. Only one spacecraft has ever visited Mercury: Mariner 10 in 1974-75. Mariner 10's discovery that Mercury has a very weak magnetic field, similar to but weaker than Earth's, was a major surprise.
5. Mercury speeds around the Sun in a wildly elliptical (non-circular) orbit that takes it as close as 47 million km and as far as 70 million km from the Sun
1. A feather would weigh several billion tons on a black hole!
this is due to the gravity of the black holes.
2. The black holes are basically a region of space with gravitational field so strong that nothing (including light) can pass from it.
3. An astronaut wouldbe stretched on its way to the black hole. This is because the black hole's extreme gravity would be pulling her feet towards itself and the astronaut would be stretched !!!
4. It is now thought that most galaxies are held together by supermassive black holes at their centers, which cluster hundreds of solar systems around them.
5. All the matter in the universe will not end up in black holes. Most stars in the universe don’t have enough mass to become black holes at the end of their lives.
