The atmosphere of Mars is 95 per cent carbon dioxide, 3 per cent nitrogen and 1.6 per cent argon. Traces of oxygen and water have also been found. Some scientists have claimed to have found traces of methane. This gave rise to the speculation that there may be life on Mars, since methane is a gas produced by many animals. But other scientists pointed out that methane is also produced by the mineral olivine, which can be found on Mars.
Friday, February 22, 2008
Thursday, February 21, 2008
How to look out for Mars?
From 27 August 2006, Earth and Mars have been closer to each other than they have been in the last 60,000 years! It has begun to appear brightly in the night sky, as seen here while looking south-east from Poodle Rock in the Valley of Fire State Park, Nevada, USA. Now Mars will be the brightest object in the night sky after the Moon and Venus.
Wednesday, February 20, 2008
What is Olympus Mons?
The tallest volcano in the solar system, Olympus Mons towers 27 kilometers (16.88 miles) above the surface of Mars.
Labels: Mars, Moon, Solar System
Tuesday, February 19, 2008
What kind of weather would you find on Mars?
The temperature varies from -140 to 20 °C (-220 to 68 °F). The polar ice caps on Mars increase and decrease in size alternately in winter and summer Mars also has dust storms, which can cover the entire planet.
Monday, February 18, 2008
Why are seasons on Mars longer than on Earth?
Mars and Earth are tilted on their axis in the same way. Therefore, Mars has almost the same kind of seasons as Earth. However, because a Martian year is equal to two years on Earth, each Martian season lasts twice as long as the seasons on Earth.
Why are seasons on Mars longer than on Earth?
Mars and Earth are tilted on their axis in the same way. Therefore, Mars has almost the same kind of seasons as Earth. However, because a Martian year is equal to two years on Earth, each Martian season lasts twice as long as the seasons on Earth.
Sunday, February 17, 2008
Is there water on Mars?
Scientists have found signs of water in rock layers. In 2006, the scientists saw new deposits of sediment on the surface of Mars. These sediments had not been there six years earlier. According to scientists at NASA, this is the strongest evidence so far that water still flows occasionally on the surface of Mars, though other scientists say the sediments could have been deposited by carbon dioxide frost or movement of dust. Samples of the minerals hematite and goethite have also been found in Mars. These minerals are sometimes formed in the presence of water.
Saturday, February 16, 2008
What is the surface of Mars like?
The surface of Mars is divided into the northern plains flattened by lava flows, and the southern highlands marked by huge craters. The planet boasts Olympus Mons, the largest volcano in the solar system.
Labels: Craters, Jupiter, Planets, Solar System
Friday, February 15, 2008
Which Planet is known as Red Planet?
Mars is the fourth planet from the Sun and is named after the Greek god of war. It is also called the red planet because it glows red in the sky. The presence of rust (iron oxide) on its surface gives the planet its color.
Spinning backwards
All the planets rotate from west to east on their axes, apart from Venus, which spins in the opposite direction. On the surface of Venus, the Sun appears to rise in the west and set in the east. The planet might have been hit by a huge space rock, reversing the direction of its spin.
Thursday, February 14, 2008
Are there volcanoes on Venus?
There are more volcanoes on Venus than there are on Earth. About 80 per cent of the planet’s surface is made up of smooth volcanic plains, and there are two major mountain ranges with volcanoes that may be active. The peak of Maxwell Montes, the highest mountain on Venus, lies 11 kilometers (7 miles) above the surface of the planet. Mount Everest rises only about 9 kilometers (6 miles) above sea level.
Wednesday, February 13, 2008
Why is a day longer than a year on Venus?
Venus goes around the Sun at a very high speed. It takes only about 225 days to complete one orbit. However, it spins much more slowly on its axis, taking about 243 days to complete a rotation. Therefore, days on Venus are longer than years.
Tuesday, February 12, 2008
Why is Venus hotter than Mercury?
Venus has a thick atmosphere, much thicker than the Earth’s. The atmosphere is mainly carbon dioxide. This greenhouse gas traps large amounts of heat within the planet. That is why Venus is hotter than Mercury, though Mercury is closer to the Sun.
Labels: Atmosphere, Earth, Mercury, Sun, Venus
Sunday, February 10, 2008
Which planet is also known as the Earth’s twin?
Friday, February 8, 2008
Looking at Mercury
The Mariner 10 space probe is the only one to have got anywhere near Mercury so far. It is sending photographs of the surface of Mercury regularly now.
Thursday, February 7, 2008
How is Mercury seen from close-up?
From up close, the surface of Mercury can be seen to be pitted with huge craters. Any meteor that comes near Mercury falls on the surface and creates a crater, as there is no atmosphere to burn the meteor up.
Labels: Atmosphere, Craters, Mercury, Meteor
Wednesday, February 6, 2008
What is the surface of Mercury like?
If you were to land on mercury, you would find a surface very similar to that of the Moon. It has dust-covered hills, cliffs and is dotted by craters. The planet also has a thick metallic core and a sandy crust.
Tuesday, February 5, 2008
What space probes have been launched to Mercury?
Labels: Mercury, Probe Messenger, Sun
Monday, February 4, 2008
Why are nights on Mercury freezing cold, although it’s the planet closest to the Sun?
Unlike Earth, Mercury is not surrounded by a thick protective blanket of air called the atmosphere. This means that the heat from the Sun escapes, leaving the planet freezing at night. While the temperature during the day can be as high as 467 °C (873 °F), at night it drops to -183 °C (-297 °F).
Sunday, February 3, 2008
Why planet Mercury has sandy surface?
Mercury has a surface that is full of hills and steep canyons, all of it covered with a mixture of sandy substances. The core of the planet is metallic, like all the rocky planets.
Saturday, February 2, 2008
What Planet is lnown as the Hot Planet?
Mercury is the planet closest to the Sun. It is also very small – about the size of Earth’s moon. It is named after the Roman messenger god because it moves very quickly.
Friday, February 1, 2008
What are the special characteristics of the gas giants?
Jupiter is the largest planet. It rotates faster than any other planet and has the most moons. Saturn is set apart by its beautiful rings, made up of dust particles and pieces of ice. Uranus is a strange planet where seasons last for more than 20 years, while Neptune is the windiest planet in the solar system.
Thursday, January 31, 2008
Saturn’s moons
At least 46 moons orbit Saturn. Each moon is unique. Enceladus is among the shiniest objects in space. Titan’s atmosphere is thicker than Earth’s. Here are the big moons, seen from behind the moon Dione.
Wednesday, January 30, 2008
The solar system
The relative sizes of the eight planets and the three dwarf planets are shown in this diagram of the solar system. Jupiter is the largest planet. The Sun, of course, is much larger than any of the planets.
Labels: Jupiter, Planets, Solar System, Sun
Monday, January 28, 2008
Jupiter’s moons
Jupiter, the largest planet in the solar system, has so many moons that we are constantly discovering new ones. This image shows some of the bigger moons and the gossamer rings around the planet.
Sunday, January 27, 2008
What are the distinguishing features of each of the rocky planets?
Mercury is the closest to the Sun and therefore its temperature can be as high as 467 °C (873 °F). Venus is covered with carbon dioxide containing droplets of sulphuric acid. This traps the Sun’s heat and makes Venus hotter than even Mercury. Mars, the red planet, is considered to be the only planet after Earth where life could exist. As far as we know, the Earth is the only planet that supports life.
Saturday, January 26, 2008
What makes gas giants unique?
The gas giants are bigger in size but lighter, as they are mainly made up of gases and ice particles. In fact, Saturn is so light that it would float if placed in water! Gas giants also spin extremely quickly and they have rings around them. These planets do not have a hard surface. Jupiter and Saturn have a semi-liquid centre that is covered by a layer of liquid gas.
Labels: Planets
Friday, January 25, 2008
What are the features of a rocky planet?
The rocky planets are made up of rocks and metals like iron and nickel. They are smaller than the gas giants but are very heavy. It is because of their weight that rocky planets rotate much slower than the gas giants.
Labels: Planets
Thursday, January 24, 2008
How were the planets formed?
After the gaseous cloud called the solar nebula collapsed upon itself due to the strength of its own gravity and formed the Sun, the dust and particles around it clumped together to form the planets. The heat of the Sun melted the ice particles nearby and eventually these rocks grew larger to form the four rocky planets. Some ice particles were too far away from the Sun to be melted. These ice pieces combined with gases to form the planets called the gas giants.
Wednesday, January 23, 2008
How were the planets formed?
Labels: Planets
Tuesday, January 22, 2008
What are the Planets?
Planets are large masses of matter that orbit around a star. Our solar system consists of eight planets – Mercury, Venus, Earth, Mars, which are called inner or rocky planets, and Jupiter, Saturn, Uranus and
Labels: Planets
Monday, January 21, 2008
What are the Planets?
Labels: Planets
Sunday, January 20, 2008
How did we learn about the Sun?
Saturday, January 19, 2008
Is the Sun really a star?
Friday, January 18, 2008
What is a solar flare?
Thursday, January 17, 2008
What is a solar eclipse?
Wednesday, January 16, 2008
How was the Sun created?
Tuesday, January 15, 2008
What is Sun?
Our solar system is made up of the Sun, eight planets, three dwarf planets and many asteroids, comets and other space rocksThe Sun is the largest object in the solar system and is located right at its centre. The planets, dwarf planets, asteroids and comets travel around the Sun in an ellipse. Our solar system was formed about 5 billion years ago, and the surface of the Sun is about 4.6 billion years old.
Monday, January 14, 2008
What are Heavenly pictures?
By drawing imaginary lines between the stars in the sky, you will notice the shapes of animals or objects familiar to you. You might see a crab, a dragon, a bear or other patterns. These star patterns are called constellations. Astronomers haveidentified 88 constellations in all. The more famous ones are the Great Bear, the Little Bear and Orion, also known as theHunter. The constellations also include characters from Greek mythology and the 12 signs of the zodiac.
Sunday, January 13, 2008
What is a black hole?
The gravity near this point is so strong that any object that gets too close to the black hole is pulled into it. Even light gets sucked into it, which is why we can’t see a black hole. Scientists use special instruments to detect a black hole’spresence. They examine the effects it has on the objects near it.
Nobody can actually see a black hole, because the extremely strong gravity inside them does not even allow any light to escape, let alone anything else.This is an artist’s impression of what a black hole may be like.
Saturday, January 12, 2008
What is a white dwarf?
Friday, January 11, 2008
How long does a star live?
A star glows for millions of years until the gases in its outer layer begin to cool, and the hydrogen in the inner core is slowly used up. The cool outer layer starts to glow red. When this happens the star is called a red giant. The red giant continues to lose its brightness until it fades away. Depending on its size, a red giant may die in an explosion, get compressed to form a black hole or become a white dwarf.
Thursday, January 10, 2008
What is a protostar?
Stars are born in clouds of dust and gases, mainly hydrogen. More and more gas is pulled together by gravity to form a cloud. After a while the cloud begins to spin. This makes the gas atoms bump into each other at high speeds, creating a great deal of heat. As the cloud becomes hotter a nuclear reaction takes place inside, and the cloud begins to glow. This glowing cloud is called a protostar. The protostar continues to contract until it becomes a star.
Labels: Stars
Wednesday, January 9, 2008
What is a Star?
A star is a huge ball of gas and dust that gives out both heat and light. When the gases in the star burn out, it dies. A star can live for millions, even billions, of years depending on its size. Each galaxy in the universe is made up of several billion stars.
Labels: Stars
Tuesday, January 8, 2008
A galactic crash
Sometimes, galaxies crash into one another due to the force of gravity. But the stars in them are too far apart to cause any real damage. Our own galaxy is on a collision course with its neighbour Andromeda. The collision will take place in about five billion years and the two will merge to form an elliptical (oval) galaxy.
Labels: Galaxies
Monday, January 7, 2008
Is the Milky Way a part of a cluster of galaxies?
The Milky Way and three of its neighbouring galaxies are part of a larger cluster known as the Local Group (because they are closest to Earth). The neighbouring galaxies in the Local Group are calledAndromeda, and the Large and Small Magellanic Clouds. Of the 35 galaxies in the Local Group, only these three can be seen with the naked eye.
Labels: Galaxies
Sunday, January 6, 2008
How did the Milky Way get its name?
In ancient Greek and Roman myths, it was believed that the goddess Hera (Juno) spilt milk across the sky and called the white streak it left a ‘river of milk’. The Romans called it Via Lactea or a ‘road made of milk’. This is how our galaxy came to be named the Milky Way.
Labels: Galaxies
Saturday, January 5, 2008
What is Messier Object 31?
The Andromeda Galaxy is also known as Messier Object 31 or M31. This galaxy is more than twice thesize of Milky Way. But it is still not the large galaxy we know of.
Labels: Galaxies
Friday, January 4, 2008
How big is the Milky Way?
The Milky Way is huge. It takes the Sun about 250 million years to orbit once around the centre of theMilky Way.
Labels: Galaxies
Thursday, January 3, 2008
Which is the largest galaxy?
Scientists do not know exactly. The largest galaxies we know of a giant elliptical (oval) galaxies located in the middle of a whole group of galaxies. One of the largest is in the central galaxy in the cluster Abell 2029.
Labels: Galaxies
Wednesday, January 2, 2008
What is the Big Bang theory?
The Big Bang theory suggests that the universe as we know it today was created after a huge explosionor ‘bang’. Georges Lemaitre proposed the theory of the Big Bang in 1927, and in 1929 Edwin Hubbleexpanded on his work.
Labels: Galaxies
Tuesday, January 1, 2008
What is Galaxy?
A galaxy is a group of billions of stars, dust and gas bound together by gravitational force. A galaxy can either be on its own or in a cluster. Galaxies come in different shapes and sizes. Scientists have divided them into three categories based on their shapes – spiral, elliptical (oval) and irregular (no shape).
The universe is a huge open space made up of billions of galaxies and an even larger number of stars. Our galaxy is called the Milky Way. Our solar system, including the Sun, the planets and their moons, forms just a tiny part of the Milky Way.
Labels: Galaxies