Mars (planet)
 |
| Mars (planet) |
This far from Earth it looks tiny even through small telescopes. Using a telescope you may be able to see Mars's polar caps grow or shrink as seasons change. Using a telescope you may also be able to see the dark surface features in its southern hemisphere. In the northern hemisphere, you may see Mare Acidalium.If you don't see any details on Mars, there might be a dust storm brewing. It undergoes climate change.
About 3 billion years ago, the Red Planet had extensive flowing water and then fell quiet Mars' climate has been much more dynamic.It has high concentrations of boron . When present in its oxidized form (borate), boron is very important in the formation of RNA.
Borates are also present which can stabilize ribose, a component of RNA. Ice packs and glaciers flowed in localized areas in the last hundred million years.Martian climate may change again. and could bolster speculation about whether the Red Planet can, or did, support life.A covering of water ice mixed with dust mantled the surface of it..
"During a Martian ice age, polar warming drives water vapor from polar ice into the atmosphere. The water comes back to ground at lower latitudes as deposits of frost mixed with dust. This ice-rich mantle smooths the contours of the land. When ice at the top of the mantling layer sublimes back into the atmosphere, it leaves behind dust. The Martian climate is overcome by sublimation, the process by which solid substances are transformed directly to vapor.
There is a clear, semi-circular lobe that had spilled from an tributary on to the plain. The lobe is imposed on a ice deposit Mars landing In the 1970s the US Vikings 1 and 2 and the Soviet Mars 3 and 5 probes all reached the surface of Mars. Mars 3 was the first probe to make a soft landing on Mars, on 2 December 1971, and sent back data for 20 seconds before it unexpectedly fell silent. Viking 1 sent back the first colour pictures from Mars, on 26 July 1976.
The aim of the VtTcmg missions was to find signs of life, but there were none. Even so, the Viking landers sent back plenty of information about the geology and atmosphere of Mars. On 4 July 1997, the US Mars Pathfinder probe arrived on Mars and at once began beaming back ‘live’ TV pictures from the planet’s surface.Mars Pathfinder used air bags to cushion its landing on the planet’s surface.
Two days after the Pathfinder landed, it sent out a wheeled robot vehicle called the Sojourner to survey the surrounding area. The Sojourner showed a rock-strewn plain which looks as if it were once swept by floods. Pathfinder and Sojourner operated for 83 days and took more than 16,000 photos.
Missions to Mars early in the 21st century may include the first return flight after 2010. The Mars Pathfinder mission provided many stunning images of the surface of the ‘red planet’, many taken by the Sojourner as it motored over the surface.
Mar’s moons
There are two moons of mars .(1) Phobos
(2) Deimos
Phobos (Mars moon)
It is very smaller as compared to earth's moon. It is very irregular in shape. It is twenty seven km long in it's longest dimension.It is actually small chunk of rocks in orbit of Mars.Phobos makes three orbits in a day because it is only three thousand miles above the surface of mars.Deimos
It is fifteen km long in it's longest dimension. It is also irregular in shape and isvery smaler in size.Deimos orbits in about thirty hours. The moons of Mars were not formed in the same way as the Earth's Moon formed . They are actually pieces of larger objects broken apart in a collision. Such moons may be formed from collisions of objects in orbit around the planet.We shall find many such small moons around the giant planets like Jupiter and Saturn.When we think of a moon, we think of the large whitish lighted circular ball that we see at night and sometimes during the day.But the moon of mars is not typical moons in the solar system.
Venus
Venus is the second planet out from the Sun - its orbit makes it 107.4 million km away at its nearest and 109 million km away at its furthest. Venus shines like a star in the night sky because its thick atmosphere reflects sunlight amazingly well.This planet is the brightest thing in the sky, after the Sun and the Moon. Venus is called the Evening Star because it can be seen from Earth in the evening, just after sunset. It can also be seen before sunrise, though. It is visible at these times because it is quite close to the Sun. Venus’s cloudy atmosphere is a thick mixture of carbon dioxide gas and sulphuric acid.
Venus is the hottest planet in the Solar System, with a surface temperature of over 470 °C. Venus is so hot because the carbon dioxide in its atmosphere works like the panes of glass in a greenhouse to trap the Sun’s heat. This overheating is called a runaway greenhouse effect. Venus’s thick clouds hide its surface so well that until space probes detected a view of a 6 km-high volcano on very high temperatures some people Venus’ surface called Maat Mons.
It is not thought there might be jungles beneath an actual photograph, but was created on the clouds computer from radar data collected by the Magellan orbiter, which reached Venus in the 1980s. The colours are what astronomers guess them to be from their knowledge of the chemistry of Venus.
Venus’s day (the time it takes to spin round once) lasts 243 Earth days - longer than its year, which lasts 224.7 days. But because Venus rotates backwards, the Sun conies up twice during the planet’s yearly orbit - once every 116.8 days.
Pressure on the surface of Venus is 90 times greater than that on Earth. Venus is the nearest planet to Earth in size, measuring 12,102 km across its diameter. Venus’s thick clouds of carbon dioxide gas and sulphuric acid reflect sunlight and make it shine like a star, but none of its atmosphere is transparent like the Earth’s. This makes it very hard to see what is happening down on its surface.
Post a Comment