Mariner 10 traveled from Earth to Mercury in 147 days. More recently, on August 3, 2004, NASA launched the MESSENGER mission to examine Mercury in orbit. On January 14th, 2008, it performed its maiden flyby. It takes 1,260 days to get from Earth to Mercury. The average distance between the planets is about 140 million miles (225 million km).
Venus orbits the sun once every 87 days and travels across the sky very quickly, so that by the time morning comes, something new is rising in the east. At dawn, clouds usually shroud the planet's face, but over time the clouds break up and are replaced by air that flows upward, leaving behind it a cloud-free face pointing toward the sun. This is because there is no atmosphere to interfere with the flow of air around Venus; therefore, there are no clouds or hazes of any kind.
The day on Venus is about 684 minutes long, which means that it takes Venusians 2 years to go around the sun twice. Because of this extremely slow rotation, one side of Venus is always dark due to sunlight being blocked by the planet itself, while the other side goes through a 24 hour cycle of light and darkness as the sun moves across the sky.
Mercury has the fastest rotation of all the inner planets, taking 58 days to complete one revolution. This means that at sunrise and sunset, you would see different parts of the planet!
Light takes 3.21 minutes to reach Mercury from Earth at an average distance of 36 million miles. This duration ranges between 2.56 and 3.88 minutes as the planets round the Sun. Therefore, one day on Mercury is equivalent to about 24 hours on Earth.
Mercury orbits the Sun once every 58 days. It is the fastest-moving planet outside of the Solar System, with winds that can exceed 400 mph. The direction of these winds changes with each rotation of Mercury, so they are always looking at something new.
The solar wind flows out from the sun in a vast bubble that extends for hundreds of millions of miles around the star. Within this bubble are particles ejected by the sun that travel at nearly the speed of light. When these particles collide with atoms in the atmosphere of Mercury they can create flashes of radiation that would be lethal to humans had they been seen from Earth.
It takes Mercury about 30 days to orbit the Sun. Because it is so close to the Earth, however, it passes across our line of sight only once per orbit, on the opposite side of the Sun from where the Earth is. So we never see it rise over the eastern horizon or set beneath the western one. Rather, it passes directly from above the north pole to below the south pole, showing us half of its face.
So far, two spacecraft have visited Mercury. The first was known as Mariner 10. Mariner 10 passed past Mercury three times in 1974 and 1975, mapping over half of the planet's surface. It also took several dozen photos from close up that revealed features never seen by humans before.
The second was named MESSENGER. MESSENGER entered orbit around Mercury on April 30, 2011. It is the first ever space mission to orbit a planet while flying by every day.
MESSENGER is providing scientists with information about how Earth's closest neighbor developed into a Planet of Worlds. The data so far has been amazing! For example, we know now that there used to be water under the surface of Mercury, but it has evaporated.
People have always been curious about other planets, especially since the discovery of other living organisms in the universe. In the 17th century, people started to think that maybe other worlds might be able to support life. Science has proved them right so many times! Today, people are still wondering about other planets, but most of them are too busy working or having fun to worry about what's going on beyond our solar system.
In conclusion, people have always asked questions about other planets, and science has always found out answers for those questions.
Mercury's tiny atmosphere and magnetic field were also identified by Mariner 10. The second mission to visit Mercury was MESSENGER.
Why do men lead dances? Because they can! The only reason men ever led a dance is because they could. If women wanted to lead, they would step up. The only time men have led a dance is when they had no choice. Either there were no women available or they did not want to risk being hit on the head with a stick.
Why do men go bald? Men go bald because nothing enrages them more than seeing a friend lose his hair. Even if it isn't real hair, they will still go nuts over a pair of scissors hitting an imaginary strand of hair off their friend's head.
Why do boys give girls presents? Boys don't give girls presents because it's expected of them, but rather because they can. They can buy anything they want at any price they desire - thus gifts are unnecessary.
Why do girls wear makeup? Girls wear makeup because it makes them feel good about themselves.