Mercury Fly-by
January 21st 2008 05:50
A view of Mercury take by the NASA's latest spacecraft Messenger
Mercury and Pluto are perhaps the two most “overlooked” plants in our solar system. There are many reasons why . The main reason is because both objects are difficult to see with the naked eye with the exception of Mercury.
Mercury’s obit is close to the sun making it difficult for us to see apart from the fact that you under certain circumstances it can be seen during daylight and at certain times of the year mercury is visible just before sunset and shortly before sunrise. Pluto is another matter it is now classed as a dwarf planet because of Pluto distance from earth and the relative size of the planet it can only be seen through a high power telescope.
A quick at Venus while on route to Mercury this image is in monochrome note the thick cloud cover shrouding the whole planet
NASA's latest spacecraft Messenger is closing in on Mercury for a high-speed, low-altitude flyby to give eager scientists their first close-up glimpse of the half-frozen, half-baked planet in more than 30 years. The flyby is the first of three close encounters planned over the next two years that will use Mercury's gravity to slow the craft enough to slip into orbit around the innermost planet in 2011. , Messenger is on a precise trajectory that will carry it within 190km of Mercury's tortured surface. Only one other spacecraft NASA's Mariner 10 - has ever visited Mercury, flying past the heavily cratered world three times in 1974 and 1975. But Mariner 10 was strictly a flyby mission, photographing just one side of the planet while collecting valuable but limited scientific data. Messenger will photograph Mercury's “dark side”.
close up view of Mercury looks very much like our Moon
Mercury is the fastest planet in the solar system, completing one orbit around the sun every 88 Earth days. ( you would be able to celebrate your birthday every 88 days instead of 365 odd day here on Earth). Mercury rotates on its axis every 59 days but because of its high orbital speed and slow rotation, a solar day sunrise to sunrise at the same point on the surface lasts 176 Earth days.( that’s what you may call a long day!) Mercury has an atmosphere of sorts the temperature fluctuation can be as much as 1,100 degrees Fahrenheit temperatures can exceed 750 degrees F during the “day” while at night side can reach 350 degrees below zero. The previous space craft Mariner 10 showed us a surface that was so heavily cratered that it looked like geological activity on Mercury ended very early in the history of the solar system much like our Moon.
Only 55% of Mercury has been explored so far there is a theory that the polar caps on Mercury may contain ice because they are not in direct sunlight. Even with earth based telescopes getting clear views of the surface of mercury is difficult because of mercury’s close proximity with the sun and mercury is visible low on the horizon here on earth where the earth’s atmosphere is turbulent making it difficult to obtain a clear image of the surface.
I have posted a simulation of what to look for in the morning sky as a guide
Mercury Venus and other planets are currently visible around 4:30 am low in the Eastern sky just before sunrise you will be able to spot them in next few days. Planets Jupiter, Neptune and Pluto are in semi- alignment although you will not see Pluto or Neptune without a telescope.
| 57 |
| Vote |
Add To: 
Subscribe to this blog
