NASA’s Messenger Enters Mercury Orbit!“It was right on the money,” said Eric Finnegan, chief engineer of
Messenger,
to BBC. His whole team was very elated and why they won’t be?
Messenger, a spacecraft by NASA has become the first craft ever to enter
Mercury orbit, the innermost planet of our solar system. This is for
the first time ever when a satellite has achieved this milestone. It was
launched more than 6 years ago.
Messenger
was launched from earth in August 2004 and since then has travelled a
distance of 7.9 billion kilometers (about 4.9 billion miles), making its
way to the mercury through some extreme conditions! It is now some 46
million Km from the Sun and about 155 million Km away from the earth.
Before Messenger, NASA had implemented the Mariner program for measuring
various characteristics of Mercury.The Messenger has seven
instruments including the Mercury Dual Imaging System (MDIS), the
Energetic Particle and Plasma Spectrometer (EPPS) mounted on it. It also
has to carry a huge shield that protects it from the intense radiations
from the Sun which may even melt the satellite! Also the instruments
which face the planet need to be protected from the radiations coming
back off the surface of Mercury.As per the strategy devised by
the NASA engineers and scientists, the Messenger will collect the data
with its seven instruments when it is about 200 Km away from the
planet’s surface and will send it back to earth when it is cooling off
at about 15,000 Km away from the surface of Mercury. Messenger is
scheduled to stay in the orbit for one year in which it will fly around
Mercury for 730 times.Mercury is supposed to be a place with
extra-ordinary extremes! The highest temperature on the planet reaches
about 600C and the lowest being negative at the poles which never
receive the sunlight and may even have water ice. The planet is very
dense and is supposed to have at least 2/3
rd of its body made up of Iron-metal composition.Mercury
takes just about 88 days to complete one revolution around the Sun.
Thus when compared with Earth’s 365 days, Mercury’s one year is just the
1/4
th of the Earth year. On the other hand, Mercury rotates
very slowly. It takes about 176 days for one rotation which is about 2
Mercury years! (Half Earth year)The journey now on will surely be
an exciting one. Mercury’s close study will reveal many new things and
will surely help in understanding the universe better! Many more space
agencies around the world are set to send their satellites to Mercury
this decade and Messenger will be a very good lead for them!
