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Missions to Neptune
Written by Dane Atkinson

VOYAGER 2: Launched August 25th of 1977 from Earth, Voyager 2 was designed to explore and find out information about each of our outer planets and investigate everything beyond our outer solar system. Currently, it's examining the solar system enviroment and trying to reach the heliopause boundary (the outer limits of our Sun's magnetic field and the outward flow of the solar winds). After penetration of the heliopause boundary, it will allow measurements to be made of the interstellar fields.

As well, Voyager 2 is transmitting a message of greetings to the universe, which includes information on Earth, it's many cultures and languages. Maybe someday, this message will reach extraterrestrial beings.

The only time Neptune was visited was by one spacecraft called Voyager 2 on August of 1989. Travelling for 12 years at an average velocity of 19 kilometers a second (about 42,000 miles an hour) to reach Neptune which is 30.06 AU away from the sun. It flew by the enormous planet passing about 4,950 kilometers
(3,000 miles) above Neptune's north pole. It was Voyager's closest approach to any planet.

While passing by, Voyager observed and collected information on the planet's atmosphere and other features. For one, it noticed the planet's rather interesting active weather, with the Great Dark Spot, and the other storms like "The Scooter". It also noticed Neptune's three faint rings, and discovered 6 new moons orbiting the planet other than Triton and Nereid which were recently discovered by telescope from Earth itself.

Continuing towards Neptune's largest moon Triton. Voyager 2 passed by this moon with a margin of 40,000 kilometers (25,000 miles). It observed geyser-like eruptions spewing invisible nitrogen gas and dark dust particles several kilometers into space from it's icy surface.

This was the last solid body the spacecraft had the opportunity to study. Voyager 2 headed out of the solar system, diving below the ecliptic plane at an angle of about 48 degrees and a rate of about 470 million kilometers a year.

If all goes well, we will be able to continue to use Voyager for collecting information for the next 25 to 30 years. After that, the nuclear power source will no longer be able to supply enough electrical energy to power the critical subsystems. Therefore, it will end up drifting through outer space, but still carrying it's packet of greeting information out into the unknown, where possibly, someday, it may come in contact with extra-terrestrial beings.

FUTURE MISSIONS: A Neptune Orbiter is being planned to observe Neptune and it's moon Triton more closely in the future because they are an important component of our future investigative efforts of the outer Solar System. The date of launch for this orbiter is currently unknown.

CONCLUSION: The greater bulk of information we have now on Neptune came from Voyager 2's encounter with the planet. This forced most scientists to rewrite what was previously known about this planet and update accordingly.