Messenger Spacecraft Orbits Planet Mercury
Messenger Spacecraft Orbiting Mercury
On March 18, 2011, NASA’s Messenger Spacecraft entered into an orbit around the planet Mercury. This is another first for the human race! No other man-made machine has ever pulled off this gravitational balancing act!
As I mentioned in the post “Mercury, the first Planet”, getting a spacecraft into orbit around the planet that is closest to the Sun is a very complicated endeavor. The Messenger spacecraft was originally launched on August 3, and did three fly-bys of the planet before successfully entering into orbit on March 18th.
The main purpose of the Messenger mission is to study the least understood terrestrial planet in our solar system.
Messenger has eight scientific instruments on board.
- Mercury Dual Imaging System: has two cameras that will image topographic information about the planet. The two cameras act like human eyes and will give the spacecraft the ability to perceive depth.
- Gamma Ray and Neutron Spectrometer: will detect gamma rays and neutrons that are emitted by elements on the planet’s surface. It will allow us to determine if there is ice on Mercury’s poles.
- Magnetometer: will measure Mercury’s magnetic field.
- Mercury Laser Altimeter: will send a laser beam to the planet’s surface and measure the amount of time it takes for the reflected beam to return. This will give us accurate measurements of the heights of topographic features.
- Mercury Atmospheric and Surface Composition Spectrometer: will measure atmospheric gasses and can detect minerals on Mercury’s surface.
- Energetic Particle and Plasma Spectrometer: measures the characteristics of charged particles in Mercury’s magnetosphere.
- X-Ray Spectrometer: will detect x-rays to determine the amounts of various elements on the planet’s surface.
- Radio Science: will measure slight changes in Messenger’s velocity as it orbits Mercury. This will help scientists determine the thickness of the planet’s crust.
According to data received from the spacecraft over the last three days, Messenger is in it’s intended orbit and operating normally.
More information can be found about the Messenger Mission at NASA’s Messenger Site.
Image Credit: NASA
Mercury is the innermost and smallest planet in the Solar System, orbiting the Sun once every 87.969 Earth days. The orbit of Mercury has the highest eccentricity of all the Solar System planets, and it has the smallest axial tilt. It completes three rotations about its axis for every two orbits. The perihelion of Mercury’s orbit processes around the Sun at an excess of 43 arcseconds per century; a phenomenon that was explained in the 20th century by Albert Einstein’s General Theory of Relativity.
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