A NASA space probe to Mercury, launched in 2004 August. It used two Venus flybys, in 2006 October and 2007 June, to adjust its trajectory. It flew past Mercury three times, in 2008 January and October and 2009 September, before going into near-polar orbit around the planet in 2011 March. The probe studied Mercury’s surface composition, geologic history, interior, magnetic field, and tenuous atmosphere, as well as searching for water ice at the poles. The mission ended in 2015 April when the probe impacted the planet.
http://messenger.jhuapl.edu/ Official mission website.
http://www.nasa.gov/mission_pages/messenger/main/ Mission page at NASA.
A NASA mission to planet Mercury and the first to orbit the planet. Launched on 3 August 2004, the spacecraft flew past Mercury three times—in January and October 2008 and September 2009—before going into near-polar orbit around the planet on 17 March 2011; the spacecraft intentionally smashed into the planet’s surface on 30 April 2015, creating a new crater on Mercury 16 metres wide in Mercury’s northern terrain, bringing a groundbreaking mission to a dramatic end. MESSENGER’s four years of observations helped lift the veil on mysterious Mercury. The primary mission was to last one year but was continually extended to last four. During that time MESSENGER mapped the entire planet in colour, including the areas unseen by Mariner 10 in 1974, the only previous probe there, as well as measuring the composition of the surface, atmosphere, and magnetosphere. By the end of the mission, MESSENGER captured almost 300,000 images of the planet’s surface, which have since been used to create the first complete digital elevation model of the planet.
The craft also investigated the geology and composition of Mercury using the following array of instruments: Dual Imaging System (MDIS), a Gamma-Ray and Neutron Spectrometer (GRNS), X-ray Spectrometer (XRS), Mercury Laser Altimeter (MLA), Atmospheric and Surface Composition Spectrometer (MASCS) and Energetic Particle and Plasma Spectrometer (EPPS), and a magnetometer on the end of a 3.6-m boom. Of the geological finds, MESSENGER found evidence of volcanoes erupting from underneath ancient lava fields, and strange ‘hollows’, which are steep holes in the surface where materials seemingly vaporized or boiled away into airless space. In September 2017, NASA announced that new models based on MESSENGER data show how certain types of comets influence the lopsided bombardment of Mercury’s surface by tiny dust particles called micrometeoroids. This study also gave new insight into how these micrometeoroid showers can shape Mercury’s very thin atmosphere (exosphere).
The surface of Mercury constructed from a montage of images taken by the Mariner 10 space probe in 1974 and 1975.
Credit: NASA
http://messenger.jhuapl.edu Introduces the MESSENGER mission to the planet Mercury. There are articles describing the spacecraft, the programme's scientific objective, and the mission design. The site's press room has news releases and spacecraft animations.
- standard form(of a linear programming problem)
- standard form(of a number)
- standard function
- Standard Global Chronostratigraphic Scale
- Standard Industrial Classification
- standard industrial classification
- standard interface
- Standard International Trade Classification
- standardization
- standardize
- standardized commodity
- standardized mortality ratio
- standardized residual
- standardizing
- standard mean open water
- standard metabolic rate
- standard ML
- standard model
- standard normal distribution
- standard normal distribution; standard normal variable
- standard of living
- standard of living, index of
- standard product of sums
- standard product term
- standard rate