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MESSENGER at Mercury
Mar. 14th, 2011 10:27 pmIn less than three days, the MESSENGER spacecraft will make its orbital insertion burn at Mercury, after a six-and-a-half-year trip that involved a flyby of Earth, two of Venus and three of Mercury itself (during which it got pictures of most of the planet, including the previously unmapped hemisphere). Data from the Mercury flybys has been made into a Google Earth layer you can download, and Steve Albers incorporated some of it into his Mercury map texture.
The main purpose of all those planetary approaches was just to bleed off energy to compensate for that gained by falling inward from Earth's orbit, so that when it returns to Mercury this week, MESSENGER will be going slowly enough to enter orbit around the planet. This has never been done before; the only other space probe to visit Mercury, Mariner 10, was a flyby probe that made three approaches in 1974.
But there won't be any pictures from orbit until March 29, so I suppose mostly what we'll hear in a couple of days is whether the orbital insertion succeeded.
Mercury is a barren, rocky, airless and moonless world that looks somewhat like a larger version of our Moon, but with differences in detail. As such, it doesn't hold quite the popular fascination that many other worlds do. Still, it is (undisputedly) a planet, and one that's been underexplored up to now because of the great difficulty of getting there. I'll be happy to see it mapped at high resolution.
The main purpose of all those planetary approaches was just to bleed off energy to compensate for that gained by falling inward from Earth's orbit, so that when it returns to Mercury this week, MESSENGER will be going slowly enough to enter orbit around the planet. This has never been done before; the only other space probe to visit Mercury, Mariner 10, was a flyby probe that made three approaches in 1974.
But there won't be any pictures from orbit until March 29, so I suppose mostly what we'll hear in a couple of days is whether the orbital insertion succeeded.
Mercury is a barren, rocky, airless and moonless world that looks somewhat like a larger version of our Moon, but with differences in detail. As such, it doesn't hold quite the popular fascination that many other worlds do. Still, it is (undisputedly) a planet, and one that's been underexplored up to now because of the great difficulty of getting there. I'll be happy to see it mapped at high resolution.