... The Sun . ... The Corona . ... Solar Wind . 18H.Solar Wind obs. ... Field . ... The first indication that the sun might be emitting a "wind" came from comet tails , observed to point away from the Sun, whether the comet was approaching the Sun or whether it was moving away. ... The corona, like the Earth's atmosphere, is held down by the Sun's gravity. ... The particles at its "roots" stay with the Sun, but those in the high corona flow out with the solar wind, to the Earth's orbit and far beyond. ...

... 24a.The Rotating Earth . ... He projected the Sun's magnified image from his telescope upon a flat white surface, and observed it there. ... The Sun's average distance from Earth, also known as the "astronomical unit" (AU), is about 150 million kilometers (93 million miles), but measuring that distance is not easy. ... Above that came the solar corona ("crown"), glowing tufts that faded into the distance, though time exposures with sensitive cameras managed to trace them to several solar radii. ...

NASA Mars Orbiter . ... The Mars Global Surveyor mission is designed as a rapid, low-cost recovery of the Mars Observer mission objectives. The science objectives involve high resolution imaging of the surface, studies of the topography and gravity, the role of water and dust on the surface and in the atmosphere of Mars, the weather and climate of Mars, the composition of the surface and atmosphere, and the existence and evolution of the Martian magnetic field. ...