Because, it turns out the tilt of the Earth is more important than distance from the sun.
AU, is the distance from the sun to the earth, so the position of the dust coincides with that of the rocky planets of the earth's solar system.
The SPEs will be lower as the distance from the Sun will increase, while the GCRs will be about the same, but the length of time will be longer than any mission in history.
It seemed to him unreasonable that the earth, on the contrary, would always travel at the same speed regardless of its distance from the sun, and when he got that straightened out, he single-handedly improved the accuracy of predicted positions by an order of magnitude.
It is currently 13.5 billion kilometres (8.4 billion miles) from the Sun, or 90 times the distance separating the Earth from the Sun.
BBC: NEWS | Science/Nature | Voyager 'at edge of Solar System'
Mr. STERN: So a few weeks after the Pluto encounter when we've chosen our target, we'll fire the engines of the spacecraft, but we'll have to fly a distance something like from here to the sun or twice that far to reach these Kuiper Belt objects.
It will make its closest approach to the Sun - at a distance of not much more than a million km from the Sun's surface - on 28 November.
From that distance, a star like the sun is visible through binoculars.
In the evening, the setting is magical as the sun sets over the Congo Mountains in the distance, and tiny lights from fishing boats flicker across the lake.
Viewed from a distance of ten light-years, the sun's side-to-side wobble due to Jupiter causes its position to change by 1.6 thousandths of an arcsecond.
Its distance from this star is only 5% of that between the Earth and the sun.
"For the May eclipse, the moon will be at the furthest distance from Earth that it ever achieves -- meaning that it will block the smallest possible portion of the sun, and leave the largest possible bright ring around the outside, " the agency said on its website.
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