by geckzilla » Mon Sep 26, 2016 2:16 am
SeedsofEarth wrote:I just finished watching the 44 hr. rotation of Saturn video, and I have a question: How was Cassini able to stay in one position as the planet rotated for 44 hours? Even if it had been in a Saturn-synchronous orbit, it still would have followed a stationary point on the planet as it rotated. In the video, it seems to be holding its position relative to the rotating planet? How was this possible?
It wasn't stationary. Per the description:
When it began taking images for this movie sequence, Cassini was 1,847,000 miles (2,973,000 kilometers) from Saturn, with an image scale of 355 kilometers per pixel. When it finished gathering the images, the spacecraft had moved 171,000 miles (275,000 kilometers) closer to the planet, with an image scale of 200 miles (322 kilometers) per pixel.
It was almost 3 million km from the planet, so it was moving relatively slowly and only covered 9.25% of the distance between itself and the planet over the 44 hour period. I'd say it was moving about 6250 km per hour, but it was also accelerating constantly as it approached.
[quote="SeedsofEarth"]I just finished watching the 44 hr. rotation of Saturn video, and I have a question: How was Cassini able to stay in one position as the planet rotated for 44 hours? Even if it had been in a Saturn-synchronous orbit, it still would have followed a stationary point on the planet as it rotated. In the video, it seems to be holding its position relative to the rotating planet? How was this possible?[/quote]
It wasn't stationary. Per the description:
[quote]When it began taking images for this movie sequence, Cassini was 1,847,000 miles (2,973,000 kilometers) from Saturn, with an image scale of 355 kilometers per pixel. When it finished gathering the images, the spacecraft had moved 171,000 miles (275,000 kilometers) closer to the planet, with an image scale of 200 miles (322 kilometers) per pixel.[/quote]
It was almost 3 million km from the planet, so it was moving relatively slowly and only covered 9.25% of the distance between itself and the planet over the 44 hour period. I'd say it was moving about 6250 km per hour, but it was also accelerating constantly as it approached.