Multimedia Gallery
- Media Type: Illustration
Sidereal time, or “star time,” is based on Earth’s rotation relative to the stars, rather than to the Sun.
Snakes, South America (Callirhinus patagoniensis, Dendrophis prasinus)
Josiah Perkins Creesy, Jr. commanded the ship, and, uncommon for the time, his wife Eleanor navigated. As a child in Massachusetts, she had learned navigation skills from her seafaring father.
An artist’s rendering of Timation 3 navigation satellite orbiting in space.
The U.S. Exploring Expedition included a formidable group of botanists, naturalists, artists, taxidermists, and other scientists.
The Doppler shift of signals from a moving satellite is used to determine the satellite's orbit compared to the location of the tracking station.
The UAT and similar transceivers are what make ADS-B possible.
Using a compass, depicted by Flemish artist Jan van der Straet, 1523-1605.
A mariner could use a cross staff to measure the Sun’s angle above the horizon at midday.
A lead line could measure water depth and bring up a sample of the bottom.
