The Sun's angular diameter, as observed from Earth, is approximately 0.5°. This is based on Earth's average distance of 93 million miles (150 million km) from the Sun. From Mercury, at an average ...

The article explores the challenge of visually detecting variations in the Moon's apparent size, which are caused by its changing distance from Earth during perigee and apogee, amidst perceptual ...

This is one of my favorite stories. In short, one of John Burk's (@occam98) students wanted to launch a space balloon. If you want all the details, this post at Quantum Progress pretty much says it ...

Elongation is the angle, in degrees, between the Sun and the planet as seen from here on the Earth. Superior planets (those that lie further from the Sun than us: Mars, Jupiter, Saturn, Uranus, ...

AFTER the successful measurement of Capella as a double star by Prof. A. Michelson's interferometer method applied to the 100-in. reflector at Mount Wilson, it was known that he intended to attempt ...

Forbes contributors publish independent expert analyses and insights. The Universe is out there, waiting for you to discover it. Intuitively, we all know that when we see an image of an object, it ...

THE existence of a source in the Crab Nebula with an angular diameter of less than 1 sec of arc has been revealed by observations of interplanetary scintillation at a frequency of 38 Mc/s (ref. 1).

Phobos is the best known irregular satellite in our solar system, but it isn't a squoon. (ESA/DLR/FU Berlin (G Neukum), CC BY-SA 3.0 IGO) Well let’s think about the physics: for a satellite to be ...