Venus is the closest planet to Earth under most circumstances. Venus orbits the sun at a distance of about 67 million miles, while the Earth orbits at about 93 million miles. From basic geometry, then, when the two planets are at their closest, which occurs when Venus is right between the...
We all depend on sunlight, but unless youlive at the equator, you won't get the same amount of it every day. Like all theplanetsin thissolar system,Earthrotates around an axis, an imaginary line between itsNorth and South poles. At the same time, it orbits the sun, finishing a new ...
In the 1960s, humans set out to discover what the red planet has to teach us. Now, NASA is hoping to land the first humans on Mars by the 2030s.
Earth's Axis Milankovitch also proposed that a change in the tilt of the earth's axis could act to affect climate. This concept is called obliquity. In general, Milankovitch theories are applied toward understanding the advance and retreat of the Ice Ages that have occurred in the past....
Why Is the Boomerang Nebula So Cold? The Coldest Place on Earth If you had to guess what is the coldest place on our planet, you might think of somewhere like Antarctica or the North Pole. Actually, the coldest thing ever recorded on Earth was created in a lab in Italy. Researchers ...
The termgeostationarycomes from the fact that the satellite appears nearly stationary in the sky to a ground-based observer. These satellites complete one orbit in about 24 hours, which is the same amount of time it takes for the Earth to rotate once on its axis. The satellite appears to ...
根据第一段“What if the Moon had never existed? For starters we know that the geophysical and climatological history of the Earth would have been different. Although there is still large uncertainty about how the Moon was formed, the most currently favored theory describes a disastrous collision ...
Supernovae, the spectacular end-of-life explosions of massive stars, can be incredibly destructive. A nearby supernova could strip away our protective ozone layer, exposing the planet to lethal levels of ultraviolet radiation. Fortunately, our position in the Orion Arm keeps us at a safe ...
Most of the oblate metal blebs themselves are flattened in a direction perpendicular to the long axis of the nodule/vesicle. These features result from alignment in the gravitational field on the LL parent asteroid, making LAR 06299 the first known chondrite to indicate gravitational direction. ...
Instead, its axis of rotation points at an unremarkable area of sky close to Alderamin (Alpha (α) Cephei), the brightest star in Cepheus. Deneb (Alpha (α) Cygni) is the closest bright star to Mars’s northern celestial pole. Observing the moons from Mars Two separate images of Deimos ...