Universe MCQ Question and Answer | Geography MCQ Question

The umbra (Latin for "shadow") is the innermost and darkest part of a shadow, where the light source is completely blocked by the occluding body. An observer in the umbra experiences a total eclipse.

The sunspots cause Aurora borealis and aurora australis, magnetic storms on the surface of the sun and polar auroras.

Eris is the largest dwarf planet in the solar system and is the largest object found in orbit around the Sun since the discovery of Neptune and its moon Triton in 1846. It has a diameter between 2,400 and 3,000 kilometres (1,490 to 1,860 miles) and is 27% more massive than Pluto.

Atmospheric refraction is the deviation of light or other electromagnetic wave from a straight line as it passes through the atmosphere due to the variation in air density as a function of height. This refraction is due to the velocity of light through air, decreasing (the refractive index increases) with increased density. Atmospheric refraction near the ground produces mirages. Such refraction can also raise or lower, or stretch or shorten, the images of distant objects without involving mirages.

Jupiter’s dusty main ring system is harder to see than Saturn’s, but it’s there nonetheless. Jupiter’s largely invisible torus of ionized plasma continually being ejected from its third-largest moon Io. This ring of superheated plasma orbits around Jupiter at a staggering minimum temperature of 99,700° Celsius, and drastically affects Jupiter’s magnetosphere and the other particles orbiting around Jupiter.

Comets are celestial bodies moving about the solar system in Elliptical orbits usually accompanied by a long shining tail. A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail. These phenomena are due to the effects of solar radiation and the solar wind acting upon the nucleus of the comet.

The galactic year, also known as a cosmic year, is the duration of time required for the Sun to orbit once around the center of the Milky Way Galaxy. Estimates of the length of one orbit range from 225 to 250 million terrestrial years.

Venus is the hottest planet in the solar system. Although Venus is not the planet closest to the sun, its dense atmosphere traps heat in a runaway version of the greenhouse effect that warms Earth. As a result, temperatures on Venus reach 870° Fahrenheit (465° Celsius), more than hot enough to melt lead.

Venus, which can be seen with the unaided eye from Earth, is the brightest planet in our Solar System. Venus was given the nickname evening star and morning star because of its bright, consistent presence.

Venus is often called the Earth's sister planet. The Earth and Venus are very similar in size with only a 638 km difference in diameter, Venus having 81.5% of the Earth's mass.