Universe — Part 1 MCQs with Explanations

If you look down at our planet from outer space, most of what you see is water; 71% of the planet's surface is covered by ocean and it is because of this that the Earth is sometimes called "the water planet". Only about three-tenths of our globe is covered with land.

Jupiter and Saturn are located between Mars and Uranus.

Black hole, cosmic body of extremely intense gravity from which nothing, not even light, can escape. A black hole can be formed by the death of a massive star. They are regions of space where gravity is so powerful that even light can't escape.

"MESSENGER" was a robotic spacecraft sent by NASA. The name is a reference to the messenger deity of the same name from Roman mythology was a NASA robotic spacecraft that orbited the planet Mercury between 2011 and 2015. The probe was launched aboard a Delta II rocket in August 2004 to study Mercury's chemical composition, geology, and magnetic field.

The color of a star mostly indicates a star's temperature, and it can also suggest the star's age. Class O stars, which are blue in color, are the hottest, and class M stars, which are red in color, are the coldest.

Galileo Galilei first resolved the band of light into individual stars with his telescope in 1610. Until the early 1920s, most astronomers thought that the Milky Way contained all the stars in the Universe.

Halley's comet will next appear in the night sky in the year 2062. It orbits the sun every 75-76 years, so this is the time between appearances. Halley's comet was recorded by Edmund Halley in 1682. It was seen again in 1758, 1835, 1910, and 1986.

Radiant energy is the energy of electromagnetic waves. It is a form of energy that can travel through space. For example, we receive the heat from the sun, which is located very far from the earth via radiation. The sun's heat is not transmitted through any solid medium, but through a vacuum. They are short waves.

The brightest star in the sky is Sirius, also known as the “Dog Star” or, more officially, Alpha Canis Majoris, for its position in the constellation Canis Major. Sirius is a binary star dominated by a luminous main sequence star, Sirius A, with an apparent magnitude of -1.46.

Planet Earth has been called the "Blue Planet" due to the abundant water on its surface. Here on Earth, we take liquid water for granted; after all, our bodies are mostly made of water. However, liquid water is a rare commodity in our solar system.

When Venus is in the middle of the Sun and Earth, it is at its closest point to Earth. During this period, Venus would be the closest planet to Earth. However, there are times when Mars is actually the closest planet.

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 because it seems In addition to being known as the evening star, Venus was also called the morning star because it could be seen for a few hours before the Sun grew too bright. The planet actually becomes brightest before the Sun rises or just after sunset.

Basically, it's a unit of length used to measure the astronomically large distances between objects beyond our Solar System. One parsec is the distance at which one astronomical unit subtends an angle of one arcsecond.

Venus is sometimes called Earth's twin because Venus and Earth are almost the same size, have about the same mass (they weigh about the same), and have a very similar composition (are made of the same material).

Uranus is a real oddball in our solar system. Its spin axis is tilted by a whopping 98°, meaning it essentially spins on its side. No other planet has anywhere near such a tilt.

Nebula is the dense cloud of gases mainly Helium & Hydrogen & dust. They occur at primary stages & then from them galaxies are formed. It is a cloud of gas and dust in outer space, visible in the night sky either as an indistinct bright patch or as a dark silhouette against other luminous matter.

Comets go around the Sun in a highly elliptical orbit. They can spend hundreds and thousands of years out in the depths of the solar system before they return to Sun at their perihelion. Like all orbiting bodies, comets follow Kepler's Laws - the closer they are to the Sun, the faster they move.

Venus is the planet that takes nearly the same number of days for rotation as it does for revolution around the Sun. This phenomenon is known as synchronous rotation or tidal locking. As a result, Venus rotates on its axis very slowly and in the opposite direction compared to most other planets. It takes about 243 Earth days for Venus to complete one rotation on its axis, and it also takes about 225 Earth days to complete one orbit around the Sun. This means that a day (rotation) on Venus is longer than its year (revolution). Therefore, the correct answer is Option B, which is Venus.

Mercury and Venus are the only planets with no natural satellites.

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.

Jupiter is the fastest spinning planet in our Solar System rotating on average once in just under 10 hours. That is very fast especially considering how large Jupiter is. This means that Jupiter has the shortest days of all the planets in the Solar System.

The Moon's atmosphere is negligibly thin, essentially vacuum, so its sky is always black, as in the case of Mercury. However, the Sun is so bright that it is impossible to see stars during the daytime, unless the observer is well shielded from sunlight (direct or reflected from the ground).

Light travels through space at just over 186,000 miles per second. The moon is just under 250,000 miles from Earth, so light from the Moon's surface has to travel more than one second (about 1.3 seconds) to reach us.

Comets go around the Sun in a highly elliptical orbit. They can spend hundreds and thousands of years out in the depths of the solar system before they return to Sun at their perihelion. Like all orbiting bodies, comets follow Kepler's Laws - the closer they are to the Sun, the faster they move.

The planets are kept in motion in their respective orbits by Gravitation and centrifugal force. The Sun's gravity pulls on the planets, just as Earth's gravity pulls down anything that is not held up by some other force and keeps you and me on the ground.

There are three sides to the moon that are visible to us on earth: the near side of the moon, the western far side, and the eastern far side. The side of the moon that is the most valuable is the near side of the moon since it faces the earth at all times and contains four of the five largest seas/oceans on the moon. These seas/oceans are: The Ocean of Storms (Oceanus Procellarum) - 2568 km in diameter, The Sea of Cold (Mare Frigoris) - 1596 km in diameter, The Sea of Showers (Mare Imbrium) - 1123 km in diameter, The Sea of Fecundity (Mare Fecunditatis) - 909 km in diameter, The Sea of Tranquility (Mare Tranquillitatis) - 873 km in diameter.

Geography (from Greek: geographia, literally "earth description") is a field of science devoted to the study of the lands, features, inhabitants, and phenomena of the Earth and planets. The first person to use the word geography was Eratosthenes (276–194 BC).

Galileo Galilei was the first to see Saturn's rings in 1610, although from his telescope they resembled handles or arms. It took Dutch astronomer Christiaan Huygens, who had a more powerful telescope, to propose that Saturn had a thin, flat ring.

Only one side of the Moon is visible from Earth because the Moon rotates on its axis at the same rate that the Moon orbits the Earth – a situation known as synchronous rotation, or tidal locking. The Moon is directly illuminated by the Sun, and the cyclically varying viewing conditions cause the lunar phases.

All the planets are satellites around the Sun. Almost every ship launched from Earth can be considered a satellite, as it is orbiting either the Earth or the Sun. Even though a space probe is going "out" from the Earth to Jupiter, it is still in orbit around the Sun, so it is still a satellite. It is certainly possible to set up a satellite so that it has a circular orbit (a circle is just an ellipse whose foci coincide). Gravity can only pull in the direction toward the planet.