The corona is the outermost layer of the Sun, starting at about 1300 miles (2100 km) above the solar surface (the photo-sphere). The temperature in the corona is 500,000 K (900,000 degrees F, 500,000 degrees C) or more, up to a few million K. The corona cannot be seen with the naked eye except during a total solar eclipse. The corona does not have an upper limit.

Correct Option: D

The corona is the outermost layer of the Sun, starting at about 1300 miles (2100 km) above the solar surface (the photo-sphere). The temperature in the corona is 500,000 K (900,000 degrees F, 500,000 degrees C) or more, up to a few million K. The corona cannot be seen with the naked eye except during a total solar eclipse. The corona does not have an upper limit.

Stars twinkle because they are point light sources. Passing through the atmosphere, the small beam of light constantly shifts by bouncing off particles in the air. The much closer planets appear instead as tiny disks in the sky. Their apparent sizes are usually larger than the pockets of air that would distort their light, so the effects of scintillation are negligible. Being closer, planets appear as discs, with the shifting of light from one side cancelling out the other.

Correct Option: D

Stars twinkle because they are point light sources. Passing through the atmosphere, the small beam of light constantly shifts by bouncing off particles in the air. The much closer planets appear instead as tiny disks in the sky. Their apparent sizes are usually larger than the pockets of air that would distort their light, so the effects of scintillation are negligible. Being closer, planets appear as discs, with the shifting of light from one side cancelling out the other.

Eris is the most massive and second-largest dwarf planet known in the Solar System. It is 27% more massive than dwarf planet Pluto. Eris is the ninthmost-massive known body directly orbiting the Sun, and the largest known body in the Solar System not visited by a spacecraft.

Correct Option: C

Eris is the most massive and second-largest dwarf planet known in the Solar System. It is 27% more massive than dwarf planet Pluto. Eris is the ninthmost-massive known body directly orbiting the Sun, and the largest known body in the Solar System not visited by a spacecraft.

The Big Dipper is an asterism consisting of the seven brightest stars of the constellation Ursa Major. In Hindu astronomy, it is referred to as the “Collection of Seven Great Sages” (Saptarshi Mandal), as each star is named after a mythical Hindu sage.

Correct Option: C

The Big Dipper is an asterism consisting of the seven brightest stars of the constellation Ursa Major. In Hindu astronomy, it is referred to as the “Collection of Seven Great Sages” (Saptarshi Mandal), as each star is named after a mythical Hindu sage.

The Steady State theory (also known as the Infinite Universe theory or continuous creation) was developed in 1948 by Fred Hoyle, Thomas Gold, Hermann Bondi and others as an alternative to the Big Bang theory. In the steady-state theory, the density of matter in the expanding universe remains unchanged due to a continuous creation of matter. It asserts that the observable universe is basically the same at any time as well as at any place.

Correct Option: C

The Steady State theory (also known as the Infinite Universe theory or continuous creation) was developed in 1948 by Fred Hoyle, Thomas Gold, Hermann Bondi and others as an alternative to the Big Bang theory. In the steady-state theory, the density of matter in the expanding universe remains unchanged due to a continuous creation of matter. It asserts that the observable universe is basically the same at any time as well as at any place.