Beyond Earth: questions with answers

Both learners looked at the same bright stars and joined them with imaginary lines. People may draw different patterns from the same stars and give them different names and stories. So the rule is that different people can imagine different patterns from the same stars.

The connecting lines are imaginary. They are drawn only for easy identification of the imagined pattern; they are not actually present in the sky.

The connected stars are a star pattern. Earlier, such groups of stars were called constellations. Currently, constellation refers to defined regions of the sky that often include these patterns, so the pattern alone is not the full meaning.

The Pole Star belongs to the Little Dipper and appears nearly fixed near North. It is outside the Big Dipper and need not be brightest. The marked Big Dipper member cannot be the Pole Star.

A large number of stars may be visible on a clear cloudless night. In big cities, only a few stars may be seen because of light pollution, smoke and dust, and viewing can also be blocked by tall buildings and trees. An open dark area away from these is better for night sky watching.

Stars fade away at dawn and appear at dusk. For daytime the reason is not that they disappear: due to the extreme brightness of the Sun, it is not possible to view other stars from Earth.

The Sun is much closer to Earth than the other star. A star that is much closer looks much bigger to us. The other stars are very far away, so they look like tiny points of light.

The motion around the Sun is called revolution. The motion about a planet's own axis is called rotation. So A is revolution around the Sun, and B is rotation about its axis.

Increasing distance starts at Mercury and ends at Neptune. Position 6 is Saturn. Pluto is not one of the eight planets.

The Moon formed naturally and orbits Earth. It is Earth's natural satellite, rather than a planet or a human-made object.

In the broad sense, an object orbiting a much larger body can be called its satellite. Here, Mars orbits the Sun.

The asteroid belt lies between the paths of Mars and Jupiter. Its many asteroids orbit the Sun and belong to the Solar System.

Solar heating releases gas and dust from a comet's frozen material. The tail develops more strongly near the Sun than far away.

The drawing shows the Solar System inside the Milky Way Galaxy. This matches the rule that our Solar System is part of the Milky Way Galaxy. A galaxy has millions to billions of stars, so the Milky Way Galaxy is not just another name for the Solar System.

The figure only shows where scientists are looking. A search is not the same as a discovery. Scientists have not found any evidence of life anywhere else in the Universe. The search is still going on.