Which Country used the armillary sphere in the past to measure the position of celestial bodies?

Scientists invent and use ____ to study space.

What are the limitations of studying space from the Earth?

( choose three answers )

What do humans use to overcome the limitations of studying space from the Earth??

A rocket takes off by ____ .

When fuel is burned, the gas produces a force in the opposite direction that pushes the rocket upwards.

What is this called?

A spacecraft takes off with the help of a ____ .

In which year was the first artificial satellite sent to orbit the Earth.

In 1969, two American astronauts became the first humans to walk on ____ .

In which year did China launch its first manned spacecraft?

In which year did China land its first lunar rover on the Moon for lunar exploration?