The Square Kilometre Array (SKA) is the largest radio telescope ever built in human history, consisting of nearly 3,000 radio antennas, each about 15 meters in diameter.
It was built specifically to study the questions of the very early universe, such as how elements heavier than helium were formed in the early universe, the formation of the first galaxies, and the trend of the evolution of the universe.
The scientific community currently believes that mysterious dark energy is responsible for the accelerating expansion of the universe. The SKA can map the distribution of hydrogen in the universe, revealing some details of its expansion after the Big Bang, detecting some of the younger galaxies, and identifying the nature of dark energy.
It's known that pulsars are rotating neutron stars observed to have pulses of radiation at very regular intervals that typically range from milliseconds to seconds. Pulsars also have very strong magnetic fields which funnel jets of particles out along the two magnetic poles. The SKA will focus on monitoring pulsars to look for evidence of gravitational waves — ripples in the fabric of space-time — predicted by Einstein's General Theory of Relativity and challenge the applicability of general relativity in extreme conditions on those pulsars.
Another fundamental question for astronomy, biology and humanity is whether life exists on other planets, which the SKA has the potential to answer. Recent astronomical discoveries have shown that gas giant planets (similar to Jupiter in our solar system) are common around other stars such as the Sun, but no habitable rocky planets (similar to Earth) have been found. However, Earth-like planets outside our solar system are possible. Observations of young stars have shown that they are surrounded by dusty disks that contain the very material that forms Earth-like planets.
By observing the process of planet formation, the SKA will be able to tell us how Earth-like planets form. It will even be able to detect radio signals from intelligent life on other planets, if indeed extraterrestrial beings use radio signals as a form of communication.