Researchers at Radboud University, ASTRON and the Delft company Innovative Solutions in Space (ISIS) are to develop a new instrument that will be onboard the Chinese Chang’e4 satellite that will be placed in an orbit behind the moon in 2018. With this instrument, astronomers want to measure radio waves from the stars and galaxies that were formed directly after the Big Bang.
The Netherlands Space Office (NSO) and the Chinese national space agency CNSA signed a partnership agreement on a mission to the moon, made possible by the organisations Memorandum of Understanding (MoU) in 2015.
This radio antenna is the first Dutch-made scientific instrument to be sent on a Chinese space mission, and it will open up a new chapter in radio astronomy. This instrument will help us find answers to vital questions concerning the origin of the universe and this project will represent a new milestone in astronomy.
Long-term Partnership
Radboud University astronomers Heino Falcke and Marc Klein Wolt are the scientific advisors for this project and have spent years working towards taking this important step. The instrument they are developing will be a precursor to a future radio telescope in space. They will ultimately need such a facility to map the early universe and to provide information on the development of the earliest structures in it, like stars and galaxies.
Albert-Jan Boonstra, programme manager at ASTRON, explained: “Our years of experience in the construction of the Westerbork radio observatory, the Low Frequency Array LOFAR and the development of the Square Kilometre Array will be put to use in the construction of this new instrument.” Experts in innovative satellite systems engineering from ISIS will be responsible for the system integration of the instrument, and its accommodation on the Chang’e 4 satellite.
The far side of the moon
Radio astronomers study the universe using radio waves, light coming from stars and planets, which is not visible with the naked eye. We can receive almost all celestial radio wave frequencies here on Earth. However, we cannot detect radio waves below 30 MHz, as these are blocked by our atmosphere. It is these frequencies in particular that contain information about the early universe, which is why we want to measure them.
As so little is known about this part of the electromagnetic spectrum, the measurements made by the Dutch radio antenna on the Chinese satellite could be the first to provide information on the development of the earliest structures in the universe. This information could help confirm the Big Bang theory. As these radio waves are so weak, the satellite needs to be placed behind the moon, where there is relatively little disturbance by radiation from sources on Earth.
Solar storms and radio pulses from planets
Another task of the antenna is to monitor the ‘weather’ in space. Powerful events such as solar storms can affect telecommunications here on earth. More knowledge on the impact of such eruptions on the surroundings will help them to better predict such events. They also want to measure strong radio pulses from planets like Jupiter and Saturn to obtain new information about their rotational speed.
Celestial Map
Finally, the team wants to produce the first reasonably accurate map of the sky at these low frequencies, which should be possible after a few complete rotations of the satellite and moon around the earth. They hope signals from the early universe will slowly emerge after a year or two of measurements and data analysis.
