FYI.

This story is over 5 years old.

Tech

China’s ‘Monkey King’ Satellite Is Looking for Dark Matter in Space

The Monkey King satellite launch ushered in new era of space science for the country.
Image: Strategic Pioneer Research Program in Space Science of the Chinese Academy of Sciences (CAS).

One of the longest standing conundrums in cosmology is accounting for dark matter, a theoretical material that emits neither energy nor light and accounts for approximately 80 percent of the universe's mass. It was first posited in the 1960s as a way of explaining the fact that there wasn't enough visible matter in the universe to account for the nature of many astrophysical processes, like the motion of galaxies. In the intervening years, a number of experiments have bolstered the theory of dark matter, such as the recent survey of dozens of galaxy clusters colliding with one another, although direct evidence of its existence remains elusive.

Advertisement

On Thursday evening, the Chinese Academy of Sciences launched the Dark Matter Particle Explorer (DAMPE) into low Earth orbit from the Gobi desert, a satellite the organization hopes will shed some light on dark matter by focusing on the origins of this mysterious substance.

Nicknamed "Wukong" (the Monkey King), DAMPE is a multinational cooperative effort between CAS, the University of Geneva, and a handful of Italian academic institutions, and will spend the first two years of its life in a 500 km altitude orbit scanning the cosmos for high energy gamma-rays, electrons and cosmic rays. After these initial two years, DAMPE will narrow its search to the most promising regions.

Equipped with a BGO calorimeter, a silicon-Tungsten Tracker, a neutron detector, and a plastic scintillator detector, DAMPE is seeking to capture high energy particles and trace them back to their origin, which the project's scientists believe to be dark matter collisions. Each scintillator is made of a material that flashes when it is struck by the ionizing radiation from a high energy particle, allowing scientists to determine the particle's energy levels and direction of origin. Taken as a whole, the stack of scintillators which comprises DAMPE is the most sensitive detection mechanism ever sent to space.

According to the project scientists, DAMPE is capable of measuring electrons and photons with high energy reach, on the order of tera-electron Volts. The energy of these particles are similar to what are produced in terrestrial particle colliders such as CERN, and DAMPE's ability to detect such high energy levels far exceeds the capacity of other space-based dark matter detectors such as the Alpha Magnetic Spectrometer (AMS) and the Calorimetric Electron Telescope (CET) on the International Space Station.

One of the leading theories claiming to account for the makeup of dark matter posits a new exotic particle called a Weak Interacting Massive Particle (WIMP). Some cosmologists think that WIMPs act as their own antiparticle, their collision producing a high energy signature of the sort that could be picked up by DAMPE. The AMS has already picked up what look like traces of such collisions, but was unable to determine their origin. If signals like those detected by AMS turns out to be WIMP signatures, then DAMPE should be able to confirm this by detecting the byproducts of these collisions at a much higher energy resolution and determining their origin.

The launch of the Monkey King on Thursday ushered in an exciting new era of space-based science for China. In addition to being the most sensitive dark matter detecting satellite ever put into space, DAMPE marked the beginning of a five-launch program which will see China put a number of groundbreaking experiments into orbit. The next two launches are scheduled for 2016 and will include the first quantum communications satellite (the goal of which is to see if photons sent from Earth to orbit can continue to be entangled with their terrestrial counterparts), as well as an X-ray telescope to study radiation emissions from black holes.