Topic: Space

Cosmic rays are powerful particles that travel across the universe. Scientists used a space telescope to discover a common feature shared by these particles and understand their origins.

Cosmic rays are incredibly powerful particles that have been traveling across the universe for millions of years. For over 100 years, scientists have been trying to understand where they come from and how they get accelerated to such high energies. Now, researchers using a space telescope called DAMPE have made an important discovery that could help answer these questions.

The DAMPE space telescope was launched in December 2015 to study cosmic rays and explore possible connections to dark matter. By examining highly precise data collected by the telescope, researchers discovered a universal pattern in the energy spectra of primary cosmic ray nuclei. This means that for every type of nucleus studied, the number of particles begins dropping much faster after reaching a certain threshold.

Scientists refer to this effect as 'spectral softening.' Normally, higher-energy cosmic rays become less common as energy increases. However, the DAMPE observations revealed that the decline becomes dramatically steeper beyond a rigidity of roughly 15 TV (teraelectron-volts). Rigidity describes how strongly a particle's path resists being bent by magnetic fields.

The findings strongly support theories suggesting that cosmic ray acceleration and movement through space are controlled by rigidity. At the same time, the data largely rules out competing explanations based on energy per nucleon (energy divided by the number of nucleons in the particle).

Why It Matters

Understanding how cosmic rays are created and move through space can help us better understand the universe and its mysteries. This discovery could also lead to new insights into dark matter, which is still a mystery.

Key Facts

• Cosmic rays are incredibly powerful particles that travel across the universe at extreme energies.
• The DAMPE space telescope was launched in December 2015 to study cosmic rays and explore possible connections to dark matter.
• Researchers discovered a universal pattern in the energy spectra of primary cosmic ray nuclei, which is known as 'spectral softening'.
• The decline in higher-energy cosmic rays becomes dramatically steeper beyond a rigidity of roughly 15 TV (teraelectron-volts).
• The findings strongly support theories suggesting that cosmic ray acceleration and movement through space are controlled by rigidity.

Key Terms

Rigidity

A measure of how strongly a particle's path resists being bent by magnetic fields

Implications

Understanding how cosmic rays are created and move through space can help us better understand the universe and its mysteries. This discovery could also lead to new insights into dark matter, which is still a mystery.