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'Catching the fastest particles in the Universe'

May 29, 2013

People of all ages who are interested in science and space phenomena will be fascinated by an upcoming lecture by Colorado State Professor Miguel Mostafa, titled, 'Catching the fastest particles in the Universe.'

Sunday, June 2
3 p.m.
Drake Center
802 West Drake Road

Ultra high-energy cosmic rays

Miguel Mostafá, Ph.D., has been studying ultra-high energy cosmic rays for over a  decade.

His presentation at CSU's Drake Centre will:

  • Explain the motivation to study ultra-high energy cosmic rays,
  • Describe the different detection techniques,
  • Describe the Pierre Auger Observatory in western Argentina, an international cosmic ray observatory, and
  • Tell us what's next in high energy particle astrophysics. 

The lecture is free and open to the public.

Rarest particles in the Universe

"Over the last decade I’ve been studying ultra-high energy cosmic rays, the most energetic and rarest of particles in the Universe," Mostafa says.

"When these particles strike the Earth's atmosphere, they produce extensive air showers made of billions of secondary particles. While much progress has been made in nearly a century of research in understanding cosmic rays with low to moderate energies, those with extremely high energies remain mysterious.

"Detecting these particles is challenging because the highest energy cosmic rays are extremely rare. The especially interesting cosmic rays, with energies over 10^20 (10 to the 20th) electron volts (equivalent to the kinetic energy of a tennis ball traveling at 53 miles per hour, but packed into a single proton!), arrive on Earth at a rate of one per square kilometer per century!"

Elusive, mysterious

Why should ultra-high energy cosmic rays interest us? For the same reason they intrigue astrophysicists – no one’s sure where they come from. They are one of the Universe’s greatest mysteries.

One of 1600 particle detectors of the ground array of the Pierre Auger Observatory. The detection area of the array is the size of the state of Rhode Island.

Incredible amounts of energy

The phenomenon of ultra-high energy cosmic rays is in itself, captivating.  Cosmic rays are comprised of electrically charged particles. The highest-energy cosmic rays have 40 million times the energy of particles accelerated by the Large Hadron Collider, the particle accelerator near Geneva, Switzerland.

The mystery is that the directions the highest-energy cosmic rays arrive from do not point to any known astrophysical objects.

Particle showers over Earth

Cosmic rays are fast moving particles that shower the earth from all directions. Many are the nuclei of hydrogen atoms and some are heavier, such as the nuclei of iron atoms.

An air shower occurs when a fast-moving cosmic ray particle strikes an air molecule high in the atmosphere, creating a violent collision.

Fragments fly out from this collision and collide with more air molecules, in a cascade that continues until the energy of the original particle is spread among millions of particles raining down upon the earth.

By studying the air showers, scientists can measure the properties of the original cosmic ray particles.

This presentation is part of the 2013 College of Natural Sciences Lecture Series.

Contact: Wendy Gleason
Phone: (970) 491-0285