GRAPES-3 Telescope

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Recently, researchers from Mumbai, Kochi, and Japan used the GRAPES-3 Telescope to study how the Earth’s upper atmospheric temperature and the Sun’s magnetic field influence muons, which are highly energetic subatomic particles originating from outer space.

About GRAPES-3 Telescope

The Gamma Ray Astronomy PeV EnergieS Phase-3 (GRAPES-3) is one of the world's leading cosmic ray observatories, designed to study the origin, acceleration, and propagation of cosmic rays. It investigates the extensive air showers produced when high-energy cosmic rays or gamma rays enter the Earth's atmosphere with energies ranging from tera electronvolts (TeV) to peta electronvolts (PeV).

Besides cosmic ray research, the telescope also plays an important role in studying solar activity, space weather, and thunderstorm phenomena by observing cosmic ray muons reaching the Earth's surface.

Location

The GRAPES-3 Telescope is located at Ooty, Tamil Nadu, where its high-altitude location provides ideal conditions for detecting cosmic ray particles with minimal atmospheric interference.

Operating Institution

The telescope is operated by the Tata Institute of Fundamental Research (TIFR), Mumbai, one of India's premier institutions for research in physics, astrophysics, and space sciences.

Key Features of GRAPES-3 Telescope

Study of Cosmic Rays

The primary objective of GRAPES-3 is to investigate the origin, acceleration mechanisms, and propagation of extremely energetic cosmic rays that continuously bombard the Earth from outer space.

Detection of Extensive Air Showers

When a high-energy cosmic ray or gamma ray enters the Earth's atmosphere, it collides with atmospheric molecules and produces a cascade of secondary particles known as an Extensive Air Shower (EAS). GRAPES-3 measures these air showers to determine the energy, direction, and nature of the incoming primary particle.

Muon Observation

One of the unique capabilities of GRAPES-3 is its ability to detect muons, which are highly penetrating charged particles generated during cosmic ray interactions. By studying changes in muon intensity, scientists can understand the influence of the Sun's magnetic field, solar storms, and variations in the Earth's atmosphere.

Advanced Detection Technology

The observatory uses a large array of plastic scintillator detectors to detect extensive air showers, while a massive Muon Detector based on proportional counters records muons with exceptional precision. Together, these instruments provide high-quality data for astrophysical research.

Scientific Importance

The GRAPES-3 Telescope contributes significantly to understanding high-energy astrophysical phenomena, including the sources of cosmic rays, solar energetic particle events, geomagnetic storms, and the interaction between space weather and the Earth's atmosphere. It also improves knowledge of thunderstorm physics and atmospheric electricity.

About Cosmic Rays

Meaning

Cosmic rays are extremely energetic charged particles that originate from outer space and continuously strike the Earth's atmosphere from all directions. They are considered among the most energetic particles in the Universe.

Discovery

Cosmic rays were discovered more than 100 years ago, opening an entirely new field of research in particle physics, astrophysics, and space science.

Nature

These particles constantly bombard the Earth at nearly the speed of light. Most cosmic rays are protons, although they also include heavier atomic nuclei and other charged particles.

Formation of Air Showers

When cosmic rays collide with molecules in the Earth's atmosphere, they generate a cascade of secondary particles known as an air shower. These showers consist of electrons, photons, muons, protons, and neutrons, many of which eventually reach the Earth's surface.

Energy Range

Cosmic rays possess an extraordinarily wide energy spectrum, ranging from approximately 10⁸ electron volts (eV) to 10²⁰ electron volts (eV), making them the highest-energy particles known in nature.