South Pole Telescope beneath a rainbow of colors | Space photo of the day for Sept. 8, 2025

Remote, freezing, and wrapped in mystery, Antarctica was the last continent to be explored and remains one of the most difficult environments on Earth to access. Its landscape of endless white, broken only by rocky outcrops and ice ridges, covers nearly 5.275 million square miles (14 million square kilometers), an area almost twice the size of Australia.

Yet this stark environment is far more than a frozen wasteland. Antarctica is one of Earth’s most important natural laboratories. Its ice cores preserve climate records stretching back hundreds of thousands of years. Its skies, free from light pollution and featuring thin, dry air, give the perfect viewing conditions for astronomers.

What is it?

Rising out of the frozen plateau is the South Pole Telescope, a key tool for radio astronomy. Completed in 2007, the 33-ft (10 meters) radio telescope was designed to study faint microwave signals from the early universe, including the cosmic microwave background, the afterglow of the Big Bang.

Where is it?

The South Pole Telescope is located near the Amundsen-Scott South Pole Station.

Why is it amazing?

Studying the cosmic microwave background helps answer fundamental questions about how the universe began, what it is made of and how it is evolving.

The South Pole Telescope has also helped astronomers probe the nature of dark energy, map galaxy clusters and help look at large-scale structures of the cosmos.

Want to learn more?

You can read more about the South Pole Telescope and radio telescopes.