BBC News | SCI/TECH | Kumbh Mela pictured from space

What is probably the largest human gathering in history has been imaged from space.

The Maha Kumbh Mela, or Grand Pitcher Festival, takes place every 12 years in Northern India and sees millions of devotees bathe in the Ganges to purify their sins. The Kumbh is held at the confluence of the Ganges and Yamuna rivers, where Hindu scriptures say the gods spilt a drop of the elixir of immortality.

This extraordinary picture was taken by Space Imaging's Ikonos satellite on Tuesday this week. Timed at 1030 am, the image shows what was happening at the start of the most sacred and busiest bathing day (Mauni Amavasya) of the festival.

Vast numbers of people are moving down to the waters. Compare the less detailed version of the same image (below) with one taken before the event in May last year (also below). Notice how the shape of the sand banks in the river has changed.

The festival lasts just over a month. The authorities have spent millions of dollars on security and other arrangements with in excess of 30 million people expected to attend.

Ikonos is the world's highest-resolution, commercial Earth-imaging satellite. It orbits 680 kilometres (423 miles) above the planet.