Three satellites are candidates to read Earths secrets... but only one will be launched

How does the temperature of the ice deep at the poles change? What happens to the air at the edge of space? Does the Earth gain more energy than it loses? These questions underlie three concepts for scientific satellites selected by the European Space Agency on September 25 to move to a new preparation phase.

The first concept, ECO, focuses on measuring Earth''s energy imbalance—the difference between the energy it receives from the sun and the energy it reflects back into space.

This measurement could help scientists understand global warming and assess the impact of mitigation efforts.

Keystone targets a region of the atmosphere between 50 and 250 kilometers high to measure atomic oxygen, temperature, and winds.

It also aims to detect minerals left behind by space debris entering the atmosphere.

Cryorad proposes measuring temperature and conditions at the base of the polar ice sheets to better understand their movement and what they might mean for future sea levels.

These three concepts were selected from four that underwent scientific review, but none have yet been chosen for launch.

NASA will select one for the Earth Explorer 12 mission, with the chosen mission expected to launch around 2036