Arctic rivers and runoff from the land pour vast volumes of freshwater into the Arctic Ocean, influencing seawater salinity, sea-ice formation and ocean circulation, thereby playing an important role in regulating Earth’s heat balance.

As northern monitoring networks decline, scientists have turned to satellite data to reconstruct two decades of river discharge and runoff, revealing a striking mosaic of regional change as warming temperatures and shifting precipitation patterns reshape the Arctic’s hydrological system in uneven and unexpected ways.

On 25 March, the first two satellites of the Celeste in-orbit demonstration mission will lift off aboard Rocket Lab’s Electron rocket from the company’s Māhia Launch Complex in New Zealand.

Celeste will play a pioneering role in elevating the future of Europe’s satellite navigation capabilities.

As ESA’s initiative for satellite navigation in low Earth orbit (LEO-PNT), the mission will be testing next-generation technologies and add new frequency bands for satellite navigation to inform the deployment of a future European operational navigation system in low Earth orbit. 

The mission will begin with two demonstrator satellites, IOD1-2, to secure and test the

Comet K1, whose full name is Comet C/2025 K1 (ATLAS), had just passed its closest approach to the Sun and was heading out of the Solar System. Though it had been intact just days before, K1 fragmented into at least four pieces while the NASA/ESA Hubble Space Telescope was watching. The odds of that happening while Hubble viewed the comet are extraordinarily miniscule.

Thanks to the success of the Arctic Weather Satellite prototype and Eumetsat’s recent greenlight to develop a full constellation of similar satellites called Sterna, the European Space Agency has awarded OHB Sweden with the contract to build 20 satellites.

This marks a major step toward better monitoring rapidly evolving weather, improving forecasts of severe events in vulnerable regions such as the Mediterranean, and closing critical data gaps over the Arctic – the fastest-warming region on Earth and a key driver of Europe’s weather systems.

ESA Impact: our story so far this year