The European Space Agency (ESA) is Europe’s gateway to space. Its mission is to shape the development of Europe’s space capability and ensure that investment in space continues to deliver benefits to the citizens of Europe and the world.
Find out more about space activities in our 23 Member States, and understand how ESA works together with their national agencies, institutions and organisations.
Exploring our Solar System and unlocking the secrets of the Universe
Go to topicProtecting life and infrastructure on Earth and in orbit
Go to topicUsing space to benefit citizens and meet future challenges on Earth
Go to topicMaking space accessible and developing the technologies for the future
Go to topicThank you for liking
You have already liked this page, you can only like it once!
As the smallest planet in the Solar System crossed the face of the Sun on Monday 9 May, one of ESA’s smallest satellites was watching.
Proba-2, smaller than a cubic metre, monitors the Sun from Earth orbit with an extreme-ultraviolet telescope. It was able to spot Mercury’s transit of the Sun as a small black disc roughly four pixels in diameter.
The Mercury transit was visible from Earth starting at 11:13 GMT and ending at 18:42 GMT. The total transit time was about 7 hours and 31 minutes.
Solar transits – where a celestial body is seen to pass across the solar disc from the perspective of Earth – are relatively rare events. Mercury undergoes around 13 transits a century, and Venus two transits every 120 years.