Aorounga impact crater in Chad. Copyright ESA/NASA
Aorounga impact crater in Chad. Copyright ESA/NASA

June 25, 2019 – Summer in the Northern hemisphere has arrived and with it the long, sunny days and hot, sticky nights.

Among barbecues and beach days is Asteroid Day, celebrated each year on 30 June, to raise awareness and educate people about small rocky bodies hurling through space that have the potential to do serious damage to our planet.

Though Earth is peppered with the pot marks of asteroid impacts across millennia, like the Aorounga impact crater in Chad, photographed here by ESA astronaut Tim Peake in 2016 from the International Space Station, we have not experienced a major impact since the Tunguska event in Siberia on 30 June 1908.

An official United Nations day of awareness, Asteroid Day encourages the public to join activities across 192 countries with scientists and specialists to talk asteroids.

For instance, do you know the difference between an asteroid and a meteorite?

A meteorite is a piece of debris that breaks off an asteroid and survives its descent through Earth’s atmosphere.

A meteorite is believed to be the cause of the Aorounga crater several hundred million years ago. Sediment buried the original crater but later eroded, forming these concentric rings.

It is not all bad. Asteroids are also a source of information about our Solar System and a potential new resources.

ESA is interested in asteroids for all these reasons. Over the past two decades, ESA has tracked and analysed asteroids that travel close to Earth, known as near-Earth objects or NEOs, of which there are an estimated 10 million larger than 10 m – the threshold above which damage on the ground could happen.

The answer to any potential threat is awareness and preparedness. ESA coordinates observatories and astronomers worldwide through its NEO Coordination Centre, located at ESA’s Centre for Earth Observation in Italy.

Building on this experience, ESA has developed a new type of automated telescope for night-sky surveys called ‘Flyeye’ and is proposing a network of these telescopes on Earth to monitor NEOs for approval by Europe’s space ministers at Space19+ this November.

Also being put forward as part of the Space Safety plans is Europe’s contribution to a pioneering international asteroid deflection experiment for planetary defence: the Hera mission, which is proposed for launch in October 2024.

On the fifth anniversary of Asteroid Day, join the main event via a 24-hour live broadcast streamed from Luxemburg City, in coordination with hundreds of other events all over Europe and the world. Talks will focus on the role of asteroids in the formation of our Solar System and the technological advances to detect, track and study them. Join the conversation online via #AsteroidDay2019.