Image: Tunguska devastation

June 7, 2018, European Space Agency
Credit: Public domain – N. A. Setrukov, 1928

Fallen trees at Tunguska, Imperial Russia, seen in 1929, 15 km from epicentre of aerial blast site, caused by explosion of a meteor in 1908 (Photo N. A. Setrukov, 1928).

Near-Earth objects are asteroids or comets, metres to tens of kilometres in size, that orbit the Sun and whose orbits come close to that of Earth's. Of the more than 600 000 known asteroids in our Solar System, over 16 000 are classified as NEOs.

On 30 June 1908, above the skies of Tunguska in Russia, such an object 30–40 m in diameter and travelling at approximately 100 000 km/hour penetrated Earth's atmosphere.

It heated to approximately 10 000ºC and exploded between six and ten km above the ground. The blast released the equivalent energy of 10–15 megatons of TNT, destroying 2200 square km of forest and leaving few traces of life.

On 30 June, the United Nations observes International Asteroid Day, which aims to raise awareness about asteroids and the need to take action to protect Earth, humankind and .

Near-Earth objects could potentially hit our planet and, depending on their size, produce considerable damage. While the chance of a large object hitting Earth is very small, it would produce a great deal of destruction.

ESA is in the forefront of global efforts to observe the skies and detect asteroids, and warnings, develop ways to deflect any that are predicted to hit us, and take action to mitigate risk and hazards when deflection is not possible.

Explore further: Asteroid coming close Friday: Don't worry, we're safe

Related Stories

Tracking the threat of asteroids and comets

May 14, 2018

In 1994, astronomers watched in awe as the comet Shoemaker-Levy 9 crashed into the planet Jupiter, creating massive fireballs exploding with the force of six million megatons of TNT—equivalent to 600 times the world's nuclear ...

Four years of NASA NEOWISE data

April 23, 2018

NASA's Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) mission has released its fourth year of survey data. Since the mission was restarted in December 2013, after a period of hibernation, the asteroid- and ...

Two small asteroids safely pass Earth this week

February 7, 2018

Two small asteroids recently discovered by astronomers at the NASA-funded Catalina Sky Survey (CSS) near Tucson, Arizona, are safely passing by Earth within one lunar distance this week.

Recommended for you

Dust storms on Titan spotted for the first time

September 25, 2018

Data from NASA's Cassini spacecraft has revealed what appear to be giant dust storms in equatorial regions of Saturn's moon Titan. The discovery, described in a paper published on Sept. 24 in Nature Geoscience, makes Titan ...

A new classification scheme for exoplanet sizes

September 24, 2018

There are about 4433 exoplanets in the latest catalogs. Their radii have generally been measured by knowing the radius of their host star and then closely fitting the lightcurves as the planet transits across the face of ...

First to red planet will become Martians: Canada astronaut

September 22, 2018

Astronauts traveling through space on the long trip to Mars will not have the usual backup from mission control on Earth and will need to think of themselves as Martians to survive, Canada's most famous spaceman half-jokingly ...

2 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

StudentofSpiritualTeaching
1 / 5 (1) Jun 08, 2018
Asteroids are a very serious threat, with grave global governmental underinvestment regarding prevention of the next strike looming for 2028 or 2036 respectively. I am just puzzled by ESA's pick of the Tunguska event for their campaign. That one had no natural cause.

See for example this good summary of unresolved questions and issues by Doug Yuchey:
https://www.themy...unguska/

Or read a possible explanation over here:
http://futureofma...etin_059
jonesdave
1 / 5 (4) Jun 08, 2018
^^^^^^^^And links to a bunch of unscientific woo to try to make his point! Cranks everywhere!

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.