Illustration of asteroid
Asteroids passing Earth.
Photo:ESA/Pierre Carril

Why Asteroid Day?

In December 2016 the United Nations General Assembly adopted resolution A/RES/71/90, declaring 30 June International Asteroid Day in order to "observe each year at the international level the anniversary of the Tunguska impact over Siberia, Russian Federation, on 30 June 1908, and to raise public awareness about the asteroid impact hazard."

International Asteroid Day aims to raise public awareness about the asteroid impact hazard and to inform the public about the crisis communication actions to be taken at the global level in case of a credible near-Earth object threat.

The General Assembly’s decision was made based on a proposal by the Association of Space Explorers, which was endorsed by Committee on the Peaceful Uses of Outer Space (COPUOS).

2029 — International Year of Asteroid Awareness and Planetary Defence

On 13 April 2029, the asteroid 99942 Apophis will pass safely at a distance of about 32,000 kilometers above Earth's surface, within the geostationary orbit, posing no threat to the planet. This extremely close approach will make the asteroid visible to billions of people with the naked eye in the clear night sky.

This will be a once-in-a-millennium event and a unique occasion for a worldwide campaign to raise awareness with regard to asteroids, their scientific and resource value and the potential hazard they pose.

In 2024, the General Assembly declared 2029 the International Year of Asteroid Awareness and Planetary Defence to take advantage on the close approach of 99942 Apophis and raise global awareness about asteroids.

This initiative aims to highlight the collaborative efforts of the Committee on the Peaceful Uses of Outer Space in mitigating potential hazards from near-Earth objects, while also providing an opportunity for a global educational campaign.

Background

Near-Earth objects (NEOs) are asteroids and comets whose orbit brings them closer than 1.3 astronomical units, or approximately 195 million kilometres, to the Sun. NEOs, that are closer than 0.05 astronomical units to Earth's orbit (about 7.5 million kilometers) and larger than about 140 meters in size, represent potentially catastrophic threats to our planet.

According to NASA’s Center for NEO Studies, there are over 36,000 Near Earth Asteroids discovered. The Tunguska asteroid event in Siberia, Russian Federation, on 30 June 1908, was the Earth's largest asteroid impact in recorded history.

On 15 February 2013, a large fireball (technically, called a "superbolide"), traveling at a velocity of 18.6 kilometers per second, entered the atmosphere and disintegrated in the skies over Chelyabinsk. According to NASA, the approximate effective diameter of the asteroid was estimated at 18 meters and its mass at 11,000 tons. The approximate total impact energy of the Chelyabinsk Fireball, in kilotons of TNT explosives (the energy parameter usually quoted for a fireball), was 440 kilotons. The Chelyabinsk event was an extraordinarily large fireball, the most energetic impact event recognized since the 1908 Tunguska blast in Russian Siberia.

The United Nations Office for Outer Space Affairs (UNOOSA) has worked on NEOs for many years, recognising a NEO impact hazard as a global issue demanding an international response. Addressing such a hazard, including the identification of those objects that pose a threat of impact and planning a corresponding mitigation campaign, requires cooperative action in the interest of public safety on the part of the global community.

Building on recommendations for an international response to a near-Earth Object impact threat, endorsed by the Committee on the Peaceful Uses of Outer Space (COPUOS) in 2013, the International Asteroid Warning Network (IAWN) and the Space Mission Planning Advisory Group (SMPAG) were established in 2014.

The International Asteroid Warning Network (IAWN) uses well-defined communication plans and protocols to assist Governments in the analysis of possible consequences of an asteroid impact and to support the planning of mitigation responses.

The Space Mission Planning Advisory Group (SMPAG) is an inter-space agency forum that identifies technologies needed for near-Earth Object deflection, and aims to build consensus on recommendations for planetary defense measures.

International cooperation on planetary defense and protection against asteroids

Documents

Useful links

ESA’s Optical Ground Station

The United Nations Office for Outer Space Affairs (UNOOSA) works to promote international cooperation in the peaceful use and exploration of space, and in the utilisation of space science and technology for sustainable economic and social development. The Office assists any United Nations Member States to establish legal and regulatory frameworks to govern space activities and strengthens the capacity of developing countries to use space science technology and applications for development by helping to integrate space capabilities into national development programmes.

 

China Space Station

The United Nations Office for Outer Space Affairs (UNOOSA) in cooperation with the China Manned Space Agency (CMSA) launched the programme, which capitalizes on the technological and innovative skills of the Government of China to benefit Member States of the United Nations, in particular developing countries, thereby contributing to the 17 Sustainable Development Goals (SDGs) through increasing access to space.

 

an abstract illustration of people engaged in an event

International days and weeks are occasions to educate the public on issues of concern, to mobilize political will and resources to address global problems, and to celebrate and reinforce achievements of humanity. The existence of international days predates the establishment of the United Nations, but the UN has embraced them as a powerful advocacy tool. We also mark other UN observances.