Earth, Moon and a space ship in outer space
ISS Progress 75 resupply ship, with the full Moon above the Earth's horizon, is pictured separating from the International Space Station shortly after undocking from the Zvezda service module.
Photo:NASA

Why Moon Day?

The General Assembly declared International Moon Day, a United Nations-designated international day to be observed annually on 20 July, in its resolution 76/76 on “International cooperation in the peaceful uses of outer space” in 2021.

International Moon Day marks the anniversary of the first landing by humans on the Moon as part of the Apollo 11 lunar mission in 1969.

The celebrations will also consider the achievements of all States in the exploration of the Moon and raise public awareness of sustainable Moon exploration and utilization.

Artemis II: What we saw

A month after completing their historic flyby of the Moon (1–11 April 2026), the astronauts from NASA’s Artemis II mission landed at UN Headquarters in New York with a message that sounded like a reminder: humanity is capable of extraordinary things when it acts together.

The four-person crew carried out the farthest human spaceflight in history, travelling beyond the far side of the Moon and safely returning to Earth after ten intense, demanding, and inspiring days.

Learn more

Background

For thousands of years, human civilizations have looked up to the sky pondering the origin and mysteries of the Moon – our only natural satellite. Ground-based observations enabled by the invention of the first telescopes opened a new chapter in our understanding of our celestial companion.

With the birth of space activities, the Moon became the ultimate destination of countless missions, including crewed flights that brought the first human footprints to another place in the universe.

As Moon exploration efforts continue taking shape with ambitious plans, this global celebration will serve not only as a reminder of success in the past, but as an annual testimony to future endeavours.

UN and Space

From the very beginning of the Space Age, the United Nations recognized that outer space added a new dimension to humanity's existence. The United Nations family strives continuously to utilize the unique benefits of outer space for the betterment of all humankind.

Recognizing the common interest of humankind in outer space and seeking to answer questions on how outer space can help benefit the people's of Earth, the General Asssembly adopted its first resolution related to outer space, resolution 1348 (XIII) entitled "Question of the Peaceful Use of Outer Space".

On 10 October 1967, the "Magna Carta of Space", also known as the Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies entered into force.

Today, the United Nations Office for Outer Space Affairs (UNOOSA) is the United Nations office responsible for promoting international cooperation in the peaceful uses of outer space. UNOOSA serves as the secretariat for the General Assembly's only committee dealing exclusively with international cooperation in the peaceful uses of outer space: the United Nations Committee on the Peaceful Uses of Outer Space (COPUOS).

UNOOSA is also responsible for implementing the Secretary-General's responsibilities under international space law and maintaining the United Nations Register of Objects Launched into Outer Space.

Resources

International Instruments

Principles Adopted by the UN General Assembly

UN System

Related Observances

 
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.

 

A rocket with the Moon in the background

On 4 October 1957 the first human-made Earth satellite Sputnik I was launched into outer space, thus opening the way for space exploration. On 12 April 1961, Yuri Gagarin became the first human to orbit the Earth, opening a new chapter of human endeavour in outer space. The race to conquer space in the 21st century has changed significantly, allowing countries such as China, India, Japan, and the European Union, to enter the space race.

 

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.