More than 700 events are scheduled to take place in 190 countries across the globe for this year's Asteroid Day celebration on Friday (June 30). If you can't make it to one of these events, don't worry: there's a live, 24-hour webcast that will feature discussions about space rocks and the possibility of an asteroid hitting the Earth.

Started in 2015, Asteroid Day commemorates the "Tunguska event” that occurred June 30, 1908, when a near-Earth object measuring about 130 feet (40 meters) wide exploded above the Podkamennaya Tunguska River in Siberia and destroyed 800 square miles (2,072 square kilometers) of forest.

The Asteroid Day LIVE webcast — which is the first-ever 24-hour live broadcast about space and asteroids, according to the organizers — will be hosted by physicist Brian Cox, a professor at the University of Manchester in England, as well as the host of popular science TV shows and the author of multiple books.

The broadcast will include programming from the European Space Agency (ESA), the Japan Aerospace Exploration Agency (JAXA) and NASA. You can find the full lineup of astronauts, astronomers and other special guests that will speak on Asteroid Day LIVE on the Asteroid Day website.

NASA has a special interest in asteroid science because of its OSIRIS-REx mission. The Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer (OSIRIS-REx) spacecraft launched on Sept. 8, 2016, and is scheduled to arrive at the asteroid Bennu in 2018. If all goes as planned, OSIRIS REx will scour the asteroid surface, collect a sample of the space rock and then return it to Earth in 2023 for scientists to study.

If you're in the Tucson, Arizona, area, the Flandrau Science Center & Planetarium at the University of Arizona will also host Asteroid Day activities relating to OSIRIS-REx over the weekend, starting Friday and running through Sunday (July 2). Events include an asteroid planetarium show and other public exhibits.

NASA's OSIRIS REx spacecraft is speeding toward a rendezvous with an asteroid. If all goes according to plan, it will return a sample of the space rock to Earth. (Image credit: NASA)

The OSIRIS-REx mission will provide a better understanding of how asteroids form and, in turn, provide insight on the conditions of the early solar system. This research will be helpful in the event an asteroid threatens to hit Earth.

The Science Channel is celebrating Asteroid Day with a lineup of related programming, starting at 8 p.m. ET/PT on Friday. The shows include "Asteroids: The Dark Secrets," "When Asteroids Attack" and "How to Survive an Asteroid Strike."

"Science Channel’s programming block will span millions of years, turning back the clock to the dinosaur-era when asteroids eradicated species and zooming towards the future to show viewers how to survive impending asteroid attacks," according to a statement.

Other Asteroid Day events are being held at various science centers, museums, schools, theaters and libraries around the world, including George Mason University in Virginia, the Kennedy Space Center in Florida, the University of Nebraskaand many more. Most events are free and available to all ages. You can find a complete list of Asteroid Day activities, or register your own event, at the Asteroid Day official website.

Follow Samantha Mathewson @Sam_Ashley13. Follow us @Spacedotcom,Facebook and Google+. Original article on Space.com.