Asteroids: A Threat from Space

A 1929 photo of trees knocked over by a meteorite blast in 1908 near Tunguska, Russia. (Image via Wikimedia Commons)

Today is Asteroid Day, marking the anniversary of the 1908 Tunguska Event, the largest asteroid impact on earth in recent history.

Here are some things you may not have known about both of them.

On the morning of June 30, 1908, an explosion over eastern Siberia flattened 770 square miles of forest. It’s believed that the explosion was the result of an asteroid or a comet that disintegrated more than three miles above the earth’s surface. It has been classified as an impact event despite the fact that no crater has been found.

Estimates of the object’s size range from 200 feet to 620 feet, depending on whether it was a comet or a more dense asteroid. Estimates of the energy from the explosion also vary widely. Recent estimates say it was equivalent to three to five megatons of TNT, about 200 times more powerful than the atomic bomb the U.S. dropped on Hiroshima, Japan during World War II.

It is estimated to have leveled 80 million trees, but no humans were reported killed, due to the remote location. Windows broke and people were knocked off their feet hundreds of miles away from the blast.

A similar, but much smaller blast occurred over Russia in 2013. An asteroid measuring about 65 feet streaked through the skies over Chelyabinsk near the Ural Mountains.

Asteroid Day was founded in 2014 by filmmaker Grigorij Richters, and Queen guitarist Brian May, who is also an astrophysicist.

The goal of the day to learn about asteroids and what we can do to protect the planet from them.

The goals of the organization are to track near-Earth asteroids, increase the discovery of near-Earth asteroids, and to promote the annual event. The first Asteroid Day was marked in 2015.

Our question: What is the difference between a meteor and a meteorite?

Today is Armed Forces Day in Guatemala, Independence Day in the Democratic Republic of the Congo, and Navy Day in Israel.

It’s unofficially National Handshake Day, National Organization for Women Day, and Social Media Day.

It’s the birthday of actress Lena Horne, who was born in 1917; boxer Mike Tyson, who is 50 today; and 18-time Olympic gold medalist Michael Phelps, who turns 31.

Because our topic happened before 1960, we’ll pick a year at random.

This week in 1962, the top song in the U.S. was “I Can’t Stop Loving You” by Ray Charles.

The No. 1 movie was “Boys’ Night Out,” while the novel “Ship of Fools” by Katherine Anne Porter topped the New York Times Bestsellers list.