Phil Plait: How to defend Earth from asteroids

Summary

The script humorously discusses asteroid impacts, comparing their sizes and effects, from the dinosaur-killing Chicxulub impact to smaller, more frequent events. It emphasizes the importance of detecting asteroids and the strategies to prevent potential catastrophes, like NASA's Deep Impact mission. The speaker highlights humanity's advantage over dinosaurs due to our space program and ability to change our fate.

Takeaways

• 🌏 Sixty-five million years ago, a massive asteroid impact led to the extinction of the dinosaurs.
• 🚀 The energy released from the asteroid impact was equivalent to a billion times the combined power of all nuclear weapons at the height of the Cold War.
• 📏 The asteroid was approximately six miles wide, and the resulting crater was 200 miles across.
• 🔍 Not all asteroids are as large as the one that hit the Earth 65 million years ago; some are much smaller but can still cause significant damage.
• 🎥 In 1992, a small asteroid entered the atmosphere over the United States and was captured on video, illustrating how even small asteroids can be destructive.
• 💥 The Tunguska event in 1908 was caused by an asteroid explosion above the Earth's surface, causing widespread damage without direct impact.
• 🛰️ NASA and other organizations are actively searching for potentially hazardous asteroids to mitigate future threats.
• 🌌 The asteroid Apophis, discovered in 2004, is a significant object of study due to its size and potential future close approach to Earth.
• 🪜 We have the technology to deflect asteroids, as demonstrated by NASA's Deep Impact mission, which successfully impacted a comet.
• ⚖️ The B612 Foundation is working on gentler methods to deflect asteroids, such as using an ion drive to slowly change their orbits.
• 🌌 The difference between humans and dinosaurs is our ability to detect and deflect asteroids, potentially preventing catastrophic impacts.

Q & A

What was the size of the asteroid that caused the extinction of the dinosaurs?

The asteroid was six miles across.

How does the energy released by the dinosaur-killing asteroid compare to all nuclear weapons built at the height of the Cold War?

The energy released by the asteroid was equivalent to one one-millionth of the combined energy of all nuclear weapons built at the height of the Cold War.

What is the size of the crater created by the asteroid that hit the Earth 65 million years ago?

The crater was 300 kilometers across, or 200 miles.

What is the significance of the asteroid impact in the Gulf of Mexico?

It is significant because it resulted in the extinction of 75 percent of all species on Earth.

What was the size of the asteroid that hit over the United States in October 1992?

The asteroid was probably about the size of a school bus when it first entered the atmosphere.

How did the 1992 asteroid impact event get recorded?

It was recorded due to the popularity of video cameras at the time, which were being used to film high school football games.

What is the name of the crater in Arizona that was created by a meteorite impact?

The crater is called 'Meteor Crater'.

What was the size of the object that created Meteor Crater?

The object was probably about 30 to 50 yards across.

What was the energy equivalent of the explosion that created Meteor Crater?

The explosion was equivalent to the energy of roughly a 20-megaton nuclear bomb.

What happened in the Tunguska region of Siberia in 1908?

A rock blew up above the ground, causing a blast that set fire to the forest and knocked down trees for hundreds of square miles.

How does the threat of asteroid impacts compare to the threat faced by the dinosaurs?

While large asteroid impacts like the one that killed the dinosaurs are rare, smaller impacts can still cause significant regional damage and economic disruption.

What is the name of the asteroid that is predicted to pass close to Earth in 2029?

The asteroid is named Apophis.

What is the significance of the 'keyhole' in relation to the orbit of Apophis?

If Apophis passes through the 'keyhole', Earth's gravity could alter its orbit in such a way that it would impact Earth in 2036.

How can we deflect an asteroid that is on a collision course with Earth?

We can deflect an asteroid by hitting it with a probe to change its orbit, or by using a probe with an ion drive to gently nudge it into a safe orbit.

What is the B612 Foundation and how are they involved in asteroid deflection?

The B612 Foundation is a group of scientists, engineers, and astronauts dedicated to predicting and preventing asteroid impacts on Earth. They propose using a probe with an ion drive to gently nudge an asteroid into a safe orbit.