Astrobiology and Planetary Conditions

Emily Graslie discusses asteroid 2012 DA14's close approach to Earth, emphasizing it poses no threat. She explains the circumstellar habitable zone, where conditions might support life, and recent revisions to its definition. The video concludes with a call to connect with SciShow on social media.

What was the main concern regarding asteroid 2012 DA14?

• It was going to collide with Earth.

• It was going to destroy satellites.

• It was going to hit the Moon.

• It was going to pass closer to Earth than any recorded asteroid.

How close will asteroid 2012 DA14 come to Earth?

• Within 10,000 kilometers

• Within 27,700 kilometers

• Within 100,000 kilometers

• Within 50,000 kilometers

Where will the best viewing of asteroid 2012 DA14 occur?

• Africa

• Southeast Asia and Australia

• South America

• North America

What is the circumstellar habitable zone?

• A zone with the least gravity

• A zone with the most sunlight

• A zone where liquid water can exist

• A zone inhabited by aliens

What did the revised model of the habitable zone suggest?

• Planets have less gravity than previously thought.

• Planets are hotter than previously thought.

• Planets are colder than previously thought.

• Planets have more water than previously thought.

What is the significance of 0.99 to 1.7 astronomical units in the new model?

• It defines the distance for the largest planets.

• It defines the best distance for water to exist.

• It defines the distance for the hottest planets.

• It defines the distance for the coldest planets.

Why is Earth considered to be on the hottest edge of the habitable zone?

• Because it is the largest planet.

• Because it has no atmosphere.

• Because of its cloud cover reflecting radiation.

• Because it is closest to the Sun.

What factors can affect a planet's temperature?

• Size and color

• Distance from the Sun only

• Mass and cloud cover

• Number of moons

What is the primary reason water-based life forms are considered the best bet for life?

• They are the most colorful.

• They are the largest organisms.

• They are the most diverse.

• We recognize them and their signs.

What is one reason why Earth is not as hot as it could be?

• It is far from the Sun.

• It has a thick atmosphere.

• It has clouds that reflect radiation.

• It has a slow rotation.