Astrobiology and Planetary Science: Life, Habitable Zones, and Earth's Geological History

What is astrobiology?

The study of life in the universe, also known as exobiology or bioastronomy.

What are some fundamental questions in astrobiology?

Are we alone in the universe? Do other stars have planets? Is there life on Mars? What are the requirements for life?

Who is the course instructor for AST309L?

Michael Endl, an astronomer and lecturer at UT Austin.

What significant discovery did Michael Endl contribute to?

The discovery of Proxima b, a possibly rocky planet in the habitable zone of the nearest star to the Sun.

What is the significance of discovering life elsewhere in the universe?

It could be regarded as the single most profound discovery in human history.

What has the 'astro' part of astrobiology achieved in recent years?

It has discovered a large sample of exoplanets and is making progress toward finding potential habitats for alien life.

What has the 'biology' part of astrobiology discovered?

Extremophiles that can survive in conditions previously thought impossible, expanding the parameters for life in the universe.

What is a scientific theory?

A summary of a hypothesis or group of hypotheses supported by repeated testing, representing our best understanding of a phenomenon.

What does the term 'theory' mean in popular culture compared to science?

In popular culture, 'theory' often means a hypothesis, while in science it refers to a well-supported explanation.

What is the Gold Standard in science and astrobiology?

The rigorous application of the scientific method and the accumulation of evidence to support theories.

What is the habitable zone?

The region around a star where conditions may be suitable for liquid water, essential for life.

What are extremophiles?

Organisms that can thrive in extreme conditions previously thought to be uninhabitable.

What is the role of asteroids in the formation of life?

Asteroids may contain amino acids and are thought to be essential for forming life.

What are the oldest Earth rocks and their age?

The oldest Earth rocks are about 4.4 billion years old.

What geological activity is caused by the movement of tectonic plates?

Earthquakes and volcanic activity result from tectonic plate movements.

What is the significance of the Hadean Eon?

It was once thought to be unsuitable for life, but liquid water may have emerged quickly during this time.

What causes the greenhouse effect?

The accumulation of greenhouse gases, such as CO2, which can lead to extreme weather patterns.

What is the CO2 cycle's role in climate stability?

The CO2 cycle has kept Earth's temperature stable for billions of years, except during outlier events like ice ages.

How does volcanic activity affect the atmosphere?

Volcanoes can pump CO2 into the atmosphere, influencing the greenhouse effect and climate.