The Origin of Stars, Planets, and Life in the Universe

Dr. Matt Bobrowskymattb@stsci.edu

Do you think there is life even just primitive forms of life on other worlds?

Poll Question:

Do you think there is intelligent life on other worlds?

YES NO UNDECIDED

The Electromagnetic Spectrum

Use a stamp “X” to select the most abundant element in the universe.

neon nitrogen hydrogen oxygen

helium carbon sodium iron

Axis of rotation

Approx. 1 light yearAxis of rotation

Rotation retardscollapse in thisdirection

Slowly spinninginterstellar cloud

Gravity makes cloudshrink. As it shrinks it spinscaster and flattens into adisk with central bulge.

Approx.100 AU

Big Questions in Science

• Where did we come from?

• Are we alone?

Questions about origins:

Other astrobiology questions:

1. How did life on Earth form?

2. Should we expect life on many other worlds?

3. Is life on other worlds like life on Earth?

4. How can we detect life elsewhere?

Poll Question:

What chemical elements were created by the Big

Bang?

The Life Cycle of Stars…

NH3

H2CH4

H2O

Put a stamp on the most abundant element in life on Earth.

neon nitrogen hydrogen oxygen

helium carbon sodium iron

The Most Abundant Chemical Elements in the Universe and in Life

• H• He• O• C• N

In the Universe In Life

• H• • O• C• N

• Life on Earth is carbon-based.• Life on Earth requires liquid water• The amino acids in life are easily

formed.

A few facts about

Life on Earth

Finding Life

• First find planets. One way uses the Doppler Effect.

Another way to find planets is to look for transits.

Kepler

Terrestrial Planet Finder

Signs of Life (not yet possible to detect with current technology)

• Seasonal changes

• Unusual abundances of gases

• Gases produced by life

• Unusual patterns of electromagnetic radiation (e.g., radio or TV broadcasts, the nighttime glow of cities)

Summary

• We have learned an enormous amount about the origins of stars and planets.

• We are just starting to learn about life in the universe.

• These explorations require a team effort involving scientists from many disciplines.

• There is still much more to explore. Your students will be able to make discoveries and help us learn even more!

NASA’s Navigator Missions: http://planetquest.jpl.nasa.gov/

Origins Education Forum: http://origins.stsci.edu/

Poll Question:

Do you think there is life even just primitive forms of life on other worlds?

Do you think there is intelligent life on other worlds?

YES NO UNDECIDED