Bellwork 10/24 What is the purpose of the Drake Equation? Why is it important for an astrobiologist to understand where a habitable zone is around a star?

Coming Up… Today: Collect practice lab data, complete research proposal Monday 10/30: Set up astrobiology lab, review Wednesday 11/1: TEST (and collect data) Friday 11/3: Finish data collection & write up

Astrobiology TED ed Astrobiology is the study of life in the universe. It investigates the origin, evolution, distribution, & future of life on Earth, & the search for life beyond Earth TED ed

What do organisms need to live? Energy Liquid Water …at least for life as WE know it…

Extremophiles Organisms living in extreme habitats on Earth Many examples of tolerance to extreme environments temperature pressure salinity pH desiccation radiation

Some Categories of Organisms Adapted to Extreme Habitats - Low pH (< 5) - High pH (> 9) - No O2 Within rock High salinity High hydrostatic pressure Very cold temp. Very hot temp. Very limited H2O Acidophiles Alkaliphile Anaerobe Endolith Halophile Barophile Psychrophile Thermophile Xerophile

A little bit about our test subjects… Brine Shrimp (Artemia franciscana) Very resilient organisms Widely used in biotoxicology tests Live in salty waters (inland and along the coast) Hatch time: 18-36 hours Life cycle

Brine Shrimp in Space! Besides being studied in labs… Brine shrimp cysts have been aboard Apollo 16 & 17 Several Russian space missions

Design your own Astrobiology Lab These types of lab are commonly known as LD50 labs Works best if you choose one variable but set a range of that variable 10% NaCl, 20% NaCl, 30% NaCl This allows you to get a better picture of how well the organisms can survive in the given condition

Example: How does Ethanol concentration effect brine shrimp survival? Rationale: Ethanol on Titan (moon of Saturn) Procedure: Set up cysts in various concentrations of ethanol (mixed in with salt water). Data Collection: Recorded shrimp hatching data after 2 days and 4 days.

Example: How does pH affect brine shrimp survival? Rationale: pH of clouds on Venus Procedure: Set up cysts in solutions with various pH (mixed in with salt water). Data Collection: Recorded shrimp hatching data after 2 days and 4 days.

Some Ideas: Salinity pH Viscosity Light (color, wavelength, time/amount) Temperature (this can be tricky with heat…just FYI)

Tasks today: Collect your practice data! This will help you design your lab efficiently. Finish your Location Research from Friday (if not finished already). This document will help you with your rationale & conclusion questions. Write out and submit lab proposal—make sure it is DETAILED. I need to know what to prepare over the weekend.