Life on Other Planets

http://www. businessinsider http://www.businessinsider.com/infographic-the-odds-of-being-alive-2012-6

Let’s take a second and appreciate our lives… In order for life as we know it to form on Earth- we must fulfill some DIFFICULT requirements: Liquid Iron Core Liquid Water to be Present Must be Tectonically Active Must Possess Atmosphere A large planet ‘buddy’ (to minimize asteroid impacts) Billions of years of existence to evolve life

The earth fulfills ALL of these… 1. Liquid Iron Core Creates a magnetic field called the magnetosphere This help keeps us alive by deflecting the solar wind…

Liquid Iron Core (cont.) The solar wind- High speed charged particles that the sun emits. DANGEROUS TO US. 1. Can destroy atmosphere 2. Is harmful to humans Without the magnetosphere to deflect these particles away, we would not be here.

A pretty cool thing about this… This is the reason for the Aurora Borealis and the Aurora Australis The Solar Wind (charged particles) react with a layer of the atmosphere to emit beautiful colors of light Usually happens at the poles

Aurora Borealis

Doesn’t have to be night

2. Liquid Water Must be Present Habitable Zone- area in a star system in which liquid water is able to exist Should be between 273-373 K (32-212 degrees Fahrenheit) Different with every star Higher mass stars = H.Z. further out Lower mass stars = H.Z. closer in

Venus and Mars… Just a bit outside of the zone… Venus to close to sun and Mars too far away

The Habitable Zone Green area = the habitable zone

3. Plate Tectonics There must be a way to recycle nutrients such as Carbon, Oxygen, Hydrogen, etc. Plate tectonics ensures Carbon is recycled in the atmosphere No Carbon = No Carbon Dioxide = No Plants Volcanic Activity = Helps create an atmosphere (Let’s not get too crazy on this topic, this is for Ms. Zolynsky’s class!)

Just know… No plate tectonics = probably no atmosphere Planet with most volcanoes ? Venus. Planet with thickest atmosphere? Venus

Mars… Used to be tectonically active Used to have an atmosphere of Carbon and Oxygen Scientists think Mars looked like this back in the day

4. Atmosphere Incredibly important for life Regulates heat Blocks UV radiation (Harmful to humans) Greenhouse Gas effect retains heat Retains molecules essential for life

Greenhouse Gas Effect Greenhouse Effect- when heat/energy is trapped by gases in our atmosphere This is actually a good thing! Without this, we would die.

Without Greenhouse Effect… Earth would be on average ZERO degrees Fahrenheit! All water would freeze Most life would die out

In all honesty… Al Gore is probably right- humans are putting in an irregular amount of CO2 into our atmosphere- but that debate is not for this class…

5. A Large Planet ‘Buddy’ Thanks Jupiter! Actually… while Jupiter does absorb some asteroids... it also ‘flings’ some towards earth

6. Billions of years for life to evolve Remember, first hundreds of millions of years had a period of heavy bombardment Planets still ‘accreting’ Very dynamic time Lots of asteroids being flung around Earth was being hit by a lot of these Happens relatively early in formation

Evolution Life arose about 3.5 billion years ago Remember: Earth is 4.5 billion years old Many catastrophic events happened over this time Asteroids/Comets Massive volcanic activity Ice Ages

Life as we know it (micro scale)… 1. Life as we know depends on a few other micro- level things 1. Carbon 2. Nitrogen 3. Oxygen 4. Hydrogen These create amino acids, DNA, and other essentials needed for life

Why these elements? Hydrogen, Oxygen, Carbon, are very abundant in the universe Odds are ‘they’ would use these elements before other ones Carbon can form many bonds, meaning it can make many molecules to create life

NEEDS LIQUID LIQUID MEDIUM 2. Life requires molecules to ‘move around’ within cells NEEDS LIQUID

Liquids NEEDS LIQUID OR GAS Needs a way for molecules to be transported INTO and OUT of the organism NEEDS LIQUID OR GAS

Which means this liquid should… Dissolve some things (but not all) Not react with certain compounds (to enable reactions)

So… life on other planets

Remember Life as we know it required all of the previous information Other life may be a bit different, but we can assume it still needs much of the previous information, with perhaps some changes

Some examples… Photosynthesis: THE SOURCE OF ALL ENERGY ON OUR WORLD We should all know this equation: Photosynthesis: THE SOURCE OF ALL ENERGY ON OUR WORLD

Using Carbon Dioxide and Hydrogen sulfide to make a sugar (energy) But somewhere else… A different organism (on a different world) may make sugar (energy) differently: Using Carbon Dioxide and Hydrogen sulfide to make a sugar (energy)

http://oceanexplorer.noaa.gov/edu/learning/player/lesson05.html This actually happens on earth, too…

Point being…. Organisms may adapt to drastically different ways to make energy So organisms may use different methods to ‘live’ on other planets Instead of oxygen, perhaps breath in hydrogen? Instead of water, perhaps liquid methane? Instead of carbon molecules, perhaps silicon molecules?

Other good molecules for life… Instead of….. Perhaps ‘they’ use…. Oxygen to breathe Sulfur Carbon for DNA and other life molecules Silicon Nitrogen for life molecules (amino acids) Phosphorus

Some possible areas… Titan- as mentioned in The Cosmos Atmosphere? Yes (Nitrogen) Liquid? Yes (Methane) Magnetosphere? Yes (Saturn’s) Green House Yes (Methane)

Europa: One of Jupiters Moons One of Jupiter’s Moons

Europa Jupiter’s Moon, believed to have a large subsurface liquid water ocean Atmosphere? Small (Oxygen) Plate tectonics? Maybe (some evidence) Molecules? Yes (C, O, H, Si,) Liquids? Yes (water)

Mars (Perhaps in the past) Mars USED to… 1. Be tectonically active 2. Have an atmosphere 3. Have liquid water 4. (Probably) have a magnetosphere But that was all in the past (billions of years ago )

And now some cool Mars pics (and Patriotism) (In reference to London 2012 Summer Olympics, The Mars Rover landed on Mars in Summer of 2012)

Mars Rover (Landed on Mars in Summer 2012)

Valleys thought to have been carved from water Crazy pics of Mars… Valleys thought to have been carved from water

A large lake? Perhaps a waterfall fell into a large river here? Crazy Pics Cont. A large lake? Perhaps a waterfall fell into a large river here?

More remnants from possible rivers Cont. More remnants from possible rivers

You can check out Mars on Google Earth if you have it downloaded! Mars Ice Lake! You can check out Mars on Google Earth if you have it downloaded!

Outside of the Solar System… These are just some… They are finding more and more and more every day

One definition to know Exoplanet - planet outside the solar system that revolves around a different star than our own

Gliese 581 A red dwarf star, much smaller than earth 22 light years from the sun (pretty close actually) 1/3 mass of sun

Some scale…

Habitable Zone of Sun and Gliese

http://www.youtube.com/watch?v=H5zSWQwpjPg Some food for thought

Gliese 667 C c This planet is part of Gliese 667, a trinary star system, thought to hold life. An artist’s impression

Kepler 452-b