Modern Telescopes and Ancient Skies New Views of the Universe An IU Lifelong Learning Class Tuesdays, May 10, 17, 24

Size and Scale Surveying the Universe from the Earth to the farthest reaches of the visible Universe

Galileo Galilei's "The Phases of the Moon" Image courtesy of Biblioteca Nazionale Florence, Italy Our closest neighbor

Visualizing the Earth from Space What do you see? –Earth –Moon –Sun –Stars Copyright 1980 by DC Comics Inc.

Welcome to Outer Space!

Earth Radius: 6400 km Distance from Sun: 150,000,000 km 1 AU, 8 light minutes Moon Radius: ¼ Earth’s radius Distance from Earth: 384,000 km

Solar System Sizes of planets NOT to scale Distance to Pluto: about 40 AU (about 320 light minutes)

The Nearest Stars The closest star to our Sun is Proxima Centauri, about 4 light years distant.

Most of the stars we see in the sky are within 250 light years

Our Sector of the Galaxy The Sun lies along one of our Galaxy’s spiral arms, known as the Orion Arm

View of the Milky Way Galaxy Our Milky Way galaxy contains two hundred billion stars. The Sun is about 26,000 light years from the center.

Our Milky Way Galaxy is part of a small cluster of galaxies.

Virgo Supercluster Our Local Group of galaxies is part of a larger supercluster of galaxy groups.

Galaxies and clusters of galaxies collect into vast streams, sheets and walls of galaxies.

The Visible Universe On the largest scales, the universe seems to be more or less uniform

With thanks to Bill Watterson, 1990

What will we cover????? How telescopes work Modern telescopes Sky viewing Space telescopes Kirkwood Obs Visiting the Gemini Observatory Future telescopes

Beginnings… This sketch of a telescope was included in a letter written by Giovanpattista della Porta in August 1609

Thomas Harriet’s Drawings of the Moon and Sun

Telescopes and how they work from lenses… to mirrors

Technology moves forward…

The 3.5-meter WIYN telescope Kitt Peak, Arizona

New Telescope Technology  “Fast” mirror  Lightweight mirror  Mirror shape controlled  Mechanically simpler mount  Temperature control

Casting the WIYN Mirror

Polishing the WIYN Mirror

The WIYN New Technology “Dome”  Compact telescope chamber  Open for ventilation  Insulated to keep cool  Heated spaces kept separate

Breaking the “cost curve” New technology provides better performance at lower cost WIYN

in 6-8 meter telescopes WIYN TECHNOLOGY

 text The importance of image quality typical ground- based image Hubble image WIYN image The Ring Nebula

Connecting the First Nanoseconds to the Origin of Life

How is the Universe put together?  The Wilkinson Microwave Anisotropy Probe tells us about the state of the Universe 400,000 years after the Big Bang. How did the Universe evolve from this…

…to this?

The cosmic web of intergalactic gas and galaxies in a young universe Intergalactic gas Clumps concentrated by dark matter lead to galaxies Observing the assembly of galaxies Galaxy building blocks observed with Hubble Simulation

WMAP also provides evidence of the first stars  Tiny fluctuations in polarization  About 200 million years after the Big Bang

We can almost see the first stars Simulation What we might see with a 30-meter telescope (Barton et al., 2004) 4 million LY hydrogen emission from hot stars Green=hot gasyellow=stars

The composition of stars and gas: everything else 90% hydrogen atoms 10% helium atoms Less than 1% everything else What is the Universe made of?

But ordinary matter is only part of the story… 96% of the Universe is something else

Galaxy interactions require more mass than we can see Antennae Galaxy (HST) Computer simulation The real thing

Dark Matter  The universe contains additional matter we cannot see  Dark matter interacts with normal matter through gravity  Dark matter does NOT interact with light the way the normal matter does  The Universe contains 5 or 6 times MORE dark matter than normal matter  All galaxies are embedded in clouds of dark matter  We do not know what it is!

“Redshift” of Galaxies  The spectra of galaxies are shifted to the red: galaxies are moving away from us.  The farther away a galaxy is, the faster it recedes from us!

Hubble’s Law

The speeds of very distant galaxies tell us the Universe is expanding faster today than in the past The brightness of stellar explosions tells us how far away galaxies are

The universe is expanding faster today than it did in early times This expansion cannot be caused by ordinary or dark matter, which slows expansion. The acceleration suggests a new repulsive force (anti-gravity) acting on very large scales The Universe is speeding up!

 Dark energy accounts for 73% of the content of the universe  Dark matter accounts for 23%  The content we’re familiar with is only 4% The New Force Is Called “Dark Energy”

 We don’t know What is Dark Energy? Identifying what dark energy is requires bigger telescopes and new techniques

Connecting the First Nanoseconds to the Origin of Life

Kirkwood Observatory Viewing  Tuesday evenings, weather permitting

Night Sky Viewing Scheduled nights –Tuesday, May 17 –Tuesday, May 24 Roof of Swain West

Next Week Telescopes in Space, including the Hubble Space Telescope New Views of the Universe – Planets around other Suns Kirkwood Obs and Rooftop, weather permitting

Is there life elsewhere? Artist’s conception of 55 Cancri’s planetary system More than 150 planets found around other stars Most are vastly different from our Solar System

 detecting planets directly is hard  planets are small and dim  planets are near much brighter stars  detecting planets directly requires large telescopes (30-meters) and/or special instruments Detecting Planets

Imaging planets around other stars “Brown Dwarf” orbiting a star at the same distance as Saturn from our Sun Gemini/Keck AO detection by Michael Liu (IfA), 2002

With a 30-meter telescope we can obtain the spectra of planets around other stars to search for the signatures of life Simulation by Sudarsky et al Simulation of the spectra of 55 Cancri’s planets