1 Assembling the Jigsaw-Puzzle Picture of the Universe Presented to the NASA Night Sky Network January 31, 2006 Dr. Jeffrey D. Rosendhal Carl Sagan Center for Earth and Space Science Education

2 Assembling a Picture of the Universe: Some Basic Questions Do we actually have all the pieces? Can we use all the colors? Can we use the smallest pieces?

3 The Electromagnetic Spectrum Our eyes see only part of the electromagnetic spectrum…

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5 Some Fundamental Characteristics of Telescopes Sensitivity - Set primarily by the number of photons that can be collected in a given amount of time/Determines the fraction of all of the possible pieces that can be used –Aperture –Image Quality –Background –Observation Time Angular Resolution - How close together can two objects be and still be seen as two objects/Determines the size of the pieces in the puzzle that can be used –Aperture –Wavelength Wavelength/The different color pieces in the puzzle –Much of the spectrum is blocked by the atmosphere –Different physical information is carried by different types of light –Different techniques have to be used to collect and use photons of different energies

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8 The World’s Most Famous Mirror

9 High energy x-rays must skip off the shiny mirror surface at shallow angles to be observed, much different than how optical light telescopes work. Collecting x-rays is like skipping stones on a pond! Just Skimming the Surface…

10 Because gamma rays cannot be focused, Swift uses a unique technique that pinpoints the location of a gamma-ray burst by the shadow cast on an array of detectors. Shadow Play…

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12 “Invisible” Light in Astronomy Each part of the spectrum provides a piece of the puzzle in understanding our universe. Star birth & star death Warm dust Stars & dust Young stars Black holes & neutron stars

13 Ultraviolet Images of a Galaxy Clearly Show the Young, Hot Stars

14 The Sombrero Galaxy as Seen by Hubble and Spitzer Different wavelengths reveal different components of the galaxy

15 Infrared measurements in Andromeda clearly reveal the hot dust

16 The Crab Nebula: The Aftermath of a Supernova The Crab Nebula is all that remains of a once-bright star. The white box on the left shows the area covered by the image on the right.

17 A visible light image of Centaurus A, an interesting galaxy observed with a wide lane of dust across its center. Visible Light View of an Interesting Galaxy

18 X-rays Reveal the Real Action! A high-energy jet blasts outward from the galaxy’s center, evidence for a powerful black hole with the mass of one billion Suns!

19 The ability to detect faint features reveals new phenomena

20 Seeing Faint Objects is Crucial… As is Taking a Time Sequence of Images

21 Spatially resolved spectroscopy reveals the presence of a Black Hole

22 X-ray observations of the center of our own galaxy clearly reveal the hot gas swirling into a massive black hole

23 Sometimes, just thinking about the meaning of what you are looking at can be very powerful

24 The Tools of Our Search We collect light from distant objects… To study fundamental questions in astronomy

25 Some current key astronomical problems are really very familiar to everyone How high is up? How far can we see? Have we discovered everything there is to discover? Twinkle, twinkle little star how I wonder what you are….? How did we get here? Where are we going? Are there other worlds? Is anybody else out there?

26 The infrared reveals the clouds of gas and dust associated with starbirth

27 Detailed study of gas clouds enable astronomers to understand the conditions that regulate the formation of stars within a cloud

28 Infrared observations allow us to see the stars forming within the clouds and the warm dust itself

29 Infrared capabilities enable astronomers to see through the dust in a cloud and observe the embedded cluster of young stars

30 Early observations of the disk around the star Beta Pictoris The kink within the disk is probably due to the presence of one or more embedded objects within the disk

31 We now know that young stellar disks are common

32 Infrared Observations of the Fomalhaut Circumstellar Disk

33 Observational capabilities have reached the point where we are now able to see structure within a disk

34 An Active Young Star With a Jet

35 The infrared also reveals outflows in young stars

36 Detection of ices in a protoplanetary disk

37 Stars with planets have retained their dust disks

38 Some stars “peacefully” eject shells of material towards the end of their lives

39 Planetary Nebulae: Remnants of Old, Dying Stars

40 Different wavelengths reveal different aspects of the physics of a supernova remnant

41 Optical and x-ray images of the remnant of SN 1987a in the Large Magellanic Cloud

42 What Happens Next? Continued access to the entire electromagnetic spectrum Improved sensitivity –Use of segmented mirrors and arrays –Spectroscopy of faint objects Continued increases in angular resolution at all wavelengths –Interferometers Use of new tools for exploring the Universe –Gravity Waves

43 The further into space we observe, the further back in time we see. Observers become time travelers through the universe. Cosmic Time Machines…

44 Infrared measurements reveal distant galaxies in the Hubble Ultra Deep Field

45 The James Webb Space Telescope will continue Hubble’s legacy with more light collecting capability in a less massive package, resolving the mysteries of our universe from above the confines of Earth! New telescopes will look back to the era when galaxies first formed

46 The Chandra X-Ray Observatory and the future, more capable Constellation-X mission, with four identical X-ray telescopes working as one, will continue to explore the limits of space and time in the hot, turbulent universe. The Whole Picture…

47 High Resolution Imaging Over small fields of view SIM will show details that currently elude large telescopes. A simulated globular cluster core is used to illustrate this. Cluster Core Model SIM HST-WFPC2 Resolution (FWHM) 53 milliarcsec Resolution (FWHM) 10 milliarcsec Field of View 0.3 arcsec “true star positions” actual field of view larger than shown

48 Telescopes that block the light from the central star can take images of planets that might be in orbit around them. The Keck Interferometer combines the light of two 10- meter telescopes to take images of hot Jupiter-size planets that shine bright in infrared light. Keck Interferometer The Terrestrial Planet Finder Coronagraph (left) and Interferometer The two Terrestrial Planet Finder observatories will search from space for planets as small as Earth and for signs about whether they can support life. Blocking out the bright light from the central stars will allow astronomers to search for earth-like planets

49 How will we know whether a planet supports life? Look for evidence of oxygen Look for liquid water Analyze the reflected light from the planet to see if the planet has an atmosphere Look for signs of biological activity (methane) and rule out other explanations.

50 LISA “dances about” as gravitational waves pass through the surrounding space. Where Do Gravitational Waves Come From?

51 Three individual craft each separated by 5 million kilometers will measure changes to tiny 4cm cubes to a precision of the width of an atom! Measure Rippling Space-Time? Incredibly Possible!