Before and Beyond

1. Before and Beyond “The Search for Terrestrial Planets” Kitwana Carter Tennessee State University Senior Electrical Engineering STARS/JPL Summer Research

2. Research Questions • What are the physical and chemical properties of Earth? • What are terrestrial planets? What planets are considered to be terrestrial? • How can terrestrial/earth-like planets be detected?

3. Topics: • Earth’s Composition • Terrestrial Planets • Planet Detection • Current Missions of Planet Quest • Future Space Travel

4. Earth’sComposition • Atmosphere • Surrounds Earth and protects us by blocking out dangerous rays from the sun • Ozone Layer • Filters out the sun’s harmful ultraviolet radiation • It is composed of Nitrogen (78%), Oxygen (21%), and other gases (1%)

5. Crust Solid Surface Layer, consists of rocks Mantle Layer of dense rock, very hot and under a lot of pressure Outer Core Liquid Molten Iron and Nickel Inner Core Solid Iron and Nickel

6. Rocky Closetostar Terrestrial Planets

7. Mercury Intermediate in size between the Earth and the moon Orbits very close to the sun and has no atmosphere Made mostly of iron Has long curved ridges

8. Venus Closest in size to the Earth So hot that periodically the outer crust may melt Aside from sun and moon, brightest object in our sky Surface: 65% low rolling plains, 25% highlands, with the rest being volcanic areas This picture shows two different perspectives of Venus. On the left is a mosaic of images acquired by the Mariner 10 spacecraft on February 5, 1974. The right image shows a rendering of Venus from the Pioneer Venus and Magellan radar images.

9. Mars About half the size of Earth Cold, frozen water exists in the polar ice caps and permafrost beneath the surface Very small gravitational field, and hence can not hold onto gases Red because of oxidized iron on surface and rust

10. Doppler shift Precise measurement of the velocity or change of position of stars that tell the extent of the star’s movement induced by a planet’s gravitational tug In Doppler shift: Light waves from a star moving toward us are shifted toward the blue end of the spectrum. If the star is moving away, the light waves shift toward the red end of the spectrum. Planet Detection

11. Astrometric Measurement Depends on the slight motion of the star caused by the orbiting planet Astronomers search for the tiny displacements of the stars on the sky Transit Method A transit occurs each time a planet crosses the line-of-sight between the planet’s parent star that it is orbiting and the observer The orbit and size of the planetary companions can be calculated from the period and depths of transits

12. Gravitational Microlensing Einstein’s Theory: Gravity bends space Light from a distant star is bent and focused by gravity as a planet passes between the star and Earth. It is used to find objects that emit no light or are otherwise undetectable. Direct Detection Advanced technologies harness special properties of light to extend our vision.

13. The aim is to answer the question: Are we alone? Is there any form of life on other small Terrestrial Planets just as there’s life on Earth? Has developed a fifteen year plan consisting of several missions to find new worlds and to explore them. Planet Quest

14. Keck Interferometry • With the light-gathering capability of the two telescopes, the resulting interferometer will give the angular resolution of an 85-meter telescope: 8.5 times that of a single Keck telescope • Studies dust clouds around stars where planets may be forming • Connects two 10-meter telescopes on top of Mauna Kea, an island of Hawaii, as an infrared interferometer with a baseline of 85 meters.

15. Asks the questions How big is the universe? How old is it? Are there other planets like Earth out there among the stars? Will measure the distances and positions of stars with unprecedented accuracy Scheduled for launch in 2009 Will determine the distances to stars and to probe nearby stars for Earth-sized planets Combines light from two or more telescopes as if they were pieces of a single, gigantic telescope mirror Space Interferometry Mission

16. Will study the formation of solar systems and will be capable of directly detecting giant planets outside our solar system. Two 8-meter class telescopes on Mount Graham, Arizona, will be connected in an infrared interferometer Will provide high resolution images of many faint objects Large Binocular Telescope Interferometry

17. A space borne telescope designed to look for Earth-like planets around stars beyond our solar system Scheduled to launch in 2007 Will use a specialized one-meter diameter telescope called a photometer to measure the small changes in brightness Kepler

18. Will study all aspects of planets outside our solar system: From their formation and development of dust and gas around newly forming stars to the presence and features of those planets orbiting the nearest stars From the numbers at various sizes and places to their suitability as an abode for life Terrestrial Planet Finder

19. TPF will take the form of either a coronagraph operating at visible wavelengths or a large-baseline interferometer operating in the infrared Final selection of TPF architecture will occur in 2006

20. Future Space Travel • One day maybe we will be able to travel between worlds!

21. Thank You! Questions ???? ?????