Chapter 22 – Astronomical Technology

How do we benefit from exploring the universe?

I. Tools of Cosmologists

A. The following types of telescopes are listed beginning with radio telescopes, radiation waves having the longest wavelength and ending with gamma and X-ray telescopes, radiation with the shortest wavelengths.

Below is the Below is the Electromagnetic SpectrumElectromagnetic Spectrum..

B. Radio Telescopes – curved metal dishes that gather and focus radio waves from space to a computer that produces an image. Able to “see” out into space up to 14 billion light years.

1. These waves are longer and not easily obscured and deflected. The waves can travel through planetary clouds or dust particles in the interstellar medium and can help image planetary surfaces beneaththick clouds

2. New Mexico array has 27 radio telescopes working together, makingit more powerful than just one telescope

3. Best for studying the following objects: cosmic backgroundradiation, regions near neutron stars and white dwarfs, supernova remnants, and cold molecular clouds.

Cosmic Background Radiation

Regions Near Neutron Stars

Supernova Remnant

Cold Molecular Cloud

C. Infrared Telescopes(a heat energy)

1.Heat energy is given off by all objects, even dark objects, such as planets.

2. Infrared Telescopes are located outside of earth’s atmosphere, these

wavelengths do not penetrate the earth’s atmosphere.

3. Best for studying the following

objects: cool stars, star forming

regions (nebular clouds), planets, comets,

asteroids.

Nebular Cloud

Comets

D. Visible Light / Optical Telescopes

1. First telescopes developed by Jan Lippershey, in 1608 in Middelburg, Holland. A spectacle maker making glasses in hisworkshop. His children are playing with some of his lenses

Jan Lippershey- First Telescope

They lined up two lenses about a foot apart to discover the local churchsteeple appears so much closer that they can actually see the birdsnesting under the spire. The excited children show their discoveryto their father, and thus the telescope is invented. News spreadsacross Europe to Galileo

2. These telescopes collect and focus visible light from distant starsand galaxies, magnifying those images. The telescopes use mirrorsand lenses to gather light.

3. There are two types:

a. Refracting telescope – uses lenses (like microscopes) i. The larger the lens, the greater the ability to gather light. ii. Yerkes Observatory in Wisconsin has a refracting telescope 40 inches in diameter.

Yerkes Observatory- Lake Geneva, Wis.

b. Reflecting telescope – uses mirrors to collect and focus light.

i. Can be bigger than refracting lenses.

ii.ii. Mt. Palomar, California, has a reflecting telescope that is 200 inches in diameter.

Reflecting Telescope

Mt. Palomar Observatory, California

iii. Multiple Mirror Telescope – large reflecting telescope with many smaller mirrors, such as six 72 inch mirrors, much more powerful than a single mirror telescope

E. Ultraviolet Telescopes

1. Satellites containing these telescopes are located outside the earth’s atmosphere because thesewavelengths do not penetrate the earth’s atmosphere.

2. Best for observing the following objects: supernova remnants, very

hot stars, and quasars.

Quasar

F. X-Ray and Gamma Ray Telescopes

1. Satellites are located outside the earth’s atmosphere; these wavelengths do not penetrate the earth’s atmosphere.

2. Best for studying the following objects: interstellar clouds, accretion disks around black holes, pulsars/neutron stars, gas inclusters of galaxies, and stellar corona

Globular Cluster

Types of Telescopes and their locations relative to Types of Telescopes and their locations relative to Earth’s atmosphere.Earth’s atmosphere.

G. Spectroscope (not a telescope)1. Breaks up white light into rainbow colors into spectrum through aprocess called interference.

a. Light is created from atomic collisions in stars, which release energy in the form of light and heat as electrons move from higher energy levels back down to lower energy levels.

2. Uses differentiation grating – which has microscopic parallel grooves, which break up light into different wavelengths into parallel bands.

3. This technology is used to determine the following information about stars: temperature, velocity and speed, direction of travel relative to earth (toward or away), and chemical composition of stars.

II Special Optical Telescope – Hubble and James Webb Space Telescope

A.Hubble Telescope 1. Named for American astronomer Edwin Hubble (1889-1953)i. Launched April 24, 1990 on space shuttle Discovery.

ii. Serviced in 12/1993, 2/1997, 12/1999, 2/2002 and 5/2009.iii. Length 43.5 ft, Weight 24, 500 lbs, Diameter 14 ft.iv. Cost 1.5 billion dollars at Launchv. Orbits the Earth at 5 miles per second, and at an altitude of

353 miles. It takes 97 minutes for Hubble to make one orbit.

vi. Can detect Ultraviolet through Infrared wavelengths of light. Has two, 25 foot solar panels to collect solar energy. Has 6 nickel-hydrogen batteries (equal to 20 car batteries).

vii. Hubble has two mirrors, one that is 94.5 in. in diameter and weighs 1,825 lbs and the second has a diameter of 12 in. and weighs 27.4 lbs.

Hubble Space TelescopeHubble Space Telescope

2. Contributions of Hubble to the study of space:

i. Best pictures of Mars

ii. Proof of black holes

iii. Evidence of quasars as active galactic nuclei

iv.Evidence for Solar Nebular Theory with pictures of discs surrounding new stars with protoplanets.

v. Pictures of the deaths of stars.

Protoplanets

Death of Stars

d. NASA has decided to cancel the latest scheduled repair mission to the Hubble telescope due to the risk to the astronauts. Hubble can continue to generate and send scientific data until early 2013 when gyroscopes and batteries will have degraded too much to send data.

B. James Webb Space Telescope (JWST) 1. Name for former NASA administrator, James Webb (1906-1992).

i. JWST’s instruments are primarily designed to work in the infra-red range of the electromagnetic spectrum.

ii. Scheduled for Launch in 2014

iii. Has a large mirror 21.3 feet in diameter and a sun-shield the size of a tennis court.

iv. JWST will orbit the sun, 1 million miles (1.5 km) from the Earth.

2. Contributions of JWST to the study of space:i. Will study every phase in the history of our universe.ii. Observe black holes, baby galaxies, supernovae and other

planet’s potential for supporting life.

James T. Webb Telescope

JTWT will orbit the sun

III Space Probes

A. Unmanned spacecraft which are launched into space in order to collect data about the solar system and beyond. Space probes are not necessarily designed to return to Earth.

B. Unlike an artificial satellite, which is placed in more or less permanent orbit around the earth, a space probe is launched with enough energy to escape the gravitational field of the earth and navigate among the planets.

C. Radio-transmitted commands and on-board computers provide the means for mid-course corrections in the space probe's trajectory; some advanced craft have executed complex maneuvers on command from earth when many millions of miles away in space.

Mars Probes

D. Radio contact between the control station on earth and the space probe also provides a channel for transmitting data recorded by onboard instruments back to earth. Instruments carried by space probes include:

a.Radiometers – a device used to measure radiant energy.

b. Magnetometers- compares strengths of magnetic fields.

c. Television cameras sensitive to infrared, visible, and ultraviolet light

d. There also may be special detectors for micrometeors, cosmic rays, gamma rays, and solar wind.

Pioneer Probe on Venus

E. A probe may be directed to orbit a planet, to soft-land instrument packages on a planetary surface, or to fly by as close as a few thousand miles from one or more planets.

Cassini Probe- Picture of Saturn

F. The data provided by a single space probe may require months or even years of analysis. Much has been learned from probes about the origins, composition, and structure of various bodies in the solar system.

Pictures from Mars

G. Scientists trying to understand the earth's weather by constructing theoretical models of global weather systems make use of the knowledge that is gained concerning the atmospheres and meteorology of the planets.

Weather Systems on Jupiter

H. Some of the probes that have been launched by US and other countries are listed below.

a. The earliest space probes in the U.S. space program were the Mariner series, which investigated Mars, Venus, and Mercury, and the Pioneer series, which explored the outer planets.

Mariner Picture of Mercury

b. Pioneer 10, launched in 1972, we received the last signal in 2003. It is still travelling to a star that is 68 light years away. It will take Pioneer 2 million years to get there. Pioneer 10 was the first human-made object to entirely escape the solar system.

c. Several Viking space probes voyaged to Mars in the late 1970s, mapping the planet and searching for life.

This plaque is on the Pioneer 10 which is in deep space.

Artist drawing of Pioneer in Neptune’s orbit looking at the sun.

d. The Voyager probes, launched in 1977, returned spectacular photos and data from brushes by Jupiter, Saturn, Uranus, Neptune, and their moons

c. Several Viking space probes voyaged to Mars in the late 1970s,mapping the planet and searching for life.

Voyager Mission Uranus

Uranus by Voyager

e. The Magellan spacecraft succeeded in orbiting Venus in 1990, returning a radar map of the planet's hidden surface.

Magellen took pictures of the surface of Venus. Below is a

venusian volcano.

f. The Japanese probes Sakigake and Suisei and the European Space Agency's (ESA) probe Giotto both rendezvoused with Halley’s comet in 1986, and Giotto also came within 125 mi (200 km) of the nucleus of the comet Grigg-Skjellerup in 1992.

Pictures from Giotto. Haley’s comet.

g. The U.S. probe Ulysses returned data about the poles of the sun in 1994.

Ulysses was launched from the Space Shuttle.

Pictures of the Sun from Ulysses.

Ulysses is still orbiting the Sun and Jupiter and sending back data and pictures. The focus has been on getting pictures and data from the Sun’s poles.

h. Launched in 1989, the Galileo spacecraft followed a circuitous route that returned data about Venus (1990), the moon (1992), and it reached Jupiter in 1995 and sent a small probe into the Jovian atmosphere to study itscomposition. Over the next eight years it orbited Jupiter 35 times, returning data about the planet's atmosphere and also about Jupiter'slargest moons, Io, Ganymede, Europa, and Callisto.

Image of Jupiter from Galileo

Jupiters Icy Moons

i. The joint U.S.-ESA probe Cassini, launched in 1997, will explore Saturn and some of its moons. Upon its arrival in 2004, Cassini will send a probe (called Huygens) into the atmosphere of Saturn's largest moon, Titan. Over three years, Cassini will conduct detailed studies of Saturn's atmosphere, rings, and magnetosphere; conduct close-up studies of Saturn's satellites Iapetus,Dione, and Enceladus; and characterize Titan's atmosphere and surface.

j. In 2003 the ESA's Mars Express achieved orbit around Mars, and although its Beagle 2 lander proved unsuccessful, the orbiter returned data on the planet. NASA's Spirit and Opportunity rovers landed on the planet shortly afterward in early 2004.

Mars – Taken By Spirit

Nasa’s Space Shuttle Program

International Space Station

IV What have we gained from studying the universe - Technologies that have “spun off” from technology developed for space flight.

A. Digital imaging technologies for early diagnosis and treatment of cancer and laser angioplasty

B. Windows visual news reader necessary for internet access

C. Air quality monitor used to help monitor exhausts from factories

D. Virtual reality

E. Enriched baby food for astronauts

F. Scratch resistant lenses

G. Athletic shoes (mid sole support in running shoes for shock absorption)

H. Flat panel televisions

I. Quartz crystal timing equipment (your watch)

J. Solar energy as possible alternative energy source

K. Satellite systems for monitoring earth’s surface (spy, weather)

L. Fire resistant material