Advanced Topics in Earth Science & Space Travel

Aileen L. Casuga

Earth Science- a special branch of science that examines the earth, how it was formed, and how it changes. It also deals with the study of the planet Earth internally and externally.

What is Astronomy?

Astronomy- is a branch of science dealing with the study of the heavenly bodies or the universe.

Ancient Astronomy Began thousands of years ago in the Middle East and, at least in the ancient world, reached a pinnacle with the Greeks 2000 years ago. At that time, the stars and planets were still mysterious lights in the sky, and the Earth was thought to be at the center of the Universe.

In the 16th Century, Nicolaus Copernicus, a Polish astonomer, proposed that the Earth is simply a planet and that all planets orbit the sun. His revolutionary view was confirmed in the following century by the Italian Galileo Galilei, using the newly invented telescope. Johannes Kepler, a German mathematician, worked out that planets orbit on elliptical paths, and the Englishman Isaac Newton explained the gravitational forces governing all orbital motions.

Modern Astronomy

From Newtons time in the 17th century onward, it was recognized that the stars are other suns, but only in the 20th century, with the work of the American astronomer Edwin Hubble, did it become clear that our Galaxy of stars is only one among countless others and that the Universe as a whole is expanding as though from a massive explosion billion of years ago.

Astronomer- is a scientist who studies the stars and other heavenly bodies.

Nicolaus CopernicusPolish astronomer Nicolaus Copernicus revolutionized science by postulating that the earth and other planets revolve about a stationary sun. Developed in the early 1500s but not published until years later, his heliocentric (sun-centered) theory disputed the Ptolemaic theory, popular at the time, which held that the sun and the planets revolved about the fixed earth. Copernicus at first hesitated in publishing his findings because he feared criticism from the scientific and religious communities. After suffering initial disbelief and rejection, however, the Copernican system ranked as the most accepted concept of the universe by the late 17th century.

GalileoItalian physicist and astronomer Galileo maintained that the earth revolved around the sun, disputing the belief held by the Roman Catholic church that the earth was the center of the universe. He refused to obey orders from Rome to cease discussions of his theories and was sentenced to life imprisonment. It was not until 1984 that a papal commission acknowledged that the church was wrong.

Cosmology The study of the origin, properties, processes, and evolution of the universe.

Cosmonaut- is a person who has been trained to fly in space. Most cosmonauts have come from Russia. Many flew in spacecraft launched by the Soviet Union. Cosmonaut are trained in the same way as the Americans astronauts.

Yuri GagarinAn air force pilot and cosmonaut, Yuri Alekseyevich Gagarin became the first human in space on the historic 1961 flight of Vostok 1. Approximately 327 km (203 mi) above the earth at his highest point, Gagarins ship made a single orbit around the planet. The total time of the flight was 1 hour 48 minutes.

Valentina TereshkovaRussian cosmonaut Valentina Tereshkova was the first woman to enter space. She piloted the Vostok 6 in orbit around the earth for four days in 1963.

Neil ArmstrongCommander of the 1969 Apollo 11 lunar mission, Neil Armstrong was the first person to walk on the moon. An aeronautical pioneer, Armstrong also took part in the first in-space docking of two vehicles. He was the first civilian to enter NASAs astronaut program.

Astrometry- is the measure of the position and apparent motions of celestial objects and attempt to understand the factors that influence such movements.

What is a Galaxy?

The Universe

The universe is everything that exists all matters, space, and time.

Most of the visible matter in the universe is grouped in huge aggregations of stars, gas and dusts called galaxies.

Galaxies

Milky Way Galaxy Our own solar system exists within one of the spiral arms of the disk-shaped galaxy called the Milky Way. This false-color image looks toward the center of the Milky Way, located 30,000 light-years away. Bright star clusters are visible along with darker areas of dust and gas.

Hubble Photo of Galaxy M100The Hubble Space Telescope captured this image of the core of galaxy M100. M100 is a spiral galaxy about 1,500 light-years from Earth.

Andromeda GalaxyThe Andromeda Galaxy, a spiral galaxy similar to our own Milky Way Galaxy, is the farthest object from Earth visible to the naked eye. Its whirlpool of stars can be seen from the Northern Hemisphere in the constellation Andromeda. The Milky Way and Andromeda galaxies are part of a group of galaxies called the Local Group, which in turn is part of larger group called the Virgo Cluster.

Galaxies M86 and M84The elliptical galaxies M86 (center) and M84 (right) are members of the Virgo cluster of galaxies, located about 50 million light-years away from our smaller cluster, the Local Group. Elliptical galaxies are populated by older stars and contain little interstellar matter. They are usually the brightest galaxies.

What are stars?

Stars are balls of gas that energy produced by nuclear reactions within their cores. Most stars are similar to the Sun, our nearest star.

Globular Star Cluster Globular clusters are compact, spherical groups of stars that occur on the outskirts of galaxies. Globular clusters are some of the oldest structures in galaxies, and contain some of the oldest stars.

Types of Stars

Supernova 1987AThe Hubble Space Telescope took this photo of the aftermath of the 1987A supernova in 1994, seven years after the light from the exploding star first reached Earth. The supernova occurred in the Large Magellanic Cloud, a satellite galaxy of the Milky Way. Scientists do not yet agree on the mechanism that created the rings surrounding the remnants of the star.

WHERE DO STARS COME FROM?

Starsarebornfromswirling clouds of gas and dust. Gravity pulls the gas and dust together. The gas and dust form a spinning ball. As it spins, it gets hotter. The gas and dust get tightly packed. Finally, nuclear fusion begins and the star starts to shine.

Formation of Stars

A STARS LIFE

Therearedifferentstages in a stars life, just as there are different stages in the lives of people. Right after a star is born it starts to get smaller. After a million years of shrinking, the star enters the main sequence of its life.Afterabout10billion years, the stars core runs out of fuel. The star grows many times larger than it was during the main sequence. At this stage the star is called a red giant. What happens next depends on the size of the star.

How do you call the group of stars that form certain patterns in the sky?

Constellations

The group of stars that form certain patterns in the sky.

Constellation

How many constellations are there in the Northern and Southern Hemisphere?

The Taurus Constellation

The Taurus constellation contains Aldebaran, one of the brightest stars in the night sky. Some 55 light-years away, Aldebaran is 100 times as luminous as the Sun and has a diameter 36 times as great. Its orange color makes it easy to identify. Taurus also contains the star cluster called the Pleiades, which appears to be a tight group of six individual stars. Each starlet in the Pleiades actually comprises several hundred stars located very close to one another but hundreds of light-years from Earth.

Constellation Names and MeaningsAncient people and astronomers often saw designs or groupings in the stars and named them after various religious figures, animals, and objects. This table lists some of the more prominent constellations and translates their names.

Constellations of the ZodiacAncient astronomers noted that the sun makes a yearly journey across the celestial sphere, part of which is represented in the picture by the blue band. The ancient astronomers associated dates with the constellations in this narrow belt (which is known as the zodiac), assigning to each constellation of stars the dates when the sun was in the same region of the celestial sphere as the constellation. The twelve zodiacal signs for these constellations were named by the 2nd-century astronomer Ptolemy, as follows: Aries (ram), Taurus (bull), Gemini (twins), Cancer (crab), Leo (lion), Virgo (virgin), Libra (balance), Scorpio (scorpion), Sagittarius (archer), Capricorn (goat), Aquarius (water-bearer), and Pisces (fishes).

What is the solar system made up of?

SOLAR SYSTEM

TheSunandeverything that orbits the Sun, including the nine planets and their satellites; the asteroids and comets; and interplanetary dust and gas. The term may also refer to a group of celestial bodies orbiting another star

The Solar system

Which is the center of the solar system?

The Sun

The Sun and its Interior

MercuryMercury orbits closer to the Sun than any other planet, making it dry, hot, and virtually airless. Although the planets cratered surface resembles that of the Moon, it is believed that the interior is actually similar to Earths, consisting primarily of iron and other heavy elements. This composite photograph was taken in 1974 by Mariner 10, the first probe to study Mercury in detail.

VenusVenus is the brightest object in our sky, after the sun and moon. Swirling clouds of sulfur and sulfuric acid obscure Venuss surface and inhibited study of the planet from Earth until technology permitted space vehicles, outfitted with probes, to visit it. These probes determined that Venus is the hottest of the planets, with a surface temperature of about 460 C (about 860 F). Scientists believe that a greenhouse effect causes the extreme temperature, hypothesizing that the planets thick clouds and dense atmosphere trap energy from the sun.

EarthAn oxygen-rich and protective atmosphere, moderate temperatures, abundant water, and a varied chemical composition enable Earth to support life, the only planet known to harbor life. The planet is composed of rock and metal, which are present in molten form beneath its surface. The Apollo 17 spacecraft took this snapshot in 1972 of the Arabian Peninsula, the African continent, and Antarctica (most of the white area near the bottom).

-namegiventotheonly natural satellite of Earth. The Moon is the second brightest object in Earths sky, after the Sun, and has accordingly been an object of wonder and speculation for people since earliest times. The natural satellites of the other planets in the solar system are also sometimes referred to as moons.Moon

Phases of the Moon

The appearance of the Moon from Earth depends on the relative positions of the Earth, Moon, and Sun. This illustration shows what the Moon looks like from Earth at different stages of the Moon's orbit.

MarsMars is the fourth planet from the Sun. It is about half as big as Earth. Mars is more like Earth than any other planet in the solar system. Its surface is like a very cold desert. There is ice, but no liquid water. Mars has reddish-brown rocks and soil. We often call Mars the red planet because from Earth, it looks bright red in the night sky.

Jupiter and its MoonsJupiter is the largest of the planets, with a volume more than 1,300 times greater than that of Earth. Jupiters colorful bands are caused by strong atmospheric currents and accentuated by a dense cloud cover. The massive planet, upper right, is shown here with its four largest satellites: Io, upper left, Ganymede, lower left, Europa, center, and Callisto, lower right.

Great Red SpotJupiters Great Red Spot is a huge storm that swirls around in the planets atmosphere. The spot is as wide as three Earths!

SaturnSaturn, distinguished by its rings, is the second largest planet in the solar system. This processed Hubble Space Telescope image shows the planets cloud bands, storms, and rings as they would appear to the human eye.

UranusUranuss blue-green color comes from the methane gas present in its cold, clear atmosphere. The dark shadings at the right edge of the sphere correspond to the day-night boundary on the planet. Beyond this boundary, Uranuss northern hemisphere remains in a four-decade-long period of darkness because of the way the planet rotates. Scientists compiled this view of Uranus from images returned from Voyager 2 in 1986, when the probe was 9.1 million km (5.7 million mi) away from the planet.

UranusUranuss blue-green color comes from the methane gas present in its cold, clear atmosphere. The dark shadings at the right edge of the sphere correspond to the day-night boundary on the planet. Beyond this boundary, Uranuss northern hemisphere remains in a four-decade-long period of darkness because of the way the planet rotates. Scientists compiled this view of Uranus from images returned from Voyager 2 in 1986, when the probe was 9.1 million km (5.7 million mi) away from the planet.

PlutoPluto is farther from the Sun than the major planets in the solar system, although it occasionally moves in closer than Neptune due to an irregular orbit. The small, rocky, and cold world takes 247.7 years to revolve around the Sun. This artist's rendition depicts Pluto, foreground; its moon, Charon, background; and the distant Sun, upper right.

What are the other members of the Solar System?

COMETS-consists of frozen gas and dust, exist in the edge of the solar system

Halleys CometThis picture shows Halleys Comet passing near the Sun in 1986. The comet is named for British astronomer Edmond Halley, who discovered that comets orbit the Sun.

MeteorA meteor, or shooting star, streaks across the night sky. Meteors begin as chunks of rock or metal drifting through space. As they fall through Earths atmosphere, they heat up until they glow bright enough to be seen from the ground.

AsteroidAsteroid Mathilde, is the third and the largest asteroid ever to be viewed at close range. The Near Earth Asteroid Rendezvous (NEAR) spacecraft flew by Mathilde in late June 1997.

Asteroid Hitting Earthasteroid hit Earth, as shown in this artists sketch, the results could be disastrous. Many scientists believe that such an impact occurred about 65 million years ago, changing the Earths climate enough to kill off the dinosaurs.

What are the instruments used by astronomers in observing the sky?

TelescopeTelescopes help us see things that are far away. They make distant objects look bigger.

Refracting TelescopeThe simplest refracting telescope has two convex lenses, which are thicker in the middle than at the edges. The lens closest to the object is called the objective lens. This lens collects light from a distant source and brings it to a focus as an upside-down image within the telescope tube. The eyepiece lens forms an image that remains inverted. More complex refracting telescopes contain an additional lens to flip the image right-side up.

Newtonian Reflecting Telescope The first reflecting telescope was designed by Sir Isaac Newton in 1668. A reflecting telescope uses a curved mirror to focus the light. Light from distant objects such as stars and galaxies enters the telescope tube in parallel rays. These rays are reflected from the concave mirror to a diagonal plane mirror. The diagonal mirror reflects the light through a hole in the side of the telescope tube to a lens in the eyepiece. Reflecting telescopes can be made larger than refracting telescopes because the curved mirror can be supported along its entire surface, while a large lens can only be supported at its edges. A large surface can collect more light from distant stars than a small surface. Modern reflecting telescopes include the 508-cm (200-in) reflector at the Palomar Observatory in California and the 400-cm (158-in) reflector at Cerro Tololo Inter-American Observatory near La Serena, Chile.

Hubble Space Telescope

The Hubble Space Telescope, free of the distorting effects of the earths atmosphere, has an unprecedented view of distant galaxies. Placed in orbit in 1990, scientists discovered soon after the telescope became operational that its 240-cm (94.5-in) primary mirror was flawed. However, a repair mission completed by space shuttle astronauts in December 1993 successfully installed corrective optics which compensated for the flawed mirror.

Early TelescopesAlthough a Dutch optician probably designed the first telescope, it was Galileo who turned it rigorously on the heavens in the early 17th century. Galileo used a refracting telescope (top) with a convex lens at the front and a concave lens at the viewing end. The 18th-century refracting telescope (middle) produced images that were blurred because of the different indexes of its combined lenses. The bottom scope is a reflecting telescope, which used two mirrors and an eyepiece lens, a setup that eliminates the problems of long viewing tubes and color distortion.

Astrophotography

Photography of astronomical objectsThe art of photographing astronomical objects and events for astronomical studies

I hope you enjoyed listening.

Thank you very much!

Aileen L. Casuga