Presentation on theme: "The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang. This theory was born of the observation."— Presentation transcript:
The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang. This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all been propelled by an ancient explosive force. The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over the ensuing billions of years.
Galaxies are sprawling space systems composed of dust, gas, and countless stars. The number of galaxies cannot be counted—the observable universe alone may contain 100 billion. Some of these distant systems are similar to our own Milky Way galaxy, while others are quite different.
Galileo Galilei was an Italian physicist and astronomer. He was born in Pisa on February 15, Galileo's father, Vincenzo Galilei, was a well-known musician. Vincenzo decided that his son should become a doctor. Galileo's observations strengthened his belief in Copernicus' theory that Earth and all other planets revolve around the Sun. Most people in Galileo's time believed that the Earth was the center of the universe and that the Sun and planets revolved around it.
Nicolaus Copernicus (19 February May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology, which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe, demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often referred to as the Copernican Revolution.
Neil Alden Armstrong (born on August 5, 1930) is a former American astronaut. He is the first person to set foot on the Moon. Armstrong is a recipient of the Congressional Space Medal of Honor.
Buzz Aldrin (born on January 20, 1930) is an American aviator and astronaut who was the Lunar Module pilot on Apollo 11, the first lunar landing. He and mission commander Neil Armstrong were the first persons to land on the Moon; shortly afterward he became the second man to set foot on the Moon.
Yuri Alekseyevich Gagarin (9 March 1934 – 27 March 1968), Hero of the Soviet Union, was a Soviet cosmonaut. On 12 April 1961, he became the first human in outer space and the first to orbit the Earth. He received medals from around the world for his pioneering tour in space.
The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star travel a mean distance of million miles (149.6 million kilometers) to reach Earth and support all life on our planet. Distance from Earth: 149,597,891 kilometers Length of Day: 609 hours, 7 minutes Surface Temp:5,538 C Gravity:28 times Earth’s
Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and generates space weather. The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and more than 15.5 million Celsius at the core. Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy. The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona, which also emit visible light but are only seen during a solar eclipse, when the moon passes between the Earth and sun.
Solar eclipses have been recorded as important events by humans for millennia. References have been found in some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey that declares, "The sun is blotted from the heavens." It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the gods, or an omen of bad things to come.
Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear almost three times as large as it does when viewed from Earth. Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat, nighttime temperatures on the surface can drop to -170 degrees Celsius. Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight. Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet rotates three times during every two orbits. Mercury speeds around the sun every 88 days.
Venus and Earth are similar in size, mass, density, composition, and distance from the sun. There, however, is where the similarities end. Venus is covered by a thick, rapidly spinning atmosphere, creating a scorched world with temperatures hot enough to melt lead and a surface pressure 90 times that of Earth. Because of its proximity to Earth and the way its clouds reflect sunlight, Venus appears to be the brightest planet in the sky.
Viewing Earth from the unique perspective of space provides the opportunity to see Earth as a whole. Scientists around the world have discovered many things about our planet by working together and sharing their findings. Some facts are well known. For instance, Earth is the third planet from the sun and the fifth largest in the solar system. Earth's diameter is just a few hundred kilometers larger than that of Venus. The four seasons are a result of Earth's axis of rotation being tilted more than 23 degrees. Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to create a constantly changing world that we are striving to understand.
The moon stabilizes Earth’s wobble, keeping our climate steady over billions of years. Rocks brought back from the moon date to the beginning of our solar system (4.5 billion years ago). We have sent more than 70 spacecraft to the moon, and 12 astronauts have walked on its surface.
A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital nodes. The next total lunar eclipse occurs on December 21, The next eclipse of the Moon is a penumbral eclipse on July 7, 2009.
The Red Planet Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change in the planet's orbit.
Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in the solar system. This water may even have pooled into lakes or shallow oceans. But where did the ancient floodwater come from, how long did it last, and where did it go? At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist at the surface for long. There's water ice close to the surface and more water frozen in the polar ice caps, but the quantity of water required to carve Mars's great channels and flood plains is not evident on— or near—the surface today.
The most massive planet in our solar system, with four planet-size moons and many smaller satellites, Jupiter forms a kind of miniature solar system. Jupiter resembles a star in composition. In fact, if it had been about eighty times more massive, it would have become a star rather than a planet.
Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first to gaze at Saturn through a telescope. Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the atmosphere. Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager spacecraft revealed that Saturn's rings are made mostly of water ice.
Unusual Uranus Once considered one of the blander-looking planets, Uranus has been revealed as a dynamic world with some of the brightest clouds in the outer solar system and 11 rings. The first planet found with the aid of a telescope. The seventh planet from the sun is so distant that it takes 84 years to complete one orbit. Uranus, with no solid surface, is one of the gas giant planet. Its atmosphere is composed primarily of hydrogen and helium. Uranus gets its blue-green color from methane gas.. As the reflected sunlight passes back through the Uranus cloud tops layer, the methane gas absorbs the red portion of the light, allowing the blue portion to pass through and resulting in the blue-green color that we see.
Neptune was the first planet located through mathematical predictions rather than through regular observations of the sky. The magnetic field of Neptune is about 27 times more powerful than that of Earth.
The world was introduced to dwarf planets in 2006, when petite Pluto was stripped of its planet status and reclassified as a dwarf planet. What differentiates a dwarf planet from a planet? For the most part, they are identical, but there's one key difference: A dwarf planet hasn't "cleared the neighborhood" around its orbit, which means it has not become gravitationally dominant and it shares its orbital space with other bodies of a similar size. Pluto's surface is composed of a mixture of frozen nitrogen, methane, and carbon monoxide ices. The dwarf planet also has polar caps and regions of frozen methane and nitrogen. In January 2006, NASA launched its New Horizons spacecraft en route to Pluto and Charon. It is expected to arrive in 2015 and will be the first spacecraft to visit the distant dwarf planet.
Though too small to earn the distinction of planet, asteroids and comets strike huge fear in the human mind. And for good reason: at some point in the future, one of the chunky rocks or icy mud balls will slam into Earth and alter the course of history. Such an impact 65 million years ago is widely believed to have killed off the dinosaurs.
Asteroids are essentially chunks of rock that measure in size from a few feet to several miles in diameter.
Ceres At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt. Gaspra Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters. Vesta The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids. Eros This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a larger body, such as another asteroid. It is almost twice the size of Manhattan Island.
Comets are balls of rock and ice that grow tails as they approach the sun in the course of their highly elliptical orbits. The glowing trails are visible in the night sky. Halley’s Comet This famous comet is named after the English astronomer Edmond Halley, who first calculated its orbit in The comet makes a complete orbit around the sun every 75 to 76 years.
There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites, working and dead. The remaining objects are space junk. That doesn’t include the millions of objects smaller than 1 centimeter.
Hubble Space Telescope (HST) This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in Since it is outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest space images possible. Iridium satellites Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of low-Earth orbiting satellites allows worldwide voice and data communication using handheld satellite phones. GPS Satellites There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.
GOES Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean. International Space Station (ISS) The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now has a permanent human presence. Voyager Space Probes In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.
Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard 1 research satellite, which ceased all functions in One of the newest is a refrigerator-size ammonia reservoir released into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.
Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational pull. When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place. With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole. Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.
The National Aeronautics and Space Administration is an agency of the United States government, responsible for the nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act. In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific discovery, and aeronautics research." NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching New Endeavors to Inspire the Next Generation of Explorers.
Laika was a Soviet space dog who became the first living mammal to orbit the Earth and the first orbital casualty. Little was known about the impact of space flight on living things at the time Laika's mission was launched. Laika died a few hours after launch, presumably from stress and overheating, probably due to a malfunction in the thermal control system. The true cause and time of her death was not made public until 2002; instead, it was widely reported that she lived for several days. On April 11, 2008, Russian officials unveiled a monument to Laika.
Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center, located at Holloman Air Force Base in New Mexico.
NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars and possibly beyond. Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material. Such skills are essential to the future expansion of human presence into deeper space. Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in hydrogen and may be home to water ice as well.
These new NASA missions are being spearheaded by the development of a state-of-the-art new spacecraft—but one with a retro feel. The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids." The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and more reliable design for future space exploration than the now-familiar space shuttle. The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they will arrive on dry land rather than via ocean splashdowns. In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to the red planet.