OBJECTS IN SPACE

1. OBJECTS IN SPACE By, Jacob Emery

2. Introduction • We live in a solar system in the vast Milky Way Galaxy. The Sun is our central star, orbited by nine planets, and containing more than 100 moons, millions of rocky asteroids, and billions of icy comets and stars.

3. Galaxies • Scientists believe that the number of galaxies in the universe could be as few as 10 billion or as many as 100 billion. • Astronomers categorize galaxies primarily by their shapes -- elliptical, spiral, and irregular.

4. NGC 4242 • NGC 4242 is a very low surface brightness spiral galaxy in the constellation of Canes Venatici. • It is estimated to be 27 million light years away!

5. NGC 5792 • NGC 5792 is a spiral galaxy, the most common type. • Images of this galaxy were taken at the Lowell Observatory.

6. NGC6946 • NGC 6946 is more than 15 million light-years away. • NGC 6946 is a big spiral galaxy that looks a lot like our own galaxy, the Milky Way. • Over the last century, astronomers have recorded six supernovae in the galaxy.

7. NGC3516 • NGC 3516 is one of Astronomers favorites. They keep turning their telescopes toward it because it is interesting and easy to study. • NGC 3516 is near the Big Dipper. • It's a spiral galaxy containing hundreds of billions of stars. • It's about a hundred million light-years away -- close as galaxies go.

8. NGC 4731 • This very dim galaxy appears a bit bent out of shape due to the gravitational effect of its neighbor. • NGC 4731 is an estimated distance of 65 million light years away. • The background is mottled with galaxies perhaps hundreds of times more distant.

9. Planets • There are nine planets including Earth that orbit the Sun. • Is our Solar System alone? Astronomers have discovered planets orbiting several other stars, but we have not found any Earth-like planets. • The inner planets are made up of mostly rock and metal and the outer planets are mostly made of ice and gas.

10. Saturn • Saturn is the second largest planet. • Saturn's rings are made of ice and rock. • It spins so fast that it bulges at the equator, and stretches its clouds into bands that encircle the globe. • Saturn has more than three dozen moons, and it's encircled by bright rings. • This view was taken by the Hubble Telescope.

11. Mercury • Mercury is the planet closest to the Sun. • It is slightly larger than Earth's Moon, and looks very much like the Moon, with craters scarring its rocky surface. • Mercury flies along in its orbit at an average speed of 29 miles per second – faster than any other planet!

12. Venus • Venus is the second planet from the Sun. • It is the hottest world in the solar system. • It has a thick atmosphere that heats its surface to almost 900 degrees Fahrenheit (480 C).

13. Jupiter • Jupiter is the largest planet in the solar system. • In fact, it is more massive than all the other planets and moons in our solar system combined. • Its core may be as hot as 54,000 degrees Fahrenheit (30,000 C).

14. Mars • Mars is the fourth planet. • Although Mars is smaller and colder than Earth, it is still quite similar to our planet. • It has a thin atmosphere and polar ice caps, and dry riverbeds across its surface. • Frozen or even liquid water may exist beneath the red Martian soil -- perhaps providing a home for living organisms. • This was taken by the Hubble Space Telescope.

15. Stars and Nebulas • On a really dark night, you can see about 1000 to 1500 stars. • Stars form deep inside vast clouds of interstellar gas and dust called nebulae. • The nearest star to Earth is the one we see every day – the Sun. It is 93 million miles away.

16. Red Rectangle Nebula • A dying star lights up clouds of dust around it in this nebula. • This old star began blowing its outer layers into space, one by one, about 14,000 years ago. • Dust grains reflect light from the star, creating the nebula's layered look. • Eventually, the star will lose all of its outer layers, exposing its hot core, which will cause vast clouds of gas around the star to glow like a neon bulb. • Image from the Hubble Space Telescope.

17. Fomalhaut • This infrared image from the Spitzer Space Telescope hints that one or more planets may orbit Fomalhaut, a nearby bright star • One side of the disk (at the bottom of the picture) is brighter than the other. This could indicate that a planet is hidden inside this portion of the disk, and its gravity is causing more of the dust grains to congregate around it.

18. Supernova 1987A • Supernova 1987A is a massive star in a nearby galaxy that blasted itself to bits. • The ring around the exploded star spans about one light-year. It formed when the star expelled a shell of gas about 20,000 years before it exploded. • Image from Hubble Space Telescope.

19. M17 Nebula • Clouds of hydrogen gas mix with small amounts of oxygen, sulfur, and other elements of a region of M17, a nebula that is giving birth to new stars. • The nebula is about 5,500 light-years away. • The energy of hot, young stars in the nebula causes the gas to glow. • The different colors represent different elements. • Image from Hubble Space Telescope.

20. M22 Star Cluster • The globular cluster M22 is just one of several bright star clusters visible in the constellation Sagittarius. • M22 contains several hundred thousand stars packed into a region of space just a few dozen light-years in diameter. • Its stars are some of the oldest in the galaxy, at more than 10 billion years.

21. Comets • Comets are a ball of frozen water and gases mixed with solid chunks of rock. • There is a vast shell of comets that surrounds the solar system. • Something disturbs the comet's orbit -- like the gravity of a passing star -- starting it on a long fall toward the Sun. • As a comet approaches the Sun, some of its ice vaporizes, freeing particles of rock as well. This material forms a bright cloud around the comet. And some of the material is pushed into a long, glowing tail.

22. Comet C/2001 Q4 • Comet C/2001 Q4 (NEAT) streaks around the Sun in this recent image. • The comet passed closest to Earth in early May. • Image from the WIYN telescope at Kitt Peak National Observatory in Arizona.

23. Comet Wild 2 • Comet Wild 2 appears to glow in this image from the Stardust spacecraft, which flew past the comet in January. • The dark part of the picture shows craters, pits, and bright spots on the surface. • The bright rays around the comet show where gas and dust is blowing into space from "jets" on the comet's surface. • It has a tail several million miles long.

24. Comet Ikaya-Zhang • Comet Ikeya-Zhang, was in its peak brightness this past February. • This false-color image shows the comet's nucleus in white and blue, and a tail of electrically charged water molecules in red.

25. Comet Borrelly • Comet Borrelly slowly tumbles through space in this image. • The comet's nucleus, which is a chunk of ice mixed with rock, measures about five miles long. • Ice is vaporizing from the bright patch near the center of the nucleus, spraying a "jet" of gas and dust into space. • Image from Deep Space 1.

26. Comet Encke • Since its discovery in 1786, Comet Encke has circled the Sun more than 60 times! • Encke orbits the Sun once every 3.3 years -- more often than any other comet yet discovered.

27. Moons • Most of the planets in our solar system have moons — planet-like bodies that orbit a bigger body. • Earth has only one moon, but some planets have many: Jupiter, for example, has 63 known moons. • A planet and its moons actually revolve about each other.

28. Titan Moon • Titan is the largest moon of Saturn. • Astronomers cannot see Titan's surface directly because a cold, hazy atmosphere envelopes the big moon. • Image by the European Southern Observatory's Very Large Telescope in Chile.

29. S/2001 U1 • S/2001 U1 is the 21st known moon of the planet Uranus. • It is a small chunk of rock that follows an irregular orbit around the giant planet.

30. Europa • Warm ice bubbling to the surface creates reddish patches on the icy surface of Jupiter's moon Europa. • A deep ocean of liquid water may exist beneath Europa's ice crust, perhaps providing a home for living organisms. • NASA released the image, which combines two pictures from the Galileo spacecraft.

31. Phobos • American astronomer Asaph Hall discovered the moons of Mars 125 years ago. • Phobos, shown in this image from Mars Global Surveyor, is the larger moon. • Its surface is covered with impact craters. The largest crater, at top left, is about six miles across and is named Stickney.

32. Earth’s Moon • The Moon probably formed very early in the history of the solar system when a large object -- perhaps several times the mass of Mars -- slammed into Earth. • Unlike Earth, the Moon has no atmosphere, and no water. • The lunar surface is covered with craters, the scars from countless boulders -- some much bigger than mountains -- that struck it over billions of years ago.

33. Asteroids • The name "asteroid" comes from a Greek word that means "starlike." When seen through a telescope, an asteroid looks like a faint star. • Asteroids are made up mostly of rock, often rich in iron and other metals, and perhaps some ice.

34. Mathilde • A close picture of Mathilde revealed the asteroid’s heavily crater surface. • One of only 4 asteroids photographed up close. • First scanned in 1997.

35. Gaspra • The surface of Gaspra, shown in a Galileo image, has been pitted by asteroid collisions. Grooves in its surface may have been caused by an impact that split Gaspra from a larger asteroid. • Galileo found that Gaspra is about 22 by 14 by 12 miles. • It's covered with impact craters, which means it's taken a pounding as smaller asteroids slammed into it.

36. 433 Eros • Images show the asteroid 433 Eros to have a 21-mile-long solid body and a face pockmarked with craters. • Observations show that Eros is left over from the formation of our solar system four and a half billion years ago. • It hasn't been heated very much, so it's still the same jumbled up mixture of rock and metal as when it formed.

37. Ceres • Ceres was the first asteroid discovered back in 1801. • Ceres is only about a quarter of the size of our own Moon. • The surface of Ceres consists of dark, carbon-rich rock mixed with a fair amount of water. • The picture at right is a circular scar -- known as the Manicouagan crater – left when an asteroid rammed into present-day Quebec about 200 million years ago.

38. Pallas • As first, Astrnomers thought Pallas was a planet, when it was discovered on March 28th, 1802. • At right, This microscopic sample of zircon is one bit of evidence that a giant asteroid slammed into Earth about 3.5 billion years ago, triggering massive changes in the environment. • Although there is no remaining impact crater, a team has found microscopic remains of the collision in Australia and Africa.

39. Conclusion The more scientists discover, the more complicated our world seems. Earth is a warm, wet planet with an oxygen-rich atmosphere – the perfect place for life, but who knows what is yet to be discovered?

40. Bibliography • http://stardate.org/ • http://www.svetn.org/Angel/section/default.asp?id=2%2DBRE%2DSCIENC%2DCURR%2D1 • http://www.astro.umontreal.ca/~opiomm/images/ngc6946/ngc6946.jpg • http://imagine.gsfc.nasa.gov/Images/news/ngc3516_big.jpg • http://www.noao.edu/outreach/aop/observers/n4731.html