The Earth is the third planet from the Sun in our Solar System. It is the planet we evolved on and the only planet in our Solar System that is known to support life. SIZE
The Earth is about 7,926 miles (12,756 km) in diameter. The Earth is the fifth-largest planet in our Solar System (after Jupiter, Saturn, Uranus, and Neptune). Eratosthenes (276-194 BC) was a Greek scholar who was the first person to determine the circumference of the Earth. He compared the midsummer's noon shadow in deep wells in Syene (now Aswan on the Nile in Egypt) and Alexandria. He properly assumed that the Sun's rays are virtually parallel (since the Sun is so far away). Knowing the distance between the two locations, he calculated the circumference of the Earth to be 250,000 stadia. Exactly how long a stadia is is unknown, so his accuracy is uncertain, but he was very close. He also accurately measured the tilt of the Earth's axis and the distance to the sun and moon.
 The Earth and the moon. Photo taken by NASA's Galileo mission in 1990. |
The Earth has one moon. The diameter of the moon is about one quarter of the diameter of the Earth.
The moon may have once been a part of the Earth; it may have been broken off the Earth during a catastrophic collision of a huge body with the Earth billions of years ago.
MASS, DENSITY, AND ESCAPE VELOCITY
The Earth's mass is about 5.98 x 1024 kg. The Earth has an average density of 5520 kg/m3 (water has a density of 1027 kg/m3). Earth is the densest planet in our Solar System.
To escape the Earth's gravitational pull, an object must reach a velocity of 24,840 miles per hour (11,180 m/sec).
LENGTH OF A DAY AND YEAR ON EARTH
 Earth rising over the moon. Photo taken by NASA's Apollo 8 mission. |
Each day on Earth takes 23.93 hours (that is, it takes the Earth 23.93 hours to rotate around its axis once - this is a sidereal day). Each year on Earth takes 365.26 Earth days (that is, it takes the Earth 365.26 days to orbit the Sun once). The Earth's rotation is slowing down very slightly over time, about one second every 10 years.
THE EARTH'S ORBIT
 Planet-Sun Orbital DiagramLabel the aphelion (farthest point in orbit) and perihelion (closest point in orbit) of a planet in orbit. Answers |
Orbital Eccentricity
The Earth' orbital eccentricity is 0.017; it has an orbit that is close to being circular.
THE EARTH'S AXIS TILT AND THE SEASONS
The Earth's axis is tilted from perpendicular to the plane of the ecliptic by 23.45�. This tilting is what gives us the four seasons of the year: Summer, Spring, Winter and Autumn. Since the axis is tilted, different parts of the globe are oriented towards the Sun at different times of the year. This affects the amount of sunlight each receives. For more information on the seasons, click here. SPEED
At the equator, the Earth's surface moves 40,000 kilometers in 24 hours. That is a speed of about 1040 miles/hr (1670 km/hr). This is calculated by dividing the circumference of the Earth at the equator (about 24,900 miles or 40,070 km) by the number of hours in a day (24). As you move toward either pole, this speed decreases to almost zero (since the circumference at the extreme latitudes approaches zero). The Earth revolves around the Sun at a speed of about 30 km/sec. This compares with the Earth's rotational speed of approximately 0.5 km/sec (at middle latitudes - near the equator).
For more information on the speed of the Earth, click here.
 The size of the atmosphere in this illustration is greatly exaggerated in order to show the greenhouse effect. The Earth's atmosphere is about 300 miles (480 km) thick, but most of the Earth's atmosphere is within 10 miles (16 km) of the Earth's surface. |
TEMPERATURE ON EARTHThe temperature on Earth ranges from between -127�F to 136�F (-88�C to 58�C; 185 K to 311 K). The coldest recorded temperature was on the continent of Antarctica (Vostok in July, 1983). The hottest recorded temperature was on the continent of Africa (Libya in September, 1922).
The greenhouse effect traps heat in our atmosphere. The atmosphere lets some infrared radiation escape into space; some is reflected back to the planet.
For more information on the greenhouse effect, click here.
ATMOSPHERE
The Earth's atmosphere is a thin layer of gases that surrounds the Earth. It is composed of 78% nitrogen, 21% oxygen, 0.9% argon, 0.03% carbon dioxide, and trace amounts of other gases. The atmosphere was formed by planetary degassing, a process in which gases like carbon dioxide, water vapor, sulphur dioxide and nitrogen were released from the interior of the Earth from volcanoes and other processes. Life forms on Earth have modified the composition of the atmosphere since their evolution.
For more information on the atmosphere, click here.
Earth Activities - Earth coloring page
- The Earth and the Moon coloring page
- Find It!, a quiz on the Earth.
- Label the Planet-Sun Orbital Diagram. Answers.
- Continents Printout: Label the continents, the poles, and the equator.
Ocean Map: Label the Oceans
- Interactive Earth Puzzle
- Make a globe from papier-m�ch�
- A simple-to-make earth pendant
- Earth day crafts
- Earth Cloze Printout: A fill-in-the-blanks activity on Earth. Answers
- How to write a report on a planet - plus a rubric.
| GENERAL INFORMATION ON SATURN |  |
Saturn is the sixth planet from the sun in our solar system. It is the second-largest planet in our solar system (Jupiter is the largest). It has beautiful rings that are made mostly of ice chunks (and some rock) that range in size from the size of a fingernail to the size of a car. Saturn is made mostly of hydrogen and helium gas. Saturn is visible without using a telescope, but a low-power telescope is needed to see its rings.
SIZE AND SHAPE
Saturn is about 74,898 miles (120,536 km) in diameter (at the equator at the cloud tops). This is about 9.4 times the diameter of the Earth. 764 Earths could fit inside a hollowed-out Saturn. Saturn is the most oblate (flattened) planet in our Solar System. It has a equatorial diameter of 74,898 miles (120,536 km) (at the cloud tops) and a polar diameter of 67,560 miles (108,728 km). This is a difference of about 10%. Saturn's flattened shape is probably caused by its fast rotation and its gaseous composition.
RINGS
Saturn's beautiful rings are only visible from Earth using a telescope. They were first observed by Galileo in the 17th century. Saturn's bright rings are made of ice chunks (and some rocks) that range in size from the size of a fingernail to the size of a car. Although the rings are extremely wide (almost 185,000 miles = 300,000 km in diameter), they are very thin (about 0.6 miles = 1 km thick).
For more information on Saturn's rings, click here.
MASS, GRAVITY AND DENSITY
Saturn's mass is about 5.69 x 1026 kg. Although this is 95 times the mass of the Earth, the gravity on Saturn is only 1.08 times the gravity on Earth. This is because Saturn is such a large planet (and the gravitational force a planet exerts upon an object at the planet's surface is proportional to its mass and to the inverse of its radius squared). A 100 pound person would only weigh 108 pounds on Saturn.
Saturn is the only planet in our Solar System that is less dense than water. Saturn would float if there were a body of water large enough!
LENGTH OF A DAY AND YEAR ON SATURN
Each day on Saturn takes 10.2 Earth hours. A year on Saturn takes 29.46 Earth years; it takes 29.46 Earth years for Saturn to orbit the sun once. ORBIT AND DISTANCE FROM THE SUN
Saturn is 9.539 AU, on average, from the sun, about 9 and a half times as far from the Sun as the Earth is. At aphelion (the place in its orbit where Saturn is farthest from the Sun), Saturn is 1,503,000,000 km from the Sun. At perihelion (the place in its orbit where Jupiter is closest to the Sun), Saturn is 1,348,000,000 km from the Sun.
TEMPERATURE ON SATURNThe mean temperature on Saturn (at the cloud tops) is 88 K (-185° C; -290° F).
MOONS
Saturn has dozens of moons (33 discovered as of August, 2004). It has 18 named moons. including Titan (the largest), Rhea, Iapetus, Dione, Tethys, Enceladus, Mimas, Hyperion, Phoebe, Janus, Epimetheus, Pandora, Prometheus, Helene, Telesto, Atlas, Calypso, and Pan (the smallest named moon of Saturn). At least a dozen others have been noted (but not named yet).
For more information on Saturn's moons, click here.
SPACECRAFT VISITS
Saturn has been visited by Pioneer 11 (in 1979) and by Voyager 1 and Voyager 2. Cassini, a spacecraft named for the divisions in Saturn's rings, is on the way and will arrive in 2004.
SATURN-EARTH COMPARISON
SATURN'S NAME AND SYMBOL
 This is the symbol of the planet Saturn. |
| SATURN'S RINGS | |
RINGS
Saturn's beautiful rings are only visible from Earth using a telescope. They were first observed by Galileo in 1610 (using his 20-power telescope). The rings are divided into 7 major ring divisions. There are two main sections (called rings A and B) plus the smaller ring (Ring C or the Crepe ring), D and F rings; the larger gap in the rings is called the Cassini division; the smaller one is the Encke division. Starting closest to Saturn, the rings and divisions are: D, C, B, The Cassini Division, A, the Encke division, and F (subdivided into G and E, and a ring with visible clumps of matter, called knots).  Saturn's moon Prometheus and Pandora, shepherding Saturn's narrow, outer F Ring. |
Saturn's bright rings are made of ice chunks and rocks that range in size from the size of a fingernail to the size of a car. Although the rings are very extremely wide (almost 185,000 miles = 300,000 km in diameter), they are very thin (about 0.6 miles = 1 km thick).
| Ring/Gap | Start radius (km) from the center of Saturn | End radius (km) | Width (km) |
|---|---|---|---|
| D | 67,000 km | 74,500 km | 7,500 km |
| C | 74,500 km | 92,000 km | 17,500 km |
| Maxwell Gap | 87,500 km | 87,770 km | 270 km |
| B | 92,000 km | 117,500 km | 25,500 km |
| Cassini Division | 117,500 km | 122,200 km | 4,700 km |
| A | 122,200 | 136,800 | 14,600 |
| Encke Gap | 133,570 km | 133,895 | . |
| Keeler Gap | 136,530 | 136,565 | 35 |
| F | 140,210 | 140,240-140,710 | 30-500 km |
| G | 165,800 | 173,800 | 8,000 |
| E | 180,000 | 480,000 | 300,000 |
Trilogy by Rick Levine
Einstein's theory that science proved right:
Energy's made from both mass and light
Although E=mc squared, my dear
The solution is more complex, I fear.
E is for energy, everywhereEinstein's theory that science proved right:
Energy's made from both mass and light
Although E=mc squared, my dear
The solution is more complex, I fear.
C squared is how much that I care
Light forces flowing without constraint
Transmuted into the love of a saint
M is for mass, by which we are bound
With our hearts in the clouds
And our feet on the ground.
Monday, October 1, 2007
TALK ABOUT IT
The Moon in Gemini influences your conversations. The Moon rules emotions and Gemini is the zodiac sign of information. Let someone know you might be seduction material if he or she is truly right for the task. How are your nonverbal skills?
The Moon in Gemini influences your conversations. The Moon rules emotions and Gemini is the zodiac sign of information. Let someone know you might be seduction material if he or she is truly right for the task. How are your nonverbal skills?
Temperance This Deck: Golden Tarot General Meaning: What is traditionally known as the Temperance card is a reference to the Soul. Classically female, she is mixing up a blend of subtle energies for the evolution of the personality. One key to interpreting this card can be found in its title, a play on the process of tempering metals in a forge. Metals must undergo extremes of temperature, folding and pounding, but the end product is infinitely superior to impure ore mined from the earth. In this image, the soul volunteers the ego for a cleansing and healing experience which may turn the personality inside-out, but which brings out the gold hidden within the heart. (This card is entitled "Art" in the Crowley deck.) |  |  |
 | Why do we see only one side of the Moon, if the Moon rotates about its axis? |
Because the Moon is also orbiting around the Earth. If the Moon didn't rotate about its axis, here's what would happen. One side would be facing us right now; two weeks later, when the Moon has gone halfway in its orbit around the Earth, the opposite side of the Moon would be facing us. Here's a picture (the Earth and the Moon should really be spheres, of course, not squares):
E A R T H
E A R T H moon
E A R T H moon
E A R T H moon
E A R T HAfter the Moon has gone halfway in its orbit around the Earth, if the Moon didn't spin on its axis, the picture would look like this: E A R T H
moon
E A R T H
moon
E A R T H
moon
E A R T H
E A R T HNotice that we on the Earth would now see the opposite side of the Moon (the Earth sees the "m" of "moon" in the first picture, but it sees the "n" of the word "moon" in the second picture). What really happens is that the Moon is rotating on its axis; it spins once a month, exactly the same length of time as it takes to orbit the Earth. So, after half an orbit around the Earth, the Moon has also spun one-half of a revolution about its axis. The correct second picture looks like this:
E A R T Hnoom
E A R T Hnoom
E A R T Hnoom
E A R T H
E A R T HNow the Moon has rotated 180 degrees, so the Earth still sees the "m" of "moon". Here's another picture. After one-quarter of an orbit (about one week after the original picture), the Moon has rotated 90 degrees on its axis, and it looks something like this:
n n n o o o o o o m m m
E A R T H E A R T H E A R T H E A R T H E A R T HOnce again, the "m" side of "moon" is facing the Earth, but it took an appropriate amount of rotation of the Moon about its axis to keep the "m" side facing the Earth. So the Moon rotates about its own axis in the same length of time that it takes to orbit the Earth. That's what keeps the same side of the Moon always facing the Earth.
How I wonder what you are?
Spectroscopy is a technique in which the visible light that comes from objects (like stars and nebulae) is examined to determine the object's composition, temperature, motion, and density.
When something is hot enough to glow (like a star), it gives you information about what it is made of, because different substances give off a different spectrum of light when they vaporize. Each substance produces a unique spectrum, almost like a fingerprint. In addition, different cool gases will absorb different wavelengths of light (and generate a signature spectrum with dark lines at a characteristic places). Because of this, you can determine the composition of gases by observing light that has passed through them.
In fact, a substance will emit spectral lines (at a particular wavelength) when it is heated, and absorb light at the same wavelength when it is cool. When the substance emits light, a bright-line spectrum or an emission spectrum is generated (these look like a series of bright lines on a black background). When the substance absorbs light (at the same characteristic wavelength), the spectral pattern that is formed is called a dark-line spectrum or an absorption spectrum (these look like a series of dark lines on a rainbow).
For example, burning sodium (Na) will always produce two very close yellow lines (near the middle of the spectrum) on a black background, and it is the only element that will do exactly this. If you look at a light source and find these characteristic yellow lines, you know that there was sodium in the glowing object that produced this light. If you look at a light source and find dark lines in the same place on the spectrum, you know that the light you're seeing passed through sodium gas somewhere on its journey to you.
Examining the Sun:
Although we think of sunlight or starlight as white, it is really composed of a spectrum of colors - you can use a prism to break up sunlight into a rainbow (red, orange, yellow, green, blue, indigo and violet) - Isaac Newton was the first person to realize this. But when the spectrum is closely examined, the rainbow is interrupted by hundreds of tiny dark lines (called Fraunhofer lines). These lines show that some wavelengths are being absorbed by gases in the outer atmosphere of the Sun, and from this, we can determine which elements are in the Sun's atmosphere.
Why Does Each Element Have a Different Signature Spectrum?:
Each element has a different atomic structure, causing it to produce (or absorb) a different set of wavelengths. It's the actions of the electrons (tiny particles that surround the much heavier nucleus) jumping between different orbitals (the many places where the probability of finding an electron is the greatest) that produce the signature spectrum for an element.
When light (or other energy) is absorbed by the atom, an electron jumps from a low energy orbital to a higher energy orbital. When an electron returns to a less energetic orbital, light (or other electromagnetic radiation) is generated. There are actually many high energy orbitals that an electron can move to, so you can get emitted light in several different wavelengths. The bigger the difference in energy of the orbitals, the shorter the wave length of the light produced (or absorbed).
History of Spectroscopy:
Joseph von Fraunhofer (1787-1826), a German scientist and inventor, observed in the early 1800s that the continuous spectrum was marred by over 700 dark lines (now called Fraunhofer lines). No one knew what caused these lines until the work of G. R. Kirchhoff.
Spectroscopy was discovered in 1859 by Gustav Robert Kirchhoff and Robert Wilhelm Bunsen (of Bunsen burner fame). They made a prism-based device that separated the visible light emitted when substances were vaporized in the flame of Bunsen's specially-designed burner (it had a high-temperature, non-luminous flame). They determined that each gas had its own signature spectrum. Kirchhoff also realized that when emitted light passed through a cooler gas of the same substance, the bright spectral lines were replaced by dark ones - in the same position (1859). So a substance will emit spectral lines (at a particular wavelength) when it is heated, and absorb light at the same wavelength when it is cool.
Kirchhoff had explained the Sun's Fraunhofer lines - the dark lines in the solar spectrum (the light from the Sun) were the same as the emission lines observed by various heated chemical substances. Kirchhoff realized that the Sun was hot and gaseous.
The first person to use the technique of spectroscopy to examine celestial objects was William Huggins (in 1863). He determined that the Sun and the stars are composed mostly of the element hydrogen. He and his wife Margaret also examined the spectra of nebulae and comets.
Related Terms:
CONTINUOUS SPECTRUM A continuous spectrum is a spectrum of emitted light that contains all wavelengths of the colors that compose white light (red, orange, yellow, green, blue, indigo, violet, from long to short wavelength). Continuous spectra are emitted by incandescent solids, liquids, or compressed gases. If some discrete lines are missing from a spectrum, it is an absorption spectrum (indicating the presence of elements that absorb particular wavelengths). | HUGGINS, WILLIAM and MARGARET Sir William Huggins (February 7, 1824-May 12, 1910) was an amateur English astronomer who was the first person to use spectroscopy to determine the compositions of astronomical objects (in 1861). He determined that the Sun and the stars are composed mostly of the element hydrogen. He also examined the spectra of nebulae and comets. Huggins' wife (they were married in 1875), Margaret Lindsay Murray Huggins (1848-1915), was a self-taught astronomer who did extensive work in spectroscopy and photography. Margaret studied the Orion Nebula extensively. William and Margaret were the first people to realize that some nebulae, like the Orion Nebula, consisted of amorphous gases (and were not a congregation of stars, like the nebula Andromeda). A lunar crater, a Martian crater, and an asteroid (#2635 Huggins) have been named for William Huggins. |
INCANDESCENT An incandescent material is so hot that it glows, producing light. Incandescent solids, liquids, and compressed gases produce a continuous spectrum; other gases produce a line or emission spectrum (only a few wavelengths are emitted). | SPECTRAL LINE A spectral line is a bright or dark line found in the spectrum of some radiant source. Bright lines indicate emission, dark lines indicate absorption. A bright spectral line represents light emitted at a specific frequency by an atom or molecule. Each different element and molecule gives off light at a unique set of frequencies. Astronomers can determine the composition of gases in stars by looking for characteristic frequencies. For example, carbon monoxide (CO) has a spectral line at 115 Gigahertz (equal to a wavelength of 2.7 mm). |
SPECTRAL TYPE The spectral type of stars is a system of classification of stars based on the stars' spectra, emission lines that correlate with each star's surface temperature (and color). There are seven major spectral types. Stars range from blue and hot to red and cool. The spectral types are: O, B, A, F, G, K, and M (from hottest to coolest). Each of these letters is divided into 10 numerical classes, from hotter to cooler: 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. For example, our Sun has the spectral type G2. | SPECTROGRAPH A spectrograph is an image of the electromagnetic spectrum of a light source. Spectrographs identify which elements are present in that star. |
SPECTRUM The spectrum is the band of colors that white light is composed of, in the order: red, orange, yellow, green, blue, indigo, violet (from long to short wavelength). Newton first discovered that sunlight could be divided into the visible spectrum. | STELLAR CLASSIFICATION Stars can be classified by their surface temperature and their absorption spectra. There are seven main types of stars. In order of decreasing temperature, they are: O - He II absorption; B - He I absorption; A - H absorption; F - Ca II absorption; G - strong metallic lines; K -bands developing; M - very red. O and B stars are uncommon but very bright; M stars are common but dim. The Sun is a G star, about average. The standard mnemonic for remembering the classes is: Oh Be A Fine Girl Kiss Me. It is supplemented by the giants and supergiants: R- and N-type stars (also known as carbon stars or C-type stars) and S-type stars. |
M1 The Crab Nebula supernova remnant in Taurus
M2 globular cluster in Aquarius
M3 globular cluster in Canes Venatici
M4 globular cluster in Scorpius
M5 globular cluster in Serpens Caput
M6 The Butterfly Cluster open cluster in Scorpius
M7 Ptolemy's Cluster open cluster in Scorpius
M8 The Lagoon Nebula starforming nebula in Sagittarius
M9 globular cluster in Ophiuchus
M10 globular cluster in Ophiuchus
M11 The Wild Duck Cluster open cluster in Scutum
M12 globular cluster in Ophiuchus
M13 Great Hercules Globular Cluster globular cluster in Hercules
M14 globular cluster in Ophiuchus
M15 globular cluster in Pegasus
M16 Eagle or Star Queen Nebula starforming nebula in Serpens Cauda
M17 The Omega or Swan or Horseshoe or Lobster Nebula starforming nebula in Sagittarius
M18 open cluster in Sagittarius
M19 globular cluster in Ophiuchus
M20 The Trifid Nebula starforming nebula in Sagittarius
M21 open cluster in Sagittarius
M22 globular cluster in Sagittarius
M23 open cluster in Sagittarius
M24 Milky Way Patch star cloud with open cluster NGC 6603 in Sagittarius
M25 open cluster in Sagittarius
M26 open cluster in Scutum
M27 The Dumbbell Nebula planetary nebula in Vulpecula
M28 globular cluster in Sagittarius
M29 open cluster in Cygnus
M30 globular cluster in Capricornus
M31 The Andromeda Galaxy spiral galaxy in Andromeda
M32 Satellite galaxy of M31 elliptical galaxy in Andromeda
M33 The Triangulum Galaxy (also Pinwheel) spiral galaxy in Triangulum
M34 open cluster in Perseus
M35 open cluster in Gemini
M36 open cluster in Auriga
M37 open cluster in Auriga
M38 open cluster in Auriga
M39 open cluster in Cygnus
M40 Double Star WNC4 in Ursa Major
M41 open cluster in Canis Major
M42 The Great Orion Nebula starforming nebula in Orion
M43 part of the Orion Nebula (de Mairan's Nebula) starforming nebula in Orion
M44 Praesepe, the Beehive Cluster open cluster in Cancer
M45 Subaru, the Pleiades--the Seven Sisters open cluster in Taurus
M46 open cluster in Puppis
M47 open cluster in Puppis
M48 open cluster in Hydra
M49 elliptical galaxy in Virgo
M50 open cluster in Monoceros
M51 The Whirlpool Galaxy in Canes Venatici
M52 open cluster in Cassiopeia
M53 globular cluster in Coma Berenices
M54 globular cluster in Sagittarius
M55 globular cluster in Sagittarius
M56 globular cluster in Lyra
M57 The Ring Nebula planetary nebula in Lyra
M58 spiral galaxy in Virgo
M59 elliptical galaxy in Virgo
M60 elliptical galaxy in Virgo
M61 spiral galaxy in Virgo
M62 globular cluster in Ophiuchus
M63 Sunflower galaxy spiral galaxy in Canes Venatici
M64 Blackeye galaxy spiral galaxy in Coma Berenices
M65 spiral galaxy in Leo
M66 spiral galaxy in Leo
M67 open cluster in Cancer
M68 globular cluster in Hydra
M69 globular cluster in Sagittarius
M70 globular cluster in Sagittarius
M71 globular cluster in Sagitta
M72 globular cluster in Aquarius
M73 open cluster in Aquarius
M74 spiral galaxy in Pisces
M75 globular cluster in Sagittarius
M76 The Little Dumbell, Cork, or Butterfly planetary nebula in Perseus
M77 spiral galaxy in Cetus
M78 starforming reflection nebula in Orion
M79 globular cluster in Lepus
M80 globular cluster in Scorpius
M81 Bode's Galaxy (nebula) spiral galaxy in Ursa Major
M82 The Cigar Galaxy irregular galaxy in Ursa Major
M83 The Southern Pinwheel Galaxy spiral galaxy in Hydra
M84 lenticular galaxy in Virgo
M85 lenticular galaxy in Coma Berenices
M86 lenticular galaxy in Virgo
M87 Virgo A elliptical galaxy in Virgo
M88 spiral galaxy in Coma Berenices
M89 elliptical galaxy in Virgo
M90 spiral galaxy in Virgo
M91 spiral galaxy in Coma Berenices
M92 globular cluster in Hercules
M93 open cluster in Puppis
M94 spiral galaxy in Canes Venatici
M95 spiral galaxy in Leo
M96 spiral galaxy in Leo
M97 The Owl Nebula planetary nebula in Ursa Major
M98 spiral galaxy in Coma Berenices
M99 spiral galaxy in Coma Berenices
M100 spiral galaxy in Coma Berenices
M101 The Pinwheel Galaxy spiral galaxy in Ursa Major
M102 Lenticular galaxy (the Spindle Galaxy NGC 5866) in Draco ? Duplication of M101 in Ursa Major ?
M103 open cluster in Casseopeia
M104 The Sombrero Galaxy spiral galaxy in Virgo
M105 elliptical galaxy in Leo
M106 spiral galaxy in Canes Venatici
M107 globular cluster in Ophiuchus
M108 spiral galaxy in Ursa Major
M109 spiral galaxy in Ursa Major
M110 Satellite galaxy of M31 elliptical galaxy in Andromeda
The Pleiades | M 45 |
- RA 3:44, Dec +21:58 (Taurus)
- Type: open cluster / reflection nebulae
- Distance: 400 ly
- aka The Seven Sisters, Subaru
- The Pleiades is easily visible with the naked eye.
- The seven "sisters" are Alcyone, Asterope (a double star), Electra, Maia, Merope, Taygeta and Celaeno; Atlas and Pleione are their "father" and "mother".
- This cluster also includes over 500 dimmer stars spread over an area four times wider than the Moon.
