ClipArt ETC

The Astronomy ClipArt gallery offers 89 images of the tools of astronomy as well as numerous stars and constellations that can be seen in the night sky. See also the Telescopes and Binoculars ClipArt gallery.

"Suppose a to be a stationary celestial object, then as the Earth makes her annual revolution around the Sun S, this object at one time will appear among the stars at e, but six months after, when the Earth comes to the opposite point in her orbit, the same object will be seen at c, the space from c to e being the annual parallax of the object a. But the distances of the stars are so great that the diameter of the Earth's orbit, or 190,000,000 of miles make no difference in their apparent places. Were the fixed stars within 19 trillions of miles, their distance could be told by their parallaxes." —Comstock, 1850

Annual Parallax

"Suppose a to be a stationary celestial object, then as the Earth makes her annual revolution around…

"Armillary Sphere, an instrument used in astronomy. In its simplest form, consisting of a ring fixed in the plane of the equator, the armilla is one of the most ancient of astronomical instruments. Slightly developed, it was crossed by another ring fixed in the plane of the meridian." — The Encyclopedia Britannica, 1910

Armilla

"Armillary Sphere, an instrument used in astronomy. In its simplest form, consisting of a ring fixed…

"An arrangement of rings, all circles of a single sphere, intended to show the relative positions of the principal celestial circles."-Whitney, 1902

Armillary Sphere

"An arrangement of rings, all circles of a single sphere, intended to show the relative positions of…

"Sir Francis Drake's Astrolabe; an obsolete astronomical instrument of different forms, used for taking the altitude of the sun or stars, and for the solution of other problems in astronomy. "-Whitney, 1902.

Astrolabe

"Sir Francis Drake's Astrolabe; an obsolete astronomical instrument of different forms, used for taking…

"Originally used for any instrument used for observing stars; afterwards used for an instrument for measurement of altitute; replaced, in modern times, by the quadrant." — Williams, 1889

Astrolabe

"Originally used for any instrument used for observing stars; afterwards used for an instrument for…

A historical astronomical instrument used to predict positions of the Sun, Moon, planets and stars.

Later Astrolabe

A historical astronomical instrument used to predict positions of the Sun, Moon, planets and stars.

A historical astronomical instrument used to predict positions of the Sun, Moon, planets and stars.

Regiomontanus' Astrolabe

A historical astronomical instrument used to predict positions of the Sun, Moon, planets and stars.

Auroras are caused by the passage of electricity through the rare air of the upper regions.

Aurora Borealis

Auroras are caused by the passage of electricity through the rare air of the upper regions.

Inclination of Axis to Orbit and Ecliptic.

Axis

Inclination of Axis to Orbit and Ecliptic.

An improvement upon the jackstaff from Davis, the Arctic navigator.

Backstaff

An improvement upon the jackstaff from Davis, the Arctic navigator.

The Big Dipper is used to find the North Star.

Big Dipper

The Big Dipper is used to find the North Star.

During new and full moon, the earth, moon, and sun are all in the same straight line, but, that during the first and last quarters, they are at right angles. The portions of the earth and moon turned toward the sun are illumined, the shaded portions are in the darkness. To an observer on the earth, the moon, at <em>a</em>, appears new, since the dark part is turned toward the person; at <em>b</em>, however, it must appear full, since the illumined portions are toward the person. At <em>c</em>, and <em>d</em>, the positions of the quarters, only one-half of the illumined half, or one quarter, is seen.

Cause of the Phases of the Moon

During new and full moon, the earth, moon, and sun are all in the same straight line, but, that during…

"Copernicus, or Nicholas Koppernigk, was the founder of modern astronomy. From a school in Thorn Copernicus went to Cracow, where he studied medicine, theology, mathematics, and astronomy. He latterly came to the following conclusions: That the sun was the center of the system; that the earth was a planet like Mars and Venus; and that all the planets revolve round the sun."&mdash;(Charles Leonard-Stuart, 1911)

Globe of Copernicus

"Copernicus, or Nicholas Koppernigk, was the founder of modern astronomy. From a school in Thorn Copernicus…

If the earth were flat, as soon as an object appeared on the horizon we would see the upper and lower parts at the same time; but if it were curved, the top parts would first be seen.

Curvature of the Earth's Surface

If the earth were flat, as soon as an object appeared on the horizon we would see the upper and lower…

The constellation cygnus.

Cygnus

The constellation cygnus.

"If we suppose a spectator placed at G, in the Earth's center, he would see the moon E, among the stars at I, whereas without changing the position of the moon, if that body is seen from A, on the surface of the Earth, it would appear among the stars at K. Now I is the true and K the apparent place of the moon, the space between them, being the Moon's parallax." &mdash;Comstock, 1850

Diurnal Parallax

"If we suppose a spectator placed at G, in the Earth's center, he would see the moon E, among the stars…

The Earth in Space.

Earth

The Earth in Space.

"Now it is the inclination of the Earth's axis, as above described, which causes the lengths of the days and nights to differ at the same place at different seasons of the year, for on reviewing the positions of the globe at A, it will be observed that the line formed by the enlightened and dark hemispheres, does not coincide with the line of the axis and the pole, but that the line formed by the darkness and the light, extends obliquely across the line of the Earth's axis, so that the north pole is in the light while the south is in the dark. In the position A, therefore, an observer at the north pole would see the sun constantly, while another at the south pole would not see it at all. Hence those living in the north temperate zone, at the season of the year when the earth is at A, or in the Summer, would have long days and short nights, in proportion as they approached the polar circle; while those who live in the south temperate zone, at the same time, and when it would be Winter there, would have long nights and short days in the same proportion." &mdash;Comstock, 1850

Earth Axis

"Now it is the inclination of the Earth's axis, as above described, which causes the lengths of the…

"Now it is the inclination of the Earth's axis, as above described, which causes the lengths of the days and nights to differ at the same place at different seasons of the year, for on reviewing the positions of the globe at A, it will be observed that the line formed by the enlightened and dark hemispheres, does not coincide with the line of the axis and the pole, but that the line formed by the darkness and the light, extends obliquely across the line of the Earth's axis, so that the north pole is in the light while the south is in the dark. In the position A, therefore, an observer at the north pole would see the sun constantly, while another at the south pole would not see it at all. Hence those living in the north temperate zone, at the season of the year when the earth is at A, or in the Summer, would have long days and short nights, in proportion as they approached the polar circle; while those who live in the south temperate zone, at the same time, and when it would be Winter there, would have long nights and short days in the same proportion." &mdash;Comstock, 1850

Earth Axis

"Now it is the inclination of the Earth's axis, as above described, which causes the lengths of the…

"The sun is so far away that it would appear at the same angle from Philadelphia, St. Louis, and Denver, and if it were noon at one of these places, it would be noon at the others. Vertical lines at the three places would be parallel. But when it is noon at St. Louis, it is 1 P.M. at Philadelphia and 11 A.M. at Denver." -Dryer, 1901

Earth Curvature

"The sun is so far away that it would appear at the same angle from Philadelphia, St. Louis, and Denver,…

"The Earth, whose diameter is 7,912 miles, is represented by the globe, or sphere. The straight line passing through its center, and about which it turns, is called its axis, and the two extremities of the axis are the poles of the Earth, A being the north pole, and B the south pole. The line C D, crossing the axis, passes quite round the Earth, and divides it into two equal parts. This is called the equinoctial line, or the equator. That part of the Earth situated north of this line, is caled the northern hemisphere, and that part south of it, the southern hemisphere. The small circles E F and G H, surrounding or including the poles, are called the polar circles." &mdash;Comstock, 1850

Earth Divisions

"The Earth, whose diameter is 7,912 miles, is represented by the globe, or sphere. The straight line…

Cause of the Curved Shape of the Earth's Orbit.

Earth Orbit

Cause of the Curved Shape of the Earth's Orbit.

"The earth shown as it would be if its axis were perpendicular to the plane of the orbit." -Wiswell, 1913

Earth's Axis Perpendicular to Plane of Orbit

"The earth shown as it would be if its axis were perpendicular to the plane of the orbit." -Wiswell,…

"A quadrant, or one fourth of a circle. The oblique lines indicate various angles with the base. The heavy line indicates the inclination of the earth's axis as compared with the plane of its orbit, which is represented by the base." -Wiswell, 1913

Inclination of Earth's Axis

"A quadrant, or one fourth of a circle. The oblique lines indicate various angles with the base. The…

"When one is at sea, or standing on the sea-shore, the first part of a ship seen at a distance, is its mast. As the bessel advances, te mast rises higher and higher above the horizon, and finally the hull, and whole ship, become visible. Now, were the Earth's surface an exact plane, no such appearance would take place, for we should then see the hull long before the mast or rigging, because it is much the largest object." -Comstock 1850

Spheroidal Form of the Earth

"When one is at sea, or standing on the sea-shore, the first part of a ship seen at a distance, is its…

"Were the Earth's orbit a perfect circle, and her axis perpendicular to the plane of this orbit, the days would be of a uniform length, and there would be no difference between the clock and the Sun." -Comstock 1850

Suns in the Equator and Ecliptic

"Were the Earth's orbit a perfect circle, and her axis perpendicular to the plane of this orbit, the…

"An Eclipse is an interception or obscuration of the light of the sun, moon, or other heavenly body by the intervention of another and non-luminous heavenly body or by its shadow."&mdash;(Charles Leonard-Stuart, 1911)

Eclipse

"An Eclipse is an interception or obscuration of the light of the sun, moon, or other heavenly body…

Eclipse of the Moon. S=Sun, E=Earth, M=Moon

Eclipse of the Moon

Eclipse of the Moon. S=Sun, E=Earth, M=Moon

Eclipse of the Sun. S=Sun, E=Earth, M=Moon

Eclipse of the Sun

Eclipse of the Sun. S=Sun, E=Earth, M=Moon

Annular eclipse of the Sun. S=Sun, E=Earth, M=Moon

Eclipse of the Sun

Annular eclipse of the Sun. S=Sun, E=Earth, M=Moon

"The elliptical circle being supposed to be the Earth's orbit, with the Sun, S, in one of the foci. Now the spaces, 1, 2, 3, etc., though of different shapes, are of the same dimensions, or contain the same quantity of surface. The Earth, we have already seen, in its journey round the Sun, describes an ellipse, and moves more rapidly in one part of its orbit than in another. But whatever may be its actual velocity, its comparative motion is through equal areas in equal times. Thus its center passes from E to C, and from C to A, in the same period of time, and so of all the other divisions marked in the figure." &mdash;Comstock, 1850

Elliptical Orbit

"The elliptical circle being supposed to be the Earth's orbit, with the Sun, S, in one of the foci.…

"Relative positions of the earth and the sun on March 21 (spring equinox) and September 21 (autumn equinox) as seen from the position occupied by the earth on June 21 (summer solstice). Rays of light and heat meet the earth vertically on the Equator, and the days and nights are everywhere of equal length." -Wiswell, 1913

Spring Equinox and Autumn Equinox

"Relative positions of the earth and the sun on March 21 (spring equinox) and September 21 (autumn equinox)…

A Great Circle is one which would be formed on the earth's surface by a plane passing through the earth's centre, hence dividing it into two equal parts. All great circles, therefore, divide the earth into two hemispheres.

Great Circle

A Great Circle is one which would be formed on the earth's surface by a plane passing through the earth's…

"The Gyroscope is an instrument constructed by M. Foucault to make the rotation of the earth visible. The principle on which it proceeds is this&ndash; that, unless gravity intervene, a rotating body will not alter the direction in which its permanent axis points. In the gyroscope there is a rotating metallic disk, the middle point of whose axis is also the center of gravity of the machine. By this device the action of gravity is eliminated."&mdash;(Charles Leonard-Stuart, 1911)

Gyroscope

"The Gyroscope is an instrument constructed by M. Foucault to make the rotation of the earth visible.…

"Dollond's divided object-glass heliometer of the third type. A is the end of the reflecting telescope, upon which the adapter B is fitted. B carries a wheel (not seen in the figure) formed of a ring racked at the outer edge, and fixed to the brass plate CC, so that the pinion moved by the handle D may turn it into any position. Two plates F, G, with the attached semi-lenses, move in slides fixed to the plate CC, &mdash;simultaneous motion, in contrary directions, being communicated to them by turning the handle E, which drives a concealed pinion that works in the two racks seen in the highest part of the figure." &mdash;The Encyclopedia Britannica, 1903

Heliometer

"Dollond's divided object-glass heliometer of the third type. A is the end of the reflecting telescope,…

"No part of the equatorial mounting is shown in the figure, as it resembles every respect that usual Fraunhofer mounting. An adapted h is fixed on a telescope-tube, made of wood, in Fraunhofer's usual fashion. To this adapter is attached a flat circular flange h. The slides carrying the segments of the divided object-glass are mounted on a plate, which is fitted and ground to rotate smoothly on the flange h. Rotation is communicated by a pinion, turned by the handle c, which works in teeth cut on the edge of the flange h. The counterpoise w balances the head about its axis of rotation. The slides are moved by the screws a and b the divided heads of which serve to measure the separation of the segments. These screws are turned from the eye-end by bevelled wheels and pinions, the latter connected with the handles a', b'." &mdash;The Encyclopedia Britannica, 1903

Heliometer

"No part of the equatorial mounting is shown in the figure, as it resembles every respect that usual…

"The type of instrument which resulted from Russian labors. The brass tube, strengthened at the bearing points by a strong truly-turned collars, rotates in the cast-iron cradle g attached to the declination axis. a is the eye-piece fixed in that axis, b the micrometer for reading both scales." &mdash;The Encyclopedia Britannica, 1903

Heliometer

"The type of instrument which resulted from Russian labors. The brass tube, strengthened at the bearing…

An illustration of a heliostat or a device that tracks the movement of the sun.

Heliostat

An illustration of a heliostat or a device that tracks the movement of the sun.

An instrument used in geography to measure angles of the sun at different times of the day.

Heliotrope

An instrument used in geography to measure angles of the sun at different times of the day.

An instrument which could more readily adapt itself to the swaying of the observer's body in a sea-way, soon displaced in good measure the astrolabe on shipboard. It in several ways modified forms for a long time served mariners as a convenient help in ascertaining the altitude of the celestial bodies. Precisely when it was first introduced is not certain; but the earliest description of it which has been found is that of Werner in 1514.

Jackstaff

An instrument which could more readily adapt itself to the swaying of the observer's body in a sea-way,…

"Let this figure represent the Earth, N being the north pole, S the south pole, and E W the equator. The lines 10, 20, 30, and so on, are the parallels of latitude, and the lines N a S, N b S, etc., are meridian lines, or those of longitude." &mdash;Comstock, 1850

Longitude

"Let this figure represent the Earth, N being the north pole, S the south pole, and E W the equator.…

The Meridian of any given place is that half of the meridian circle which passes through that place and both poles. A meridian of any place reaches from that place to both poles, and therefore is equal to one-half of a great circle, and, with the meridian directly opposite to it, forms a great circle called a meridian circle. There are as many meridians as there are places on the equator or on any parallel. Parallels are small circles which pass around the earth parallel to the equator.

Meridians and Parallels

The Meridian of any given place is that half of the meridian circle which passes through that place…

Meridians of longitude are the imaginary vertical lines that run around the Earth. These lines divide Earth into time zones, and measure 0-90 east and west.

Meridians of Longitude

Meridians of longitude are the imaginary vertical lines that run around the Earth. These lines divide…

Telescopic view of the moon, 1901.

Moon

Telescopic view of the moon, 1901.

Moon.

Moon

Moon.

Cartoon crescent moon with clouds behind.

Moon

Cartoon crescent moon with clouds behind.

The satellite of the earth, and classed as one of the secondary planets. It revolves around the earth in an almost circular orbit once each sidereal month, at a mean distance of 238,818 miles.

Moon

The satellite of the earth, and classed as one of the secondary planets. It revolves around the earth…

"When the Moon falls into the shadow of the Earth, the rays of the Sun are intercepted, or hid from her, and she then becomes eclipsed. when the Earth's shadow covers a part of her face, as seen by us, she suffers only a partial eclipse, one part of her disc being obscured, while the other part reflects the Sun's light. But when her whole surface is obscured by the Earth's shadow, she then suffers a total eclipse, and of a duration proportionate to the distance she passes through the Earth's shadow." &mdash;Comstock, 1850

Moon Eclipse

"When the Moon falls into the shadow of the Earth, the rays of the Sun are intercepted, or hid from…

The phases of the moon.

Moon Phases

The phases of the moon.

"Let S be the Sun, E the Earth, and A, B, C, D, F, the Moon in different parts of her orbit. Now when the Moon changes, or is in conjunction with the Sun, as at A, her dark side is turned towards the Earth, and she is invisible, as represented at a. The Sun always shines on one half of the Moon, in every direction, as represented at A and B, on the inner circle; but we at the Earth can see only such portions of the enlightened part as are turned towards us. After her change, when she has moved from A to B, a small part of her illuminated side comes in sight, and she appears horned, as at b, and is then called the new Moon. When she arrives at C, severel days afterwards, one half of her disc is visible, and she appears as at c, her appearance being the same in both circles. At this point she is said to be in her first quarter, because she has passed through a quarter of her orbit, and is 90 degrees from the place of her conjunction with the Sun. At D, she shows us still more of her enlightened side, and is then said to appear gibbous as at d. When she comes to F, her whole enlightened side is turned towards the Earth, and she appears in all the spendor of a full Moon." &mdash;Comstock, 1850

Moon Phases

"Let S be the Sun, E the Earth, and A, B, C, D, F, the Moon in different parts of her orbit. Now when…

Finding the north star with the Big Dipper and Cassiopeia.

North Star

Finding the north star with the Big Dipper and Cassiopeia.

"Two stars in the Big Dipper opposite the handle indicate the direction toward the North Star, which, though not very bright, is the first very noticeable star in line." -Wiswell, 1913

Finding the North Star

"Two stars in the Big Dipper opposite the handle indicate the direction toward the North Star, which,…

The shape of the earth is that of a round ball or sphere slightly flattened at two opposite sides. Such a body is termed a <em>spheroid</em>. There are two kinds of spheroids-<em>oblate</em> and <em>prolate</em>; the former as the shape of an orange, the latter that of a lemon. The straight line that runs through the centre of a sphere or spheroid and terminates at the circumference is called the <em>diameter</em>. If the sphere rotates-that is, moves around like a top-the diameter on which it turns is called the <em>axis</em>. In the oblate spheroid the axis is the shorter diameter; in the prolate spheroid the axis is the longer diameter.

Oblate and Prolate Spheroid

The shape of the earth is that of a round ball or sphere slightly flattened at two opposite sides. Such…

"The observatory. This view is from the field, looking north. On the left is seen the winding Schuylkill, and the rolling country beyond; and on the right, the distant hills of Montgomery county."—Lossing, 1851

Observatory

"The observatory. This view is from the field, looking north. On the left is seen the winding Schuylkill,…

"Observatory at Delhi."

Ancient Indian observatory

"Observatory at Delhi."

"The orbits of Mars, Earth, Venus, and Mercury." &mdash; Encyclopedia Britanica, 1893

Orbits

"The orbits of Mars, Earth, Venus, and Mercury." — Encyclopedia Britanica, 1893

"Relative distance of the Planets. Having now given a short account of each planet composing the solar system, the relative situation of their several orbits, with the exception of those of the Asteroids, are shown in this figure. The orbits are marked by the signs of each planet, of which the first, or that nearest the Sun, is Mercury, the next Venus, the third the Earth, the fourth Mars then come those of the Asteroids, then Jupiter, then Saturn and lastly Herschel." &mdash;Comstock, 1850

Planet Distance

"Relative distance of the Planets. Having now given a short account of each planet composing the solar…

"Circular Motion of the Planets." &mdash;Comstock, 1850

Planet Motion

"Circular Motion of the Planets." —Comstock, 1850

"Elliptical Orbits.&mdash;It has been supposed that the Sun's attraction, which constitutes the Earth's gravity, was at all times equal, or that the Earth was at an equal distance from the Sun, in all parts of its orbit." &mdash;Comstock, 1850

Planet Motion

"Elliptical Orbits.—It has been supposed that the Sun's attraction, which constitutes the Earth's…

"The motion of Saturn, Jupiter, and Mars with respect to Earth." &mdash; Encyclopedia Britanica, 1893

Planet Rotations

"The motion of Saturn, Jupiter, and Mars with respect to Earth." — Encyclopedia Britanica, 1893