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Поисковые слова: mercurysurface
English astronomer and mathematician who, at the age of 24, was
the first person to predict the position of a planetary mass beyond
Uranus. But, unfortunately, Adams did not publish
his prediction. Galle
confirmed the existance of Neptune
based on independent calculations done by
Le Verrier.
(4k jpg)
the ratio of the amount of light reflected by an object and the amount
of incident light; a measure of the reflectivity or intrinsic brightness
of an object (a white, perfectly reflecting surface would have an albedo of
1.0; a black perfectly absorbing surface would have an albedo of 0.0).
the point in its orbit where a planet is farthest from the Sun;
when refering to objects orbiting the Earth the term apogee
is used; the term apoapsis is used for orbits around other bodies.
(opposite of perihelion)
Danish astronomer who
assisted Galle with the first observations of
Neptune.
After receiving its predicted position from Le Verrier,
Galle and d'Arrest began searching.
With Galle at the eyepiece and d'Arrest reading the chart, they scanned the
sky and checked that each star seen was actually on the chart. Just a few
minutes after their search began, d'Arrest cried out, "That star is not on
the map!" and earned his place in the history books.
(90k jpg)
asteroids are assigned a serial number when they are discovered. It has no
particular meaning except that asteroid N+1 was discovered after asteroid N.
(see appendix 5)
= 149,597,870 km; the average distance from the
Earth to
the Sun.
1 AU is a long way -- at 100 miles per hour (160 kph) it would take over
100 years to go 1 AU.
the "Northern Lights"; caused by the interaction between the
solar wind,
the Earth's magnetic field and the upper atmosphere. A similar effect
happens in the southern hemisphere
where it is known as the aurora australis.
One of the earliest American astronomers of note;
rose from poverty and overcame a lack of formal education to become
the first director of the Harvard College Observatory where he
studied Saturn
and (with Lassell)
discovered its moon Hyperion.
(a.k.a Tyge Ottesen)
Danish astronomer whose accurate astronomical observations formed
the basis for Johannes Kepler's laws of planetary motion.
(141k jpg;
38k jpg;
more;
The Noble Dane: Images of Tycho Brahe, from the Museum of the History of Science in Oxford)
An inferior planet is said to be "in inferior conjunction" when it is directly between the Earth and the Sun. It is "in superior conjunction" when it is on the opposite side of the Sun from the Earth. A superior planet is "in conjunciton" when it is on the opposite side of the Sun from the Earth. A superior planet obviously cannot have an inferior conjucntion. When the Earth is at inferior conjuction with respect to an observer on a superior planet we say that planet is "in opposition" from Earth's perspective.
. (nice diagram)
Polish astronomer who advanced the heliocentric
theory that the Earth and other planets
revolve around the Sun.
This was highly controversial at the time as
the Ptolemaic view of the universe, which was the
prevailing theory for over 1000 years, was deeply ingrained in the
prevailing philosophy and religion.
(It should be noted, however, that the heliocentic idea was first put forth by
Aristarcus of Samos in the 3rd century BC, a fact known to Copernicus but long
ignored.)
(470k html/gif;
12k gif;
129k jpg;
more)
rotation or orbital motion in a counterclockwise direction when viewed looking down
from above the north pole of the primary (i.e. in the same sense to most satellites);
the opposite of retrograde.
The north pole is the one on the same side of the
ecliptic as the Earth's north pole.
(The word "prograde" is sometimes used to mean "direct" in this sense.)
the eccentricity of an ellipse (planetary orbit) is the ratio
of the distance between the focii and the major axis. Equivalently the eccentricity
is (ra-rp)/(ra+rp) where ra is the apoapsis distance
and rp is the periapsis distance.
a relative quiet volcanic eruption which puts out basaltic lava
that moves at about the speed one walks; the lava is fluid in nature;
the eruptions at the Kilauea volcano on the island of Hawaii are effusive
oval. That the orbits of the planets are ellipses, not circles, was first
discovered by Johannes Kepler based on the
careful observations by Tycho Brahe.
a dramatic volcanic eruption which throws debris high into the
air for hundreds of miles; lava is low in silicate; can be very
dangerous for people near by; an example is Mount St. Helens in 1980
a strand of cool gas suspended over the
photosphere by magnetic fields, which
appears dark as seen against the disk
of the Sun;
a filament on the limb of the Sun seen in
emission against the dark sky is called a
prominence.
American public official, writer, and scientist. Played a major part
in the American Revolution and helped draft the Constitution.
His numerous scientific and practical innovations include the lightning
rod, bifocal spectacles, and a stove.
named for the Greek Earth goddess Gaea, holds that the Earth
as a whole should be
regarded as a living organism and that biological processes stabilize
the environment.
First advanced by British biologist James Lovelock in 1969.
German astronomer who,
with Heinrich Louis d'Arrest,
made the first observation of
Neptune based
on calculations by Le Verrier.
Though Galle was the first to observe Neptune,
its discovery is usually credited to
Adams (who made an
earlier calculation) and Le Verrier.
Jupiter's four largest moons:
Io,
Europa,
Ganymede and
Callisto; discovered independently by
Galileo and Marius.
(Galileo proposed that they be named the Medicean stars, in honor
of his patron Cosimo II de Medici; the present names are due to Marius)
Italian astronomer and physicist. The first to use a telescope to study the
stars. Discoverer of the first moons of an extraterrestrial body (see above).
Galileo was an outspoken supporter of Copernicus's
heliocentric theory. In reaction to Galileo,
the Church declared it heresy to teach that the Earth moved and imprisoned
him. The Church clung to this position for 350 years; Galileo was formally
exonerated in 1992.
(16k gif;
136k jpg)
(See also the Galileo exhibit at Institute and Museum of History of Science, Florence ITALY;
The Galileo Project from Rice and APOD 980913)
King of Great Britain and Ireland (1760-1820). His government's policies fed
American colonial discontent, leading to revolution in 1776.
geosynchronous orbit
a direct, circular,
low inclination orbit in which the satellite's
orbital velocity is matched to the rotational velocity of the planet;
a spacecraft appears to hang motionless above one position of the
planet's surface.
granulation
a pattern of small cells seen on the surface of
the Sun caused by
the convective motions of the hot solar gas.
increase in temperature caused when incoming solar radiation is passed but
outgoing thermal radiation is blocked by the atmosphere (carbon dioxide and water
vapor are the major factors).
Very important on Venus and
Earth but very weak on Mars.
English astronomer who applied Newton's laws of
motion to historical comet data and predicted correctly
the reappearance of the comet
which now bears his name.
(12k jpg; more)
American astronomer whose observations proved that galaxies are
"island universes", not nebulae inside our own galaxy.
His greatest discovery was the linear relationship
between a galaxy's distance and the speed with which it is moving.
The Hubble Space Telescope is named in
his honor. (133k html/gif;
60k gif;
bio material)
Dutch physicist and astronomer who first described the nature of
Saturn's rings (1655) and discovered
its moon Titan;
also pioneered the use of the pendulum in clocks.
(7k jpg;
more)
the inclination of a planet's orbit is
the angle between the plane of its orbit and the
ecliptic;
the inclination of a moon's orbit is
the angle between the plane of its orbit and the plane of its primary's equator.
A Renaissance Catholic court instituted to seek out and prosecute heretics.
inferior planets
the planets Mercury
and Venus are called inferior planets because their
orbits are closer to the Sun
than is Earth's orbit.
(The other planets are called "superior planets.)
a region of charged particles in a planet's upper atmosphere;
the part of the Earth's
atmosphere beginning at an altitude of about
25 miles and extending outward 250 miles or more.
American astrophysicist, probable
discoverer of the dark narrow gap in the outer part
of the A ring of Saturn, and the second director of
Lick Observatory.
Keeler was (probably accidentally) cheated of
his rightful fame when the A ring gap became known as "Encke's Division".
Encke had earlier seen a broad, poor contrast feature in the A-ring
which is quite different
from the sharp, distinct gap that Keeler recorded on the very first night of
observing with the Lick 36-inch refractor.
On the other hand, the gap may have been seen even earlier by Francesco De Vico, William Lassell and the Rev. William R. Dawes.
The history of visual observations of gaps in Saturn's rings is very confusing.
German astronomer and mathematician. Considered a founder of modern
astronomy. Using the positional data carefully
amassed by Tycho Brahe,
Kepler formulated the famous
three laws
of planetary motion.
They comprise a quantitative formulation of
Copernicus's theory that
the planets revolve around the Sun.
(16k jpg;
86k jpg;
more;
yet more)
Dutch-born American astronomer best known for his study of the surface of the
Moon; discovered Miranda
and Nereid,
found an atmosphere on Titan.
(Dr.Kuiper was solidly Americanized; his name is pronounced to rhyme with "viper.")
(a short bio; 22k jpg)
French
(originally Italian, Giuseppe Luigi Lagrangia; born in Turin,
moved to Paris and became a French citizen)
mathematician and astronomer; made a number of contributions to the
study of celestial mechanics.
(5k gif)
Lagrange points
Lagrange showed that three bodies can lie at the apexes of an equilateral
triangle which rotates in its plane.
If one of the bodies is sufficiently massive compared with the other two,
then the triangular configuration is apparently stable.
Bodies at such points are sometimes refered to as Trojans.
The leading apex of the triangle is known as the leading Lagrange
point or L4; the trailing apex is the trailing Lagrange point or L5.
The colinear with the other two bodies are the L1, L2 and L3 unstable equilibrium points which can sometimes be useful places for spacecraft, eg SOHO.
(more and
more)
British astronomer, discovered Neptune's
largest satellite, Triton and (with
Bond) discovered
Saturn's moon
Hyperion.
A successful brewer before turning to astronomy.
(22k jpg;
more)
French mathematician whose prediction of the position of an undiscovered
planet (Neptune)
that caused perturbations in the orbit of
Uranus was the first to be confirmed (by
Galle) though Adams had made
a similar but unpublished prediction some months earlier.