- bar
- A unit of pressure, equal to the sea-level pressure of Earth's
atmosphere; 1 bar is equivalent to 0.987 atmosphere or 10,000 newtons
per square meter.
Barnard, Edward Emerson 1857-1923
- American astronomer. Barnard discovered Jupiter's satellite Amalthea and Barnard's star, the second-nearest star system to the Sun.
basalt
- A general term for dark-colored, igneous rocks composed of minerals
that are relatively rich in iron and magnesium.
blackbody temperature
- The temperature of an object if it is reradiating all the thermal
energy that has been added to it; if an object is not a blackbody radiator,
it will not reradiate all the excess heat and the leftover will go toward
increasing its temperature.
black hole
- An object whose gravity is so strong that the escape velocity exceeds
the speed of light.
Bode, Johann 1747-1826
- German astronomer. He is known for the bogus "Bode's Law" which attempts
to explain the sizes of the planetary orbits.
bolide
- An exploding meteorite.
Bond, William Cranch 1789-1859
- American astronomer. One of the earliest American astronomers of note,
Bond rose from poverty and overcame a lack of formal education to become
the first director of the Harvard College Observatory. At the observatory, he studied Saturn and (with William Lassell) discovered its moon Hyperion.
bow shock
- The outermost part of a planetary
magnetosphere; the place where the
supersonic flow of the solar wind is slowed
to subsonic speed by the planetary magnetic field.
Brahe, Tycho 1546-1601
- Danish astronomer. His accurate astronomical observations formed
the basis for Johannes Kepler's laws of
planetary motion.
breccia
- A course-grained rock, composed of angular, broken rock fragments
held together by a mineral cement or a fine-grained matrix.
butte
- A conspicuous, isolated, flattop hill with steep slopes.
