This Month in the History of Astronomy - March
- Mar 4, 1904 - George Antonovich Gamow, a foundational
figure in the development of nuclear astrophysics, particularly as
it applied to the stars' source of energy (in the late 1920's and
1930's), the origin of the elements, and, later, to big bang
cosmologies.
The latter he developed in the post-WWII period, though the 1953
theoretical paper mentioning the possibility of a photon remnant
(see: cosmic microwave background) went largely unnoticed until
it was actually discovered serendipitously a dozen years later.
Gamow was one of only a few scientists to flee Stalin's pre-WWII
Soviet Union (rather than Nazi Germany) for the West, in 1933,
feeling that his work and security were threatened by the
ideological emphasis on correct Marxist-Leninist thinking.
His Ph.D. student Vera Rubin went on to fame in the fields of galaxy
rotation and dark matter.
- Mar 5, 1512 - Gerardus Mercator, famed mapmaker.
- Mar 6, 1787 - Joseph Fraunhofer, pioneer German
spectroscopist, namesake of the prominent absorption lines
in the sun's spectrum.
- Mar 7, 1792 - John Herschel, only child of William (the
discoverer of Uranus), first to thoroughly survey the southern
hemisphere's sky, and the discoverer of photographic fixer (sodium
thiosulfate). Herschel was president of the Royal Astronomical Society,
and is said to have also invented the terms "photography" (1839) and
"snapshot" (1860), and normalized the use of "positive" and "negative"
in the field of photography.
- Mar 7, 1837 - Henry Draper, who made the first photograph
of a stellar spectrum and compiled a catalog of stars still in use
today (known by their HD numbers).
- Mar 9, 1564 - David Fabricius, discoverer of the first
variable star (Mira, or Omicron Ceti).
- Mar 11, 1811 - Urbain Leverrier, who predicted the
existence of Neptune, based on its perturbation of the orbit of
Uranus, which lead to its quick discovery ~1° away from where
he had calculated it should be (1846). He was director of the Paris
Observatory from 1854 to 1870, and again from 1873 to 1877.
Leverrier had originally started out in chemistry, under the famed
Gay-Lussac, but when he applied for a position at the Ecole
Polytechnique in that field he was offered one in astronomy
instead. He started out in celestial mechanics with a study
of the stability of the solar system (1839), going out 200,000
years into the future. Due to large uncertainties then in the
masses of the planets his conclusions were limited, though it
did give him some idea of the range over which the planets'
orbital elements vary with time.
AFter working on comets' orbits for a few years he turned his
attention to the problem of Uranus's orbit, which led to the
discovery of Neptune.
He would later attack the problem of Mercury's orbit, something
he'd first worked on in 1843, which is not a perfectly closed
ellipse. The point of perihelion advances at a very tiny rate,
so one could say the ellipse slowly rotates over time. Following
his success with Nepture, this led Leverrier to predict the
existence of a hypothetical planet, "Vulcan", with an orbit
inside Mercury's (1859). This, of course, was never found. The
gravity of the existing planets could account for all but 0.77%
of the orbit's rotation, the remaining 43 arc-seconds per century
remaining a mystery for fifty years: it would take Einstein's
General Theory of Relativity to correctly account for the advance
in the perihelion of Mercury, owing to the slight curvature of
spacetime so close to the sun.
- Mar 12, 1835 - Simon Newcomb: preeminent American post-Civil
War astronomer; Director of the Nautical Almanac Office and Professor
of Mathematics and Astronomy in the U.S. Navy, at the Naval Observatory,
and at Johns Hopkins. He was a founding member and the first president
of the American Astronomical Society (1899-1905).
His numerical constants for calculating ephemerides (the precise positions
on the sky of celestial objects as a function of time) remained the
international standard until their refinement during the Space Age.
Newcomb discovered the slowing rotation rate of the earth, to the tune
of about two milliseconds per day per century, by carefully analyzing the
times of past and historical eclipses. The deceleration is the result of
lunar tidal interactions, where the earth effectively "pushes" the moon
away into a larger orbit, at the rate of about a dozen feet per century,
costing earth rotational energy, which the moon gains as orbital energy.
The observation was so convincing that Charles Darwin's son was able to
first work out the actual mathematics of the interaction, knowing in
advance what the correct answer should be.
(Since the moon's higher orbit is slower, this is an example of how
gravitational systems exhibit what a thermodynamicist would call a
negative heat capacity, meaning things get cooler/slower when
energy is put into the system, an important consideration in the
dynamics of star clusters, galaxies, and clusters of galaxies.)
Newcomb also collaborated with physicist Albert Michelson in making
more accurate measurements of the speed of light, and estimated the
elasticity of the earth, finding it to be slightly more rigid than
steel.
At the time of the construction of the first large telescopes and
observatories, at the end of the nineteenth and the beginning of
the twentieth centuries, roughly 1890-WWI, probably half the
practicing astronomers in the US were former students or research
assistants of Newcomb.
In the 1990's, astronomer Bradley Schaefer compiled evidence that
Newcomb was the model or prototype, of a sort, used by Sir Arthur
Conan Doyle for the character Moriarity in the Sherlock Holmes
mysteries -- a mind of the first order, and thus a worthy adversary
for Holmes.
Newcomb is probably one of only a few professional astronomers buried
at Arlington National Cemetery.
Choice quote:
There are tens of thousands of men
who could be successful in all the ordinary walks of life, hundreds
who could wield empires, thousands who could gain wealth, for one
who could take up this astronomical problem with any hope of success.
The men who have done it are therefore in intellect the select few of
the human race, an aristocracy ranking above all others in the scale
of being.
- Mar 13, 1855 - Percival Lowell, wealthy Bostonian who
established his own observatory outside Flagstaff and jumped on the
Mars "canals" bandwagon started by Schiaparelli (see next entry).
- Mar 14, 1835 - Giovanni Sciaparelli, Italian astronomer at
the Brera Observatory in Milan for forty years (1860-1900). Very early
on he was the discoverer of the asteroid Herperia.
Following observations of the Comet of 1862, Sciaparelli was to
compile solid observational evidence on comets and meteors to show
that the latter are on highly elliptical and nearly parabolic orbits
about the Sun just like the former, and that therefore meteor showers
must be the remnants of disintegrated comets (1866), confirming a
hypothesis that had been around for a long time.
In 1877 the observatory acquired a far superior telescope and
Sciaparelli turned his attention to the planets. He incorrectly
determined that both Mercury and Venus were tidally locked in
their rotation rates, so as to always keep one side facing the
Sun (like the moon always shows the same side to the earth).
Sciaparelli is best remembered now for his detailed mapping of Mars
at oppositions from 1879-90 using admitedly imprecise but perhaps
suitable terminology which when translated led to the fanciful
belief of there being 'canals' (as well as 'seas' and 'continents')
on the planet for some forty or fifty years, especially in the U.S.,
Great Britain, and France -- though these did lead to the founding
of the Lowell Observatory in Flagstaff, AZ, and much science fiction
literature, like The Martian Chronicles and War of the Worlds.
- Mar 14, 1879 - Albert Einstein, developer of a theory of
gravity in terms of spacetime curvature dependent on the energy
density. 1921 Physics Nobel Prize for work done 15 years earlier
on the photoelectric effect, the basis of modern solid state light
detectors. (photo at right from 1916)
- Mar 15, 1713 - Nicolas Lacaille, whose measurements
confirmed the Earth's equatorial bulge, due to its rotation; namer
of fourteen southern constellations.
- Mar 18, 1914 - Yakov Zel'dovich, Soviet astrophysicist and
cosmologist, notable for his work on the development of anisotropy
and structure in the universe. Zeldovich started out researching the
mechanism of oxidation of nitrogen, and the propagation of shock waves
and flame fronts in explosions, which led to his involvement with
early uranium fission theory, chain reactions, and the role slow
neutrons play. His work in nuclear and particle physics in the 1950's
included early work on the conserved vector current
(CVC) model for the weak interaction; when subsequently developed more
fully by Richard Feynmann and Murray Gell-Mann a Nobel Prize resulted
(1969). This direction led Zeldovich into the field of big bang
cosmological theory and the development of "Zeldovich pancakes" --
flattened structures in the very early universe which would later become
super-clusters of galaxies (roughly). This work motivated astronomers to
make much better determinations of the helium abundance in the oldest,
first generation stars, such as are found in some globular clusters and
the Milky Way's halo stellar population. Zeldovich was also an advisory
contributor to the early Soviet space program.
- Mar 21, 1927 - Halton C. ("Chip") Arp, iconoclastic American
astronomer who was one of the first two astronomy Ph.D.'s to come out
of Cal Tech after the 200" telescope went into operation (1949) and the
astronomers of the Mount Wilson and Palomar Observatories "came down off
the mountain" and became faculty members with classes and students.
(Allan Sandage was the other.)
[ Short biography ]
[ 1975 Amer. Inst. of Physics Interview ]
[ Arp's chapter
in the 2006 book Against the Tide ]
- Mar 22, 1799 - Friedrich Argelander, compiler of star
catalogues who was the first to make a detailed study of variable
stars, and who created the first international astronomical
organization. Argelander also made an early determination of
the direction in which the Sun was moving relative to the other
stars. For many years a star Argelander studied on a list by
Groombridge turned out to have the highest proper motion of any
star known, though "Argelander's Star" is now only third, behind
Barnard's star and Kapteyn's star.
- Mar 24, 1835 - Josef Stefan, Austrian physicist who first
came up with the relationship between the amount of radiation emitted
by a body (E) and its temperature (T), the former scaling as the
fourth power of the latter (1879). Stefan's former student Ludwig
Boltzmann put the relationship on a sound theoretical footing five
years later using thermodynamic principles and the kinetic theory
of James Clerk Maxwell (better known for Maxwell's Equations of
electromagnetism), and also showed that Stefan's law only held for
perfect absorbers of light (which are also perfect emitters), now
known as blackbodies. Thus, the equation widely used by astrophysicists
ever since, E = σ·T4, is today called the
Stefan-Boltzmann Law, and σ is Stefan's constant. With this
advance, Stefan was the first to be able to measure the Sun's
surface temperature as being 6,000°C from the total amount
of energy it emitted.
- Mar 24, 1893 - Walter Baade, first to resolve the Andromeda
galaxy's companions into individual stars and developer of the concept
of stellar populations in galaxies.
- Mar 26, 1834 - Hermann Wilhelm Vogel, photochemist and the
discoverer (in 1873) of the dye sensitization of photographic emulsions.
This makes them sensitive to wavelengths other than their natural
ultraviolet, violet, and blue light sensitivities. "This made photography
much more useful to science, allowed a more satisfactory rendering of
colored subjects into black-and-white, and brought actual color
photography into the realm of the practical." (wikipedia)
By adding various aniline dyes to emulsions Vogel found several that
added sensitivity to various parts of the spectrum, which corresponded
closely with the wavelengths of light the dyes by themselves absorbed.
Vogel was himself an accomplished photographer and taught the later famed
Alfred Stieglitz between 1882 and 1886.
- Mar 27, 1927 - George Abell, who catalogued 2712 clusters
of galaxies off the newly completed sky survey (1958) and determined
the relative numbers of galaxies with various intrinsic brightnesses
(aka the galaxy luminosity function), as part of what would become
the most famous and widely used Ph.D. project in modern astronomical
history.
He not only systematically visually scanned all 900+ fields of the
survey but also made many of the plates with the Palomar 48" Schmidt
telescope/camera, joining the project as a grad student after it was
about a third completed. He worked for 5-6 years on an extended catalog
which came out in 1987 and covers the southern hemisphere; it has nearly
4,000 clusters of galaxies.
Educated at Cal Tech, where he took freshman chemistry from two-time
Nobel Prize winnere Linus Pauling, mathematical physics as a junior
from Carl Anderson, as well as astronomy from Alfred Joy, and Jesse
Greenstein as a senior, Abell was the first Ph.D. student of Donald
Osterbrock. He worked at the Griffith Observatory as a lecturer during
his grad student days (after being a guide there as an undergrad), and
spent his professional career at UCLA, where he was astronomy department
chair from 1968 to 1975.
With Peter Goldreich, also at UCLA, he worked out that planetary
nebulae -- a name with an historical origin having nothing to do
with planets -- originated from red giant stars. The central star
of such objects is the core of the previous red giant, while the
surrounding nebula represents the star's outer layers, expelled
during a phase of pulsational instability and then ionized by the
hot stellar remnant, which will eventually cool to a white dwarf.
Abell wrote a popular 101 level textbook, "Exploration of the Universe"
(the first person to use color illustrations), helped found the
Committee on Scientific Investigation of Claims of the Paranormal,
was president of the Astronomical Society of the Pacific (1969-71),
and was scheduled to take over as editor of the Astronomical
Journal at the time of his death by heart attack in 1983.
- Mar 28, 1749 - Pierre Laplace, mathematician who invented
the metric system and the nebular hypothesis for the origin of the
solar system.
- Mar 30, 1879 - Bernhard Schmidt, Estonian optician and
lens-maker who came up with the telescope design that now bears his
name. This uses a spherical primary mirror, which is much easier and
cheaper to make than a parabolic surface, combined with a specially
shaped thin lens at the center of the mirror's curvature, known as
a 'corrector plate', to remove spherical aberration over a large
area at the focus.
Such designs lend themselves to having a very fast (short) focal ratio
and were often built as Schmidt cameras used only for wide-field survey
photography at the prime focus, such as the 48" used for the Palomar
Observatory Sky Survey in the immediate post-WW II era.
Many smaller consumer telescopes have a small convex secondary mirror
attached to the inside of the corrector plate, in what is known as a
Schmidt-Cassegrain configuration, which makes for a compact, lightweight
design with a somewhat slower (longer) focal ratio.
- Mar, 1693 (exact day unknown) - James Bradley, crack
astrometrist who discovered the aberration of starlight (1725–1728)
and the nutation of the Earth (1728–1748). Bradley was the third
ever Astronomer Royal, starting in 1742, succeeding Edmond Halley.
His discovery of the aberration of starlight was actually made while
attempting to be the first to detect a stellar parallax, and it led
both to an improved value for the speed of light and the realization
that the stars were much further away than previously thought.
He waited through one full cycle of the nodes of the moon (18.6 years)
to publish his discovery of the nutation of the Earth, to check that
it was correct.
Discoveries and other firsts
- Mar 1, 1982 - The Soviet Venera 13 sends back the first
color photos of Venus from the surface. The spacecraft miraculously
functioned for a little more than two hours before succumbing to
the 850°F surface temperature. (Venera 14 followed w/more
photos 4 days later.)
- Mar 2, 2021 - NASA’s Perseverance rover on Mars, just
twelve Martian days after landing, makes the first ever measurement
of the speed of sound in the Martian atmosphere, using the SuperCam
laser on a rock ~10 feet away. In spite of the atmosphere there
being only ~1% as thick as earth's atmosphere, the speed is a
little over 2/3rds as fast as it is on earth: 790 ft/sec versus
our 1125.
- Mar 4, 1979 - Jupiter's ring, by Voyager 1, which was
at its closest distance to Jupiter on the 5th; volcanic activity
was discovered on Io on the 8th.
- Mar 5, 1223 b.c. - The date of the first documented total
solar eclipse, recorded on a clay tablet found in the ruins of Ugarit
(Syria). The oldest record from China, on an "oracle bone" made by the
Shang people, is only six years younger. It would be 792 years before
the oldest verifiable European record, of the Aug 3, 431 b.c., annular
eclipse, was made by the Greek historian Thucydides.
- Mar 6-14, 1986 - First comet flybys, VEGA 1 and Giotto
(360 mi.) at Halley's.
- Mar 6, 2015 - The Dawn spacecraft first enters orbit around
the largest asteroid, Ceres (see Jan 1, 1801).
At a minimum altitude of only 385 km, Dawn is closer to the surface of
Ceres than the International Space Station is to earth. Dawn was launched
in 2007, went into orbit around the asteroid Vesta in July, 2011, and
then left it 14 months later for the 2½ year trip to Ceres. After
being lowered to an orbit with a minimum altitude of only 200 km for
Ceres' perihelion passage in April, 2018, Dawn ran out of fuel as
expected at the end of Oct, 2018, and will remain silently in orbit
for at least a few decades.
- Mar 7, 1794 - William Wilkins, an architect, lighthouse builder,
and amateur astronomer, observes a bright spot in a dark part of a nearly
first quarter moon for some five minutes, making for one of the enduring
mysteries in the field of lunar transient phenomena (LTP). The "star in
the moon" was also reported to have been seen by an unnamed servant of
royalty "who is curious for a person in his situation, and fond of
looking at the stars, had some time before seen something extraordinary
in the moon". The situation was complicated by there having been an
occultation of the bright star Aldebaran only an hour earlier, but the
time of Wilkins' observation is not subject to much doubt since he'd
originally gone out to see if he could spot Mercury before it set in
west.
- Mar 7, 1970 - The first total solar eclipse broadcast in
color TV, by CBS. The eclipse path cut across far southern Mexico,
the Gulf of Mexico, and parts of the extreme SE Atlantic U.S. coast
(Florida to N. Carolina), to the Maritimes of eastern Canada.
- Mar 7, 1973 - The discovery by Czech astronomer Luboš
Kohoutek at the Hamburg Observatory in Germany of one of the four
comets found by (and named after) him. C/1973 E1 was discovered almost
ten months before its Dec 28th perihelion, at the 16th magnitude, and
at quite a large distance from the sun (4½ AU), and on such a
near-parabolic orbit that it was presumed to be a fresh, new comet
from the Oort Cloud making its first trip into the inner solar system
-- and a perihelion distance of only 0.14 AU. As such it was initially
predicted to reach extreme brightness levels around and shortly after
perihelion and was billed as the "comet of the century".
Even though it reached an easy naked eye visual magnitude of -3 and
sported a tail up to 25° long, Comet Kohoutek didn't live up to
the extremely lofty expectations and became synonyomous with an
over-hyped dud. It is now thought to be a very long period
Edgeworth/Kuiper Belt object (period on the order of 100,000 years),
and may have partially disintegrated just before perihelion, which
was likely it's first time this far into the solar system.
Comet Kohoutek was the first comet observed from earth orbit, by both
the Skylab 4 and Soyuz 13 space stations, allowing observations far
into the ultraviolet (Lyman-α) for the first time. This third
Skylab mission (but still numbered #4) was rescheduled so as to
make the best use of the opportunity, and the hydrogen halo, likely
from dissociated water vapor, surrounding the comet was found to be
3x the diameter of the sun. This was done using a slightly modified
far UV camera that had originally flown on Apollo 16.
See also: Skylab launch
- Mar 10 (±1-2 days), 1977 - Uranus's rings are discovered
during NASA Kuiper Airborne Observatory occultation observations. [photo
at right: James Webb Space Telescope, 2023, using two infrared wavelengths
centered on 1.4 and 3.0 microns; 11 of the planet's 13 dusty rings can be
seen.]
- Mar 11, 1960 - Pioneer V becomes the first spacecraft
launched into an orbit around the sun, the first "artificial planet".
The last communication with it took place ~100 days later when it
was at a distance of over 22 million miles. It continues to orbit
the sun inside earth's orbit, with a period of 312 days.
The wording of the above is important, because the previous year
(Jan 2) the Soviet Union's Luna 1 spacecraft had a malfunction in
its upper rocket stage burn time being too long (caused by problems
in the ground-based control system), missed the moon by more than
three times its radius (it was supposed to impact the surface), and
then became the first spacecraft to go into a heliocentric orbit.
It was the first object to exceed earth's escape velocity and
directly observe the solar wind in situ, and it currently orbits
between earth and Mars. Luna 2 would successfully complete the
mission some eight months later.
- Mar 13, 1781 - Uranus itself, by William Herschel. The
planet had previously been mapped as the star 34 Tauri by Flamsteed
some 65-70 years (~¾ths of an orbital period) earlier, just one
of numerous observations -- perhaps as early as 128 B.C. -- of it
which were found post-discovery, making it easy for a rather good
orbit to be quickly determined, even though the actual field of
celestial mechanics wouldn't be invented for another two decades
or so.
The discovery launched Herschel into fame and fortune. He became the
King's Astronomer and his side-business building telescopes for other
people flourished. This vastly increased funding led to him getting
two new and better telescopes that he started using to survey the
space between the stars. Within a few years he had his first
list of a thousand nebulae and other non-stellar object. Several
years later, a second list with a thousand more was completed. The
work would be continued by his wife, Caroline, and son, John,
eventually becoming the General Catalogue some five decades later.
More than a century after the discovery of Uranus, Henry Draper
would produce the New General Catalogue; objects today are still
known by their NGC numbers.
- Mar 13, 1989 - A solar storm interferes with communications
and the power grid in Quebec, blacking out 6 million Canadians for
nine hours.
- Mar 13-14, 1986 - The European Space Agengy's (ESA) Giotto
craft flies by Halley's Comet, the first spacecraft ever to image a
comet's nucleus up close. It was also the ESA's first deep-space
mission.
Built by British Aerospace, the designers and engineers were almost
certain Giotto would not survive the mission due to high speed (68
km/s = 152,000 miles per hour) impacts with dust particles, even
though it had a "Whipple Shield", one that was very similar to what
would be flown on the NASA Stardust mission launched a dozen years
later. Giotto did lose one camera after closest approach (370
miles) and its spin was knocked off kilter for about ½ hour
by a particle estimated to be between 0.1 and 1 gram, though it
was able to recover.
- Mar 16, 1926 - Robert Goddard launches first liquid-fuel
rocket, which reaches an altitude of 12 meters (the moon is only 20
million times farther).
- Mar 16, 1966 - First orbital docking, Gemini 8.
- Mar 17, 1958 - First solar-powered spacecraft launched
(Vanguard 1).
- Mar 18, 1899 - William Henry Pickering, the younger brother
of Harvard College Observatory director Edward Pickering, discovers
Saturn's largest (132 mi diameter) outer, irregular moon Phoebe (Saturn
IX). It was the first moon to be discovered photographically, the plates
having been taken seven months earlier by DeLisle Stewart in Peru.
The trajectory of NASA's Cassini spacecraft to Saturn and its time of
arrival were specifically chosen to permit a close flyby of Phoebe in
2004, making it the best studied of the irregular moons of the outer
planets.
In 2009, the Spitzer infrared space telescope discovered a large ring
interior to Phoebe's orbit, first hypothesized in the 1970s by Steven
Soter, presumably originating from material eroded off its surface by
micrometeoritic impacts; the ring debris is thought to migrate inward
and collect on the next inner moon, Iapetus, causing it to have a dark
leading hemisphere (since it's tidally locked so as to always have one
side facing Saturn).
- Mar 18, 1965 - First "space walk", Alexei Leonov.
- Mar 18, 2011 - NASA's MESSENGER spacecraft enters orbit
around the planet Mercury, the first ever to do so. Launched 6½
years earlier, it took a flyby of earth, two of Venus, and three of
Mercury to reduce its speed sufficiently using a minimum of fuel.
MESSENGER orbited Mercury once every twelve hours. It was able to
photograph the entire surface (nearly 100,000 images), allowing it
to discover water ice at the planet's north pole inside craters
shadowed from ever receiving any sunlight, where carbon-containing
organic compounds were also found; such water had been suspected
from earth-based radar studies. MESSENGER discoverd Mercury's
magnetic field is offset far to the north of the planet's center,
and with a laser altimeter instrument it was able to make a 3-D
map of the planet. Having run out of propellant to keep its orbit
from decaying, MESSENGER crashed to the planet about four years
after arriving there.
- Mar 23, 1840 - First photo of the Moon, a daguerreotype,
was taken.
- Mar 25, 1655 - Titan, Saturn's largest satellite, discovered
by Christian Huygens. C.H. discovered Saturn's ring system the same
year. (See the 14th of next month.)
- Mar 25, 1951 - 21 cm wavelength radiation from atomic
hydrogen in the Milky Way was first detected, by Harold Ewen, working
on his Ph.D. thesis under Edward Purcell at Harvard. The detection
equipment consisted of a horn, rather than an antenna or dish, which
was stuck out the window of the fourth floor lab. Because the horn
was titlted up at ~45°, at one point it collected so much rain
water and sent it down the waveguide into the building that the lab
suffered minor flooding. Dutch astronomer Hendrik Van de Hulst had
first worked out the prospects for detecting the 21cm line (and other
spectral lines in the radio part of the spectrum) seven years earlier,
and by a strange coincidence was visiting Harvard for the Spring
semester of 1951, so the Dutch effort to detect the line, which had
been in progress for several years, followed with success also in
only seven weeks. 1420.4 MHz studies of the hyperfine HI line
continue to form the basis of a big part of modern radio astronomy.
- Mar 28, 1802 - Heinrich W. Olbers discovers the 2nd asteroid,
Pallas, in the constellation Virgo while making observations of the
position of Ceres, which had only been discovered fifteen months
earlier [see Jan 1st].
- Mar 28, 1807 - Vesta, the brightest asteroid, discovered
by Olbers in Virgo. This was the fourth such object found.
- Mar 28, 1949 - British astrophysicist Fred Hoyle first
uses the phrase "big bang", during the popular BBC radio show Third
Programme, as a term of derision, because he disliked exploding
universes.
- Mar 29, 1974 - First flyby of Mercury, by Mariner 10.
- Mar 30-31, 1986 - Halley's Comet ejects a million tons
of fine particles which emitted radiation from organic molecules.
©2002-2023, Chris Wetherill. All rights reserved. Display here does
NOT constitute or imply permission to copy, republish, or redistribute
my work in any manner for any purpose without prior written permission.
[ Back to February ||
On to April ]
[ To: History Directory ||
Main VISNS page ]