Asteroid 4 Vesta, the brightest asteroid visible from Earth, and one of the larger, at about 530 km wide, was first spotted on March 29th1807 by Heinrich Wilhelm Olbers. It is named after the Roman goddess of the home and hearth, who always had a fire burning in her temples as a reminder. Vesta is the second most massive asteroid (after Ceres, which had been discovered the year before) but is only the third biggest by volume (Pallas, also discovered by Olbers, five years earlier, takes second place).
Vesta was visited recently (July 2011) by NASA’s Dawnspacecraft, which took the above image (actually it’s a collection of many images stuck together). Observations show it to be an oblate spheroid, but irregularities in shape and the low mass mean it doesn’t qualify as a dwarf planet under the current naming rules.
2002 – Launch of the Reuvan Ramaty High Energy Solar Spectroscopic Imager (HESSI, or RHESSI) to study solar flares.
Asteroid 2 Pallas was discovered on March 28th, 1802, by Heinrich Wilhelm Olbers, physician by day, astronomer by night, and the man after whom the Olbers Paradox (the one about why the sky is dark if the universe is infinite) is named. He discovered Pallas while trying to locate Ceres, which had been discovered by Giuseppe Piazzi the previous year.
Pallas is at the larger end of the minor planet scale, being about 550 km wide on average (it isn’t round). It is a B-type body, one of the less common asteroid types. B’s are similar to the much more populous C-types, but with a greater albedo, and different a absorption lines in their spectra.
Pallas is named after the Greek goddess Athena (she was often referred to as Pallas Athena/Athene), goddess of wisdom, daughter of Zeus and Metis, owner of the Aegis, and friend of owls. Her Roman equivalent was Minerva.
On March 28, 1900, asteroid 454 Mathesis was discovered from Heidelberg by Friedrich Karl Arnold Schwassmann. Mathesis is a main belt asteroid of about 81.6 km diameter, having, apparently, a rather pleasing year of 1555.5 days, and an equally pleasing albedo of 0.0555. I wonder if that’s why it was named after mathematics?
Schwassmann was discoverer of 22 asteroids, but this was his first without the assistance of the even more prolific discoverer, Max Wolf .
Messier 93, NGC2447, was discovered on this day in 1781. This binocular object is an open cluster about 3,600 light years away, spanning approximately 10 light years, in the constellation Puppis. It was the last open cluster to be discovered by Charles Messier himself. M93 contains a good collection of blue giant stars, as well as quite a few red giants, possibly in clusters of their own. It’s hard to say how many stars a cluster contains, mainly because they get in each other’s way when you try to count them. This one has at least 80 identifiable members, but may well turn out to be several hundred strong.
1892 – Asteroid 326 Tamara, discovered March 19 1892 by Johann Palisa. It is a C-type asteroid of about 93 km wide in the main belt, named after Tamar the Great, Queen of Georgia.
1892 – Asteroid 332 Siri was also discovered on March 19th 1892, but by Max Wolf at Heidelberg. It’s a fairly small object, about 40km wide. The origin of the name is not known, and I haven’t been able to find any likely candidates. Part of the problem, of course, is that, as with the aforementioned Tamara, and the next on this page, Isara, the name could have been altered to fit some perceived idea of what an asteroid’s name should sound like.
1893 – Asteroid 364 Isara was discovered by Auguste Charlois. It is a member of the large Flora family of S-type asteroids, which may be parents of the L chondrite meteorites. The Isère river, from which this asteroid derives its name, flows from the Alps and joins the Rhone near Valence in southern France.
1919 – Karl Wilhelm Reinmuth discovers asteroid 911 Agamemnon, a “Greek camp” Jupiter Trojan of approximately 83 km radius (making it probably the second biggest).
Asteroid 136 Austria was discovered on March 18th 1874 by Austrian astronomer Johann Palisa. Because it was his first discovery, he got a bit patriotic when it came to choosing a name, although he did stick to the convention of Latinising the name, rather than use Österreich or Oesterreich.
136 Austria is in the main belt, is about 40 km wide, and may or may not be an M-type. A study by Clarke et al published in the Abstracts of the 25th Lunar and Planetary Science Conference suggest it may be more of an S-type.
Caroline Herschel was the sister of the more famous William. She was born this day in 1750 in the German town of Hannover, but moved to London in 1772 to join her elder brother, after which she became a lean, mean, comet hunting machine, finding eight of them in eleven years. She also discovered an impressive clutch of deep sky objects, mostly open clusters, and was awarded the Gold Medal by the Royal Astronomical Society. After William’s death she moved back to Hannover, where she died in 1848.
Herschel wasn’t the tallest astronomer in history, and at 4 foot 3 inches she might possibly be the shortest person ever to find a comet (I need to check up on that). Her diminutive stature was caused by a bout of typhus at the age of ten. Her father sounds less than doting, and is reported to have told his fifth child that, because of the deformity caused by this illness, she would never marry. Nice man.
Captain Alan LaVern Bean, USN, was born on this day in 1932 in Wheeler, Texas (100 miles east of Amarillo).
Bean clocked up 69 days in space aboard Apollo 12 (he was the 4th person to undertake the highly improbable act of walking on the Moon) and Skylab mission SL-3. Following his retirement from NASA, Bean turned his attention to painting. As far as I know, he is the only artist to incorporate genuine Moon dust into his work.
1895 – Asteroid 400 Ducrosa discovered by Auguste Charlois. It was named after Joseph Ducros, a technician at the Nice Observatory.
Captain Eugene Andrew Cernan USN, born this day in 1934 in Chicago, Illinois. A veteran of Gemini 9A and Apollo 10, Cernan was also last man back to the lunar module Challenger on the Apollo 17 mission, and therefore currently holds the honour of being the “last man on the Moon” (which is also the title of his memoir). He is also a member of one of the most exclusive clubs ever– the extremely small collection (three) of people who have been to the Moon twice. And as if that weren’t enough, he holds the lunar land speed record (11.2 mph).
Gene Cernan died in Houston, Texas, on January 16th, 2017.
1879 – Birth of Albert Einstein in Württemburg. Where do you start? Probably by saying “Google him”. Einstein’s main claims to fame are, of course, Special Relativity (1905), a theory describing the relationship between space and time, and General Relativity (1915), which concerns gravitation. He also, in 1916, predicted gravitational waves, almost exactly 100 years before they were discovered
1885 – Asteroid 247 Eukrate discovered by Robert Luther..
1904 – Asteroid 524 Fidelio discovered by Max Wolf.
Uranus(named after a primal Greek god of the sky, the son and husband of Gaia, and father of the Titans) was discovered on this day in 1781 by William Herschel. It’s the 7th furthest planet from the Sun, orbiting at approximately 2.8 billion km, and is often classed as an ice giant with Neptune, as well as being a gas giant. Uranus is the third largest planet by radius (about 25,000km, or 4 Earths), but only the fourth largest by mass (roughly 14 times as massive as Earth).
As with the other giant planets, Uranus has a plentiful supply of moons (27 at the last count). The largest five are Oberon, Titania, Umbriel, Miranda and Ariel. None of the Uranian moons are particularly large, with the biggest, Titania, being less than half the size of our Moon. The naming convention for Uranian moons is that they are all characters from either the plays of Shakespeare or The Rape of the Lock by Alexander Pope. Most of the Shakespearean names were taken from The Tempest and A Midsummer Night’s Dream, but I suppose they started running out after a while, so nowadays anything goes.
Uranus also has a ring system. The rings, of which 13 are known, are dark, narrow, and probably quite young (less than 600 million years old). They are thought to be the remnants of one or more shattered moons. The rings can be clustered together in three groups: nine main rings, two dusty ones, and two outer rings, including the brightest, the ε (epsilon) ring.
The atmosphere of Uranus (by which I mean the outer layers) usually presents a blank face to watching humans, and the Voyager photographs painted a picture of a serene world. But recently (August 2014) a collection of enormous bright spots have been observed, showing that giant storms can sometimes flare up on the planet.
1980 – CALYPSO, one of the smaller of Saturn’s fifty-three named moons, was discovered on this day in 1980. It’s an irregularly-shaped Trojan, trailing 60 degrees behind the larger moon Tethys at the L5 Lagrangian point, something I’m still planning on writing a blog about (another Trojan, Telesto, occupies a position 60 degrees ahead of Tethys, called the L4). Calypso is named after a daughter of the Titans Oceanus and Tethys.
1969 – APOLLO 9, under the command of James McDivitt, splashed down in the North Atlantic on March 13th 1969, after just over 10 days in orbit.
1855 – Birth of Percival Lowell, proponent of Martian canals, and founder of the Lowell Observatory, one of the oldest in the United States.
Yuri Alekseyevich Gagarin was born on March 9th, 1934, in the village of Klushino, near Ghatsk, in the western USSR. Ghatsk is a small town of about 30,000 people, and is now, unsurprisingly, called Gagarin. The family home is now a museum to the first human in space (the feat was achieved on April 12, 1961, and was Gagarin’s only spaceflight). His parents, incidentally, both worked on a collective farm. It just doesn’t get any more Soviet than that, does it?
Gagarin was a heavily decorated guy, achieving the rare honour of Hero of the Soviet Union, which he shares with the likes of Lenin, Leonid Brezhnev, and (slightly more unusually) President Nasser of Egypt. Surely though, his most prized possession must have been the Gold Medal of the British Interplanetary Society (BIS).
1882 – Main belt asteroid 223 Rosa discovered by Johann Palisa. Now then, here’s something we don’t see every day: 223 Rosa is classified as both a C-typeand a P-type asteroid, meaning it probably contains carbonaceous material (C) and water ice (P). The “P” in P-type stands for Pseudo-M, as they belong to a group that has many of the same properties as M-type asteroids, but a lower albedo, which stopped them slotting into the M-type bracket. Rosa was the thirty-second of Palisa’s 122 asteroid discoveries. The thinking behind the name remains a mystery.
1974 – British satellite Miranda launched to test three-axis gyro systems.