Messier 101, also known as the Pinwheel Galaxy (NGC 5457) in Ursa Major, was discovered on March 27, 1781, by Pierre Méchain. It is more than 20 million light years distant, contains around 1 trillion stars, and measures approximately 170,000 light years across (probably quite similar to the Milky Way, although our galaxy is hard to measure from the inside).
M101 has its own group of galaxies (called the M101 Group, obviously), and is one of a collection of groups of galaxies (including our own Local Group) that make up the Virgo Supercluster, a vast conglomeration of more than 100 groups of galaxies.
1886 – Spiral galaxy NGC 2981, in the constellation of Leo, was discovered by Samuel Oppenheim (or possibly Johann Palisa – there is a little uncertainty).
1886 – Barred Spiral galaxy NGC 2926 and spiral galaxy NGC 2944 (both in the constellation Leo Minor) were discovered by Johann Palisa. These two are listed separately from the above NGC 2981 because they are definitely Palisa’s.
1906 – Discovery of asteroid 594 Mirielle by Max Wolf at Heidelberg. It was named after a poem by the French poet Frédéric Mistral. In the poem, written in the Occitan language, Mirèio is a farmer’s daughter who runs away from home to escape her father’s poor choice of suitors for her.
1964 – Launch of Kosmos 27 on a planned trip to study the hostile Venusian atmosphere (when it would probably have been known as Zond 3MV-1 No 3). Unfortunately, an upper stage malfunction resulted in a mission duration of approximately one day, and a fiery death in Earth’s atmosphere.
1968 – Death of Yuri Gagarin, hero of the Soviet Union, aged 34.
Explorer 3was launched on March 26th 1958 from Cape Canaveral, using a Juno I four stage launcher, the same rocket that had been used to launch (successfully) Explorer 1 and (less than successfully) Explorer 2.
Explorer 3 looked almost exactly like Explorer 1, hence the non-committal title of the above photograph, and had the same task, to explore the Earth’s radiation belts. Those whip-like things sticking out from the body are transmitting antennae, kept extended by the rotation of the satellite.
Asteroid 561 Ingweldediscovered by Max Wolf in 1905. The prevailing view seems to be that Ingwelde was named after the opera by Max von Schillings. I’m inclined to agree, as the opera had been doing the rounds in the years leading up to 1905. Following its premiere in Karlsruhe (1894) it had been revived in Munich in 1896, directed by no less a person than Richard Strauss (albeit for only three performances).
Titan, Saturn’s largest moon, and the second largest moon in the Solar System (behind Ganymede, which is only ever so slightly bigger), was discovered on March 25th 1655 by the Dutch astronomer Christiaan Huygens. As the first moon to be discovered around Saturn there was no immediate pressure on Huygens to find an impressive name for it, so he settled for Luna Saturni (Saturn’s moon). It wasn’t until Cassinidiscovered a further four Saturnian moons that a naming system became an issue, and even then the solution wasn’t particularly imaginative (“Saturn IV” to start off with, then “Saturn VI” after a couple more were found). It was JohnHerschell, son of the more famous William, who came up with the name Titan, as well as the names of the other six saturnian moons known at the time.
Titan, as you can see from the picture below, is shy, and doesn’t like to show us a great deal of surface detail. It is the only moon in the Solar System with a substantial atmosphere, so dense in fact that the surface pressure is about half as great again as on Earth. It is also suspected of having the potential to support microbial life, making it a very tempting place for Earthlings to visit.
In the hierarchy of Saturnian moons, Titan is right at the top of the pile. It has a mass of 1.34 x 1023 kg (that’s about twice the mass of our own lightweight moon) which makes it far and away the biggest, accounting for 96% of the combined mass of all Saturn’s satellites.
1928 – Jim Lovell (commander of Apollo 13)born today in Cleveland, Ohio. Captain James Lovell, USN, is a veteran of four space flights (he was the first man to achieve the feat) totalling 29 days: Gemini 7, Gemini 12, Apollo 8, and Apollo 13. He is also the only person to fly to the Moon twice without landing on it.
On March 24 1860 Karl Theodor Robert Luther discovered the C-type asteroid 58 Concordia from the Düsseldorf-Bilk Observatory. As you may remember (I mention it every so often) Luther discovered 24 asteroids in all. This one was named after the Roman goddess of marital harmony and understanding. The name was chosen by Karl Christian Bruhns, the recently appointed professor of astronomy at the University of Leipzig.
Concordia is a main belt asteroid, 90-odd km wide, orbiting at between 2.5 and 2.8 AU, and taking 4.44 years to orbit the Sun. It is a member of the Nemsis family, a medium-sized asteroid family with about 250 known members, predominantly C-types.
1781 – Messier 105 (NGC 3379). If you think back a couple of days you might remember me mentioning a group of galaxies in Leo containing M95 and M96, both of which were discovered on March 20th 1781. M105 is also in the group, and it was discovered on March 24th 1781, also by Messier’s assistant Pierre Méchain, who was on a roll. Unlike the other two, this one is an elliptical galaxy, and is known to have a supermassive black hole at its centre.
M105 is the brightest elliptical galaxy in this particular group. It is an E1 type, and is approximately 38 million light years away from Earth. The “E” rating for galaxies is based on their elongation, where “E0” is fairly round, while “E7” is extremely stretchy. E1 galaxies are only slightly elongated.
Messier 94, also known as NGC4736, was discovered today in 1781 by Pierre Méchain. It is a spiral galaxy in the constellation Canes Venatici, and is about 16 million light years (4.91 megaparsecs) away from us.
M94 has its own grouping of galaxies within the Virgo Supercluster, called (unsurprisingly) the M94 group . The group has about 20 members.
Asteroid 327 Columbia was discovered by Auguste Charlois on March 22nd, 1892. It is in the main belt, has an absolute magnitude of 10.1, and is of unknown spectral type.
Asteroid 327 was named after Christopher Columbus, the Genes explorer who helped kick-start the Spanish colonisation of the Americas. Any mental image you might have of Columbus’ appearance is from a portrait made after his death. There are no known paintings of Columbus dating from his lifetime. So I won’t be including one here.