November 11 – Philae Lands on Comet 67P/C-G

2015Four years years ago today ESA successfully landed (or bounced) their Philae lander on comet 67P/Churyumov–Gerasimenko, having been launched from the Rosetta spacecraft some hours earlier.

The Philae Lander viewed from Rosetta, a few hours into the flight to Comet 67P. (Image credit: ESA)

Rosetta had been launched from French Guiana in 2004, and a soft landing on the target comet was going to be the highlight of the trip. One of Philae’s thrusters was known to be faulty before separation from Rosetta, but there wasn’t much that could be done about it so they went ahead anyway. Earlier I said that Philae “bounced” onto 67P, which I think needs a little more information. There isn’t much gravity on a comet; so if you bounce, you’ll bounce high. Philae bounced just over half a mile (1 km) before coming down again. It was a whisker away from not coming back down and carrying on into space.

Fortunately, despite landing at a jaunty angle and in an unfavourable location, Philae was able to deploy some of the experiments on board, and was capable of several periods of communication with ground controllers via Rosetta.

November 11 – Discovery of Asteroid 253 Mathilde (1885)

253 Mathilde is a dark main belt asteroid of about 50km wide, discovered on this day in 1885, and named after the wife of Maurice Loewy, the director of the Paris Observatory .

Asteroid 253 Mathilde as seen from the NEAR Shoemaker probe (image credit: NASA)

Mathilde is a rare beast among early asteroid discoveries, as we actually have close-up photographs of her, taken by the passing NASA mission, NEAR Shoemaker, which was on its way to rendezvous with the near-Earth asteroid, 433 Eros. This made Mathilde only the third asteroid to be photographed from close range. Unfortunately the immensely fast speed of the spacecraft, combined with the immensely slow rotation of the asteroid, means we only have pictures of one side.

November 11 – Launch of Gemini XII (1966)

The Gemini XII spacecraft, with help from a Titan-II launch vehicle, lifted off from Cape Canaveral “Launch Complex 19” (LC-19) on the evening of November 11th, 1966.

The two-man crew were Jim Lovell and Edwin “Buzz” Aldrin.  The name Buzz, apparently, came from the inability of one of his sisters to pronounce the word “brother”. Their mission lasted for 3 days, 22 hours and 34 minutes, allowing the craft to make 59 orbits of the Earth, and giving Aldrin time to pop outside for three EVAs (one a day).

The crew of Gemini XII onboard USS Wasp. (Image credit: NASA)

This was the final manned Gemini flight; the craft can currently be seen at the Alder Planetarium, Chicago.  It was also the final flight to launch from LC-19.


November 11 – Discovery of Asteroid 179 Klytaemnestra (1877).

Today in 1877, Canadian-American astronomer James Craig Watson discovered his final asteroid, the large main belt member 179 Klytaemnestra. This stony S-type asteroid is about 75 km across, and has a light curve giving it a rotation period of 11.13 hours, varying in by magnitude by 0.55.

A light curve is pretty much exactly what you might think. It’s a curve showing variations in brightness of the target object. Variations in the light intensity recorded can be used to infer how long it is taking the asteroid to rotate. The same method can be used to predict the shape of the asteroid.

The Murder of Agamemnon, by Pierre-Narcisse Guérin. Louvre, Paris.
The Murder of Agamemnon, by Pierre-Narcisse Guérin. Louvre, Paris.

As was fairly normal in the early days of asteroid naming, this one is a mythological Greek reference. The Spartan princess Clytemnestra was the wife of Agamemnon, king of Mycenae, and became infamous by killing both her husband and the Trojan princess Cassandra, whom he had chosen as a reward for his part in the victory over Troy.


1875 I love this name. Vesto Melvin Slipher, the American astronomer responsible for providing the first proof of universal expansion, was born today in Mulberry, Indianna. Slipper lived to the grand old age of 93, and spent his entire working life at the Lowell Observatory in Flagstaff, Arizona. His brother, Earl, was also an astronomer, specialising in the study of Mars.

I have no idea where his parents got the name Vesto from, but if you conjugate the Italian verb vestirsi (to wear or get dressed) you come across it pretty quickly (1st person present indicative – I dress).


1982Launch of the fifth NASA shuttle mission, STS-5, using shuttle Columbia. The four-man crew was the first to undertake an “operational” shuttle mission, by deploying two commercial satellites.