What’s Up this Week: February 19 – February 25, 2007

Article written: 20 Feb , 2007
Updated: 31 Jul , 2007
by

NGC 2170. Credit: Doc G., Dick Goddard and Adam Block/NOAO/AURA/NSFMonday, February 19 – Today is the birthday of Nicolas Copernicus. Born in 1473, he was the creator of the modern solar system model which illustrated the retrograde motion of the outer planets. Considering this was well over 530 years ago, and in a rather “unenlightened” time, his revolutionary thinking about what we now consider natural is astounding.

While we still have dark skies on our side, let’s head for a handful of difficult nebulae in a region just west of Gamma Monocerotis.

For binoculars, check out the region around Gamma, it is rich in stars and very colorful! You are looking at the very outer edge of the Orion spiral arm of our galaxy. For small scopes, have a look at Gamma itself – it’s a triple system that we’ll be back to study. For larger scopes? It’s Herschel hunting time…

NGC 2183 and NGC 2185 will be the first you encounter as you move west of Gamma. Although they are faint, just remember they are nothing more than a cloud of dust illuminated by faint stars on the edge of the galactic realm. The stars that formed inside provided the light source for these wispy objects and at their edges lies intergalactic space.

To the southwest is the weaker NGC 2182, which will appear as nothing more than a faint star with an even fainter halo about it, with NGC 2170 more strongly represented in an otherwise difficult field. While the views of these objects might seem vaguely disappointing, you must remember that not everything is as bright and colorful as seen in a photograph. Just knowing that you are looking at the collapse of a giant molecular cloud that’s 2400 light-years away is pretty impressive!

Tuesday, February 20 – Today in 1962, John Glenn became the first American to orbit the Earth three times while aboard Friendship 7.

Today in history also celebrates the Mir space station launch in 1986. Mir (Russian for “peace”) was home to both cosmonauts and astronauts as it housed 28 long duration crews during its 15 years of service. To date it is one of the longest running space stations and a triumph for mankind. Spaseba!

Tonight the slender first crescent of the Moon makes its presence known on the western horizon. Before it sets, take a moment to look at it with binoculars. The beginnings of Mare Crisium will show to the northeast quadrant, but look just a bit further south for the dark, irregular blotch of Mare Undarum – the Sea of Waves. On its southern edge, and to lunar east, look for the small Mare Smythii – the “Sea of Sir William Henry Smyth.” Further south of this pair and at the northern edge of Fecunditatis is Mare Spumans – the “Foaming Sea.” All three of these are elevated lakes of aluminous basalt belonging to the Crisium basin.

For telescope users, wait until the Moon has set and return to Beta Monocerotis and head about a fingerwidth northeast for an open cluster challenge – NGC 2250. This vague collection of stars presents itself to the average telescope as about 10 or so members that form no real asterism and makes one wonder if it is indeed a cluster. So odd is this one, that a lot of star charts don’t even list it!

Wednesday, February 21 – Tonight the Moon begins its westward journey after sunset in a position much easier to observe. The lunar feature we are looking for is at the north-northeast of the lunar limb and its view is often dependent on libration. What are we seeking? “The Sea of Alexander von Humboldt”…

Mare Humboldtianum is seen in this picture as fully revealed, yet sometimes it can be hidden from view because it is an extreme feature. Spanning 273 kilometers, the basin in which it is contained extends for an additional 600 kilometers and continues around to the far side of the Moon. The mountain ranges which accompany this basin can sometimes be glimpsed under perfect lighting conditions, but ordinarily are just seen as a lighter area. The mare was formed by lava flow into the impact basin, yet more recent strikes have scarred Humboldtianum. Look for a splash of ejecta from crater Hayn further north, and the huge, 200 kilometer strike of crater Bel’kovich on Humboldtianum’s northeast shore.

When the Moon begins to wester, let’s head for Beta Monocerotis and hop about 3 fingerwidths east for an 8.9 magnitude open cluster that can be spotted with binoculars and is well resolved with a small telescope – NGC 2302. This very young stellar cluster resides at the outer edge of the Orion spiral arm. While binoculars will see a handful of stars in a small V-shaped pattern, telescope users should be able to resolve 40 or so fainter members.

Thursday, February 22 – Today in 1966, Soviet space mission Kosmos 110 was launched. Its crew was canine, Veterok (Little Wind) Ugolyok (Little Piece of Coal); both history making dogs. The flight lasted 22 days and held the record for living creatures in orbit until 1974<\b> – when Skylab 2 carried its three-man crew for 28 days.

With tonight’s Moon in a much higher position to observe, let’s begin with an investigation of Mare Fecunditatis – the Sea of Fertility.

Stretching 1463 kilometers in diameter, the combined area of this mare is equal in size to the Great Sandy Desert in Australia – and almost as vacant in interior features. It is home to glasses, pyroxenes, feldspars, oxides, olivines, troilite and metals in its lunar soil, which is called regolith. Studies show the basaltic flow inside of the Fecunditatis basin perhaps occurred all at once, making its chemical composition different from other maria. The lower titanium content means it is between 3.1 and 3.6 billion years old!

The western edge of Fecunditatis is home to features we share terrestrially – grabens. These down-dropped areas of landscape between parallel fault lines occur where the crust is stretched to the breaking point. On Earth, these happen along tectonic plates, but on the Moon they are found around basins. The forces created by lava flow increase the weight inside the basin, causing a tension along the border which eventually fault and cause these areas. Look closely along the western shore of Fecunditatis where you will see many such features.
Now, let’s take a walk across the Sea of Fertility and see how many lunar challenge features you can identify!

(1) Taruntius, (2) Secchi, (3) Messier and Messier A, (4) Lubbock, (5) Guttenberg, (6) Montes Pyrenees, (7) Goclenius, (8) Magelhaens, (9) Columbo, (10) Webb, (11) Langrenus, (12) Lohse, (13) Lame, (14) Vendelinus, (15) the Luna 16 landing site

Friday, February 23 – In 1987, Ian Shelton made an astonishing visual discovery – SN 1987a. This was the brightest supernova in 383 years.

Since the stars of our study constellation of Monoceros are quite dim when the Moon begins to interfere, why not spend a few days really taking a look at the Moon’s surface and familiarizing yourself with its many features? Tonight would be a great time for us to explore “The Sea of Nectar.”

At around 1000 meters deep, Mare Nectaris covers an area of the Moon equal to that of the Great Sandhills in Saskatchewan, Canada. Like all maria, it is part of a gigantic basin that is filled with lava, and evidence of grabens exists along its western basin edge. While Nectaris’ basaltic flows appear darker than those in most maria, it is one of the older formations on the Moon and as the terminator progress, you’ll be able to see where ejecta belonging to Tycho crosses its surface.

For now? Let’s have a closer look at the mare itself and its surrounding craters… Enjoy these many features which are also lunar challenges – and we’ll be back to study each later in the year!

(1) Isidorus, (2) Madler, (3) Theophilus, (4) Cyrillus, (5) Catharina, (6) Dorsum Beaumont, (7) Beaumont, (8) Fracastorius, (9) Rupes Altai, (10) Piccolomini, (11) Rosse, (12) Santbech, (13) Pyrenees Mountains, (14) Guttenberg, (15) Capella

Saturday, February 24 – Tonight let your imagination sweep you away as we go mountain climbing – on the Moon! Tonight all of Mare Serenitatis will be revealed and along its northwestern shore lie some of the most beautiful mountain ranges you’ll ever view – The Caucasus to the north and the Apennines to the south.

Like it’s earthly counterpart, the Caucasus Mountain range stretches almost 550 kilometers and some of its peaks reach upwards to 6 kilometers – a summit as high as Mount Elbrus!

Slightly smaller than its terrestrial namesake, the lunar Apennine mountain range extends some 600 kilometers with peaks rising as high as 5 kilometers. Be sure to look for Mons Hadley, one of the tallest peaks that you will see at the northern end of this chain. It rises above the surface to a height of 4.6 kilometers, making that single mountain about the size of asteroid Toutatis.

Today in 1968, during a radar search survey, the first pulsar was discovered by Jocelyn Bell. The co-directors of the project, Antony Hewish and Martin Ryle, matched these observations to a model of a rotating neutron star, winning them the 1974 Physics Nobel Prize and proving a theory of J. Robert Oppenheimer from 30 years earlier.

Would you like to get a look at a region of the sky that contains a pulsar? Then wait until the Moon has well westered and look for guidestar Alpha Monocerotis to the south and bright Procyon to its north. By using the distance between these two stars as the base of an imaginary triangle, you’ll find pulsar PSR 0820+02 at the apex of your triangle pointed east. In the picture below, I wonder which “star” it is?

Sunday, February 25 – Tonight your lunar assignments are relatively easy. We will begin by identifying “The Sea of Vapors.”

Look for Mare Vaporum on the southwest shore of Mare Serenitatis. Formed from newer lava flow inside an old crater, this lunar sea is edged to its north by the mighty Apennine Mountains. On its northeastern edge, look for the now washed-out Haemus Mountains. Can you see where lava flow has reached them? This lava has come from different time periods and the slightly different colorations are easy to spot even with binoculars.

Further south and edged by the terminator is Sinus Medii – “The Bay in the Middle.” With an area about the size of both Massachusetts and Connecticut, this lunar feature is the mid-point of the visible lunar surface. In 1930, experiments were underway to test this region for surface temperature – a project begun by Lord Rosse in 1868. Surprisingly enough, results of the two studies were very close, and during full daylight temperatures in Sinus Medii can reach the boiling point as evidenced by Surveyors 4 and 6 – which landed near its center.

Now take a hop north of Mare Vaporum for a look at “The Rotten Swamp” – Palus Putredinus. More pleasingly known as the “Marsh of Decay,” this nearly level surface of lava flow is also home to a mission – the hard-landing of Lunik 2. On September 13, 1959 astronomers in Europe reported seeing the black dot of the crashing probe. The event lasted for nearly 300 seconds and spread over an area of 40 kilometers


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