What’s Up this Week: January 22 – January 28, 2007

Article written: 22 Jan , 2007
Updated: 31 Jul , 2007
by

McNeilMonday, January 22 – Be out early tonight to catch the slender crescent Moon as we begin our journey designed to acquaint you with specific craters. Around midway on the terminator, you will spot a conspicuous old crater called Langrenus. Named for Belgian engineer and mathematician Michel Florent van Langren, this handsome old crater stretches out over 132 kilometers in diameter. Look closely at its walls, they rise above the surface by 1981 meters and the deepest part of the floor drops down below 4937 meters – deeper than Mount Cotacachi in Ecuador is tall. Is the Sun rising over its brilliant east wall? If so, look closely and see if you can spot Langrenus’ central mountain peak rising up 1950 meters. Then get out your skis, because that’s as high as the base elevation in Jackson Hole, Wyoming!

Tonight we’re going in search of another Herschel 400 object, despite the Moon. Wait until Orion has well risen and our lunar companion has ducked west. Our mark will triangulate with Xi and Nu and point back in the direction of Betelgeuse. It’s name? Collinder 83…

It is believed that it may have been observed by Hodierna before 1654, but its discovery is credited to William Herschel in 1784 and cataloged by him as H VIII.24. It hangs out in space some 3600 light-years away and most catalogs refer to it as NGC 2169. At a rough magnitude of 6, it is very well suited to even smaller binoculars. Although diffuse nebulosity accompanies this 50 million year old cluster, even a small telescope should be able to resolve out its 30 or so stellar members. But no matter which optics you chose to look at this cluster with, one bright asterism will stand out – the number ’37.’ Enjoy and write down your observations!

Tuesday, January 23 – During the early hours, take the time to view the northeast quadrant of the Moon and identify the emerging Mare Crisium. The “Sea of Crisesâ€? stretches out about 400 by 500 kilometers – an area about the size of the state of Washington. Mare Crisium is not only unique for its lack of connection with any other maria, but it is home to a gravitational anomaly called a mascon. This “mass concentrationâ€? might possibly be the fragments of the asteroid or comet whose impact with the lunar surface created the basin buried beneath the lava flow. The mascon creates an area of high gravity and causes changes in orbits of lunar probes. This excess gravity has even been known to cause low orbiting lunar satellites to either crash land or be flung out into space!

Tonight I ask you to once again take out your telescopes and explore a region with me that we have previously visited – M78. It is for the very sake of amateur astronomy that I ask you to do this… And here is why.

On January 23, 2004 a young backyard astronomer named Jay McNeil was checking out his new 3″ telescope by taking some long exposures of M78. Little did Jay know at the time, but he was about to make a huge discovery! When he later developed his photographs, there was a nebulous patch there that had no designation. When he reported his findings to the professionals, they confirmed it had no official designation and that Jay had stumbled onto something quite unique! It is believed that Jay’s discovery was a variable accretion disc around a newborn star – IRAS 05436-0007. Little is known about the region, but it seems that it had been caught in a photo once in the past but never studied. Even the Digital Sky Surveys had no record of it!

Although Jay’s discovery might not be bright enough tonight to be seen just south of M78, it is a variable and circumstance plays a big role in any observation. Before you think that being a backyard astronomer has no real importance to science – remember a teenager in a Kentucky backyard with a 3” telescope…

Catching what professionals had missed!

Wednesday, January 24 – Today is the birthday of American solar astronomer Harold Babcock. Born in 1882, Babcock proposed in 1961 that the sunspot cycle was a result of the Sun’s differential rotation and magnetic field. Would you like to have a look at the Sun? Although solar observing is best done with a proper filter, it is perfectly safe to use the “projection method.â€?

First off, NEVER look at the Sun directly with the eye or with any unfiltered optical device, such as binoculars or a telescope! We’re not joking when we say this will blind you. Exposed film, mylar, and smoked glass are also UNSAFE. But don’t be afraid, because we’re here to tell you how you, too, can enjoy the Sun. A safe way to observe sunspots is to “projectâ€? an image of the Sun through a telescope or binoculars onto a screen. This can be a simple as cardboard, a paper plate, a wall or whatever you have handy. If you’re using a telescope, be sure that finderscope is securely covered. If you’d like to try binoculars, just keep the cover on one of the two tubes. By using the shadow method, you will see a bright circle of light on your makeshift screen. This is the solar disc. Adjust the focus by moving the distance of the screen from your scope or binoculars until it is about the size of a small plate. If the image is blurry, use your manual focus until the edges of the disc become sharp. Even though it might take a little practice, you’ll soon become proficient at this method and you’ll be able to see a surprising amount of detail in and around sunspot areas. Happy and SAFE viewing to you all!

Today in 1986, the United States Voyager 2 was the first spacecraft to fly by Uranus, providing us on Earth some of the most outstanding photographs and information on the planet to date. After 10,382 days of successful operation, Voyager 2 still continues on towards the stars carrying a phonograph record of “The Sounds of Earth.â€?

Thursday, January 25 – Today is the birthday of Joseph Louis Lagrange. Born in 1736, this French mathematician made important contributions to the field of celestial mechanics.

Tonight let’s journey to the lunar surface to have our first look of the year at crater Posidonius. Located on the north-eastern shore of Mare Serenitatis, this huge, old, mountain-walled plain in considered a class V crater. Spanning 84 by 98 kilometers, you can plainly see where Posidonius is shallow – dropping only 2590 meters below the surface. Tonight it will resemble a bright, elliptical pancake on the surface, but we’ll return to study it later in the year.

For now, let us return to Orion and have a much closer look at the blue/white giant – Beta Orionis.

The seventh brightest star in the sky is known by the name Rigel. Very little is known about its true distance from Earth, but it is widely accepted that it is around 900 light-years away. This white-hot star has a surface temperature of about 12,000 degrees Kelvin and is thousands of times more powerful than our own Sun. If it were as close to us as Sirius, it would shine with a light as bright as 20% of the full Moon! But look closely at the brilliant star… Intermediate sized telescopes under good conditions will find a 6.7 magnitude blue companion. Although it is not always an easy double star, you’ll find it on the list for many challenges. But, chances are, we’ll never see the C star that accompanies the B!

Even if you just view Rigel with your eyes tonight, marvel at this young and powerful star. When the light you see left this star, the Crusades had began…the Vikings were sailing to discover America…the Mayan Empire was beginning to crumble…paper was a new concept…and the very numbers we use today were just beginning to catch on!

Friday, January 26 – Today in 1962, the US space program launched a lunar probe named Ranger 3. Its mission was to image the Moon right up until impact, land a seismometer, study gamma rays and report on surface reflectivity of radar… But, it didn’t happen. Two days after launch, the ill-fated Ranger 3 was on a runaway course towards the lunar surface when it received a reverse command and lost contact with Earth. As a result, it overshot its mark by 36,800 kilometers and still remains in heliocentric orbit.

Tonight all of Mare Serenitatis and Mare Tranquillitatis will be revealed and it is fitting that we should take a look at both the “Sereneâ€? and “Tranquilâ€? seas. Formed some 38,000,000 years ago, these two areas of the Moon have been home to most of mankind’s lunar exploration. Somewhere scattered on the basalt landscape on the western edge of Tranquillitatis, perhaps a few remains of the Ranger 6 mission lay scattered about, forming a small impact crater of their own. Its eyes were open, but blinded by a malfunction…forever seeing nothing. To the southwest edge lie the remnants of the successful Ranger 8 mission which sent back 7137 glorious images during the last 23 minutes of its life. Nearby, the intact Surveyor 5 withstood all odds and made space history by managing to perform an alpha particle spectrogram of the soil while withstanding temperatures considerably greater than the boiling point. Not only this, but it also took over 18,000 pictures!

Look closely at the maps and you will find this is also home to the Apollo 11, Apollo 16 and Apollo 17 landers, as well as Luna 21. It is an area that you can deeply appreciate for its historical significance…and an Astronomical League Lunar Challenge!

Saturday, January 27 – On this day in 1967, tragedy struck at Pad 34. During a training exercise atop a Saturn 1B rocket, astronauts Command Pilot Virgil I. Grissom, Senior Pilot Ed White, and Pilot Roger B. Chaffee gave their lives to further human exploration of space as fire swept through their module. Named Apollo One, stop for a moment tonight to remember these brave souls. “They gave their lives in service to their country in the ongoing exploration of humankind’s final frontier. Remember them not for how they died but for those ideals for which they lived.â€? (From the memorial on Launch Complex 34.)

Tonight we will begin our lunar explorations as we look to the north and identify the “Sea of Coldâ€? – Mare Frigoris. This long, vast lava plain extends 1126 kilometers across the surface from east to west, yet never ranges more than 72 kilometers from north to south.

Look for the unmistakable dark ellipse of crater Plato caught on Frigoris’ southern central shore. Named after the famous philosopher, this Class V crater spans approximately 101 kilometers but is a shallow 1 kilometer deep. The bright rim of Plato’s enclosure is very ragged and can rise as high as 2 kilometers above the surface, casting unusual shadows on the lava covered floor.

At around 3 million years old, Plato is more ancient than Mare Imbrium to its south. For 300 years astronomers have been keeping a watchful eye on this crater. Hevelius called it the “Greater Black Lake,â€? due its low albedo (surface reflectivity). Despite its dark appearance, Plato is well known as a home for lunar transient phenomena such as flashes of light, unusual color patterns and areas that could be outgassing. Enjoy this lunar feature which will point the way to others in the future!

Sunday, January 28 – Today take the time to honor shuttle commander Dick Scobee, pilot Mike Smith, astronauts Ellison Onizuka, Judy Resnik, Ron McNair and Greg Jarvis, and teacher Christa McAuliffe. They were the crew onboard the Challenger when it exploded on this day in 1986. “We will never forget them, nor the last time we saw them, this morning, as they prepared for the journey and waved goodbye and slipped the surly bonds of Earth to touch the face of God.â€? (President Ronald Reagan) Godspeed…

Today also celebrates the birth of Johannes Hevelius (1611) who published the first detailed maps of the Moon. This evening let’s honor our brave crew and Hevelius as we have a deeper look at the “Sea of Rains.â€? Our mission is to explore the disclosure of Mare Imbrium – home to Apollo 15.

Stretching out over 1123 kilometers over the Moon’s northwest quadrant, Imbrium was originally formed when a huge object impacted the lunar surface creating a gigantic basin around 38 million years ago. The basin itself is surrounded by three concentric rings of mountains. The most distant ring reaches a diameter of 1300 kilometers and involves the Montes Carpatus to the south, the Montes Apenninus southwest, and the Caucasus to the east. The central ring is formed by the Montes Alpes, and the innermost has long been lost except for a few low hills that still show their 600 kilometer pattern through the eons of lava flow.

Originally the impact basin was believed to be as much as 100 kilometers deep. So devastating was the event that a Moon-wide series of fault lines appeared as the massive strike shattered the lunar lithosphere. Imbrium is also home to a huge mascon and images of the far side show areas opposite the basin where seismic waves traveled through the interior and shaped its landscape. The floor of the basin rebounded from the cataclysm and filled in to a depth of around 12 kilometers. Over time, lava flow and regolith added another 5 kilometers of material, yet evidence remains of the ejecta which was flung more than 800 kilometers away, carving long runnels through the landscape.

Written by Tammy Plotner


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