Sep 10

A Nearby Galactic Exemplar

Source: ESO Photo Release eso1037

NGC 300. Source: ESO
ESO has released a spectacular new image of NGC 300, a spiral galaxy similar to the Milky Way, and located in the nearby Sculptor Group of galaxies. Taken with the Wide Field Imager (WFI) at ESO’s La Silla Observatory in Chile, this 50-hour exposure reveals the structure of the galaxy in exquisite detail. NGC 300 lies about six million light-years away and appears to be about two thirds the size of the full Moon on the sky.(read more)

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Sep 10

MESSENGER Team Completes Two-Week Orbital Flight Test

Credit: Messenger mission

Calvino Exposes Layers beneath the Rudaki Plains.
Credit: NASA/Messenger

The MESSENGER team has just wrapped up a two-week flight test to ensure that the Mercury-bound spacecraft is ready for orbital operations. On March 18, 2011, MESSENGER will become the first spacecraft to enter into orbit about Mercury, embarking on a year-long mission to study in depth the planet closest to the Sun. The completion of this recent test provides a high-fidelity verification of the tools, processes, and procedures that are needed to conduct flight operations at Mercury.

“Even though we have more than six months to go until orbit, we wanted to do this test now to make sure that we had enough time to make adjustments,” says MESSENGER Mission Operations Manager Andy Calloway, of the Johns Hopkins University Applied Physics Laboratory in Laurel, Md., “But everything worked as expected. We have proven, not just in the ground tests but now in flight, that the sequences and planned daily activities can be conducted safely and as expected. We are quite pleased with the results.”

The flight test took place from August 17 to August 29. In order to force the spacecraft to rotate in space and to gather science data in a manner similar to the operations the probe will experience during the orbital phase of the mission, the ephemerides used onboard the spacecraft had to be modified. “We had to convince the spacecraft that it was in Mercury orbit,” Calloway says. “We also intentionally chose a two-week period with Sun and Earth geometries similar to those that MESSENGER will see during the orbital phase of the mission.  The goal was to exercise the flight system in flight conditions as nearly identical as possible to those that will be experienced in orbit to validate performance, and to run as many of the same processes as possible to match a typical fortnight of orbital operations.”

In support of the two-week flight test, team members worked with NASA’s Deep Space Network (DSN) schedulers and engineers to put in place an orbit-like track schedule that is very different from cruise.  This schedule consists of daily contacts to play back stored data, upload commands, and monitor vehicle health, while pointing the high-gain antenna at Earth, plus about five hours a day for radio science measurements while the spacecraft points away from Earth and conducts science operations.

“During MESSENGER’s cruise phase, we typically have had three to four DSN tracks a week, for about six to eight hours each,” Calloway says. “But during orbit we will be tracking the spacecraft for 13 hours a day, including weekends and holidays. We needed to see if that was a realistic track schedule and one that we could maintain with our staffing plan, ground tools, and automation scripts.”

Approximately once a week during orbit, mission operators will perform brief propulsive maneuvers, where they fire MESSENGER’s small thrusters to unload angular momentum that builds up in the probe’s reaction wheel assemblies due to continuous external forces pushing on the spacecraft – primarily from the Sun. “During the test, they performed three such maneuvers successfully,” says APL’s Eric Finnegan, the MESSENGER Systems Engineer. “We were able to demonstrate that such momentum management actions can be executed safely and routinely without any impact to science data gathering.”

During the two weeks of the test, the team also exercised a variety of orbit-like scenarios and activities, including eclipse power management, star tracker management, quick data acquisition, variable downlink data-rate changes, command timing biases, weekly ephemeris loads, bi-weekly command loads, and instrument memory checks.

During the second half of the test, the science instruments conducted a series of observations as if the spacecraft were in orbit about Mercury.  For example, the Mercury Dual Imaging System collected more than 1,400 images, as if mapping the planet, and the Mercury Laser Altimeter fired four times over the course of two days, as if ranging to the planet’s surface. The command sequence directing these activities was generated using the mission’s automated science-planning tool, as all sequences will be during the prime mission.

“Our entire cruise phase, and even the three Mercury flybys, have only been warm-ups for the main event of our mission,” says MESSENGER Principal Investigator Sean Solomon, of the Carnegie Institution of Washington. “These two weeks of flight tests have been our dress rehearsal, to ensure that our spacecraft and our flight team are ready for opening night.”

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Sep 10

14th EAAE-IAU astronomical school held in Varna

The 14th EAAE-IAU astronomical school for teachers was held in Varna during September 1st-5th. More than 40 bulgarian teachers participated in the school.

A group picture during the Summer School.

The greatest interest was displayed towards the lecture “Training to teach astronomy”: a cooperative opportunity for EAAE and IAU , and towards Prof. Rosa Ros’s workshop New experiments on gravitational lenses.

Teachers were split into two groups: first group - teaching astronomy to 5-7th graders, second group – teaching astronomy to 10-12th graders.

During the school, teachers attended the following general lectures:  
1.“ Training to teach Astronomy: a cooperative opportunity for EAAE and IAU – by Prof. Rosa Ros.
2. SMARTNET – results and perspectives – by Prof.  Diana Kyurkchieva
3. „NAOP-Varna’s capabilities for teaching astronomy”– by Svezhina Dimitrova.

Lecture by Rosa Maria Ros.

Each group did practical exercises and received instruction, according to to the age of their students and topics from the curriculum. During the exercises, teachers from the first group modeled spatial maps of the constellations and the Solar System. They eagerly used Internet astronomical educational resources and methodological ideas for their application to solve different astronomical problems as part of the practical exercise. There were shown a large number of interesting computer presentations on gravity, phases of the Moon, space flight, sizes and distances in the Universe, light and shadows, life in the Universe, and optical phenomena in the atmosphere. Teachers learned how to make virtual astronomical observations in the classroom. They developed ideas for lessons based on Computer planetarium. Teachers enjoyed the lesson about actual and virtual observations of stars, stellar systems, stellar clusters and the Milky Way, which was held in the Planetarium.

Teachers working in a workshop.


The good weather allowed observations of solar prominences with an H-alpha filter, and during the night – a lesson in orientation using the night sky. The electronic astronomy lessons of the Ministry of Education, Youth and Science were also presented. As is customary for EAAE schools, surveys was distributed at the end of the school.

Solar observation during the Summer School..

Teachers gave positive evaluations for the organization and conduction of the school, the quality of lectures, the practical exercises, and observations. They expressed the desire to have such schools every year, and to include more practical exercises.

Night sky observation during the Summer School..

The Summer School was extremely useful, and motivated teachers for their work in the beginning school year.

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Sep 10

Moon Sketch from West Cork - I am the Moon Look at Me - International Observe the Moon Night - What's Up for September 2010

I am the Moon – Look at Me  by Deirdre Kelleghan

15 Day Moon Durrus, West Cork Ireland 26th August 2010 23:05 UT – 00:08 UT Pastel and conte on black paper 200 mm Dob/ FL 1,200 mm / 32 mm eyepiece

I am the Moon – Look at Me by Deirdre Kelleghan

We are privileged to live on a beautiful but fragile planet moving through space at 18.5 miles per second. We are born, live and die here; in our lifetimes we owe it to ourselves to become even a little knowledgeable of our place in the Universe.  Just a small fraction of us ever get to leave the planet and become acutely aware of the startling reality that we do in fact live in space.

We all admire humans and robots who explore off planet, but each of us here on the Earth can still reach out to grab a bit of wonder for ourselves by simply looking up. Our moon is a beautiful object whether you look at it with an instrument or just by eye.

The Moon is our nearest natural orbiting satellite, so let us stand a while and look at it together.

Let’s think about what we see when we gaze upward.  On International Observe the Moon night the moons appearance is described as waxing gibbous.  The gibbous shape of the moon on September 18th is exactly in-between the first quarter and full moon. This phase gives us the opportunity to view naked eye most of the Maria. In the northern section close to the terminator, Mare Imbrum, (The Sea of Rains) just a bit to the right is Mare Serenitatis,  (The Sea of Serenity) below Imbrium is Mare Insularium, (The Sea of Islands). Below Serenitatis, is Mare Tranquillitatis   (The Sea of Tranquillity), the place where men first stood upon the moon.

Just three days previous most people would refer to it as a half moon but have a think for a minute or two. The Moon is a spherical object, like a ball, it moves around our planet approximately once every twenty nine days.  On its journey it presents a different shape to us depending on its position to the sun in relation to the person viewing the near side from Earth.  The sun illuminates the moon’s surface and reflects that light towards our eyes. When the moon is at first quarter, half of its surface is lit up by the sun. At all times one half of the moons surfaces is bathed in sunlight while the other half rests in total darkness.

The Earth and the moon do a little orbital dance together which the sun lights up for our pleasure.

This dance involves the larger Earth partner holding the moons near side face towards itself the entire time .The orbital waltz created by the Earth and the moon as they swing around the sun together produces various phenomena during their annual soiree. These include eclipses, both lunar and solar, depending on the angle and varied positions between the three of them, the dancers and their light.

When you use your eyes only to look at the moon on International Observe the moon night, what are you looking at exactly? You will see the moon present itself to you when it is positioned a little more than one quarter way around the Earth. You will see the bright limb of the moon; you will see the line that separates daytime on the moon from night time on the moon. It is called ‘The Terminator’. Look closely and observe the darker markings ‘The Maria’ large lava filled impact basins. You will see the brighter higher areas and maybe if you have good eyesight you will see some of the larger craters and their rays. The lovely small rounded area to the upper right of The Sea of Tranquillity, close to the limb, is Mare Crisium (the sea of crisis).

With even a small pair of binoculars your view will be enhanced with detail. With a telescope depending on the size and quality of the eyepieces your view will be awesome.  There is a lifetimes worth of observing to be had with the moon alone. The contrast, the rich lunarscape, the play of light against the blackness of space, it is an exploration adventure available for all to view.

What\'s Up for September 2010 - The Moon

In this podcast Jane Houston Jones talks about the Moon and International Observe the Moon Night

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