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Ottawa Centre Monthly Observing Challenges

Beginning in 2007, Ottawa Centre introduced a new item to its monthly meetings: an observing challenge object. Each month the centre will post a description of an interesting object. Members are invited to observe, sketch, photograph, or otherwise learn about this object. At the subsequent monthly meeting, an agenda item will provide an opportunity to share your thoughts, photos, sketches, or comments.

July 2009

Lunar: Tranquility Base (Apollo 11)

by Murray Campbell

In honour of the 40th anniversary of the Apollo moon landings, the lunar challenge this month is to observe the area in which Apollo 11 landed, Tranquility Base. Note: you cannot see the lander or any other signs of the landing - they are too small for any telescopes located here at Earth. Even the Hubble telescope cannot resolve the moon lander.

Apollo 11 landed in the Sea of Tranquility, a dark Mare easily visible by its approximate "North America" shape. The Mare can bee seen with the naked eye or binoculars.

It is best viewed 5-7 days after New Moon, or 4 days after Full Moon.

Sea of Tranquility and Location of Tranquility Base
Image from Virtual Moon Atlas.

Use your telescope at medium- to high magnification to inspet the lower left part of the Sea of Tranquility.  With good seeing you should be able to resolve two tiny craters near the landing site.

Source Maps: Rukl Map # 35 Arago;
Viscardy Page 276; or Hatfield Map # 2f8.

Again, the Eagle is not specifically observable but the southern region of Mare Tranquillitatus is relatively easy to locate, and is chock-a-block Full of interesting craters, domes, and Rimae.

The challenge is to record your observations of the Rimae Hypatia, and note many other surface features of this region.

Location of Tranquility Base
Image from Virtual Moon Atlas.

You cannot see the lander, but this scale model can help imagine what it was like on the surface.

Scale Model of Tranquility Base
Breaking news: NASA's Lunar Reconnaissance Orbiter, orbiting the Moon with high-resolution cameras, has returned the first images of the Apollo landers since the missions ended. Apollo11 seen from LRO.  Image from NASA.
Image: NASA

Deep Sky: NGC5866 (M102) Spindle Galaxy

by Attilla Danko:

The deep-sky challenge this month is to observe galaxy NGC 5866 (M102), in various levels of detail depending on your observing equipment.

M102 is a beautiful edge-on galaxy with a prominent dark lane. It can be difficult to detect because of its low surface brightness and observing any detail requires dark skies and a moderately large scope.

M102 from SDSS
Image from Sloan Digital Sky Survey.

M102 is in the constellation Draco, above the handle of the Big Dipper.

Finder chart for M102
Image from Starry Night.

Look above Alkaid and Mizar, the last two stars in the Big Dipper's handle. Find Edasich, the "middle" star in Draco's tail, and position about one Telrad-field to the left of that star, and one Telrad-field down.

In a small scope, the challenge is to detect the galaxy and observe the edge-on shape and bulge.

M102 Finder Chart, Close-Up
Image from Starry Night.

In a large scope, you will be able to detect a thin dust lane that cuts across the disk. The dark lane is inclined 2 degrees from the perfect centre of the disk. Challenge-Jul2009-M102Gates.jpg
Image: Elinor L. Gates
Imagers can attempt to capture detailed structure in the dark lane. Hubble image of M102
Image: Hubble

Previous Challenge Objects

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