Skies Over Louisville: Summer 2009

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Click here for July's What's Up Video from NASA.

Click here for August's What's Up Video from NASA.

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Hubble Telescope

The summer months offer a good collection of constellations and bright planets for beginning observers, as well as comfortable nights to view them (just remember the bug spray!). The first full moon occurs on June 7th and is called the Strawberry Moon since it coincides with the ripening of these summer berries. July’s full moon is on the 7th and is called the Hay Moon, marking the time when farmers would plant their hay. The last summer full moon, called the Grain Moon, is on August 5th, marking the time when farmers would plant the grains to be ready for a fall harvest.

The planet Saturn is visible in the constellation Leo, the Lion, in the southwestern sky, but you need to catch them before the end of June when they set in the evening sky. This planet is known for its large ring system. The width of these rings are about 100,000 miles and contain about 500 to 1000 rings made of ice and rock. Twice during Saturn's 29-year orbit the rings appear edge-on to us from Earth. When these reflective rings are edge-on to us, they appear to disappear, adding nothing to Saturn's brightness. We see Saturn looking unusually dim, but it is a good time to look at Saturn through a telescope and see it without its rings. The rings will be edge-on in September 2009.

The largest of the planets, Jupiter, is clearly visible all summer long in the southern sky, looking like a very bright star. Jupiter acts like a giant mirror, reflecting much of the sunlight that falls on its cloud tops. Some of this light is reflected back towards the Earth, making Jupiter the brightest object in the southern sky. Through a good pair of binoculars it is possible to see the four largest moons of Jupiter, Io, Europa, Ganymede, and Callisto.

In the northern sky Ursa Major, the Big Bear, slowly rotates around Polaris, getting closer to the horizon as summer progresses. The Big Dipper is made up of the seven brightest stars from Ursa Major. The two stars at the front of the dipper can be used to find the North Star, Polaris, in the constellation Ursa Minor, the Little Bear.

The southern sky is full of bright constellations. The Summer Triangle contains three bright stars, each one belonging to its own constellation: Vega, the brightest star in Lyra, the Harp; Deneb, brightest in the constellation Cygnus, the Swan; Altair, brightest of Aquila, the Eagle. If you are in a place where there is little light pollution and a dark sky, you may even see the faint glow of the Milky Way as it passes across the sky through the center of this triangle of bright stars. For this reason the Summer Triangle is also known as the Gateway to the Milky Way.

Low in the southern sky is the largest of all constellations, the giant Scorpius, marked by the bright red star Antares.

Lunar Resources

Follow the Apollo 11 mission in this online interactive mission tracker!
See the Apollo landings sites from space.
Land on the Moon with Google Earth special feature.

To Ask the Astronomer a question, send your email to planet @ louisville.edu.
To listen to the Sky hotline, call 502-852-6664 and press 4 for the Sky this Month.