Last modified: Wednesday, July 1, 2009
Eastern sky crowded before dawn in July
FOR IMMEDIATE RELEASE
July 1, 2009
BLOOMINGTON, Ind. -- The longest total solar eclipse of this century will happen on July 22, when the moon's shadow will appear on the ground at sunrise in India and speed eastward. After the shadow leaves the Chinese mainland near Shanghai and moves out over the Pacific Ocean, the maximum eclipse will occur about 195 miles east of Iwo Jima, where observers will see the sun disappear for six minutes and 39 seconds. Details are available at http://eclipse.gsfc.nasa.gov/SEmono/TSE2009/TSE2009.html. An interactive map of the path of the ecipse can be seen at http://eclipse.gsfc.nasa.gov/SEgoogle/SEgoogle2001/SE2009Jul22Tgoogle.html. The next total solar eclipse visible in North America will be in 2017.
The eastern sky will be crowded before dawn in July. Venus will rise about three hours before the sun all month, appearing well above the eastern horizon as a beautiful "morning star" in the brightening sky.
Accompanying Venus to its upper right (south) will be Mars, a hundred times fainter and looking like a twin of the orange star Aldebaran nearby. Joining the party will be two star clusters, the Hyades (including Aldebaran) and the Pleiades. From July 17 to 20 the crescent moon will drift past all of them, creating a series of striking formations. The constellation Taurus the Bull, where all of this will happen, will be hard to recognize.
Jupiter will rise in the southeast and dominate the southern sky in the constellation Capricornus the Goat for most of the night. The huge planet will be opposite the sun in August, so it will appear almost as large as it can get this month. It will be highest in the south around 3 a.m. local time, when viewing should be best in binoculars or a telescope.
Saturn will linger above the western horizon after sunset this month, finally setting around midnight. Its famous rings may not be visible, since they are now tilted only a few degrees to our line of sight. They will become edgewise to Earth on Sept. 4, but by then Saturn will be too close to the sun in our sky to be seen.
Mercury will be out of sight in the solar glare as it passes behind the sun during July.
Viewing information and graphics for the planets are available at http://www.space.com/spacewatch/.
The southern branch of the Delta Aquarid meteor shower will peak before dawn on July 28, with meteors appearing several nights before and after the peak as well. The long bright streaks will seem to come from a point in the constellation Aquarius in the southern sky during the hours just before morning twilight. The bright planet Jupiter will serve as a nearby marker this time around. In a dark sky there should be about 10 meteors per hour at the peak, with only minor interference from the moon.
On July 3, Earth will reach its greatest distance from the sun for the year, called aphelion. Those sweltering in summer heat in the Northern Hemisphere may find it hard to believe that they are about 3 percent farther from the sun than they were in January. Those experiencing winter in the Southern Hemisphere will be easier to convince. The difference is caused by the tilt of Earth's axis. The part of the planet tilted toward the sun is much warmer than the part tilted away, because more sunlight reaches the ground instead of being absorbed by the atmosphere.
The moon will be full on July 7, at third quarter on July 15, new on July 21 and at first quarter on July 28.