August 2003 Sky from the Keeble Observatory
Mars! Mars! Mars! We've
been writing for two months about the fleet of probes on their way
to the red planet. We've told you that Mars will be at opposition
(opposite the Sun in the sky) in late August, a mere 34.6 million
miles from Earth.
We're actually seeing a close convergence of two events . Mars
will be at opposition on the 28th, and also very close to perihelion
at the same time that Earth is very close to aphelion. (Perihelion
is when a planet is closest to the Sun; aphelion is when their separation
is farthest. These events are at opposite ends of the long axis
through the elliptical orbit. Opposition means that the planet is
on the opposite side of the sky from the Sun's apparent position.)
In this case, very close means that opposition happens a mere
two days before Mars reaches perihelion on 30 August. The proximity
with Earth's aphelion on 4 July is a little less tidy, but our orbit
is more nearly circular than Mars' orbit.
Closest approach will be just before 6:00 am EDT on the 27th. The
last time we got this close there were saber-toothed cats and mastodons
in North America! That was in August or September of 57,617 BCE,
depending on whose calculations you believe. Of course, the months
hadn't been invented yet! The next opportunity won't take quite
as long . keep a sharp eye on 2287 August 29!
Unfortunately, viewing Mars from the vicinity of the Center of
the Universe (Ashland!) won't be ideal. At best, the planet will
be about 37 degrees above the southern horizon at about 1:30 am
. from our vantage point at the Keeble Observatory, Mars won't even
clear the tree line until almost 11:00 pm. This relatively low altitude
will also exacerbate atmospheric interference from haze and sky
glow. As we approach the dates for opposition, we'll post on the
Keeble homepage to let folks know if we will be trying any observing.
To follow the latest news on this event and to see some interesting
simulations, check out the International Marswatch web site at http://elvis.rowan.edu/marswatch/news.php
Lunar phases for 2003 August: First Quarter on the 5th, at 3:29
am; Full on the 12th, at 12:49 am; Last Quarter on the 19th, at
8:49 am; New Moon on the 27th, at 1:27 pm.
Saturn emerges from behind the Sun and is visible in the predawn
towards the east. Mercury is low towards the northeast at sunset,
and we've lost Jupiter and Venus in the Sun's glare. Mars rises
earlier each night - rising as the Sun sets on the 28th, visible
through the night for the whole month.
Our overhead view at mid-month, roughly an hour after sunset, brings
the bright star Vega close to zenith. The constellation Hercules
is at zenith, extending a bit to the west, but this faint tetrahedron
is not obvious, except on clear, moonless nights. Bright red Antares,
in Scorpio, is almost due south. The brightest star in the constellation
Bootes, Arcturus, is almost due west. To the northwest we see the
familiar big dipper of Ursa Major. Following the sweep of the
handle towards the west will lead you to Arcturus, and continuing
the arc towards the southwest will bring into view Spica, in the
contellation Virgo. This is low in the sky, and may not be visible
through the horizon haze. Returning to Vega and turning towards
the east, you'll see the bright triangle formed by Vega, Deneb (in
Cygnus) and Altair (in Aquila). Cygnus (the Swan) marks both the
plane of the Galaxy and the direction in space towards which the
entire solar system is moving as we orbit the center of the Milky
Way, which divides the sky roughly from south-southwest to north-northwest.
For your own monthly star chart, you can direct your web browser
You will find extensive descriptions of what's worth looking for,
and you can download and print a single copy for your personal use.