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Go to Dinner, See a Movie, Then Observe Mars!
Free Public Star Parties for the
Unique 2003 Mars OppositionFour Saturday Evenings
Powell Hall Exhibition Center
Hosted by the AAC and the
Florida Museum of Natural History
On the night of August 26–27, Mars will be closer to Earth than at any time in nearly 60,000 years!
And will outshine all other celestial objects in the night sky
Mars is usually a disappointingly small ochre disk in the night sky except when Earth and Mars are near each other. But when Mars and Earth are close, Mars can shine as the brightest nighttime celestial object and reveal an orangy disk large enough to show a polar cap, dark surface features, clouds and even dust storms! 
There is still time to see Mars! Earth is gradually pulling away from Mars but through September 2003 Mars will still shine brilliantly in the night sky and loom large in good telescopes. (See Schedule below.)
But, this event occurs only about every 2.1 years (when Mars, we say, is in "opposition" to the Sun's position on the sky). Even then Mars can still appear quite small in telescopes.
However, the non-circular orbits of Earth and Mars allow for extraordinarily close approaches. These "favorable" close approaches (or "favorable oppositions") occur only once every 15 to 17 years. (The last was in 1988.)
In late August 2003 Mars will again have one of these highly favorable close approaches, the closest, in fact in almost 60,000 years! (Ref. A. Vitagliano)
On the morning of 2003 August 27 Mars wil be "only" 34,646,418 miles (55,758,006 kilometers) from Earth (measured center to center) at 5:51 a.m. Eastern Daylight Time.
Although Earth and Mars will only be marginally closer than at other favorable oppositions, 2003 presents the best opportunity to observe Mars up close.
Mars will not be nearly this close for another 15 years!
Get More Information
- Powell Hall Schedule for observing Mars
- Other Mars Watch Events around the World
- FAQs why our events are on late Saturday nights
- Diameter of Mars: Why it changes so much
- Links for more info about Mars (updated 09-08-03)
- Mars Previewer II, a free program for observing Mars
- What Can I See?, our page about observing Mars
During late August and into September, the Alachua Astronomy Club, Inc. and the Florida Museum of Natural History will give you a chance to view Mars through telescopes in front of Powell Hall on late Saturday evenings. Don't miss this opportunity to see Mars "up close" with your own eyes!
S ee latest images from Hubble Space Telescope and Ground Based Amateur Telescopes
(updated 08-09-03)
Mars Mania Many oppositions of Mars, especially favorable oppositions, often bring on "Mars Mania." But which planet actually comes closest to Earth? Is it Mars or what? Do you know? Click for answer!
Next Opposition At the next opposition of Mars (November 2005), the "red planet" will appear only 79 percent as large as in 2003. In fact, Mars will not appear any larger from Earth than it does this year until August 28, 2287.)
Go to Dinner
(On Your Own!)Watch a Movie
(On Your Own!)Then
See Mars!
Come to
Powell Hall
What See the planet Mars
Through Telescopes Provided by
The Alachua Astronomy Club, Inc.
WHAT CAN
I SEE?(updated 08-23-03)
Where In Front of Powell Hall
(Education & Exhibition Center of the Florida Museum of Natural History)
SW 34 Street & Hull Road, UF Campus, Gainesville FL
See Powell Hall for Exact LocationDates Four Consecutive Saturday Nights
(Beginning Saturday Labor Day Week 2003)
August 30, September 6, 13 and 20Time 11:00 p.m. until 12:30 a.m. EDT (Weather Permitting)
(If skies cloudy, event cancelled — see FAQs below)
Powell Hall
The Museum will be open for restroom access on each of Mars event dates. Museum exhibits will be open to visitors for extended hours Aug. 30 and Sept. 13 from 9:00 p.m. to 12:30 a.m. The Museum will hold the events weather permitting.
For more information, contact Dr. Patti Anderson, Education Coordinator, at the Museum,
352-846-2000, Ext. 206.
- Why is the starting time so late (11:00 p.m. ET)?
Answer In late summer 2003 Mars rises near the time of sunset. So, Mars is too close to the horizon in early evening to observe. Since celestial objects are best observed when highest above the horizon, Mars will be at its best later in the evening. (In fact, Mars will be highest in the sky during the middle of the night.)
Also August and September often have poor weather due to summer thunderstorms. Since thunderstorms tend to dissipate after sunset, the chance of clear skies is greater later in the evening.
- Why Saturday nights?
Answer Saturday nights make it easier for people to stay up late since Sunday is not a workday or school day for many people. We will also run this event for several weekends to improve the chances of people seeing Mars since cloudy weather is often common at this time of year.
- Why from Powell Hall rather than a dark site?
Answer During late summer and early fall Mars is the most brilliant object in the night sky. (Venus, which is even brighter, is too close to the Sun to be seen at this time.) Mars can even be spotted from a city environment at this time. So dark skies are not needed. Powell Hall is a convenient, well-known and safe place to view Mars.
Note: Anyone going out in late evening or early morning can easily spot Mars in the night sky. No knowledge of the night sky is necessary! The brilliant, beautiful orange glow of Mars is unmistakable – no other star or planet can compete with Mars this summer or early fall!
- What If Skies are Cloudy?
Answer Mars observing cannot be done if skies are cloudy so we must cancel the event. (If skies are partially cloudy, we will try to hold the event.) Come on down and see if we have telescopes set up. Hopefully, we will have clear skies on at least one or more of the event nights. This is one of the reasons we have scheduled Mars observing on four nights.
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Why the Martian Disk Changes its Apparent Diameter
The disk of Mars changes its apparent diameter (see Fig. 1) depending on its distance from Earth.
Mars appears smallest (Fig. 1a) when on the other side of the Sun from Earth (see Fig. 2). This position is called conjunction.
Mars appears largest (Fig. 1b-d) when "opposite" Sun's position in sky (also see Fig. 2). This position is called opposition.
The Martian orbit is about 1.5 times larger than Earth's orbit (see Fig. 2).
When Mars is farthest from Earth (conjunction) it can be over five times farther from us than when closest (opposition)! This also makes the disk of Mars seem to change by over five times! (See Fig. 2.
Can you see why the distance between Earth and Mars can change by over five times from Fig. 2? (Click on Fig. 2 to find answer.)
You can see the remarkable difference by comparing the image sizes in Fig. 1a when Mars is closest to Earth and Fig. 1c when Mars is at an "average" opposition distance.)
Nevertheless, because the Martian orbit is non-circular, some oppositions place Mars farther away than at other oppositions.
If Mars is at opposition and also near its farthest point from the Sun (called aphelion), we have an "unfavorable opposition" (see Fig. 3). Then the disk of Mars appears smaller (see Fig. 1b) than at an "average opposition" (Fig. 1b).
But if Mars is at opposition and also near its closest point to the Sun (called perihelion), we have an "favorable opposition" (see Fig. 4). Then the disk of Mars appears at it largest possible value (see Fig. 1d).
Note: Distance shown in figures 2–4 are in AUs. Astronomers measure distances in the solar system in Astronomical Units (AU) where 1 AU is the average distance of the Earth from the Sun (about 93,000,000 mi or 150,000,000 km).
Fig. 1. The Changing Apparent Diameter of Mars. Numbers in parentheses give the angular diameter of the plant in arc seconds (one arc second = 1/3600 of a degree)
[Click above image to see a Mars animation]
The Earth's orbit is also slightly non-circular but only about one-sixth as much as the Martian orbit. So, this makes some favorable oppositions even "more favorable" than others.
This happens in 2003 since the Earth reached its 2003 aphelion (farthest distance from Sun) on July 4, 2003 with the Martian perihelion date only eight weeks later (August 29).
Thus, the year 2003 produces the closest approach of Mars in nearly 60,000 years (Fig. 1d)!
Fig 2. Orbits of Earth and Mars
(Click to enlarge in separate window)
Mars is farthest from Earth at conjunction and about five times closer to Earth at opposition
Fig 3. Unfavorable (Aphelic) Opposition
(Click to enlarge in separate window)
An opposition when Mars is farthest from the Sun produces an unfavorable opposition
Fig. 4. Favorable (Perihelic) Opposition
(Click to enlarge in separate window)
At favorable oppositions Mars is closest to Sun & appears 2x larger than at unfavorable oppositions
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More Material on MarsSky & Telescope Magazine Articles
- Erasing the Ancient Martian Landscape
- Mars at Its All-Time Finest
- A Mars Record for the Ages
- Mars in 2003: Which Side Is Visible?
Note: The last article contains Sky & Telescope's Mars Profiler, a JavaScript utility that tells you what is visible on Mars for any date and time. It also shows a map of Mars so that you can identify any bright and dark markings you see.
- Mars's Dazzling Sky Show
- Martian Flare Watch
- Martian Moons in 2003
(incl. Java script applet for finding Phobos and Deimos)- Storm Watch on Mars
If you would like your own utility for showing the disk of Mars, download this free software from Sky & Telescope (© 1997-1999 Leandro Rios).
This small handy program, given the observer's date, time and time zone, calculates physical data for Mars and draws an image of the globe. This image can be saved or printed. You can also hover over the planet's image with the mouse and see the latitude, longitude and the name of the albedo feature under the pointer. Information computed includes the central meridian, angular diameter, phase and magnitude of the red planet for any date and time. Mars Previewer will draw circles on the globe to allow for the representation of equator, terminator, rotation axis and dark limb. The program can orient the globe with either north or south at the top and reverse east/west directions.
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