Hurtling toward Mars at 22,000 mph, Earth is heading for its closest
encounter with the Red Planet in a dozen years.

Once in about every fifteen years a startling visitant makes his
appearance upon our midnight skies –a great red star that …
mounting higher with the deepening night, blazes forth against the
dark background of space with a splendor that outshines Sirius and
rivals the giant Jupiter himself. — from Mars by Percival Lowell

By the time you finish reading this sentence, you’ll be 50
kilometers closer to the Red Planet.

Earth and Mars are converging at 10 km/s (22,000 mph) as the pair head for a
close encounter next month. On June 21st Mars will lie just 68 million km
from Earth — the nearest it’s been in a dozen years.

“The next few months will be a great time to look at Mars,” says astronomy
professor George Lebo, a NASA Summer Faculty Fellow at the Marshall Space
Flight Center. “You won’t need a telescope to see it. By early June Mars
will outshine everything except Venus, the Moon, and the Sun itself .”

Mars is already a brilliant morning star. Early rising observers in the
northern hemisphere can spot the Red Planet about 30 degrees above the
southern horizon. Sky watchers south of the equator will see Mars arcing
high overhead before dawn. In either hemisphere, the planet is easy to pick
out near the spout of the teapot-shaped constellation Sagittarius. Mars is
bright and doesn’t twinkle like a real star — its steady copper-hued gaze
is unmistakable.

In the weeks ahead the Red Planet will grow even brighter as it approaches
opposition on June 13th, the date when Earth and Mars are lined up on the
same side of the Sun. Astronomers call the arrangement opposition because
Mars and the Sun will lie on opposite sides of our planet’s sky. Mars is at
opposition once every 26 months.

If the orbits of Mars and Earth were perfectly circular, then the distance
between two planets would be least at the moment of opposition. But that’s
not the case. Earth’s orbit is slightly elliptical and the martian orbit is
substantially more so. As a result, our closest approach to Mars won’t
happen until eight days later on June 21st.

By that time Mars will no longer be a morning star — it’ll be a dazzling
“all-nighter,” rising near sunset and reaching its highest point in the sky
at midnight. Modest telescopes will reveal normally invisible details
including martian clouds and icy polar caps. See Sky and Telescope’s “A
Grand Return of Mars” for more information.

Throughout the coming months Mars will linger in a region of the sky that’s
home to the very center of our galaxy. This will be a treat for dark sky
observers who can see the faint Milky Way, a hazy band of stars that bisects
the sky along the galactic plane. The Milky Way cuts through Sagittarius and
brightens near the spout of the teapot — right by Mars! There lies the
galactic center, the lair of a supermassive black hole around which our
entire pinwheel galaxy spins.

Despite their proximity in the sky, Mars and the galactic center are really
very far apart. A spacecraft from Earth traveling at light speed would
arrive at the Red Planet in only a few minutes. Reaching the inner regions
of our galaxy would take an extra 30,000 years!

If spacecraft could travel at the speed of light, we could visit Mars any
time we wished. However, NASA’s advanced propulsion systems aren’t yet that
advanced. We have to choose our opportunities carefully and visit Mars when
the planet is nearby — in other words, at opposition.

NASA’s latest Mars probe, 2001 Mars Odyssey, blasted off on April 7th and
it’s hurtling toward the Red Planet even faster than we are. Earth’s
approach will slow and then reverse as Mars reaches opposition in June, but
Mars Odyssey will continue until it enters Mars orbit on October 24th.
During the probe’s two and a half year mission, it will monitor space
radiation, seek out underground water, and identify interesting minerals on
the martian terrain.

Because of Mars’ eccentric orbit, not all oppositions are alike. At the next
one, on August 28, 2003, Mars and Earth will be just 56 million km apart —
closer than any opposition since 1924. It will be the perfect time to send a
new batch of robotic explorers to Mars. Indeed, NASA plans to launch a pair
of Mars Exploration Rovers in 2003, and the European Space Agency will send
a lander of its own, the Beagle 2, which will ride to Mars on board the Mars
Express Mission.

Favorable oppositions of Mars recur with a 15-to-16 year cycle. Perhaps the
series of close encounters 15 years from now could be our first opportunity
to send humans to the Red Planet!

Meanwhile, don’t miss the ongoing show. Mars is out there now, fiery red and
beckoning from your own back yard!