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17 AUG |
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16 AUG |
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10 AUG |
CHULA VISTA, Aug. 20, 2003 -- For all those individuals who have failed to turn their heads skyward in recent weeks to take the opportunity to observe what really is a once in a lifetime bit of celestial wonderment, I have only one thing to say:"Shame on you!"
But it's not too late. Next Wednesday morning, at 2:51 a.m. PDT to be exact, Mars, the fourth planet outward fro the sun, will be closer to the Earth — at 34.6 million miles — than it has been since 57,617 BC, or when Neandertals were the dominant intelligent hominid species on the planet.
What our brutish-looking (but exceedingly well cold-adapted) cousins thought of this ruddy jewel blazing against the velvet of the night sky is pure conjecture, as they left no written account nor artistic representation of the event, but had they had access to telescopes, they surely would have been as overcome with rapture as anyone who happens to take a peek at Mars right now.
During a trip to observe the annual Perseid meteor shower on Mt. Laguna the night of Aug. 12, a colleague trained his moderate-sized telescope at Mars stationed next to the near full moon and shouted in amazement upon placing his eye to the magnifying lens.
Braced by my Bachelor’s degree in astronomy and countless hours of observing, I smiled in complete satisfaction.
Because of the solar system’s geometry, Mars comes closest to Earth when it is nearest the point in its orbit when it is nearest the sun (perihelion) and when it is also in opposition to Earth (when our planet lies directly between it and the sun). The two planets’ game of celestial tag brings them close to one another every 15 to 17 years and offers less optimal viewing opportunities every 14 months.
For the record, in astronomical terms, Mars will stand at -2.9 magnitude and 25.1 arcseconds across on the night of Aug. 26-27 — or about 10 times brighter and three times larger than it did in early April of this year when it was 110 million miles from us.
During the last favorable opposition in the summer of 1988, Mars reached 23.8 arcseconds in diameter. It was 24.9 arcseconds across in 1971.
Mars will not be this bright and this close again until 2287.
Where to look for Mars
At opposition, Mars rises at sunset is visible all night long. With its fiery copper color, it is unmistakable in the southeastern sky after dusk.
By midweek, Mars should be high enough for prime viewing about 10 p.m. The Red Planet will remain a fixture in the night sky through the end of the year when it will still outshine all but the very brightest stars.
For the next month, it will be nearest to the Earth, and appear larger in a telescope, than it has since 1988.
The current Martian “invasion” should fan public fascination with astronomy to the degree not seen since the 1986 visit of Halley’s Comet.
During the 1998 opposition, I sketched the Red Planet nightly through my three-inch refractor from my family’s backyard, distinctly noting the largest Martian surface marking, called Syrtis Major (imaging you are looking at a colossal India), as well as the icy-white southern Martian polar cap.
Fifteen years later I am better equipped in the telescope department and more connected in the networking department after recently becoming a member of the San Diego Astronomy Association.
Rich Bentley, who helped write a calibration software package that was used on the Hubble Space Telescope while working at the Center for Astrophysics and Space Science at UCSD, coordinates the SDAA’s South County star parties and has conducted numerous activities for schools in the Chula Vista area in his three years while holding the position.
Astronomy lends itself particularly well to young minds eager to probe the wonders of the universe. Bentley estimates that during busy parts of the school year that there is a star party conducted by the SDAA somewhere in the county every night.
“Teachers get into contact with us and we work out dates and have them at the school. During the school year, we get quite busy. Some weeks we have star parties every night around the county,” he said.
“It’s really fascinating. They really like it. Once teachers hold one, they try to set them up once a year. Teachers say the kids talk about it for weeks,” he said.
Bentley has been a SDAA member for more than a decade and owns a owns 10-inch Newtonian reflector (with a Dobsonian mount) and 11x70 binoculars (with observing mount). He uses both pieces equipment at educational star parties he helps arrange and took the telescope to last weekend’s members-only star party at the association’s dark-sky Tierra del Sol observing site to observe Mars.
Bentley, who has been an avid amateur astronomer for a great portion of his life, is personally fascinated by globular clusters (concentrations of hundreds of thousands of ancient stars that obit the center of our galaxy in a galactic halo). He and his wife made a recent trip to Bolivia where he had a chance to observe the one of the largest and brightest globular clusters in the southern sky, Omega Centauri, through a 20-inch Dobsonian. “It’s really spectacular. It’s even remarkable as a naked eye object,” he said.
Bentley and his wife have made other astronomy-inspired odysseys, most notably to Rumania in 1999 to observe a total solar eclipse and to Tunisia for the Leonid meteor shower.
“It’s just a really fun thing to do. It think it’s nice to learn about the universe. I’m interested in science in general.Astronomy has a lot to tell us about where we live in the universe,” he said.
Public star parties are being held at the SDAA’s Tierra del Sol site the weekend before and the weekend after Mars’ closest approach to Earth. Observing in either window will be fine, as a few days’ difference will not perceptibly affect either the size or the brightness of the Red Planet.
I had a chance last month to visit the Tierra del Sol site and photographed Mars through the association’s 22-inch Lipp Ritchey Chretien reflector.
How to photograph Mars
Mars is so bright, in fact, that it is easily photographed with digital cameras. Settings as low as ISO 200 with an f/5 optical system can produce very satisfying images at 1/60th of a second, though slower optical systems (f/8 to f/10) may require ISO values of 400 to 800 at exposures of 1/60 second. Higher ISO values can also be coupled with shorter exposures (1/125 second) to produce equally fine images.
Syrtis Major is a wonderful sight at 200x through an eight-inch reflecting telescope.
For those wishing to take the 60-mile drive eastward this weekend, they should locate the Tierra del Sol site on the association’s Web site and take note of common courtesy points regarding excessive use of unshielded lights such as flashlights and car beams. (Parking lights are fine when entering to exiting the property.)
Visitors are encouraged to arrive before dusk to both find a suitable parking spot as well as make a few truckloads of new friends. Don’t be surprised to find more than 100 “party-goers” at the site with a wide array of both commercially and home-built telescopes. Though the SDAA’s 22-inch telescope is currently being refurbished, someone had their personal 20-inch scope out for observing last weekend.
Even if you only observe from the backyard, the views over the coming weeks will still be quite spectacular.
(The SDAA holds public observing sessions the first Wednesday of every month after dark in the Prado near the Reuben H. Fleet Science Center in Balboa Park.)
For those who have not been following the unfolding celestial drama over the past few months, now is the time to observe the Red Planet before the south polar cap dramatically recedes to a pin prick. The polar cap was quite pronounced in May and June but has begun to noticeably shrink as Mars experiences summer in its southern hemisphere.
Mars will still be a prime nightly target through the first week of October when its disk will subtend 20 arcseconds. Noticeable surface detail should be visible through the end of November when Mars shrinks to half its present size and dims by two magnitudes (one-sixth of its present brightness).
A pointers on observing the Red Planet:
Mars is actually so brilliant now that it appears more or less as a bright salmon pink orb at lower magnifications (40 to80x). It is only at higher magnifications (200 to 300x) that enough contrast is obtained to make out fine surface detail.
In order to bring out more surface detail (regardless of magnification), a red filter (a Wratten 25 or 23A) should be used and can be conveniently screwed into the end of the eyepiece. A green(W 58) or blue-green (W64) filter will bring out more detail in the polar cap and surface frosts while blue (W38A or W80A) and violet (W47) filters will highlight atmospheric phenomenon such as water vapor clouds and polar hoods.
Observers with small (3- to 6-inch) telescopes may find that a yellow (W15) filter does a rather nice job.
For those who do not have access to sophisticated filters, observing Mars through a light layer of high-level haze or incoming clouds also proves just as effective.
On the night of closest approach, Syrtis Major will not be facing the Western Hemisphere but the famous volcanic Tharsis region will. For those who become nightly Mars-watching addicts, Syrtis Major will be well situated for viewing by the first weekend in September.
For more information, including an interactive profiler that displays a map of current observable Martian features, please visit the Web site at www.skyandtelescope.com.