During oppostion (today) Mars will shine ten times more brightly than a 1st-magnitude star, and some of the planet’s surface features will show up through backyard telescopes.
Once Mars is above the horizon, it’s about the brightest, most easily seen object in the sky. Only the Moon, Venus, Jupiter and the star Sirius are brighter. Mars comes into opposition this year on April 8, meaning that the Earth will be positioned exactly between the planet and the Sun, as shown in the graphic below: Mars takes a little more than twice as long as the Earth to make one orbit around the Sun – both planets come close to each other once every 26 months. Every 17 years, Mars comes its closest orbital distance to Earth; about 35 million miles. The last time that Mars was about as close as it can be in its orbit was on August 2003. This means that it will reach its closest point again in 2018, on July 31st, to be exact. But views of Mars this season are already looking up: Shortly after Mars reaches opposition, on April 14, Mars makes its closest approach to Earth for the year of 2014, coming within 57 million miles of Earth.
How to Find Mars: Where you will find Mars in the sky depends on your location, the current date and the time of night you’re looking. Around 9 p.m. on the night of Mars’ opposition, you will find Mars above the bright star Spica in the southeast. But there’s another easy, accurate way of finding the Red Planet: use a program like Starry Night®. It is as simple as telling Starry Night® your observing location. It will show the sky for the present time and date. If you won’t be observing until later, change the time accordingly.
Using Starry Night to find Mars:
Click on the “Find” tab and look down the list of solar system objects for Mars. Click on the check box to the left of “Mars” to turn on its label, and then click on the arrow button to the far left of “Mars” and select “Centre” from the popup menu that appears. Starry Night® will then show you the present position of Mars, assuming it’s above the horizon. Mars is far brighter than anything that’s likely to be close to it except the Moon, so it should be easy to spot, even in a light-polluted city sky.
What to Look For on Mars:
Like Earth, Mars is tilted relative to its orbital plane, and so it has seasons. Its pole however, points in a different direction than the Earth, so the seasons on Mars are one season “out of phase” from those on Earth. In April 2014, early spring on Earth’s northern hemisphere corresponds with Fall on Mars’ northern hemisphere. Viewing through a telescope, you should have excellent views of the prominent north polar cap, which will be tilted towards Earth. You may also be able to view the sunlit slope of Olympus Mons, as it crosses the terminator of Mars during the 2014 apparition. The many space voyages to Mars have shown us that it is a planet of spectacular topography, from the heights of Olympus Mons, the tallest shield volcano in the solar system, to the depths of the Valles Marineris, a chasm which dwarfs the Grand Canyon. However, seen from the Earth, these features vanish because, like our view of the Full Moon, the lighting comes from directly overhead, so there are no defining shadows.
What we do see is a pattern of light and dark, a mosaic of darker bare highlands and lighter sand-covered lowlands. Most of these darker regions are concentrated on Mars’ southern hemisphere, so they will be well presented during this apparition of Mars. The most prominent dark marking on Mars is Syrtis Major, located at Martian longitude 290°. It is usually seen as a triangular wedge shape, sometimes with a curved tip. Between it and the south pole is a large bright area called Hellas.
Extending westward from Syrtis Major is a narrow dark band, Sabaeus Sinus, ending in a forked blob, Meridiani Sinus, so named because it defines the zero meridian in the Martian longitude system. This is the area that the Mars Rover, Opportunity, is currently exploring. Further west, at longitude 100°, is Solis Lacus, sometimes called “the eye of Mars” because of its resemblance to a gigantic eye. West of this is what Mars observers often call “the boring side of Mars” because of its lack of dark markings.
Studies of Mars from orbiting space probes reveal otherwise, since this vast plain is the location of Mars’ gigantic shield volcanoes. The dark markings begin again at around longitude 180° with the broad streak of the Mare Sirenum. This lies south of the crater Gusev, where the second Mars Rover, Spirit, is on the ground exploring. Mare Sirenum extends westward into Mare Cimmerium(longitude 230°) and then Syrtis Major comes into view again.
Mars looks so big and bright to the naked eye that the view through an amateur telescope might disappoint at first. Jupiter has its belts and moons, Saturn has its rings, but Mars looks like nothing more than a tiny orange dot at first glance. But there are several secrets to getting Mars to reveal its sights to you. The first secret is often the hardest to manage: you need a good telescope. Mars is just about the most demanding telescopic object out there, and requires good optics. A telescope you pick up at the local mall or off eBay is very unlikely to come close to what’s needed. Unfortunately many people fall into this trap and end up with nothing more than a plastic toy.
Sad to say, the same amount of money, spent at a store specializing in telescopes, would yield a much more worthy telescope capable of a lifetime of satisfying observing. For satisfying views of Mars, a telescope of 4 inches aperture is about the minimum I would recommend. With Mars, as with other astronomical objects, aperture rules, and any increase in aperture will pay real benefits in the quality of the view. Because of the tiny size of Mars’ disk, even at its closest, magnification is paramount. I’ve found that 200 power is the minimum with which to see the surface detail on Mars, and 300 power is even better. Good quality eyepieces are important, and often a Barlow lens is essential to get the necessary power boost. Color filters are probably more useful for Mars than for any other planet. My favorite is the #21 orange, which accentuates dark surface markings. It tends to enhance the contrast of Mars’ detail and also to cut some of the glare from its bright surface. A #82A blue filter is very useful for enhancing the high clouds that appear above the poles and along the limb of the planet, and low contrast detail.
Welcome to Mars Training Camp!
You can have the finest hardware in the store, and yet still have a disappointing first experience with Mars. The reason is that your eye and brain need to be trained in order to tease out faint detail at the limits of visibility. I’ve found that the best way of doing this is to make drawings of the planet at every opportunity. “Oh, no,” I hear you cry, “I’m not an artist!” Artistic skill is not a requirement; heaven knows I don’t have any! What you are doing is attempting to copy, as accurately as you can, what you see on the disk of Mars. At first you won’t see much, but as you concentrate, you’ll soon be seeing more and more. As with deep sky observing, it sometimes helps to use averted vision, looking slightly off to one side of the planet. While an ordinary HB pencil will do, you may get better results from a softer lead, such as a 2B. I find an “artist’s stump” very useful.
This is a tight roll of blotting paper sharpened at both ends, available from any artist’s supply store. You use this to “smudge” the pencil lines, so that they take on a more realistic smooth shading. Finally an eraser with a sharp point is useful for removing shading to show white areas. Ordinary paper will do, but you can organize your observations better if you use a standard form. Start your drawing with a circle 40 mm in diameter to represent the disk of Mars. Except when very close to opposition, Mars shows a slight phase because the sunlight is coming from one side or the other; draw this in first. Then draw in the areas that change little as Mars rotates, namely the polar regions. Finally, draw in the darker shadings towards the center of the disk, and note the time. This is important, because Mars is rotating on its axis, and the apparent positions of surface features change fairly rapidly.
Your first sketches will be rough, but you’ll find that they improve with each one you attempt. For each sketch, record at least the date and time; the observing form suggests a lot more data that can be recorded. If you want to document your observation more thoroughly, use the blanks on the observing form. There are three circles for drawings: the left and right ones are for normal sketches, perhaps with and without a filter, while the middle one is for a diagram using numbers to indicate the darkness of features on a scale of 0 to 10. In order to compare observations around the world, dates and times are recorded in Universal Time (UT) which is a 24-hour clock based on the prime meridian in Greenwich, England.
For example, if you made your drawing at 11:30 pm EST on November 3rd 2005, you would convert this to 04:30 on November 4th in Universal Time (5 hours later). “Seeing” measures the steadiness of the image, usually with one of scales devised by Pickering or Antoniadi: I = Perfect seeing, without a quiver II = Slight quivering of the image with moments of calm lasting several seconds III = Moderate seeing with larger air tremors that blur the image IV = Poor seeing, Constant troublesome undulations of the image V = Very bad seeing, hardly stable enough to allow a rough sketch to be made “Transparency” measures how clear the sky is; oddly enough, a very hazy sky (transparency 1 or 2) often yields very good seeing, while a perfectly clear sky (6) is often hopelessly unsteady for seeing fine planetary detail. “CM,” “Ls,” “De,” and “Ds” are discussed below.
As the Planet Turns
One final step is needed in order to compare your drawing to published maps like this one. You need to know what longitude on Mars was central on the disk at the time you made your drawing. You can do this easily using the Arkansas Sky Observatory’s Mars Physical Ephemeris Calculator.
For example, for the drawing mentioned above, enter 11 04 2005 and 04h 30m in the ASO calculator, and you get a central meridian of 244.8°. You can then compare your drawing to the features visible at that longitude on the map. Careful studies of Mars sometimes use some other quantities, such as “Ls,” which measures Mars’ position in its orbit around the Sun, “De,” the declination of the Earth as seen from Mars, and “Ds,” the declination of the Sun as seen from Mars.
These can be looked up in this table. However, for a quick and easy picture of what Mars looked like at the time you made your drawing, check out a magnified view of Mars in Starry Night® at the time of your drawing, since the program does all the calculations for you automatically! You should only compare your drawing to a map after you finish the observation, so as not to be influenced by what the map shows. At first, you will probably see nothing but vague smudges, but after a week or two of “training,” you should be seeing much more detail. Some nights you may see nothing at all, and that may in fact be what is really there.
The problem is with atmospheres: the atmosphere of Earth being unsteady and smearing the image of Mars, and the atmosphere of Mars sometimes carrying widespread dust storms which block our view of the surface. An online group like MarsObservers will keep you abreast of the weather and dust storms on Mars. The finest Mars observers on Earth post their images and drawings there every day, and there’s always lively discussion of current events on the red planet. A day on Mars, known as a “sol,” is 39 minutes longer than a day on Earth.
This means that if you observe Mars at the same time each night, the features on Mars will appear to drift in longitude because of Mars’ slightly slower rotation rate. In fact it takes about 37 days before you will see exactly the same face of Mars at the same time. Taking good clear pictures of Mars has long been a major challenge to both professional and amateur astronomers alike. Making an exposure at the precise instant when the atmosphere is absolutely steady has been next to impossible. In recent years this has changed thanks to modern computer technology, and superb images of Mars are being taken regularly by a large number of amateur astronomers around the world.
One secret weapon is the lowly webcam. Using a webcam, you can make many exposures of Mars in rapid succession. Some will be good, some will be bad. If you discard the bad ones and combine the good ones in a computer process called stacking, you can produce an image that is much sharper than any of the images that went into it. Then programs like Adobe Photoshop allow you to further enhance the contrast and sharpness. The result is images which exceed the quality of anything that even the pros could manage more than a decade ago; some even come close to images taken with the Hubble Space Telescope.
Your local camera shop has several cameras to choose from that they can recommend which will take great shots of Mars and other planets.
Don’t Give Up! Although Mars is a challenging object for the amateur astronomer, it is ultimately very rewarding. It is the only planet whose surface we can observe directly, and it is the planet that most closely resembles the Earth.
Further reading: Crash’s Celestial Guide to 2014 Astronomy