Mars will put on a great show this year, as it will be closer to earth than any time since 2003 and won’t be this close again until 2035. Mars is often a disappointment even a powerful telescope, because most of the time it is distant from the earth and difficult to resolve, however, this year (particularly around May-September) it will appear large enough to show detail on the planet even in a small telescope.
This article will focus on what to see and expect through a telescope and a camera.
What to Expect
The following table gives you an idea of what to expect. In the left column the Date is listed. In second column the relative size, phase and aspect of the planet is shown. In the third column, the magnification needed to make the planet appear the same size as the moon does with the naked eye. In the last column is the best time to view the planet (which is when it is highest in the sky and less subject to atmospheric disturbance).
Up until about April Mars will look like a moderately bright Orange star, and it may difficult to tell apart from the similarly bright Saturn and some of the other bright reddish stars like Antares. Starting May, it becomes noticeably brighter and will appear as second in brightness only to Jupiter. Jupiter is further east in the sky. By July and August Mars will look like a brilliant orange star in the east at the beginning of the evening.
| Date | Appearance & Relative Size | Magnifi- cation | Apparent Size | Best Time |
|---|---|---|---|---|
| Feb-1-2018 |  | 320x | 5.61” | Dawn |
| Mar-1-2018 |  | 270x | 6.68” | Dawn |
| Apr-1-2018 |  | 210x | 8.45” | Dawn |
| May-1-2018 |  | 160x | 11.09” | Early Morning |
| Jun-1-2018 |  | 120x | 15.31” | Early Morning |
| Jul-1-2018 |  | 85x | 20.89” | Midnight |
| Aug-1-2018 |  | 75x | 24.34” | Late Evening |
| Sep-1-2018 |  | 85x | 20.87” | Late Evening |
| Oct-1-2018 |  | 115x | 15.81” | Evening |
| Nov-1-2018 |  | 150x | 11.88” | Evening |
| Dec-1-2018 |  | 190x | 9.28” | Evening |
Features visible in a Telescope
Mars has many interesting features including albedo marking’s, polar caps, clouds and large-scale dust storms all of which can be seen in an amateur telescope. These features vary over time and depending on season.
On June 9, 2016, the author captured this image of Mars with a 12” Dobsonian telescope. Visible in this image are various surface features including Olympus Mon's (Nix Olympus) the tallest mountain in the solar system as well as clouds and hazes around the Martian North and South Poles)
Surface Features
The most distinct feature on Mars are the albedo feature’s which are caused by variations in ground composition, for instance the most prominent feature Syrtis Major is dark because a lack of dust and basaltic rock. Under excellent conditions the volcanic feature Olympus Mons can be seen, but more likely it will be accessible only by imagers.
South Polar Cap
The Martian South Polar area will start to become visible in May, 2018, and as it begins to move into sunlight the polar hazes that obscure the polar cap begin to disappear and reveal the cap as a bright white feature on the planet. The South Polar Cap remains in view but shrinks over time as it moves into the Mars Southern hemisphere summer. This feature can be seen even in a small telescope and easily visible in a modest size telescope.
Martian Clouds and Dust Storms
As the Martian Southern Hemisphere progresses there is an increased chance of seeing dust storms, sometimes these can encircle the planet with an Orange Haze that obscures detail. Look for Bluish hazes on the limb of the planet as well as areas of frosts which look similar in appearance.
South Polar Cap
The Martian South Polar area will start to become visible in May, 2018, and as it begins to move into sunlight the polar hazes that obscure the polar cap begin to disappear and reveal the cap as a bright white feature on the planet. The South Polar Cap remains in view but shrinks over time as it moves into the Mars Southern hemisphere summer. This feature can be seen even in a small telescope and is easily visible in a modest size telescope.
Martian Clouds and Dust Storms
As the Martian Southern Hemisphere progresses there is an increased chance of seeing dust storms, sometimes these can encircle the planet with an Orange Haze that obscures detail. Another interest feature is the development of Bluish hazes and clouds on the limb of the planet. If you look at the image from June 9, 2016, can you see the white/blue cloud areas?
In 2001 a major dust storm enveloped Mars and was captured by the Hubble telescope as shown in the following image.
In 2001 Hubble capture an amazing large scale dust storm on Mars. Credit NASA
Moons Phobos and Deimos
Mars has 2 tiny moons Phobos and Deimos that are just 22km and 12km across respectively. Seeing them in an amateur telescope is a difficult challenge, however, this year offers the best chance to see them due to the closeness of Mars. The difficulty in seeing the moons is due to their proximity to the planet itself which overpowers the moons in it's glare. During 2016 the author managed to photograph both moons with a 12” Dobsonian telescope as can be seen in this image.
These 2 images show the moons Phobos and Deimos (Marked “P” and “D”) taken about 30 minutes apart . To capture the moons a longer camera exposure was required with has overexposed Mars. Credit: Author
Conclusions
Currently, there is a dearth of planets in the sky, however, this is starting to change as Jupiter, Mars and Saturn will soon return the night sky. This year Mars is having a particularly good return and is well worth looking for, particularly around June onwards.
References
Mars' Calendar. http://www.planetary.org/explore/space-topics/mars/mars-calendar.html
The 2018 Perihelic Apparition of Mars. http://www.alpo-astronomy.org/jbeish/2018_MARS.htm