When it is nearby, seeing Mars through a telescope is a spectacular sight. When it is at its farthest, the view is much less inspiring.
Although it’s our neighbor in space, the distance between Mars and Earth fluctuates massively over a two-year period. At their closest, they can be just 35,000,000 miles (56 million km) apart. When they are on opposite sides of their respective orbits, Mars can be 250,000,000 miles (401 million km) away.
You won’t be surprised to learn that the view you’ll get of Mars in your telescope when it’s 7x closer to us is spectacular compared to when it is at its most distant.
At its closest, the disc can be 25 arcseconds in diameter, at its furthest, it can be just 3.5″ across, smaller than Uranus in your telescope. This has a significant impact on the planet’s apparent magnitude too, which can be as dim as +2.0, or as bright as -3.0.
Suffice to say, you need to pick your moment to look at Mars. As the image above shows, much of the time it is a tiny, uninspiring red dot. When it is nearby, however, it is a large disc, rich in features to be discovered.
Read on to find out when you should be looking for the Red Planet, and what to look for when you’ve found it.
When Is Mars Visible?
2020 was a great year for seeing Mars. In October of that year, it closer to Earth than it had for more than eight years. We saw the Martian disc reach 22 arcseconds wide, and it shone at magnitude -2.6.
Since the cycle of Mars growing and shrinking takes about two years, 2021 was a fallow year for astronomers wanting to study it.
Of course, that means this year, 2022, presents us with another opposition event. In December, Mars will be closer than we’ve seen it since 2020 and we’ll be able to study its surface features and moons Phobos and Deimos.
The table below shows the rise and set times for the red planet at mid-month for the year. The third column shows what time it will be at its highest.
From an observing perspective, Mars is a morning planet for most of the year. It can be studied in late evenings from September and becomes a true evening planet after its opposition on 07 December.
Although this chart is set for a mid-US timezone, the times will be approximately the same for local timezones in most of the northern hemisphere.
For more detail on when and where to look for Mars in each month of 2022, use our guide on this page.
When Is Mars at its Brightest?
The chart below shows how the brightness (magnitude) of Mars varies throughout 2022.
You can see that the planet is dimmest (the highest magnitude) at the beginning of the year. The improvement is steady for the first eight months of the year, moving from 1.5 in January to 0.1 in August.
After that, the rate of brightening in dramatic. Mars reaches its brightest mid-month magnitude of -1.7 in December. For a few days around the opposition event on the seventh, Mars will be as bright as magnitude -1.9.
The increase in brightness throughout the year is a result of Mars moving towards us. The chart below shows Mars and Earth steadily getting closer and closer to each other.
You’ll see that it is furthest from us in January and closest around the opposition in early December. Even so, the approach in 2022 is far from the best.
This year, Mars comes within 51 million miles of Earth. In 2020, the Red Planet approached to within 39 million miles, making 2020 a significantly closer opposition.
Finally, let’s take a look at how big Mars is in our sky this year. As you might already expect, it appears much larger than at any point in 2021.
The chart below shows the size of its diameter in the middle of each month, measured in arcseconds. The disc is still Uranus-sized at the start of the year but quadruples in size at the time of opposition.
For comparison, the 2020 opposition saw the Martian disc reach 22.6 arcseconds wide, which is a third larger that this year’s best.
If you’re planning to find our neighbor with your telescope, keep reading to see how to do it.
How to Find Mars In A Telescope
It might not be at its best this year, but the earlier you look, the larger and brighter the Martian disc will appear.
Here’s our guide to getting the best of Mars in 2022.
Step 1: Is Mars in the Sky Tonight?
As mentioned above, Mars is best viewed in the mornings until at least September 2022. Until that time, it will always be highest in the sky just before dawn breaks.
For the last quarter of the year, evening viewing of Mars is possible, which is more in-tune with most hobby astronomer’s lives. It’s also at this time, as you’ve seen, that Mars begins to rapidly grow in brightness and disc size.
By the end of November and for most of December, Mars is visible all night long and highest in the sky around midnight. This is also when we’ll be able to see the most detail on the Martian surface because the planet will be on its closest approach to us.
Step 2: Finding Mars Without a Telescope
In the earliest months of the year, Mars is relatively small, dim, and low on the horizon in pre-dawn skies. It moves from Ophiuchus to Sagittarius, Capricornus, and Aquarius from January to May.
After that, the planet gets noticeably larger and brighter as we continue though 2022. It travels through Aries in July before entering Taurus in August, where it remains for the rest of the year.
As the ‘Red Planet’ name for Mars suggests, what makes this planet easy to pick out against the stars is it shines with an obvious red hue. By the second half of the year, it will also be brighter than almost all of the stars nearby.
Step 3: Finding Mars With a Small Telescope
Make sure that your telescope is ready to go, i.e. you have aligned the finderscope. If you don’t have a telescope yet, these are our top picks for telescopes to see Mars.
Aim your finderscope at the red ‘star’ you picked out above and take a look through a wide field of view eyepiece.
While actual stars will remain as pinpricks of bright light, Mars will appear as a distinct disc, albeit a small one as 2022 begins.
Mars is still relatively bright, so don’t be shy to use larger magnifications to see what you can observe on its surface. However, keep in mind that the disc is too small to see details of the Martian surface until the last four or five months of this year.
Step 4: Improving Your View With a Telescope Filter for Mars
To observe more details on the Martian surface, it helps to use a telescope filter to enhance surface contrast and reveal more features that you might otherwise miss.
Discover the best telescope filter for each planet in our handy table
Filters remove unwanted light from your view, leaving useful colors behind. With fewer colors reaching your eyes, your brain is much better at interpreting the differences it sees, so you can tease out different features on the Martian surface.
These are the most useful filters for observing Mars. Click the filter number to buy one (or just check the price) on Amazon, which will open in a new tab.
#21 Orange – Enhances darker surface areas against the general bright orange background of the planet.
#23A Light Red – Highlights the planes and does a good job too with dust storms and the polar ice caps. If you were to choose just one filter for observing Mars, this should be it.
#56 Light Green – A good choice for dust storms and ice cap viewing.
#82A Light Blue – It’s hard to imagine blue improving the Red Planet’s view in a telescope, but it darkens the rust-colored disc and shows off the polar ice caps.
What Can You See on Mars With a Small Telescope?
When Mars is large and presenting good viewing, it is the best planet for detailed surface feature observations. Its surface is varied enough to show deserts, differently shaded landscapes, polar ice caps, and even clouds and dust storms.
The image below gives a map of what was visible on the Martian surface at its last big opposition in October 2020. Click the image for a full-screen version.
Keep in mind that the features mapped above were caught with a camera through an 8″ telescope at opposition, so we can rarely see this level of detail. Even if you have the scope and conditions, our eyes never reveal as much as a camera can.
If you have a smaller scope than that, what can you expect to see when Mars is at its closest?
Thankfully, Mars delivers even for a small telescope… when it is nearby. The best feature to see is the southern polar ice cap, which is pointed towards us at opposition. Its white stands out against the rust. Even a 3-inch to 4-inch scope will reveal it.
The other surface features rely on being able to distinguish differences between light and dark areas of the surface. Depending on which side of the planet is facing us when you look, try and see Syrtis Major or Mare Acidalium, More details on both, below.
Finally, you can also see dust storms through a small telescope but we’d rather not because that means better surface features are being obscured.
Target 1: How to See Polar Ice Caps on Mars
Even though Mars has almost no atmosphere, the top and bottom of the planet both experience the growth of polar ice caps during the respective northern and southern winters. We can see these using a small telescope, especially when Mars is closer.
The southern cap tends to be most obvious when Mars is at opposition (closest to us). Have the patience to wait for moments of good seeing and note the distinct white ice caps against the red of the planet.
As the image above perfectly demonstrates, the size of the ice caps is subject to seasonal variations on Mars. When the southern hemisphere is experiencing its winter, the ice cap is much larger, as shown in the left image. This makes it much easier to see in a planetary telescope.
Target 2: Martian Surface Features
The Martian surface has Valles Marineris, a valley deeper and longer than the Grand Canyon, and the tallest volcano in the solar system – Olympus Mons. However, a smaller telescope will not reveal these to us directly. Instead, we need to hunt for larger features that are more obvious.
Discover more about Mars: What is Mars Made Of, And Why Is It Red?
You may already know that the Moon has mares, which are the darker ‘seas’ visible on its surface. Well, the Martian surface has these too.
There are two of these darker areas which are large and distinct enough to be seen with a small telescope: Syrtis Major and Mare Acidalium.
Syrtis Major is a roughly triangular area of darkness pointing towards the north pole. On the other side of the planet, Mare Acidalium is a dark region in the north of the planet which extends southwards.
Use a Martian map, like this one, as your guide to see what else you can discover.
Target 3: Dust Storms
By their nature, Martian dust storms are unpredictable.
They tend to be massive and can be picked up in a telescope when the planet is nearby. Sometimes, on average every five years, the whole planet becomes enshrouded in sand.
Our advice is to keep up with discussions on Cloudy Nights’ solar system observing forum. This is where conversations about Martian dust storms will be had as soon as they happen.
Got a Larger Telescope? See Our Guide to Major Surface Features on Mars
Summary
Mars is iconic.
Its red body is a sight all astronomers want to see and explore with their telescopes.
Enigmatically, it only reveals itself fully to us for three or four months every two years. Happily, 2022 is a year when this happens.
Get your telescope prepared to point in the direction of Mars from around September onwards, to witness its growing, brightenting disc, and to see how many surface features you can idenitfy.
