Mars now at Opposition - the best time to view or photograph the red planet for the next two years

It's all to do with different orbits....

Here on Earth we complete orbits around the Sun more quickly than Solar System planets that are further away, such as Mars, Saturn, Jupiter etc. 

Think of it as being like the inside of a running on a running track. Over time the Earth will move further away from the other planets as we "lap" them.  We could for example be on the other side of the Sun and a long distance from them.

Opposition refers to the times when our respective orbits take us as close as we're going to get to a another planet for a while. In other words, we're directly "opposite" it. 

Mars as seen from the HST (Hubble Space Telescope) during the 2016 Opposition. More here. 

The Mars 2025 Opposition occurs on the 16th of January, Sydney time but there's no rush.

If you see other dates such as the 15th of January for the event, they might be for say the USA. Don't worry however.

Oppositions are slow moving events - planets are great viewing in the weeks leading up to opposition and for weeks afterwards. They're not one of these "blink and you'll miss it" type of astro events. 

Mars will be fantastic viewing for the rest of January 2025 and well into February.

How often do Mars oppositions occur?

Planetary oppositions don't occur every 12 months. The reason is that by the time it takes for Earth to return to the same spot as the previous year, the other planet has moved on in its own orbit. Mars' orbit is about twice as long as Earth's which mean our planets spend more than a year before they are at opposition again. 

Mars oppositions occur roughly every 27 months, so viewing and imaging opportunities like the current one aren't common.

In comparison, Jupiter oppositions happen every 13 months and Saturn every 378 days or practically every year. 

Why are some Mars oppositions closer than other?

You might see headlines along the lines of "the best you'll see Mars until" etc. Some planetary oppositions bring us closer than others. This is because all planets travel around the Sun not in circular orbits, but elliptical orbits which are elongated. During their orbits they're slightly closer to the Sun than other times of the year. Even though the planets are aligned and opposite each on the same side Sun, the distance between them can vary. 

The 2027, 2029 and 2031 oppositions won't bring Mars as close to us as it is in 2025. We'll have to wait until 2033 to get closer to the red planet.

Where's Mars located in the night sky at the moment?

When planets are at opposition, they're usually visible for most if not all of the night. They rise early in the evening and are visible all night until the Sun rises.

For 2025, the opposition of Mars occurs not long after the Jupiter opposition some weeks ago.  Both will be in the sky at the same time. You will see Jupiter will rise a little before Mars. 

The view from Sydney on the 16th of January around 10.30pm local time. The size of the astro objects in illustration are to indicate relative brightness, not how large they'll appear in the sky. Image produced by Stellarium.

It will be hard to miss Jupiter as it's brightest object in the sky when it gets dark. Mars will be brightly glowing a deep red colour to the right of Jupiter and the slightly below. 

Is this something to do with the "parade of the planets I've heard about?"

Yes.  Mars, Jupiter, as well as Venus and Saturn can be all seen together. More here.

What sort telescope do I need to see Mars?

Mars reveals itself to be a planet in even fairly small telescopes.  A 70mm or 80mm refractor will show this as long as it's a f/8 or f/10 telescope. Wide field telescopes like a 80mm f/4 or f/5 might have trouble producing a large enough image to show Mars as planet. 

Bear in mind that Mars, along with the other planets, appears quite small in the night sky.  Here' a comparison with Mars and the Moon during a recent occultation where Mars disappeared behind the Lunar disk. 

Almost any set of binoculars will show Jupiter as a round "dot" instead of a star along with up to four of its moons spread out from either side of the giant planet. Even powerful binoculars won't show much else when used to look at Mars. 

Here at BINTEL we can assist with some telescopes that are well regarded for planetary viewing. A good example would be the Celestron StarSense Explorer DX 6.

This uses the famous Celestron SCT (Schmidt-Cassegrain Telescope) optical system that manages to pack a fairly long f-ratio telescope into a compact and portable tube.  Celestron SCT type telescope are a great astronomical all rounder. They produce large planetary images with enough aperture to collect light from faint object such as nebulae, galaxies and more. 

More details on this telescope here. 

Dobsonian telescopes or "Dobs" are sometimes overlooked as planetary telescopes and better known for deep-sky viewing - which is a shame as they offer great views of Mars, Jupiter and Saturn due to their comparatively long focal length. The solid mounts found on Dobs also result in steady viewing with little vibration. 

One such Dob that would be a great Mars viewing companion is the saxon 8" Dobsonian.

We'd be hard pushed to find a better value for money telescope for the planets - more information can be found on saxon Dobsonian telescopes here.

What am I going to see when I look at Mars through a telescope?

The size of Mars will depend on the size of your telescope and the type and magnification of the eyepiece. It should appear as a bright orange red "ball". One of the buzzes of using a telescope to view planets is when what appears to be a bright star with your eyes turns out to be a distant world through the eyepiece. 

Mars is unique as it's the only Solar System planet that we can easily see details on the surface.  You'll be able to spot the white polar caps which are made of frozen carbon dioxide (dry ice to us poor humans) as well as large lighter and darker areas of surface markings.

The red planet rotates at a similar rate to Earth. This means you'll see different surface features from night to night. 

Mars is fuzzy tonight part 1: Why is "seeing" important?

We all notice how stars "twinkle", but did you notice that the same stars can twinkle more on some nights compared to others? This is caused by air current above our heads. Just how steady the air is called the "seeing" by astronomers.  (Even a totally clear night can have poor air quality - it's not related to cloud cover blocking your view.) 

As Solar System planets have a lot of detail on a very small astro object, they can be impacted by the quality of the air.  Mars through a telescope might sometimes appear to shimmy and shake around and you could even have problems seeing the edge of the planet as it wavers about.  If you wait for a few minutes, the seeing might improve suddenly. You'll be presented by a razor sharp view of Mars and then it might go back to being a bit blurry.  Other times you might have to head out the follow nigh if things are bad enough.

We sometimes have BINTEL customers worried there's something wrong with their telescopes or they haven't have properly focused them, especially when they start using their new telescope. Don't stress - the views will improve. 

Mars is fuzzy tonight part 2: Dust storms

The red planet is renowned for vast dust storms that sweep across the planet hiding surface details 

Two 2001 images from the Mars Orbiter Camera on NASA’s Mars Global Surveyor orbiter showing Mars' surface being almost totally covered by a dust storm that originated in the planet's southern region. Image via NASA. More info here.

These dust storms seem to coincide with oppositions much to the frustration of astronomers! Luckily, the 2025 Mars opposition seems to be a dust free encounter. (Fingers crossed.)

We'll be talking more about Mars in the coming days as the 2025 Opposition rolls on.

Cheers,

Earl White

BINTEL

16th January 2025