Mars has been a major focus of astronomers, researchers, and future explorers for several years now. While our neighboring planet has always been important, the fact that NASA, SpaceX, and others are planning actual manned visits in the future (and plenty of unmanned missions) has it at the front of everyone’s mind.

Initially, Mars will only be visited by highly-trained astronauts, but if all goes well, it is not unlikely that people will go there for work, tourism, and much more.

While there are still a lot of unknowns when it comes to traveling to Mars, one thing is almost certain. When people start visiting, one of the first things that they will do is pull out a camera and take a selfie with the Earth in the background. This raises the question: What will it look like?

We can see Mars from Earth. It typically looks like a small red dot with the naked eye, but it is definitely visible. Determining just how bright an object in the sky will be, however, is complicated. There are many factors that go into what makes an object bright in the sky, including its distance, how close it is to the sun, how reflective the surface of the object is, the atmosphere where the observer is, and more.

When looking at the brightness of planets, it is important to note that it is not a constant thing. As Mars travels around the sun, it can be at times closer to Earth and other times further away. Also, just like our Moon is sometimes a bright full moon and other times a dim new moon, the same happens with planets.

When thinking about how bright an object will be in the night sky, it is generally done by comparing it at its brightest level.

So, what would Earth look like from the surface of Mars?

Well, we don’t have to wait to find out. Mars rovers have taken pictures of Earth from the Martian surface. While Earth is definitely visible, it isn’t the brightest object in the sky. In fact, it appears slightly less bright than Mars does from Earth.

If all the objects in the Martian night sky were lined up at their brightest, Earth would be the 5th brightest one:

• Phobos – Phobos is one of two Martian moons, and it is the brightest object in the sky, though compared to our Moon, it is about 16 times dimmer. It is tiny compared to our Moon, though it does orbit much closer.
• Deimos – Deimos is the other Martian moon, and it is far less bright than Phobos, but it will still be the second brightest object in the sky.
• Venus – Venus is the third brightest object in the Martian sky.
• Jupiter – Jupiter comes in fourth when measured at its brightest point, though most of the time it would actually be slightly brighter than Venus due to the size, orbital path, and other factors.
• Earth – As mentioned, Earth comes in 5th on the list and would appear as a dim blue ball, in contrast to how Mars is a dim red ball to us here at home.

The Earth’s moon, interestingly enough, would actually be visible from Mars and rank somewhere in the top 25 objects, behind several other planets and about a dozen of the brightest stars.

If you ever get a chance to visit Mars, the sky will look somewhat familiar, though with known objects in different locations. The stars will largely have very similar brightnesses since they are so far away that the change in location won’t make much of a difference.

After you take that selfie of Earth, make sure to get to safety because, unlike Earth, the Martian surface is dangerous.

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