Does it sometimes feel like the planets are so bright that they’re looking back at you? Well, one of them is! The European Space Agency (ESA) has just released a series of images from the Mars Express satellite showing the Earth and Moon from Mars.
Venus and Mars are currently putting on a display in the night sky. Just after sunset, Venus is the brightest object in the night sky after the Moon and, just above and to the left, Mars is visible as a fainter, red object.
Orbiting around Mars, but far too faint for the naked eye to observe, is the Mars Express satellite. It has orbited the planet over 24,000 times since its launch from Earth 20 years ago, and it spends its time studying the Martian atmosphere and surface. For its 20th birthday, Mars Express decided to turn its cameras away from the surface of Mars and back towards Earth.
The Earth and Moon as seen from Mars. Mars Express snaps a series of images of the Earth to celebrate its 20th birthday. The Moon can be seen as a faint point moving around the brighter, stationary Earth. Credit: European Space Agency
ESA also held a live stream from Mars as part of Mars Express' birthday celebrations, which you can watch here
Robots on Mars
When Mars Express first began its orbit, there was relatively little activity on the Martian surface. These days, Mars Express orbits above 8 Martian rovers and landers, and more are planned!
A map of Mars showing the locations and planned locations of the current Mars landers and rovers. Credit: The Planetary Society
Mars Express also now has more company in the skies. Earlier this year, Abu Dhabi's Hope spacecraft released an atlas of Mars using over 3000 images that it has taken while orbiting Mars, aiming to show Mars in all its glory.
An atlas of Mars from the Emirates Mars Mission. Credit: Abdullah Al Ateqi, Dimitra Atri and Dattaraj B. Dhuri, Center for Space Science/New York University Abu Dhabi
Life on Mars
For me, before starting my current job at the Centro de Astrobiología (CAB) in Madrid in September 2022, I didn't think much about Mars. But, here in Madrid, it’s a big topic. At the CAB, researchers work on everything to do with Mars, from developing instruments for Mars rovers to studying how life on Earth might survive on Mars and where Martian life might have lived.
For ESA and NASA, a major research goal is attempting to find evidence of life on Mars, past or present. Researchers think that, in the past, the surface of Mars looked much more like that of Earth, where oceans would have covered most of the northern hemisphere of the planet. Like on Earth, this may well have provided the conditions to cultivate and harbour life.
An artist’s impression of what Mars might have looked like 4 billion years ago. Credit: Hickman-Lewis, Natural History Museum
Today, the surface water on Mars has long since dried up, but it is still possible that life has prevailed. The ambitious Mars Sample Return project, a joint ESA and NASA mission, plans to take rock samples from key locations on Mars where life might exist and bring them back to Earth for study. This is a complicated project that involves multiple Mars rovers (which will take the samples and launch them into Mars’ orbit) and satellites (which will ‘catch’ the samples in Mars’ orbit and deliver them to Earth), with samples expected to arrive back on Earth in the 2030s.
A Universe full of life?
Finding evidence of life on another planet is a pretty big deal. Today, the only place in the Universe where we know life exists is here on Earth. If life can evolve on one of our closest neighbours, it tells us that either life on the two planets has a common origin or – perhaps even more excitingly – it is much easier for life to evolve than has previously been thought.
We now know of the existence of thousands of planets in orbit around other stars, so finding life on Mars would give us a whole new perspective on the habitability of these planets and the many others not yet discovered. Maybe it isn’t just a satellite around Mars that is taking a photo of the Earth as we are looking up at the stars.