IS THERE LIFE IN THE SOLAR SYSTEM? Over the next few years, space probes will be visiting alien worlds looking for life. Our first contact with extraterrestrials could be just around the corner The main candidates in the Solar System to harbour life are Mars, Europa and Titan In this section: Mars | Europa | Titan

There may be no little green men living in our Solar System. However, there are plenty of places where more primitive life might be able to survive.

Many astronomers now believe that life has a good chance of evolving wherever the conditions are right. So our Solar System could be teeming with living creatures!

Join us as we take a voyage around the Sun's family looking for life...

The Moon

In the 19th century, many astronomers were convinced the Moon was inhabited by intelligent aliens. We now know that this isn't true. The Moon has no atmosphere, so life couldn't survive there.

Even so, the Apollo astronauts were held in quarantine after their trips to the Moon - just in case they had picked up any space bugs.

The rocky planets

The Earth is a rocky planet, so it seems sensible to look for life on other rocky planets too. We can ignore Mercury, because it's too close to the Sun, so it's too hot. And Pluto is too cold and far away to support life.

At first glance, Venus is an inhospitable planet. It is cloaked in thick clouds of sulphuric acid. These trap heat and fry the planet to over 500ºC.

Unsurprisingly, Venus was assumed to be a dead world. But now some scientists think life could survive in the clouds.

But the most likely candidate is Mars. Out of all the planets in the Solar System, Mars is most like Earth. And it's also the most likely to contain life.

Is there life on Mars?

The gas giants

The giant gassy planets have no solid surface on which life could roam. But could life still fly around in the atmosphere of a gassy planet?

Scientists have wondered whether creatures like jellyfish could survive on Jupiter or Saturn, feeding on organic material in the clouds. However, no evidence has yet been found that such creatures exist.

Moons of Jupiter and Saturn

The moons of Jupiter and Saturn may also be good places to look for life.

Titan, the largest moon of Saturn, could be similar to how the Earth was at the point when life started.

Learn more about life on Titan

Europa, the sixth moon of Jupiter, is the last candidate in the Solar System that may hold life. Europa is a frozen moon - but it may hide an exciting secret...

Discover Europa's secret

But to find intelligent life, we have to look further afield. Finding new planets outside our own Solar System is the first step.

Find out more about planet hunting