NO EARTH-LIKE PLANETS EXIST WITHIN 100,000 LIGHT YEARS

That's the conclusion from the latest batch of exoplanets found that comprise a total of 32 new discoveries with new observatory technology.

Science has discovered about 75 exoplanets in 30 different planetary systems. The search for small planets - those with a mass of a few times that of the Earth known as super-Earths and Neptune-like planets - has already covered vast areas of outer space.

Some 24 of the discovered exoplanets have a mass below Earth's and most new low-mass candidates reside in multi-planet systems, with up to five planets per system.

The Geneva Observatory has been able to measure the back-and-forward motions of stars by detecting small changes in a star's radial velocity.

Such a precision is crucial for the discovery of exoplanets and the radial velocity method, which detects small changes in the radial velocity of a star as it wobbles slightly under the gentle gravitational pull from an (unseen) exoplanet.

More recently one exoplanet or "super Earth" was found was found to be a lava covered world with density similar to that of the Earth's. Such observations have given astronomers a great insight into the diversity of planetary systems and help humans understand how they can form.

Scientists have found three candidate exoplanets around stars that are metal-deficient.

Such stars are thought to be less favourable for the formation of planets, which form in the metal-rich disc around the young star. However, planets up to several Jupiter masses have been found orbiting metal-deficient stars, setting an important constraint for planet formation models.