Researchers from Europe have found a batch of "Super-Earths" orbiting a nearby star along with two other solar systems containing small planets.
The findings from these scientists show that Earth-like planets may be fairly common.
"Does every single star harbor planets and, if yes, how many?" asked Michel Mayor of Switzerland's Geneva Observatory. "We may not yet know the answer but we are making huge progress towards it," Mayor said in a statement.
The three planets that the researchers found are about 42 light years away. They are towards the southern Doradus and Pictor constellations. The three planets are larger than the Earth at 4.2 times the mass, 6.7 and 9.4. They move at a rapid speed around their star. One of the planets moving in four days compared the Earth's 365 days around the Sun. The slowest of the three takes 20 days to orbit their light source.
The scientists found the planets using the High Accuracy Radial velocity Planet Searcher or HARPS, a telescope at La Silla observatory in Chile. That source has helped locate more than 270 exoplanets. Most of the planets that have been found are giants like our solar system's Jupiter or Saturn. It is much more difficult to find smaller planets that are the size of the Earth.
As science makes advancements in instruments that view the heavens though more smaller planets have been found.
"With the advent of much more precise instruments such as the HARPS spectrograph ... we can now discover smaller planets, with masses between 2 and 10 times the Earth's mass," said Stephane Udry, who also worked on the study.
The HARPS uses spectrographic measurements to locate orbs in deep space. Direct images can not be directly made by these instruments.