Their orbits last between three and five days, meaning they follow paths close to their stars, Nasa said.
Jon Morse, director of astrophysics at Nasa, said: "We expected Jupiter-size planets in short orbits to be the first planets Kepler could detect.
"It's only a matter of time before more Kepler observations lead to smaller planets with longer period orbits, coming closer and closer to the discovery of the first Earth analog."
"It is a good sign that the satellite is working so well in such a small amount of time, which gives an indication of what is coming next"
Francisco Diego, research fellow in physics and astronomy at the University of London
Francisco Diego, a research fellow in physics and astronomy at the University of London, told Al Jazeera: "It is very significant, although this kind of discovery were expected, because the Kepler mission is tuned to find planets far smaller than the ones it is finding now.
"But it is a good sign that the satellite is working so well in such a small amount of time, which gives an indication of what is coming next."
It was also revealed at the American Astronomical Society meeting in Washinton on Monday that the Kepler Telescope had found two unclassifiable objects circling a star.
"The universe keeps making strange things stranger than we can think of in our own imagination," Morse said.
Borucki said that the pair of objects, which are about 14,500 degrees Celsius, are thousands of degrees too hot and too big to be planets, and are too small to be stars.
Jason Rowe, a Nasa researcher who first spotted the objects, is calling them "hot companions" at present.
Rowe has suggested that they could be newly born planets - about 200 million-years-old - which have extremely high temperatures.
However, Ronald Gilliland, from the Space Telescope Science Institute, thinks that they could be dying stars which are shedding outer layers - called dwarf stars.
The Kepler has a three-year mission to scan a region of the sky containing about 140,000 stars to continuously look for planets.
It surveys changes in brightness of stars - an indication that planets are circling them.
The size of the planet can be ascertained from the size of that dip in brightness and its temperature measured from the size of the star it orbits and the time period of that orbit.
"The Kepler observations will tell us whether there are many stars with planets that could harbour life, or whether we ight be alone in our galaxy," Borucki said.
"It is estimated to take three years to find and verify an earth-size planet."
Diego said: "Planets the size of the earth are much smaller and further away from stars. So they will typically take a year [to find].
"That is were the satellite will make major discoveries in two or three years to come."