NASA's Spitzer space telescope accidentally discovered a new planet while conducting other studies. This planet -- almost the size of Mars and covered with an ocean of molten rock -- was described by one of the space agency's scientists as being just around the corner from Earth, cosmically speaking.

UCF-1.01 and Earth are separated by a mere 33 light-years, according to NASA. The diameter of UCF-1.01 is about 5,200 miles (8,400 kilometers), about two-thirds that of Earth.

Because of UCF-1.01's proximity to the star it orbits, its surface temperature is possibly more than a crispy 1,000 degrees Fahrenheit (600 degrees Celsius), which means it probably will not be a destination for Earthlings on their first interstellar tour.

The discovery of UCF-1.01 was accidental as the scientists were studying another heavenly body -- a Neptune-size planet named GJ 436b, which, incidentally, is also quite the hot spot: One estimate is that its surface temperature is in the area of 822 degrees Fahrenheit (439 degrees Celsius),

Larger planets are comparatively easy to find, but they are generally gas giants that have neither an atmosphere nor a rocky surface like those of Earth, according to National Geographic News. As a result, scientists mostly scan the skies in search of smaller worlds, which should be more likely to support life as we know it.

For example, NASA's Kepler space observatory is actively hunting for Earth-size planets around stars like the Sun. In three years, it has found more than 3,000 potential new worlds. However, Kepler scans the area of the universe between 100 and 2,000 light-years away from Earth, so it has a pretty big blind spot closer to home.