It’s deja vu all over again.
It’s another batch of newly discovered earth-like planets, according to NASA officials, who on Thursday said that the Kepler space telescope has found another batch of planets.
U.S. space agency officials announced Thursday they have discovered another series of planets, the latest such planets to hit the space agency’s radar.
The space agency made the announcement Thursday, saying the latest discover reveals some of the smallest earth-like planets yet discovered. Space agency officials said the latest batch of planets was discovered using the Kepler space telescope, which is responsible for a number of newly discovered planets. The discovery of three rocky planets around one red dwarf suggests that the galaxy could be teeming with similar rocky planets.
The discoveries boost the list of confirmed extra-solar planets to 729, including 60 credited to the Kepler team. Kepler scientists have another 2,300 candidate planets awaiting additional confirmation.
The team of astronomers announced the discovery of three earth-like planets, one of which reportedly closely resembles Mars. All three planets are thought to be rocky, similar to Earth, but orbit so close to their star that it makes them too hot to be in the habitable zone. Of the more than 700 planets confirmed to orbit other stars, only a handful are known to be rocky, according to NASA scientists.
“Astronomers are just beginning to confirm thousands of planet candidates uncovered by Kepler so far,” said Doug Hudgins, Kepler program scientist at NASA Headquarters in Washington. “Finding one as small as Mars is amazing, and hints that there may be a bounty of rocky planets all around us.”
The latest finding was done under the guidance of astronomers at the California Institute of Technology in Pasadena. The team used data publicly released by the Kepler mission, along with follow-up observations from the Palomar Observatory and the W.M. Keck Observatory atop Mauna Kea in Hawaii.
The team noted that the latest discovery reveals the smallest solar system known to exist, adding that it reveals a wide range of planets that exist within the Milky Way galaxy.
None of the newly discovered planetary systems are like our solar system, though Kepler-33, a star that is older and bigger than the Sun, comes close in terms of sheer numbers. It has five planets, compared to our solar system’s eight, but the quintet all fly closer to their parent star than Mercury orbits the Sun.
“This is the tiniest solar system found so far,” said John Johnson, the principal investigator of the research from NASA’s Exoplanet Science Institute at the California Institute of Technology in Pasadena. “It’s actually more similar to Jupiter and its moons in scale than any other planetary system. The discovery is further proof of the diversity of planetary systems in our galaxy.”
The discovery comes just weeks after NASA announced the discovery of hundreds of exoplanets, noting that some are likely to reside in the habitable zone. In December 2011, scientists announced the mission’s first confirmed planet in the habitable zone of a sun-like star: a planet 2.4 times the size of Earth. Later in the month, the team announced the discovery of the first Earth-size planets orbiting a sun-like star outside our solar system.
The Kepler Mission is specifically designed to survey a portion of our region of the Milky Way galaxy to discover dozens of Earth-size planets in or near the habitable zone and determine how many of the billions of stars in our galaxy have such planets. The challenge for astronomers is to find terrestrial planets, such as those one half to twice the size of the Earth, especially those in the habitable zone of their stars where liquid water and possibly life might exist. Scientists say the results of the mission could better allow us to understand the diversity of planets within the universe, along with how planets and life form.
The telescope discovers planets by tracking parts of the sky, searching for when a planet crosses in front of its star as viewed by an observer. Terrestrial planets produce a small change in a star’s brightness of about 1/10,000 (100 parts per million, ppm), lasting for 1 to 16 hours. This change must be periodic if it is caused by a planet. In addition, all transits produced by the same planet must be of the same change in brightness and last the same amount of time, thus providing a highly repeatable signal and robust detection method.
Once detected, the planet’s orbital size can be calculated from the period (how long it takes the planet to orbit once around the star) and the mass of the star using Kepler’s Third Law of planetary motion. The size of the planet is found from the depth of the transit (how much the brightness of the star drops) and the size of the star.
From the orbital size and the temperature of the star, the planet’s characteristic temperature can be calculated. Knowing the temperature of a planet is key to whether or not the planet is habitable since only planets with moderate temperatures are habitable for life similar to that found on Earth.
