Astronomers have detected our “grotesque” twin: A planetary system arranged much like our own solar system, a new study says.
Dubbed GJ676A, the system has two rocky planets orbiting close to its host star, and two gas giants orbiting far away. This means the system is arranged like our system—though in GJ676A, everything is much larger.
For instance, the smallest rocky planet in GJ676A is at least four times the mass of Earth, while the largest gas giant is five times the size of Jupiter.
Other multiple-planet systems have been discovered, such as HD10180, which has been called the richest exoplanetary find ever because of the seven to nine planets orbiting its host star.
But HD10180’s planets are all gas giants in relatively close orbits, while GJ676A has both rocky and gas planets—and its “Neptune-like” planet takes 4,000 days to make one orbit.
The long orbits of GJ676A’s gas giants and the short orbits of its close-in, extremely hot super Earths are what led the astronomers to dub GJ676A our solar system’s twin.
Source: National Geographic News – Solar System’s “Grotesque” Twin Found
Continue reading Researchers discover our twin solar system, GJ676A – where everything is 4x larger
Using results from the High Accuracy Radical Velocity Planet Searcher (HARPS) at the European Southern Observatory, the scientists say there are likely tens of billions of planets in the Milky Way galaxy alone that may be able to sustain life.
They estimate that one hundred of those planets are in the sun’s immediate neighborhood — which in space-speak is 30 light years away.
**The fastest known technology allows us to travel 1 light year in ~100 years
The generally accepted (though perhaps shortsighted) definition of a planet that can sustain life is one that has a mass between one and 10 times that of Earth, as well as a rocky surface, and the ability to sustain liquid water — meaning the planet’s surface temperature is neither too hot that water would evaporate nor too cold that it would freeze.
Although there are no planets that meet those criteria in our own solar system, the report suggests that they are common around other stars.
via LA Times
Continue reading Scientists estimate billions of habitable planets in the Milky Way