Discovery Of Two Planets Opens New Era In Science

Astronomers have discovered two huge planets, only the second and third found outside the solar system, and at least one could have a warm, watery “broth” perhaps ideal for the chemistry of life.

Geoffrey Marcy, professor of physics and astronomy at San Francisco State University, announced Wednesday that one each has been found orbiting the stars 70 Virginis, in the constellation Virgo, and 47 Ursae Majoris, a star within the Big Dipper.

He told a national meeting of the American Astronomical Society that the discoveries open a new era in which scientists can seriously address, for the first time, a real possibility of other worlds like the Earth existing around stars other than the sun.

“We are at a watershed,” said Marcy. “There is a dawning of a new field in science. These new planets offer a challenge to us to compare them with those in our solar system.”

Marcy’s announcement came about three months after Swiss astronomers announced discovery of a planet in orbit of the star 51 Pegasi. Marcy and other American astronomers have confirmed the Swiss discovery.

All of the discoveries are based on long-term measurement of gravitational variations in the stars.

Other astronomers said the rapid-fire discovery of planets moves science closer to investigating directly the existence of life beyond the solar system.

All three stars hosting the new planets are within 40 light years of the Earth and each is about the size of the sun.

Marcy said the planet orbiting 70 Virginis is about nine times larger than Jupiter, the largest sister planet to Earth. The planet orbits the star every 116 days. He said the heat from the host star would keep the planet at about 185 degrees Fahrenheit, a temperature that would permit the presence of liquid water.

He said the water would be like “a nice toasty warm bath” or a “broth” that possibly could permit formation of complex organic molecules, such as amino acids and proteins, “that presumably led to life on Earth.”

Marcy said the 70 Virinis planet may not have a solid surface and may be mostly gaseous, similar to Jupiter. But it could have moons, he said, where life could form.

The planet about 47 Ursae Majoris has a mass of about three times that of Jupiter and has a circular orbit of just over three years. It, too, may have water, but Marcy said it probably would be frozen. He compared it to the water that is thought to be on Mars.