Astronomers detect first Earth-size planets orbiting another star
By Brian Vastag, Published: December 20 - Washington Post
In a milestone hailed by scientists as a key step toward finding another Earth-like world, astronomers Tuesday announced the discovery of two blazingly hot planets roughly the size of Earth some 950 light years distant.
The discovery “demonstrates for first time that Earth-size planets exist around other stars, and that we can detect them,” said Francois Fressin, an astronomer at the Harvard-Smithsonian Center for Astrophysics who led the discovery team.
The two planets orbit a star much like our sun, but they whiz around it so fast and so close that their surfaces sizzle like frying pans.
“They’re way too hot to be anything like our own Earth,” said Sara Seager, a planet hunter at the Massachusetts Institute of Technology and a member of the discovery team.
The implication: No life — at least life as we can conceive it — is possible on the new planets.
Still, finding these hot Earth-sized planets is “seriously cool,” said Lisa Kaltenegger, who studies so-called exoplanets at the Max Planck Institute in Heidelberg, Germany, and was not involved in the research. “These discoveries are a great technological step forward.”
The planets were announced Tuesday in the journal Nature and during a NASA teleconference.
Detected by NASA’s Kepler space telescope, the two planets, dubbed Kepler 20e and Kepler 20f, are almost certainly rocky like Earth and not gaseous like Jupiter, Kaltenegger said.
The smaller planet, Kepler 20e, is about the size of Venus but much closer to its star, zooming around it every six days. An Earth year, by contrast, is 365 days.
The larger planet, Kepler 20f, is just three percent larger than Earth. “It’s the first Earth-sized planet” ever detected orbiting another star, Seager said. “It is a big milestone.”
Kepler 20f is a bit farther out from its star, completing an orbit about every 20 days. Its surface temperature is hotter than a pizza oven — about 800 degrees Fahrenheit.
The two planets nestle in among three other larger planets tightly circling the star Kepler 20.
“It’s a beautiful planetary system,” said Dimitar Sasselov, a planet hunter at the Harvard-Smithsonian center and a member of the discovery team.
But it’s also a puzzling one. None of the five planets lie within the so-called habitable zone, the narrow band of space around a star where water can exist as liquid. Instead, all five planets hug their star, orbiting closer than Mercury is to the sun.
And, unlike our solar system, the two newly-found rocky planets are interspersed with three larger, gassy, Neptune-like planets.
“The architecture of that solar system is crazy,” said David Charbonneau of Harvard University. “In our solar system, the two different kinds of planets don’t mingle. This is the first time we’ve seen anything like this.”
The finds mark a key moment in the accelerating search to bag and tag planets outside our solar system. Since the first such detection in 1995, multiple teams employing ground and space telescopes have found more than 700 planets orbiting other stars, according to an online catalogue.
The message, says Seager, is simple: Planets abound wherever we look. “We think every star has planets,” she said.
NASA launched the $600 million Kepler space telescope in 2009 on a mission to find other Earth-like planets. So far, the telescope has found 33 confirmed planets and 2,326 possible planets, but they are all too big or too hot to qualify as Earth-like. The telescope detects planets by staring at 150,000 stars near the constellation Cygnus. When light from a star dims, or winks, it indicates a possible planet passing by. If Kepler sees the same wink three times, astronomers infer a planet. The time that passes between winks indicates the planet’s orbital period, or year.
Earlier this month, Kepler scientists announced a planet square in its star’s habitable zone. Dubbed Kepler 22b, that planet is about 1.4 times as wide as Earth, likely too large to host a rocky surface. “It’s too big, we think, for life,” Seager said.
The next milestone for Kepler will be the big one: The detection of an Earth-sized world with a surface temperature just right for life. Kepler scientists are confident they will soon spot such an Earth 2.0.
“One of these days — whether next year or two years from now — Kepler will confirm a true Earth analog,” Sasselov said. “And that will be a historic moment.”
When asked whether the Kepler team planned to give the newly found Earth-sized planets a catchier name, Sasselov balked. “Everybody wants pretty names,” he said. “But what do we do? There will be thousands of these planets.”
Wednesday, December 21, 2011
Saturday, December 10, 2011
Higgs boson "the God particle" getting closer
Higgs particle: Getting closer
By Joel Achenbach
The Higgs particle is also known as the Higgs boson, or “the God particle,” a term that Leon Lederman used some years ago and which delighted journalists but surely offended photons and electrons throughout the universe. The Higgs is named after Peter Higgs, a theorist who four decades ago predicted its existence as part of the Standard Model of particle physics. No one’s ever found one. Discovering the Higgs is a central purpose of two very elaborate experiments being conducted at the Large Hadron Collider at CERN. On Tuesday, the CERN scientists will announce their latest batch of results, and, as Scientific American has reported, rumors abound that they’ve homing in on the Higgs. More here from Nature.
CERN has itself said that there will be no “discovery” announcement, and the best bet is that the two experiments haven’t quite nailed the Higgs with certainty but are getting very close. “I am looking for closure, and I don’t expect to get it next week,” a leading theorist tells me by email.
As SciAm notes, certainty in this case is made difficult by the fact that, even with the elaborate infrastructure in place at the LHC, there’s no way to catch a Higgs and bottle it up like a lightning bug.
“...the CMS and ATLAS detectors cannot directly catch Higgs bosons; those particles would decay into other particles immediately after being created in the LHC’s proton collisions. Instead, physicists must analyze the subatomic debris from the decays and reconstruct what happened.”
As my editor, Claudia, has pointed out, we’re at a point where a lot of major discoveries are indirect. No one shouts “Land ho!” from the crow’s nest anymore. Instead we find planets like Kepler 22-b, utterly invisible even with the most advanced telescope, but found through fluctuations in the light of its parent star. We are devising new ways to peel back layers of the onion.
Physicists are hoping to discover some “new physics” with the LHC. At the very least, they’d like to find a new particle they hadn’t even imagined. The Higgs, however, is kind of a familiar particle, as undiscovered particles go. It’s supposed to be lurking there somewhere because otherwise the Standard Model has a gaping hole in it. What matters most about the Higgs, beyond whether it exists at all, is how massive it is. If it’s high-mass, that gives you a different universe than a low-mass Higgs. Among other things, the “stability” of the vacuum is in play. A low-mass Higgs leads to a less stable vacuum, is what I hear.
I hope that we can all agree that a stable vacuum is better than an unstable one. We’ve got enough problems.
By Joel Achenbach | 10:15 AM ET, 12/10/2011
By Joel Achenbach
The Higgs particle is also known as the Higgs boson, or “the God particle,” a term that Leon Lederman used some years ago and which delighted journalists but surely offended photons and electrons throughout the universe. The Higgs is named after Peter Higgs, a theorist who four decades ago predicted its existence as part of the Standard Model of particle physics. No one’s ever found one. Discovering the Higgs is a central purpose of two very elaborate experiments being conducted at the Large Hadron Collider at CERN. On Tuesday, the CERN scientists will announce their latest batch of results, and, as Scientific American has reported, rumors abound that they’ve homing in on the Higgs. More here from Nature.
CERN has itself said that there will be no “discovery” announcement, and the best bet is that the two experiments haven’t quite nailed the Higgs with certainty but are getting very close. “I am looking for closure, and I don’t expect to get it next week,” a leading theorist tells me by email.
As SciAm notes, certainty in this case is made difficult by the fact that, even with the elaborate infrastructure in place at the LHC, there’s no way to catch a Higgs and bottle it up like a lightning bug.
“...the CMS and ATLAS detectors cannot directly catch Higgs bosons; those particles would decay into other particles immediately after being created in the LHC’s proton collisions. Instead, physicists must analyze the subatomic debris from the decays and reconstruct what happened.”
As my editor, Claudia, has pointed out, we’re at a point where a lot of major discoveries are indirect. No one shouts “Land ho!” from the crow’s nest anymore. Instead we find planets like Kepler 22-b, utterly invisible even with the most advanced telescope, but found through fluctuations in the light of its parent star. We are devising new ways to peel back layers of the onion.
Physicists are hoping to discover some “new physics” with the LHC. At the very least, they’d like to find a new particle they hadn’t even imagined. The Higgs, however, is kind of a familiar particle, as undiscovered particles go. It’s supposed to be lurking there somewhere because otherwise the Standard Model has a gaping hole in it. What matters most about the Higgs, beyond whether it exists at all, is how massive it is. If it’s high-mass, that gives you a different universe than a low-mass Higgs. Among other things, the “stability” of the vacuum is in play. A low-mass Higgs leads to a less stable vacuum, is what I hear.
I hope that we can all agree that a stable vacuum is better than an unstable one. We’ve got enough problems.
By Joel Achenbach | 10:15 AM ET, 12/10/2011
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