Astronomers Wednesday have discovered ‘MEarth.’
No, not mirth (although some could use it this holiday season).
“MEarth”, as in “mega-earth”:
Astronomers said Wednesday that they had discovered a planet composed mostly of water.You would not want to live there. Besides the heat — 400 degrees Fahrenheit on the ocean surface — the planet is probably cloaked in a dark fog of superheated steam and other gases. But its discovery has encouraged a growing feeling among astronomers that they are on the verge of a breakthrough and getting closer to finding a planet that something could live on.
“This probably is not habitable, but it didn’t miss the habitable zone by that much,” said David Charbonneau of the Harvard-Smithsonian Center for Astrophysics, who led the team that discovered the new planet and will reports its findings on Thursday in the journal Nature.
Geoffrey W. Marcy, a planet hunter from the University of California, Berkeley, wrote in an accompanying article in Nature that the new work provided “the most watertight evidence so far for a planet that is something like our own Earth, outside our solar system.”
Only 2.7 times the size of Earth and 6.6 times as massive, the new planet takes 38 hours to circle a dim red star, GJ 1214, in the constellation Ophiuchus — about 40 light-years from here. It is one of the lightest and smallest so-called extrasolar planets yet found, part of a growing class of planets that are less than 10 times the mass of Earth.
Dr. Charbonneau’s announcement capped a week in which the list of known planets, including these “super-Earths,” grew significantly.
An international team of astronomers using telescopes in Australia and Hawaii reported in one paper that they had found three planets, including a super-Earth, orbiting 61 Virginis, a star in the constellation Virgo that is almost a clone of the Sun. It was the first time, they said, that a super-Earth had been found belonging to a star like the Sun; the other home stars have been dwarfs. And in a separate paper, they reported finding a planet somewhat larger than Jupiter at the star 23 Librae.
And in yet another paper, a subset of the same group reported finding a super-Earth and probably two bigger planets circling HD 1461, a star in Cetus.
Paul Butler of the Carnegie Institution of Washington, who was involved in all three papers, said astronomers thought that one-third to one-half of all Sun-like stars harbored such super-Earths orbiting at scorching distances much closer than Mercury is to the Sun.
In the 15 years since the first extrasolar planet was found, more than 400 have been detected. The field is getting more intense as dedicated planet-hunting instruments like the Kepler satellite from the National Aeronautics and Space Administration, due to report a new batch of such planets next month, get into the game.
Alan P. Boss, a planetary theorist at the Carnegie Institution of Washington, said of the planet hunters, “Give them a couple more years and they’re going to knock your socks off.”
Dr. Charbonneau’s planet, only 1.3 million miles from its home star, is distinguished by its relative coolness — a consequence of the dimness of GJ 1214, which puts out one three-hundredth of the Sun’s energy. He and his colleagues had set out to search for planets around such stars, noting that they are more numerous and that it is easier to discern planets around them.
His planet-hunting equipment is a bank of eight telescopes called MEarth, pronounced “mirth,” on Mount Hopkins in Arizona. Each telescope is only 16 inches in diameter, no bigger than those that grace the backyard of many amateur astronomers. They monitor the light of 2,000 nearby stars, looking for the regular blips caused when a planet passes by, or transits.
In May, Zachory Berta, a first-year graduate student of Dr. Charbonneau, called the group’s attention to blips in the Ophiuchus star that seemed to be happening every 1.6 days. If he was right, Mr. Berta said, the next transit would occur at 6 a.m. on May 13.
Dr. Charbonneau was in Washington later that day preparing for a State Department dinner when he got a group e-mail message that began: “We have a winner. Congrats Zach!”
From the drop in starlight, the astronomers could calculate the diameter of the Ophiuchus planet, known now as GJ 1214b. Then they used a sensitive spectrograph on a 3.6-meter telescope in Chile to measure its gravitational tug on the star, thus deriving the planet’s mass. Using those two numbers, Dr. Charbonneau and his colleagues could calculate the density of the planet, about one-third that of Earth.
“What we probably have here is a water world,” Dr. Charbonneau said.
Dr. Charbonneau said the weight of the new planet’s presumptive atmosphere kept the water liquid rather than just boiling into space. He acknowledged that a different recipe, with more rock and a very puffy atmosphere, would also fit the data. That is unlikely, he and other planet experts say, but the steam-world theory may be soon tested.
The new planet is close enough to be studied directly by telescopes on or near Earth. Indeed, Dr. Charbonneau said his team had already applied for observing time on the Hubble Space Telescope.
“Our own TV signals,” he said, “have already passed this star.”
Actually, MEarth is the bank of telescopes on Mount Hopkins in Arizona that discovered this world. I just used a play on words.
It’s interesting that we’re discovering these water planets recently using ground telescopes. Must be that Microsoft planet discovering software works pretty good.
Well, President Obama did make a decision Wednesday when he had a talk with NASA head Charles Bolden.
And boy, the North Alabama Space Administration ain’t gonna like it!
President Barack Obama will ask Congress next year to fund a new heavy-lift launcher to take humans to the moon, asteroids, and the moons of Mars, ScienceInsider has learned. The president chose the new direction for the U.S. human space flight program Wednesday at a White House meeting with NASA Administrator Charles Bolden, according to officials familiar with the discussion. NASA would receive an additional $1 billion in 2011 both to get the new launcher on track and to bolster the agency’s fleet of robotic Earth-monitoring spacecraft.
The current NASA plan for human exploration is built around the $3.5 billion Constellation program, which would provide a way to get humans to the space station and beyond. But its initial launcher, Ares 1, has faced a string of cost and technical problems, and it was excluded from several options for future space flight put forth earlier this year by an outside panel chaired by retired aerospace executive Norman Augustine. Although that panel suggested a $3 billion boost to NASA’s $18.7-billion-a-year budget in order to take a firm next step in human space flight, Obama’s support for a $1 billion bump next year represents a major coup for the agency given the ballooning deficit and the continuing recession. And NASA just won a $1 billion boost from Congress for 2010 in a bill signed by the president.
According to knowledgeable sources, the White House is convinced that scarce NASA funds would be better spent on a simpler heavy-lift vehicle that could be ready to fly as early as 2018. Meanwhile, European countries, Japan, and Canada would be asked to work on a lunar lander and modules for a moon base, saving the U.S. several billion dollars. And commercial companies would take over the job of getting supplies to the international space station.
“The decision is not going to make anyone gasp,” said one source in the White House, which hopes to ease congressional concerns about the impact of the new plan on existing aerospace jobs. But the decision, which has not yet been formally announced, is sure to spark opposition from Senator Richard Shelby (R-AL) and other members who fear that any change to the current Constellation rocket program will lead to mass layoffs in their states. Indeed, Shelby inserted language into the final 2010 spending bill for NASA requiring congressional approval before any changes are made to Constellation.
Former U.S. President George W. Bush proposed sending humans back to the moon in 2004. Since that time, however, interest has grown in other destinations. While the U.S. partners focus on lunar exploration, the White House is more intrigued by missions to asteroids and Phobos and Deimos as a precursor to a human landing on the Red Planet in the distant future. That option was given particular prominence by Augustine panel members when they testified this fall before congressional committees. To prepare for human visits, NASA may order additional robotic missions to the martian moons and asteroids in coming years.
The new program would jettison Ares 1. To appease congressional critics like Shelby, the Administration hopes to ensure that research and development work on the new rocket would proceed without significant job losses at NASA centers like Marshall Space Flight Center in Huntsville, Alabama.
But Shelby appears to be preparing for battle. In a 14 December letter to NASA’s inspector general, he said that several Augustine panel members were registered lobbyists who took “direct advantage of their temporary roles on the Commission to further their personal business.” He asked the inspector general to conduct a thorough investigation into the matter.
Augustine could not be reached for comment. The panel did include the president of a company that stands to gain from a recompetition of the new launcher, but none of the committee members were registered lobbyists, according to a report in the Orlando Sentinel. But there were numerous staffers from industry backgrounds who helped compile the Augustine report released in October. Shelby’s press secretary, Jonathan Graffeo, did not return calls requesting comment.
The report has kindled heated debate within Congress, the aerospace industry, and the White House regarding what direction the president should take. Obama chose from several options presented to him by NASA, the Office of Management and Budget, and the Office of Science and Technology Policy. Those options included keeping the budget flat and delaying a new launcher, building a heavy-lift launcher with an additional $1 billion for the agency, ramping up NASA’s annual budget by $3 billion for an aggressive program, or abandoning space flight altogether and reducing NASA’s budget. The president’s decision to go with the second option is a major departure from his 2010 budget plan, which called for a 5% increase in 2010—the boost just approved by Congress—but then remaining flat through 2014.
This is a major coup for the nascent commercial space companies, such as Elon Musk’s SpaceX, who have yet to prove they can safely transport humans to Earth orbit.
The 2018 time frame for a “simpler” heavy-lift launch vehicle is interesting also, since any such vehicle, even using the mainstream chemical rocket technology, is a major undertaking involving many people and locations.
Maybe a bone to throw to Senator Shelby, as the article suggests?