(Press-News.org) Astronomers announced today that they have discovered a new type of planet - a rocky world weighing 17 times as much as Earth. Theorists believed such a world couldn't form because anything so hefty would grab hydrogen gas as it grew and become a Jupiter-like gas giant. This planet, though, is all solids and much bigger than previously discovered "super-Earths," making it a "mega-Earth."
"We were very surprised when we realized what we had found," says astronomer Xavier Dumusque of the Harvard-Smithsonian Center for Astrophysics (CfA), who led the data analysis and made the discovery.
"This is the Godzilla of Earths!" adds CfA researcher Dimitar Sasselov, director of the Harvard Origins of Life Initiative. "But unlike the movie monster, Kepler-10c has positive implications for life."
The team's finding was presented today in a press conference at a meeting of the American Astronomical Society (AAS).
The newfound mega-Earth, Kepler-10c, circles a sunlike star once every 45 days. It is located about 560 light-years from Earth in the constellation Draco. The system also hosts a 3-Earth-mass "lava world," Kepler-10b, in a remarkably fast, 20-hour orbit.
Kepler-10c was originally spotted by NASA's Kepler spacecraft. Kepler finds planets using the transit method, looking for a star that dims when a planet passes in front of it. By measuring the amount of dimming, astronomers can calculate the planet's physical size or diameter. However, Kepler can't tell whether a planet is rocky or gassy.
Kepler-10c was known to have a diameter of about 18,000 miles, 2.3 times as large as Earth. This suggested it fell into a category of planets known as mini-Neptunes, which have thick, gaseous envelopes.
The team used the HARPS-North instrument on the Telescopio Nazionale Galileo (TNG) in the Canary Islands to measure the mass of Kepler-10c. They found that it weighed 17 times as much as Earth - far more than expected. This showed that Kepler-10c must have a dense composition of rocks and other solids.
"Kepler-10c didn't lose its atmosphere over time. It's massive enough to have held onto one if it ever had it," explains Dumusque. "It must have formed the way we see it now."
Planet formation theories have a difficult time explaining how such a large, rocky world could develop. However, a new observational study suggests that it is not alone.
Also presenting at AAS, CfA astronomer Lars A. Buchhave found a correlation between the period of a planet (how long it takes to orbit its star) and the size at which a planet transitions from rocky to gaseous. This suggests that more mega-Earths will be found as planet hunters extend their data to longer-period orbits.
The discovery that Kepler-10c is a mega-Earth also has profound implications for the history of the universe and the possibility of life. The Kepler-10 system is about 11 billion years old, which means it formed less than 3 billion years after the Big Bang.
The early universe contained only hydrogen and helium. Heavier elements needed to make rocky planets, like silicon and iron, had to be created in the first generations of stars. When those stars exploded, they scattered these crucial ingredients through space, which then could be incorporated into later generations of stars and planets.
This process should have taken billions of years. However, Kepler-10c shows that the universe was able to form such huge rocks even during the time when heavy elements were scarce.
"Finding Kepler-10c tells us that rocky planets could form much earlier than we thought. And if you can make rocks, you can make life," says Sasselov.
This research implies that astronomers shouldn't rule out old stars when they search for Earth-like planets. And if old stars can host rocky Earths too, then we have a better chance of locating potentially habitable worlds in our cosmic neighborhood.
INFORMATION:
Astronomers find a new type of planet: The 'mega-Earth'
2014-06-02
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
'Neapolitan' exoplanets come in three flavors
2014-06-02
The planets of our solar system come in two basic flavors, like vanilla and chocolate ice cream. We have small, rocky terrestrials like Earth and Mars, and large gas giants like Neptune and Jupiter. We're missing the astronomical equivalent of strawberry ice cream - planets between about one and four times the size of Earth. NASA's Kepler mission has discovered that these types of planets are very common around other stars.
New research following up on the Kepler discoveries shows that alien worlds, or exoplanets, can be divided into three groups - terrestrials, gas giants, ...
Harsh space weather may doom potential life on red-dwarf planets
2014-06-02
Life in the universe might be even rarer than we thought. Recently, astronomers looking for potentially habitable worlds have targeted red dwarf stars because they are the most common type of star, comprising 80 percent of the stars in the universe. But a new study shows that harsh space weather might strip the atmosphere of any rocky planet orbiting in a red dwarf's habitable zone.
"A red-dwarf planet faces an extreme space environment, in addition to other stresses like tidal locking," says Ofer Cohen of the Harvard-Smithsonian Center for Astrophysics (CfA).
Cohen ...
Because you can't eat just one: Star will swallow two planets
2014-06-02
Two worlds orbiting a distant star are about to become a snack of cosmic proportions. Astronomers announced today that the planets Kepler-56b and Kepler-56c will be swallowed by their star in a short time by astronomical standards. Their ends will come in 130 million and 155 million years, respectively.
"As far as we know, this is the first time two known exoplanets in a single system have a predicted 'time of death,'" says lead author Gongjie Li of the Harvard-Smithsonian Center for Astrophysics (CfA).
She presented her research today in a press conference at a meeting ...
Long-term results encouraging for combination immunotherapy for advanced melanoma
2014-06-02
New Haven, CT — The first long-term follow-up results from a phase 1b immunotherapy trial combining drugs for advanced melanoma patients has shown encouraging results — long-lasting with high survival rates — researchers report. First author Mario Sznol, M.D., professor of medical oncology at Yale Cancer Center, is presenting the updated data at the 2014 annual conference of the American Society of Clinical Oncology (ASCO) in Chicago.
Sznol, clinical research leader of the melanoma research program at Yale Cancer Center, was the senior author on the original study of ...
Does your stomach bacteria protect you from obesity?
2014-06-02
The germ Helicobacter pylori is the cause of most stomach ulcers, but new research in Alimentary Pharmacology & Therapeutics suggests that treating the bacteria is linked to weight gain.
It is estimated that 50% of the global population may be infected with H. pylori; however, only 20% of infected people experience symptoms. New evidence suggests that patients treated for the infection developed significant weight gain compared to subjects with untreated H. pylori colonization.
By reviewing data taken from forty-nine studies with data from ten European countries, Japan, ...
Britain's urban rivers cleanest in 20 years
2014-06-02
Scientists from Cardiff University have found that Britain's urban rivers are the cleanest they've been in over two decades.
The 21-year study of over 2300 rivers measured the presence of clean-river invertebrates - a yardstick for river health – which during the days of heavy industry and poor sewage treatment had declined considerably, but now appear to be making a comeback.
Although climate change has warmed British rivers by around 1-2 degrees over recent decades, the findings suggest that improved pollution control has managed to offset its damaging effects on ...
Cystic fibrosis and diabetes link explained
2014-06-02
Many people with cystic fibrosis develop diabetes. The reasons for this have been largely unknown, but now researchers at Lund University in Sweden and Karolinska institutet have identified a molecular mechanism that contributes to the raised diabetes risk.
"The increased risk of diabetes has previously been explained by the fact that cystic fibrosis causes damage to the pancreas, where the blood-sugar regulating hormone insulin is produced. We are the first research group to show that the mutated gene that causes cystic fibrosis also plays an important role in the release ...
Ice Storm Project and maternal stress
2014-06-02
Montreal, June 2, 2014 - A new study finds a link between prenatal maternal stress (PNMS) and the development of symptoms of asthma and autism in children.
A team of scientists from The Douglas Mental Health University Institute and from McGill University has been studying women who were pregnant during the January 1998 Quebec ice storm since June of that year and observing effects of their stress on their children's development (Project Ice Storm).The team examined the degree to which the mothers' objective degree of hardship from the storm and their subjective degree ...
Blunting rice disease
2014-06-02
A fungus that kills an estimated 30 percent of the world's rice crop may finally have met its match, thanks to a research discovery made by scientists at the University of Delaware and the University of California at Davis.
The research team, led by Harsh Bais, associate professor of plant and soil sciences in UD's College of Agriculture and Natural Resources, has identified a naturally occurring microbe living right in the soil around rice plants — Pseudomonas chlororaphis EA105 — that inhibits the devastating fungus known as rice blast. What's more, the beneficial soil ...
Obese, older, Caucasian women on dialysis most at risk for rare, deadly condition
2014-06-02
AUGUSTA, Ga. – Obese, Caucasian females over age 50 with diabetes and on dialysis because their kidneys have failed are among those at highest risk for the rare and deadly condition calciphylaxis, according to an analysis of the United States Renal Data System.
Calciphylaxis occurs when calcium and phosphorus bind to form a biological cement that blocks and inflames small blood vessels, putting patients at risk for major infection and skin ulcers as well as patches of dying skin, said Dr. Lu Huber, nephrologist at the Medical College of Georgia at Georgia Regents University.
"It's ...