Tag Archives: goldilocks

New class of star-stripped super-Earths discovered

Astrophysicists have discovered a new class of exoplanets whose atmospheres and volatile elements have been blown away by the star they’re orbiting. Their findings help cover a previously uncharted gap in planetary populations and offers valuable insight for locating new worlds to colonize.

Too close for comfort.
Image credits: ESO/ .Calcada

There’s an old Latin saying along the lines of “dosage makes the poison,” and that holds true even on immense scales. Planets are on the receiving end of a huge amount of energy emitted by their host star as heat, radiation and charged particles — commonly known as solar winds. Earth sits comfortably in the Goldilocks zone, close enough to the sun so it won’t freeze over but not too close, so it doesn’t bake and burn. It’s also far enough from the sun to allow its magnetic field to effectively repel much of these particles and radiation. But not all earth-like planets are so fortunate.

By using data from NASA’s Kepler space telescope, astrophysicists from the University of Birmingham have discovered a new class of ‘stripped’ rocky planets. These Earth-like planets orbit very close to their stars, and are subjected to a torrent of high-energy radiation and extreme temperatures. Over time, this heat causes the volatile substances in the rocks to escape into the atmosphere. Radiation, in turn, strips the outer gaseous layer, leaving only a shrunk rocky core exposed.

‘For these planets it is like standing next to a hairdryer turned up to its hottest setting,” said Dr Guy Davies, from the University of Birmingham’s School of Physics and Astronomy. “There has been much theoretical speculation that such planets might be stripped of their atmospheres. We now have the observational evidence to confirm this, which removes any lingering doubts over the theory.’

The team used asteroseismology to characterize the stars and their planets they were investigating much more accurately than ever before. Asteroseismology uses the natural resonances of stars to reveal their properties and inner structures.

The findings are important in helping us understand how stellar systems evolve over time. It also highlights the crucial role the host star plays in shaping the planets orbiting it.

Dr Davies added: ‘Our results show that planets of a certain size that lie close to their stars are likely to have been much larger at the beginning of their lives. Those planets will have looked very different,’ Dr Davies added.

The full paper, titled “Hot super-Earths striped by their host stars” has been published online in the journal Nature Communications and can be read here.

Secrets of dinosaur footprints revealed, thanks to goldilocks effect

A groundbreaking research conducted by the University of Manchester showed that terrain thought to be ruled only by giant dinosaurs was shared by numerous other smaller species. Dr. Peter Falkingham made a very interesting discovery, showing that dinosaurs can create lasting footprints, but under the right circumstances, combined with the right animal weight.

The research is extremely important because significant dinosaur track sites played a keyrole in understanding and simulating mesozoic environments, but these simulations may be flawed, and numerous other species may have walked the same areas, without leaving any footprints behind.

Dubbed the Goldilocks effect (that word seems to be everywhere these days), because every condition has to be just right, this finding also relied on computer simulations, with researchers modifying the conditions of the mud and dinosaur weight; they showed that only really big dinosaurs have a significant chance of leaving a footprint when the mud was tougher, while in softer mud, it was the other way around.

“That’s very hard to do with physical modeling, more so when you need to do it 20 times in 20 different types of mud. But the real advantage of computer modeling is that everything is controllable. We were able to ensure that in every simulation we could look at the effects of each variable (for instance, the shape of the foot, or the weight of the animal) independently. Now we can use this “Goldilocks” effect as a baseline for exploring more complicated factors such as the way dinosaurs moved their legs, or what happens to tracks when a mud is drying out.”

Picture source

The Kepler mission: searching for planets in the Goldilocks area

The Goldilocks area is one of the most interesting for astronomers throughout the known Universe, as it has great hope for finding planets similar to our Earth. The Kepler 10b planet is not the most hospitable one you could think of: located some 560 million light years away from our planet, and with a surface temperature hot enough to melt steel, it is however the first one located with the Kepler space telescope, which was launched by NASA with the role of finding habitable planets in the Goldilocks area, not too cold and not too hot; many have nicknamed it Hubble’s smaller brother.

Since the first planet beyond our solar system has been found in 1992, it’s been pretty much of a roll, with the count now being over 500, and the finds will grow a whole lot in the near future, partially thanks to the Kepler telescope; one of the leading astronomers of the project is Geoff Marcy, who helped spot 70 planets out of the first 100 ever to be found.

What sometimes gets lost in the shuffle when a nice result shows up on all of the Web pages and the newspapers around the world — what you don’t realize is to get that result meant that five or 10 people were burning that midnight oil, trimming the errors down to the point that the Earth-size planets are detectable. It’s easy to dismiss the discoveries as, Oh, it’s new computers, or it’s new optics. These things happen because amazing people dream and then put their dreams into perspiration-dripping action.

He also seems very optimistic about the future of Kepler, and for good reason: just this week he managed to find nine planets, and this is just the beginning.

“Honestly, Kepler’s so good that it’s hard to beat it. It gets the numbers. Kepler’s going to find thousands. There’s going to be another follow-up to Kepler, either from Europe or the U.S. or both. They’ll find thousands. I bet by 2020, there’ll be 10,000 planets, and by 2030 there might be another 20,000 or 30,000 more planets.”

The bad news is that the number of the planets will find will plateau, and not grow exponentially; the good news is that it’s not the numbers we should be looking at increasing, it’s the quality of the findings. We should be looking at planets with an atmosphere, and with a temperature between the freezing and boiling point. The odds of life on Earth may be one in a billion, but there are a lot more than 1 billion planets out there, so if we keep looking, we’re bound to find something.

First rocky habitable Earth-like planet

A recently discovered planet is just about the right size and is in the right place to host life; as a matter of fact, astronomers seem quite sure it hosts life, and we’re talking more than microbes. Still, current technology doesn’t allow scientists to search for chemical markers of life.

About 20 light years away, it revolves around a red dwarf, and has been nicknamed Gliese 581g – the “g” stands for Goldilocks.

“Personally, given the ubiquity and propensity of life to flourish wherever it can, I would say that the chances for life on this planet are 100 percent. I have almost no doubt about it,” Steven Vogt, professor of astronomy and astrophysics at University of California Santa Cruz, told Discovery News.

The discovery comes as a result of an 11 year program to get as much information as possible with ground-based instruments and telescopes; these instruments work by measuring minute variations caused by gravitational tugs of orbiting planets.

Red Dwarf

“This is really the first ‘Goldilocks’ planet, the first planet that is roughly the right size and just at the right distance to have liquid water on the surface,” astronomer Paul Butler, with the Carnegie Institution in Washington, D.C., told reporters during a conference call Wednesday.

“Everything we know about life is that it absolutely requires liquid water,” he added. “The planet has to be the right distance from the star so it’s not too hot, not too cold… and then it has to have surface gravity so that it can hold on to a substantial atmosphere and allow the water to pool.”

The planet is roughly three times larger than Earth, so it’s big enough to hold an atmosphere. It’s also quite old, and even more interesting, it’s tidally locked to the Sun, in a similar fashion to the Moon locked to the Earth: the planet’s star always ‘sees’ the same side, which is perpetually warmer and lighted, while the other one is dark and cold. As a result, temperatures are pretty stable, and vary greatly, which also encourages life.

“This planet doesn’t have days and nights. Wherever you are on this planet, the sun is in the same position all the time. You have very stable zones where the ecosystem stays the same temperature… basically forever,” Vogt said. “If life can evolve, it’s going to have billions and billions of years to adapt to the surface.”

“Given the ubiquity of water, it seems probable that this thing actually has liquid water. On the surface of the Earth, everywhere you have liquid water you have life,” Vogt added.

Astronomers seem quite convinced that many more such planets will be discovered in the not so distant future, and we will be entering a new stage in studying Earth-like planets.

“That being said, it is so close and we have found this thing so soon that it suggests we will start finding a lot of these things in the future and eventually we will find systems that do transit. This is a harbinger of things to come.”

The research will be published in the Astrophysical Journal