Entries in Planet (4)


Astronomers Discover Habitable Planet Around Nearby Star

Habitable planet orbits Tau Ceti Image credit: J. Pinfield/RoPACS network at the University of Hertfordshire(NEW YORK) -- Perhaps Earthlings aren’t alone in their celestial neighborhood.

An international team of scientists has discovered at least one new habitable planet – and, considering the vastness of space, this planet is fairly close.

A planet with conditions that can sustain life is one of five orbiting a star neighboring the sun, astronomers from the United Kingdom, USA, Chile and Australia recently revealed in an official statement. The star, called Tau Ceti, is located 12 light years away.

In an interview with ABC News, Steven Vogt, a professor at the University of California, Santa Cruz, said he believed there actually might be two planets in the Tau Ceti system with “conditions conducive to life” – though the official announcement described just one.

“In order for a planet to be inhabitable, it should lie in a zone that is neither too hot nor too cold to allow for liquid surface water and, potentially, life,” said Vogt, who was part of the international team that made the discovery.

A planet with a mass approximately five times that of Earth was the smallest planet found to be orbiting in the habitable zone of any Sun-like star, said a statement issued by the team of researchers.

The findings came after almost 14 years of gathering data from more than 6,000 observations from three different telescopes located in Chile, Australia and Hawaii.

“What is unique about this star is it’s amazingly nearby – that you can actually see it with the naked eye,” said Vogt. “There are nearly 18 stars that are this close to us. This is the 19th closest star, and that is why it is special.”

The results of the study followed the use of a new mathematical computational method that employed noise modelling, allowing the team to detect the new planets and their conditions.

“We chose Tau Ceti for this noise modeling study because we had thought it contained no signals,” said Hugh Jones from the University of Hertfordshire. “And as it is so bright and similar to our Sun, it is an ideal benchmark system to test out our methods for the detection of small planets.”

Jones is one of numerous astronomers on the team that also includes James Jenkins from the Universidad de Chile, a visiting fellow at the University of Hertfordshire; Chris Tinney of the University of New South Wales and Mikko Tuomi from the University of Hertfordshire.

Tuomi was the lead mathematician behind the mathematical noise modeling employed in the research.

Other scientists included Paul Butler of Carnegie Institution for Science, Simon O’Toole of the Australian Astronomical Observatory and Brad Carter from the University of Southern Queensland.

John Barnes and David Pinfield were also involved and supported by the University of Hertfordshire.

“This is an exciting study, and we look forward to many more similar findings – as it seems very common that lots of stars have their own planets which we can look into,” Tinney told ABC News.

“The emerging knowledge from this study is that it is almost certain to us now that almost every star has its own planets orbiting around it,” said Vogt. “This means there might be more planets than there are stars.”

Vogt added that even though there are numerous planets with similar habitable conditions, the team’s future strategy would be to focus on those nearest to Earth.

“This is very interesting because it allows for the possibility of sending robotics, sending signals, and have two-way communication with some life that might be out there,” he said.

Copyright 2012 ABC News Radio


Alpha Centauri, Nearest Star System, Has Earth-Sized Planet

iStockphoto/Thinkstock(NEW YORK) -- Many scientists, in their quest to determine just how lonely we are in the universe, have wondered whether there are any planets in Alpha Centauri, the closest star system to our own.  And now, the first results are in -- and yes, there is at least one planet orbiting Alpha Centauri B, one of the three stars clustered together there.  

European astronomers, using a 3.6 meter telescope at the La Silla Observatory in Chile, report it is remarkably small -- about as massive as Earth.  Worlds that small have been beyond earthlings’ capacity to detect them until just very recently.

The newly found planet is probably hellish being that it's only about four million miles from its host star (we’re 93 million miles from ours).  It’s also fast, completing one orbit -- one “year” -- in only 3.2 of our days.

For now, the most remarkable thing about the planet, say the astronomers, is that they found it at all.  It is much too distant to be seen directly.  Instead, they watched the planet make its star wobble slightly, pulled around by the planet’s gravity as it circled from one side to the other.

Their measurements showed the star moved from side to side at a top speed of 1.8 km (about 1.1 miles) per hour -- “about the speed of a baby crawling,” they said.

“It’s an extraordinary discovery and it has pushed our technique to the limit,” said Xavier Dumusque of the Geneva Observatory in Switzerland, who is lead author of the paper reporting the find in this week’s edition of the journal Nature.

The astronomers were able to detect the little world over a distance of 25 trillion miles, but just barely.  They kept watching for four years until they were sure.

It’s hardly a twin of Earth, but it is a neighbor of sorts and one more sign that the Milky Way galaxy is thick with planets.

Copyright 2012 ABC News Radio


Kepler 22b: Scientists Discover New Earth-Like Planet

Stockbyte/Thinkstock(MOFFETT FIELD, Calif.) -- Scientists at NASA's Ames Research Center in Moffett Field, Calif., announced on Monday the discovery of Kepler 22b, which may be about as close to resembling our planet as we're going to get about 600 light years away.

The Kepler space telescope discovery team said this planet is about 2.4 times wider than the Earth but its similar distance from a sun-like star might mean the average temperature on Kepler 22b is 72 degrees Fahrenheit.

Kepler scientist Natalie Batalha proclaimed, "It is right smack in the middle of the habitable zone."

She and her team came across the planet after spending five years peering through telescopes, looking for what is appropriately termed "Goldilocks" planets that are neither too hot nor too cold but just right for sustaining liquid water -- the key to life.

Geoff Marcy of the University of California-Berkeley, a Kepler investigator, calls it "a phenomenal discovery in the course of human history."  But he adds Kepler 22b "is probably rocky with a thick layer of water and gas, making it more like Neptune in our solar system."

Copyright 2011 ABC News Radio


Like Tatooine in 'Star Wars,' Planet Found with Two Suns

Artist's illustration of Kepler-16b. NASA/JPL-Caltech/T. Pyle(WASHINGTON) -- Early in the original Star Wars film, there is a scene in which a restless Luke Skywalker gazes at the sunsets -- twin suns, hanging over the horizon of his home planet of Tatooine.

It was a fanciful, charming idea by filmmaker George Lucas, and it now turns out the real thing -- or something very much like it -- might actually exist.  Scientists reported Thursday that they have found a planet circling two stars, about 200 light-years away from Earth.  Because every sun is a star, you might well see a double sunset from that planet.

Of the 1,600 so-called exoplanets so far discovered orbiting other stars, this is the first in a nice, stable, circular orbit around a binary star system.

"The Star Wars link is striking," said Alan Boss of the Carnegie Institution for Science, who was a co-author of the study in Friday's edition of the journal Science.  "The colors of the stars are a bit different from what Lucas showed, but if you could stand on that planet, you would see something pretty close to that."

The discovery was made using instruments on NASA's Kepler spacecraft, a telescope launched in 2009 to search for planets orbiting distant stars.  The newly found planet, known as Kepler-16b, was much too far away to be seen directly, but the instruments were sensitive enough to detect a tiny dimming of the two stars, once every 229 Earth days, as that faraway planet passed in front of them and blocked a little of their light.

"This mission has been a lot of fun because we're discovering all sorts of stuff like this," said Nick Gautier, the Kepler project scientist at NASA's Jet Propulsion Laboratory in Pasadena, California.

Boss said, "This is just unqualified good stuff."

Kepler-16b was something of a surprise to space scientists.  Many stars in the night sky are, indeed, double stars, but researchers had long debated whether they could even have planets.  Gravity from the two suns would whipsaw planets in different directions, some argued, pulling them apart before they could even form.

What would it be like on Kepler-16b if we could go there?  Not pleasant, Boss said.  Even if they can't see it, they can calculate its size and its distance from the two stars at the center of its solar system.  The planet, about as massive as Saturn, is probably a gas giant like Saturn or Jupiter, which means it probably does not have a solid surface on which one could stand.  And the two stars, which circle close together, are both smaller and dimmer than our sun.

So it would be cold there -- "like a cold winter day in Antarctica," Boss said.  "Not very nice."

Copyright 2011 ABC News Radio

ABC News Radio