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Earth-like worlds may exist in nearby system

by Jacob Aron

There could be two Earth-like planets within cosmic spitting distance of our own. Both are likely too close to their star to host life, but the discovery opens the possibility of other planets in the system with more temperate climates.

Alpha Centauri is a binary star system just 4.3 light years away from our own. In 2012 astronomers announced that the system had a planet, which they dubbed Alpha Centauri Bb as it was apparently orbiting the smaller of the stars, Alpha Centauri B.

The team said it was a rocky world slightly more massive than Earth. But in 2013, other researchers called into question the existence of Bb, saying the evidence wasn’t good enough.

“If you ask anyone working in exoplanets, they would all have a different opinion about the existence of Alpha Centauri Bb,” says Brice-Oliver Demory of the University of Cambridge.

That’s why he and his colleagues have been using the Hubble Space Telescope to search for planet. They weren’t able to find it, but have instead seen hints of a second Earth-sized world in the system.

Star wobble

The original claim was based on the radial velocity method – a planet-hunting technique which looks at how the gravitational pull of a planet slightly wobbles its star. Demory’s Hubble search took a different approach, looking for signs of a dip in the light from Alpha Centauri B caused by the planet passing in front of, or transiting, the star. These two methods are independent of each other, so seeing Bb transit would reinforce the earlier patchy radial velocity data.

The original measurements suggested that Bb, if it exists, takes three or so days to orbit its star. But not all planets make transits as seen from Earth, because it depends on how the planet and star are aligned.

Demory’s team observed Alpha Centauri B in 2013 and 2014, for a total of 40 hours. The 2013 data showed signs of a transit consistent with Bb’s suggested orbital parameters, but it seemed to last slightly longer than expected, and the statistical validity of the signal disappeared when combined with the 2014 data. That doesn’t mean Bb isn’t there, just that if it exists, it is unlikely to transit as seen from Earth.

That still leaves a puzzle over what caused the 2013 signal. The team ruled out errors with Hubble itself or spots on the surface of the star, which can sometimes be mistaken for exoplanets.

They also dismissed the possibility of interference from Alpha Centauri A, the other star in the binary system, or from an unrelated, more distant star system that could have just been passing behind.

Scorchingly close

The only explanation left was that there is another planet in the system. The observations point to an Earth-sized planet with a year lasting no more than 20.4 days, putting it slightly further out than Bb but still scorchingly close to the star.

Astronomers have confirmed nearly 2000 exoplanets so far, and the evidence suggest many stars host multiple planets, just like our own solar system. That means confirming the discovery of one planet around Alpha Centauri B – even one with a hot, close orbit – hints at other planets in the system that might be more hospitable. “If you see one planet, the chance is there are other planets in the system,” says Demory.

“They work they’ve done holds tight; they give a very well balanced view on what this transit could be,” says Paul Wilson of the Paris Institute of Astrophysics in France. He’s not sure there is enough evidence yet to support a full discovery, but is keen to encourage the team. “I hope they will be able to detect an Earth-sized planet through the transit method. That would be fantastic.”

Unfortunately it’s going to be difficult to confirm either of these planets with our current generation of telescopes. Hubble could do it, but it would have to stare at Alpha Centauri for 20 days with no guarantee of finding anything, which would be seen as a waste of time for our most important space telescope, says Demory.

Upcoming instruments like the European Extremely Large TelescopeMovie Cameraor the Cheops space telescope might be able to see the new planet, but the best option could be a small satellite dedicated to staring at Alpha Centauri. Such a mission would only cost around $2 million. “It could be crowdfunded,” says Demory. Anyone fancy chipping in to find our nearest neighbours?

Reference: arxiv.org/abs/1503.07528

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Bizzare & Odd

This Space Cloud Smells Like Rum And Tastes Like Raspberries

So there’s a giant cloud hanging out in the Milky Way galaxy that smells a little bit like rum and tastes a little bit like raspberries. Here’s why Sagittarius B2 may be the most delicious cloud in space.

Let’s work our way up the ladder on this one. We’ll start at the bottom step, where things are unimaginably tiny. A carboxyl group is a group of atoms that looks like this: (C(O)OH). A carboxylic acid is any acid that has a carboxyl group. Glue one single extra atom of hydrogen on that group and you have formic acid, the most simple carboxylic acid. In fact, this acid is so basic that ants’ bodies can make it. If you have ever been stung or sprayed with ant venom, you have probably felt the sting of formic acid.

Let’s take another step up the ladder and add booze. Mix ethanol with formic acid and you have ethyl formate, which is an ester. Esters are the most famous of the aroma compounds and are responsible for most of the floral, fruit, and wine smells. A good proportion of esters are simply combinations of carboxylic acids and alcohols. To non-chemists who nevertheless paid attention in chemistry class, esters are known as the “smell molecules.”

Ethyl formate has a role to play in both fruit and wine. Drinkers know it as the “scent of rum,” but it comes wafting out of a lot of alcohols from cognac to whisky. Berry pickers will also know ethyl formate if they get their mouth around it; it’s one of the chemicals that gives raspberries their distinctive flavor. So smell it and it smells vaguely of rum; taste it and it tastes vaguely of raspberries.

When we examine ethyl formate on an even larger scale, we get the weird twist — way out in space, a cloud of gas is laden with ethyl formate, which means it smells like rum and tastes like berries.

Or perhaps we have this all the wrong away around. Perhaps we should have started large instead of small, because Sagittarius B2, the dust cloud 400 light-years away from the center of the galaxy, predates both the raspberry and rum. So maybe we should say that rum smells of cosmic dust cloud, and raspberries taste of it.

Source io9.gizmodo.com

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Space

Trump just ordered the Pentagon to establish a Space Force ‘immediately’

The United States seems to have always been pioneers in the space program. They were the first ones to actually walk on the moon, and they created the first ever reusable space vehicle in the space shuttle.

Now if President Donald Trump has his way, the country will again be pioneers when it comes to outer space exploration. Not only does he want to reignite the space program which has more or less been dormant in the country since the space shuttle program was retired, but he wants to create the first ever space force.

In fact, he has gone as far as to make the request of the Pentagon itself to implement this task force. He has gone as far as to tell their Department of Defense to start to put such a force into effect. In a press, In fact, President Trump has been quoted as saying:

“Our destiny beyond the Earth is not only a matter of national identity but a matter of national security, ”

If this program is implemented it will become the sixth branch of the military and actually the only branch of the air force that has been created in 71 years.

According to Trump it is imperative to the nation’s security, but is this really true? Well, we never know what could be lurking in space, and no this isn’t a reference to extraterrestrials, although you never know. But what about asteroids or comets that could have the ability to cause destruction to the earth, and such a task force could help eliminate this problem not only for the United States but the rest of the world as well.

Whatever, the reasons President Trump could have a point that maybe this is not just an idea to consider, but again the United States could get the wheels in motion. So, perhaps the universe imagined by Gene Roddenberry in Star Trek where there is a branch of the military known as Starfleet could actually be to the point of becoming a reality.

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Space

A trip to the ISS will cost you $55 million

Image Credit: Axiom Space

Space tourism firm Axiom Space is offering people the opportunity to spend ten days aboard the space station.

Based in Houston and founded by former International Space Station manager Michael T. Suffredini, the company has plans to not only offer trips to the ISS but to also build and launch its own modules.

Eventually, these will detach and become an independent facility known as the Axiom International Commercial Space Station.

This week the firm has revealed its price for a full ten-day stay aboard the ISS – $55 million – which will cover, not only the orbital stay, but also transportation and a 15-week astronaut training program.

The goal will be to launch the first module in 2019 and the first commercial customers in 2020.

“It is an honor to continue the work that NASA and its partners have begun, to bring awareness to the profound benefits of human space exploration and to involve more countries and private citizens in these endeavors,” Suffredini said in a statement.

The interiors of the new modules will be designed in partnership with French architect Philippe Starck.

“This is a dream project for a creator like me with a genuine fascination for aviation and space exploration,” he said. “The greatest human intelligence in the world focuses on space research.”

Source: Space.com |

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