SpaceJibe

February 22, 2017

Major Discovery! 7 Earth-Size Alien Planets Circle Nearby Star

Astronomers have never seen anything like this before: Seven Earth-size alien worlds orbit the same tiny, dim star, and all of them may be capable of supporting life as we know it, a new study reports.

“Looking for life elsewhere, this system is probably our best bet as of today,” study co-author Brice-Olivier Demory, a professor at the Center for Space and Habitability at the University of Bern in Switzerland, said in a statement.

The exoplanets circle the star TRAPPIST-1, which lies just 39 light-years from Earth — a mere stone’s throw in the cosmic scheme of things. So speculation about the alien worlds’ life-hosting potential should soon be informed by hard data, study team members said. [Images: The 7 Earth-Size Worlds of TRAPPIST-1]

“We can expect that, within a few years, we will know a lot more about these planets, and with hope, if there is life there, [we will know] within a decade,” co-author Amaury Triaud, of the Institute of Astronomy at the University of Cambridge in England, told reporters on Tuesday (Feb. 21).

TRAPPIST-1 is an ultracool dwarf star that’s only slightly larger than the planet Jupiter and about 2,000 times dimmer than the sun.

The research team, led by Michaël Gillon of the University of Liège in Belgium, originally studied the star using the TRAnsiting Planets and PlanetesImals Small Telescope (TRAPPIST), an instrument at the La Silla Observatory in Chile. (This explains the star’s common name; the object is also known as 2MASS J23062928-0502285.)

TRAPPIST spotted regular dimming events, which the team interpreted as evidence of three different planets crossing the face of, or transiting, the star. In May 2016, Gillon and his colleagues announced the existence of these three alien worlds, called TRAPPIST-1b, TRAPPIST-1c and TRAPPIST-1d. All three, the team reported, are roughly the size of Earth and may be capable of supporting life.

The astronomers kept studying the system, using TRAPPIST and a number of other telescopes on the ground. This follow-up work suggested that the supposed TRAPPIST-1d transits were actually caused by more than one planet, and also revealed evidence of additional possible worlds in the system.

A three-week observation campaign by NASA’s Spitzer Space Telescope in September and October 2016 helped clear all of this up. Spitzer’s transit data confirmed the existence of planets b and c, but revealed that three worlds are responsible for the originally detected “TRAPPIST-1d” signal. And Spitzer also spotted two more exoplanets in the system, for a total of seven.

These seven worlds — which Gillon and his colleagues announced in the new study, published online today (Feb. 22) in the journal Nature — are all roughly Earth-size. The smallest is about 75 percent as massive as Earth, while the largest is just 10 percent heftier than our planet, the researchers said.

“This is the first time that so many planets of this kind are found around the same star,” Gillon said in Tuesday’s news conference. [Gallery: The Strangest Alien Planets]

All seven alien worlds occupy tight orbits, lying closer to TRAPPIST-1 than Mercury does to the sun. The orbital periods of the innermost six worlds range from 1.5 days to 12.4 days; the outermost planet, known as TRAPPIST-1h, is thought to complete one lap in about 20 days. (Spitzer spotted just one transit by TRAPPIST-1h, so its orbital path is not well-known.)

The six inner planets are in near-resonance, meaning their orbital periods are related to each other by a ratio of two small integers. This arrangement suggests that the worlds formed farther out in the system and then migrated in to their current positions, study team members said.

Data gathered by the various telescopes suggest that all six inner planets are rocky, like the Earth; not enough is known about planet h to determine its composition.

Because the seven alien worlds orbit so tightly, they’re probably all tidally locked, Gillon said. That is, they likely always show the same face to their host star, just as Earth’s moon only shows the “near side” to us.

And powerful gravitational tugs, both from TRAPPIST-1 and neighboring planets, could heat up the worlds’ insides considerably, leading to lots of volcanism, especially on the innermost two worlds, the researchers added.

Despite these characteristics — extreme closeness to their star and tidal locking — the TRAPPIST-1 system is a promising place to search for E.T., study team members said.

TRAPPIST-1 is so dim and cool that its “habitable zone” — that just-right range of distances where liquid water could exist — is quite close to the star. And even tidally locked planets are thought to be potentially habitable, as long as they have atmospheres that can transport heat from the day side to the night side, Gillon said.

“You’d have just a [temperature] gradient, but it’s not catastrophic for life,” he said.

Indeed, modeling work performed by the team suggests that three of the seven TRAPPIST-1 planets (e, f and g) are in the habitable zone. And it’s possible that, given the right atmospheric conditions, water — and, by extension, life as we know it — could exist on all seven, Gillon said.

Such speculation is preliminary, he and other team members stressed; more data will be needed before the TRAPPIST-1 planets’ habitability can be gauged with confidence. Such work is already underway. The team has been studying the worlds’ atmospheres with NASA’s Hubble Space Telescope, for example.

Detailed characterization — and the search for signs of possible life, such as oxygen and methane — will have to wait until more powerful instruments come online, Triaud said. But that wait shouldn’t be long: NASA’s $8.8 billion James Webb Space Telescope is slated to launch in late 2018, and huge, capable ground-based scopes such as the European Extremely Large Telescope and the Giant Magellan Telescope are scheduled to come online in the early to mid-2020s.

“I think that we’ve made a crucial step toward finding [out] if there is life out there,” Triaud said. “Here, if life managed to thrive, and releases gases similar to that that we have on Earth, then we will know.”

Characteristics of the seven TRAPPIST-1 worlds, compared to the rocky planets in our solar system. (NASA/JPL-Caltech)

Characteristics of the seven TRAPPIST-1 worlds, compared to the rocky planets in our solar system. (NASA/JPL-Caltech)

If there were life-forms on one or more of the TRAPPIST-1 worlds, what would they see? Because of the star’s dimness, even daytime skies would never get brighter than Earth’s are just after sunset, Triaud said. (Still, the air would be warm, because most of TRAPPIST-1’s light is radiated in infrared, not visible, wavelengths.) And everything would be suffused in a sort of salmon-colored glow.

“The spectacle would be beautiful, because every now and then you would see another planet, maybe about as big as twice [Earth’s] moon in the sky, depending on which planet you were on,” Triaud said.

Future work may help determine just how common such seemingly exotic vistas are in the sun’s neck of the cosmic woods.

“About 15 percent of the stars in our neighborhood are very cool stars like TRAPPIST-1,” Demory said in the same statement. “We have a list of about 600 targets that we will observe in the future.”

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February 11, 2017

Ten reasons why NASA’s James Webb Space Telescope will kick some cosmic butt

Filed under: Big Bang, Cool, Cosmology, Extraterrestrial Life, Gadgets, Space Exploration — bferrari @ 3:05 pm

Here are ten amazing facts about the JWST that you might not have known.

James Webb Space Telescope

James Webb Space Telescope

1. It’s as big as a tennis court

With a sunshield 22 metres (72 feet) in length, the size of a tennis court, and a mirror 6.5 metres (21 feet) wide the JWST, which is due to launch in October 2018, is over twice the size of the Hubble Space Telescope, making it the largest space telescope ever launched.
2. The mirrors are coated in a golf ball’s worth of gold
The JWST’s mirrors are covered in gold to optimise them for infrared light, with the gold further protected by a thin layer of glass. The thickness of this gold coating is 0.00001 centimetres across the 25 square-metre mirror’s surface, and in total the gold weighs 48.25 grams, roughly equivalent to the weight of a golf ball.
3. It’ll be about four times further from Earth than the Moon

The JWST will take about a month to reach a position 1.5 million kilometres (930,000 miles) from Earth known as Lagrange point 2, or L2. Here the telescope’s observations will be unhindered by Earth and the Moon although, if it malfunctions (as happened with Hubble), we currently have no way to go and fix it.

 

4. It could see a penny 24 miles away

The angular resolution of the JWST, which is the sharpness of the images, is incredibly precise. It can see at a resolution of 0.1 arc-seconds, which means that it could resolve a penny 24 miles (40 kilometres) away or a football 340 miles (550 kilometres) away.

5. It could find water on exoplanets

One of the JWST’s most notable abilities is that it will be able to detect planets around nearby stars by measuring infrared radiation, and it will even be able to measure the atmospheres of exoplanets by studying the starlight that passes through. By doing this it will be able to determine if an exoplanet has liquid water on its surface.

6. It’s seven times more powerful than the Hubble Space Telescope

The giant mirror of the JWST is made of 18 individual hexagonal segments composed of lightweight beryllium. It is almost three times the size of Hubble’s mirror, boasting a light-collecting area seven times greater, but both mirrors weigh almost the same owing to the lighter materials used on the JWST’s mirror.

7. It’ll see the first light of the universe

One of the goals of the JWST is to observe the first stars and galaxies that formed just a few hundred million years after the Big Bang, an era of the universe that is not fully understood. The telescope will be sensitive to infrared light, which will enable it to do this.

8. It will unfold to its massive size in space

Many features of the JWST, including its giant mirrors and sunshield, are designed to be launched on a rocket in a smaller payload. The telescope will launch in a compact outfit and will unfold in its full configuration once it reaches space.

9. One side is hotter than Death Valley, the other is colder than Antarctica

The side of the JWST that will always face the Sun, the bottom of the sunshield, will reach temperatures of 85°C (185 °F). The other side, which houses the mirrors and science instruments, will operate at a much nippier -233°C (-388 °F).

10. It could keep working for a decade

The official mission lifespan for the JWST is between five and ten years. The telescope is limited by the amount of fuel it has on board used to maintain its position, which will be enough for a ten-year lifetime. Of course, other factors like budget cuts or malfunctions could end the mission earlier.

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Scientists Recreated The Sun In A Lab

Filed under: Uncategorized — bferrari @ 2:41 pm

And it could generate free, clean energy forever.

Scientists recently took a step toward generating cheap, unlimited power forever.

The process uses fusion, which binds together the nuclei of lighter atoms into heavier atoms. The byproduct of fusion is huge amounts of energy—with no dangerous radioactive waste. And it gets better: Fusion utilizes hydrogen, something that’s in abundant supply in water.

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The fusion of lighter atoms is achieved by heating hydrogen to a plasma state — around 80 million degrees Celsius. The problem? That’s so hot, the plasma would burn any container built for it.

So, scientists at Germany’s Max Planck Institute for Plasma Physics didn’t build a physical container. Instead, their Wendelstein 7-X (W7-X) fusion energy device generated a magnetic field to contain the plasma. (I’m going to call it a “force field,” and you’re not going to stop me.) The force field keeps the superheated hydrogen from even touching the sides of its container. It’s called a stellerator, or “star in a jar,” because it works like our sun does. The scientists said in December that the containment system works as planned. Now they can proceed to the next step in their experiment.

Fusion is superior to fission, the nuclear power we’ve used since 1954, in lots of ways. Fission splits atoms of heavy, radioactive elements like uranium and plutonium, releasing huge amounts of energy.

Fusion generates four times as much power from an equal mass of fuel as fission does. It generates 4 million times as much energy as burning coal, oil or gas, all of which create pollution. Fission generates radioactive waste, which remains deadly for thousands of years and can’t be stored safely anywhere on Earth.

Fission uses expensive, rare uranium or plutonium as its fuel. Fusion uses hydrogen, which is free, because there is basically an unlimited supply of it in water.

W7-X’s interior plasma chamber. | Sean Gallup/Getty

“The fuel source is found in seawater in quantities sufficient to last tens of thousands of years,” physicist David Gates told Space.com. Fusion’s byproduct is helium, an inert, nontoxic gas. And unlike plutonium and uranium, the fuel for and byproducts of fusion can’t be used to make nuclear weapons.

One of the worst things about fission plants is that they can melt down, like the one at Chernobyl, Ukraine that spread radiation all over Europe in 1986. Or the one at Fukushima, Japan that irradiated much of that country in March 2011. A meltdown happens when a fission reaction goes out of control, creating a chain reaction.

It’s hard enough to create the conditions for fusion in the first place. Any disturbance simply ends the reaction, and there’s only a tiny amount of fuel in the reactor vessel at any given time.

Fusion, once we perfect it, is expected to be cheaper than fission. The best part is that scientists from all over the world are collaborating on the W7-X project. They seek to create a clean, cheap and virtually limitless energy source for everyone on earth. That’s a goal we can all be proud of.

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