Jupiter Shines Near the Moon Tonight: How to See It

If your sky is clear tonight (Feb. 10), be sure to check out the southeast sky about an hour or so after sundown for an eye-catching site: Jupiter and the moon shining together.

Weather permitting, stargazers can find the celestial meet-up on about halfway up in the southeastern evening sky. You'll immediately see the moon, which will be at its waxing gibbous phase, en route to becoming a full moon on Valentine's Day (Friday, Feb. 14).   

This evening, observers may notice a very bright, silvery "star" shining with a steady glow to the right or lower right of the moon. That's not a star, however, but in reality, the biggest planet in our solar system: Jupiter. Both moon and planet will keep each other company as they move across the night sky through the course of the night. [Jupiter Reigns in February's Night Sky (Video)]

Casual observers looking skyward will almost certainly wonder what that bright object near the moon happens to be, and I would encourage all of my fellow broadcast meteorologists to let their listeners and viewers in on what they're seeing in the night sky. 

Jupiteris ideally placed for evening viewing, shining high and free where trees and other obstructions reach in vain to hide it, and where even the ill-effects of atmospheric seeing are at their least. Jupiter currently shines between the legs of Gemini. It reaches its highest point in the sky — transiting the meridian, as the astronomers would say — around 9:30 p.m. your local time. It sets during the predawn hours, soon after 4 a.m. your local time.

For amateur astronomers, Jupiter is the best of the planets and a superb telescopic object. Its disk shows more illuminated surface area than all the other planets combined. Users of the very smallest telescopes or even steadily held binoculars can identify Jupiter’s some or all four of its bright moons at any given time.

But the planet's disk itself also draws a lot of attention. In large telescopes, observers with telescopes can view its cloud belts, sometimes one or more can look strongly disturbed, full of knots and sprouting festoons or on the other side of the coin, perhaps looking like pale belts crossing the planet. And recent reports suggest that the famous Great Red Spot now appears darker than it has been for several years.  As always, seeing much detail on Jupiter requires a good quality telescope, good atmospheric seeing, and patience behind the eyepiece.

Lastly, if clouds hide your view of the moon with Jupiter, don't fret.  They'll be together again on March 9.

Source: SpaceCom

'Tatooine' Alien Planets May Form Far from Twin Suns

Worlds with twin suns like Luke Skywalker's fictional home world Tatooine in "Star Wars" may be born far from the stellar heart of their alien solar systems, scientists say.

Although Earth may orbit around a single star, most sun-like stars are binaries — two stars orbiting each other as a pair. In fact, there are many three-star systems, even going up as high as seven-star systems.

Worlds that orbit around binary stars are known as circumbinary planets. The first real-life alien planet with two suns ever discovered by astronomers is Kepler-16b, a gas giant found orbiting the star Kepler-16 about 200 light-years from Earth. [NASA Discovers 1st Real-Life 'Tatooine' Planet (Gallery)]

Planets are born from protoplanetary disks of gas and dust that orbit stars. Scientists had thought the very strong gravitational pull binary stars would exert on these disks might disturb the material within too much for it to easily coalesce into worlds. This made the existence of circumbinary planets in real life a bit of a mystery.

The alien planet Kepler-16b has two suns just like the fictional planet Tatooine in the "Star Wars" universe, home of Luke and Anakin Skywalker.See how the planet's twin sun setup works in this Space.com infographic.
Credit: Karl Tate, Space.com

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How 'Tatooine' alien planets are born

To learn more about how circumbinary worlds form, researchers analyzed the twin-sun planet Kepler-34(AB)b, which is located about 4,900 light-years from Earth. This world, also known as Kepler-34b, is about 22 percent of the mass of Jupiter (the largest gas giant in our solar system) and 76 percent the width of Jupiter. It orbits its two sunlike stars at about the same distance as Earth is from the sun, and was discovered used NASA's Kepler space telescope.

The scientists performed high-resolution, 3D computer simulations of the early stages of planet formation around binary stars. These used an intricate model that calculated the effect of gravity and physical collisions on and between one million planetary building blocks, each 60 miles (100 kilometers) wide.

The researchers discovered the majority of the simulated exoplanets that resulted originated far from their binary stars.

"Taking into account data on collisions as well as the physical growth rate of planets, we found that Kepler 34(AB)b would have struggled to grow where we find it now," study author Zoe Leinhardt, an astrophysicist at the University of Bristol in England, said in a statement.

In the area close to binary stars, the planetary building blocks experienced what the researchers called "super-catastrophic erosion events," breaking up into smaller chunks instead of merging into planetary embryos. This made circumbinary planets in the inner parts of binary systems unlikely, they said.

Twin-sun planet migration

The researchers suggest that Kepler 34(AB)b, like many other knowncircumbinary planets, may have migrated inward from where they originally formed to where astronomers see them now. A minimum safe distance for Kepler 34(AB)b's formation would be about 1.5 astronomical units (AU). (One AU is the average distance between Earth and the sun.)

"Our results seem to indicate that all inner circumbinary planets have migrated," Leinhardt told Space.com.

One possible exception may be the circumbinary planet Kepler-47c, which is further away from its stars than any other known circumbinary planet.

"Circumbinary planets have captured the imagination of many science-fiction writers and filmmakers," study lead author Stefan Lines at the University of Bristol in England said in a statement. "Our research shows just how remarkable such planets are. Understanding more about where they form will assist future exoplanet discovery missions in the hunt for Earth-like planets in binary star systems."

Future research will involve more complex models incorporating gas into the protoplanetary disk, which should drag on planetary building blocks in the disk and could significantly change its dynamics.

"Most of the mass in the disk is thought to be in gas," Leinhardt said. "The gas should make the environment even less conducive to growth."

In addition, the planetary building blocks in the research team's models are currently large and all start at the same size.

"They are large because we are limited by our computational capability," Leinhardt said. "We have been working over the past year to make our (computer) code faster and able to run with larger numbers of particles, from millions to billions."

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Ancient star helps scientists understand universe's origins.

(Reuters) - Australian astronomers have found the oldest known star in the universe, a discovery that may help to resolve a long-standing discrepancy between observations and predictions of the Big Bang billions of years ago.
Dr Stefan Keller, lead researcher at the Australian National University Research School, told Reuters his team had seen the chemical fingerprint of the "first star". After 11 years of searching, the star was discovered using the SkyMapper telescope at the Siding Spring Observatory.

"This star was formed shortly after the Big Bang 13.7 billion years ago," Keller said.

"It's giving us insight into our fundamental place in the universe. What we're seeing is the origin of where all the material around us that we need to survive came from."

Simply put, the Big Bang was the inception of the universe, he said, with nothing before that event.

The ancient star is about 6,000 light years from Earth - relatively close in astronomical terms. It was one of 60 million stars photographed by SkyMapper in its first year.

"This is the first time we've unambiguously been able to say we've got material from the first generation of stars," Keller said. "We're now going to be able to put that piece of the jigsaw puzzle in its right place."

The composition of the newly discovered star shows it formed in the wake of a primordial star, which had a mass 60 times that of our Sun.

Keller said it was previously thought primordial stars died in extremely violent explosions that polluted huge volumes of space with iron. But the ancient star shows signs of pollution with lighter elements such as carbon and magnesium - with no sign of iron.

"What that means is we had a long-held theory that the first stars to form would be extremely massive because they are formed out of pure hydrogen and helium," he said.

"A star is like an onion - it has all these layers and the heaviest material like iron is right down in the core. The only thing to come out of it was the carbon and a little bit of magnesium from that supernova and that's what we're seeing today in the star that we've discovered."

The discovery was published in the latest edition of the journal Nature.