Jupiter has been described as the vacuum cleaner of the solar system. The planet’s powerful gravity sucks in comets and asteroids. They’re destroyed as they slam into Jupiter’s atmosphere. That keeps those objects from possibly threatening Earth and the other inner planets.Scientists have seen several of these impacts. They’ve seen some of them directly, as bright flashes of light. For others, they’ve seen the aftermath — big, dark scars in Jupiter’s atmosphere.One of the most recent impacts came last summer. Amateur astronomers in Asia saw a bright flash of light on August 28th. One of them even recorded the flash on video. It lasted several seconds.An early analysis said the flash was similar to another one a couple of years earlier. It probably was the equivalent of a blast on Earth in 1908. Known as the Tunguska event, it occurred when an asteroid or comet exploded in the upper atmosphere. It leveled hundreds of square miles of Siberian forest.The biggest impact yet seen on Jupiter took place in 1994. Jupiter’s gravity pulled apart a large comet. It then pulled in the remains, which created about a dozen big blasts. The scars from those impacts were visible for months.Jupiter keeps company with the Moon the next couple of nights. It looks like a brilliant star. It’s to the left or upper left of the Moon tonight, and closer below the Moon tomorrow night. Script by Damond Benningfield

Moon and Jupiter

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There might be three ways to build a habitat on the Moon or Mars. You could bring along everything you need for the habitat from Earth. You could build it from local materials. Or, according to one NASA research team, you could grow it — using fungi.
The team has been working on the technique for years. It uses mycelia — the part of a fungus that grows out of sight. It’s tough, and it can form large networks of interlocking threads. And it can grow quickly.
Researchers have come up with several possible ways to use mycelia. One would be mixing it with the dirt on the Moon or Mars to make bricks. Another would be to make a layered structure, with water ice, the fungi, and a type of algae. And yet another would use an inflatable structure, with “baked” mycelia forming rigid walls and algae producing oxygen to inflate it.
For Mars, the mycelia would have to be engineered in a way that it couldn’t escape and take root on the Red Planet — potentially destroying evidence of any microscopic life there.
So there’s still a lot of work to be done before anyone can produce a “fungal growth” on the Moon or Mars.
The two worlds are close together in the early morning sky the next few days. Mars looks like a bright star. It will stand to the lower left of the Moon at dawn tomorrow, and about the same distance to the upper right of the Moon on Monday.
We’ll have more about Mars tomorrow.
Script by Damond Benningfield

Moon and Mars

At heart, just about every star is a potential cannibal. Stars that travel through space alone don’t get the chance to act on that instinct. But those with close companions sometimes do act on it. They can pull gas from the companion, eventually leaving the companion with no more than its hot core.



A recent study found a handful of such systems. Three of them are in Cygnus, the swan. One example is called 60 Cygni.



Its two stars are about as far apart as Mars and the Sun. The main star appears to be more than 10 times as massive as the Sun. It’s also much hotter and brighter than the Sun. The companion appears to be a stripped-down core — its outer layers have been cannibalized by the heavy star.



When the system was born, the stripped star probably was the more-massive member. As it reached the end of the prime phase of life, it puffed up. That allowed the companion to start pulling away some of the dying star’s outer layers of gas. Eventually, all of the material in the outer layers might have been transferred to the other star, making it the bigger member of the duo.



In time, that star will begin to expand as well. So the stripped-down companion may begin to pull away its outer layers — cannibalizing the cannibal.



Cygnus is low in the northeast not long after the sky gets good and dark. But you need binoculars or a telescope to find its possible cannibals.



Script by Damond Benningfield

Cannibal Stars

Planetary scientists can hardly move these days without splashing into a new ocean — or at least a possible one. They’ve discovered that oceans of liquid water may be hidden below the icy crusts of many smaller bodies: several moons of the giant planets, the largest member of the asteroid belt, and even remote little Pluto.



One of the more recent “ocean worlds” may be Mimas, a moon of Saturn. It’s less than 250 miles in diameter. Its main feature is a giant impact crater. It’s so big that it makes Mimas look like a “death star” from Star Wars.



Mimas is pockmarked by a lot of craters. Many of them are so old that scientists had thought the little moon was dead, with nothing happening inside it. But precise measurements of Mimas’s orbit and its rotation on its axis revealed some odd “wobbles.”



Scientists proposed a liquid ocean as a possible explanation for those wobbles as early as 2014. A study released earlier this year solidified the case. It found that the ocean could lie 15 miles or so below the surface, and account for up to half of the moon’s volume. The ocean would have formed no more than 25 million years ago. That’s not enough time for evidence of it to show up on the surface. So the ocean remains hidden deep inside this “death-star” moon.



Look for Saturn especially close to our own moon in the wee hours of tomorrow morning. It looks like a bright star just above the Moon at dawn.



Script by Damond Benningfield

Moon and Saturn

Most people keep their hands as far from snakes as possible. But handling a snake was the job for the mythological serpent bearer. He’s represented in the stars as the constellation Ophiuchus, which is in the east and southeast at nightfall. The head of the snake is above Ophiuchus, with its tail below.



In one story, the constellation represented a serpent god. In another, it was a god wrestling with a snake. And in still another, it was an ancient healer who learned the secret of life by watching snakes.



His left hand — the one holding the snake’s head — is represented by two stars: Yed Prior, which leads the way across the sky, and Yed Posterior.



In our sky, the stars are separated by less than the width of your finger held at arm’s length. But they’re not related. One is a little more than a hundred light-years away, while the other is about 160 light-years.



Both stars are more massive than the Sun. So even though they’re much younger than the Sun, they’ve already moved past the prime of life. They’ve burned through the hydrogen fuel in their cores. That’s caused their outer layers to expand to giant proportions. So they’re many times bigger and brighter than the Sun.



Yed Prior and Yed Posterior are about a quarter of the way up the east-southeastern sky at nightfall, with Yed Prior slightly higher. Under even moderately dark skies, they’re easy to see — outlining the hand of the serpent bearer.



Script by Damond Benningfield

The Hand

The giant families of stars known as globular clusters are like carnival rides: They do a lot of bobbing up and down. And they may lose a bit of themselves with every gyration.



An example is the cluster Messier 12. It’s probably more than 16,000 light-years from Earth. It contains a couple of hundred thousand stars, all packed into a ball about 75 light-years across. That means the stars are much closer together than the stars in our part of the galaxy.



Like all globulars, M12 travels at an angle to the Milky Way’s disk. So it periodically passes through the disk. During each pass, the gravity of the disk may pull away some of the stars on the outskirts of M12.



A study a couple of decades ago found a lack of lower-mass stars in the cluster. Heavier stars tend to congregate in a cluster’s core, where they’re held fast by the gravity of the other stars around them. Less-massive stars migrate to the outskirts, where they’d be easy to pull away.



Today, M12 contains about 200,000 stars. But it could have lost several times that number over its 13-billion-year lifetime. So as many as a million of the cluster’s stars might now be orbiting the center of the galaxy on their own — pulled away from their birthplace.



Messier 12 is in Ophiuchus, the serpent bearer, which is in the east and southeast at nightfall. But you need a telescope to see this possibly vanishing cluster of stars.



Script by Damond Benningfield

Moon and Jupiter

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