StarDate

In May of 1921, technology went haywire. Telegraph lines shut down, and some telegraph offices caught fire. Some railroads briefly ground to a halt. Telephones crackled, and some radio transmissions were nothing more than static.

The cause of this mayhem was a massive storm on the Sun. A clump of sunspots almost a hundred thousand miles wide produced violent eruptions. They sent clouds of charged particles racing through the solar system.

When the clouds hit Earth, our planet’s magnetic field guided the particles toward the surface. That created spectacular displays of the northern and southern lights. And it set up electrical currents in phone wires, railroad tracks, and the ground itself. These currents overloaded the era’s technology.

The vanguard of the cloud headed for Earth 100 years ago today. But things got really interesting the next day. Telegraph service in the northeastern U.S. and elsewhere dropped out as fuses blew and generators were overloaded. On May 14th and 15th, electrical fires burned down a telegraph office in Sweden. They also claimed a railroad station in Brewster, New York, and perhaps a railroad control tower near Grand Central Terminal. As a result, the disturbance is known as the New York Railroad Storm, although problems were recorded around the world.

If a storm of that power hit Earth today, it could knock out satellites, phone service, and entire power grids — perhaps bringing modern technology to a standstill.

Script by Damond Benningfield

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We’ve all learned the value of covering up or turning away when we sneeze over the last year or so. Water droplets can carry viruses, so a sneeze can be a big problem.

Fortunately for us, the Sun usually turns away when it sneezes — but not always. The sneezes that aim at Earth can cause big problems — perhaps even catastrophic ones.

A solar “sneeze” is known as a coronal mass ejection. It occurs when there’s a big magnetic storm on the surface of the Sun. The storm can trigger an outburst of charged particles — billions of tons of them. The cloud of particles races through the solar system at millions of miles per hour.

Most of the time, such clouds are directed away from Earth. Sometimes, though, they take dead aim at our planet. When they hit, they cause brilliant displays of the northern and southern lights. More ominously, they can damage or destroy satellites, disrupt communications, and knock out power grids.

An event in 1859 — the most powerful yet seen — knocked out most telegraph service. Another, in 1921, burned down buildings and disrupted train service; more about that tomorrow.

We haven’t been hit by anything that big since then. But it’s almost certain that we will be — whether it’s this year or a hundred years from now. And the effects could be devastating. Powerful impacts could destroy much of the power grid, leaving parts of the U.S. and other countries in the dark for months — blacked out by a “sneeze” from the Sun.

Script by Damond Benningfield

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Hydrogen and helium are best known as the gases that make things float — from zeppelins to birthday balloons. Both elements are rare here on Earth — there’s even been a shortage of helium in recent years.

But there’s a huge supply of both elements just 93 million miles away — in the Sun. Together, they account for more than 98 percent of the Sun’s mass. And like most stars, the Sun has only a sprinkling of the heavier elements that are common here on Earth, such as oxygen, carbon, and neon.

Hydrogen and helium are the lightest and simplest of all elements. They were created in the Big Bang. Almost everything else was forged later — either in the hearts of stars, or in stellar explosions or mergers. These elements were scattered into space, where they could be incorporated into later stars, like the Sun.

Today, about 73 percent of the Sun’s mass is hydrogen, while most of the rest is helium.

When the Sun was born, those numbers were a little different. But the Sun’s core is hot enough to sustain nuclear fusion. Hydrogen atoms “fuse” together to make helium, releasing the energy that powers the Sun. So today, most of the core’s mass consists of helium, while the surrounding layers are still mostly hydrogen.

Fusion converts almost 700 million tons of hydrogen to helium every second. The Sun is so huge, though, that it won’t run out of fuel any time soon — it’ll stay in the prime of life for billions of years.

Script by Damond Benningfield

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Every mission to the planets creates as many new questions as it answers.

An example is Messenger, the only spacecraft to orbit the planet Mercury. It mapped smooth volcanic plains that are billions of years old. And it found smaller smooth patches that may be more recent — perhaps the result of eruptions as recently as a billion years ago. Yet Messenger’s pictures weren’t quite clear enough to confirm their origin. So geologists can’t work out the details of Mercury’s volcanic history.

The large plains cover about a quarter of Mercury’s surface. They formed as molten rock bubbled up through the crust — a process that ended three-and-a-half billion years ago.

Many of the smaller volcanic regions are much younger. They appear to be related to volcanic vents — indentations in the ground that may have produced explosive eruptions. And channels in the smaller plains could have been carved by flowing lava.

Scientists might get confirmation of that scenario in a few years. A European mission will enter orbit around Mercury in 2026. It will provide sharper views of the surface, and better maps of its composition. That may help solve the mystery of Mercury’s volcanoes — while posing new questions for future missions to the Sun’s closest planet.

Mercury is in the early evening sky now. It looks like a bright star quite low in the west-northwest as night falls, well above brighter Venus. It’ll remain in view for most of the month.

Script by Damond Benningfield

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There’s an old bit of advice about how to sculpt an elephant: Start with a piece of marble, then chip away everything that doesn’t look like an elephant. Nature may be following that advice in sculpting the planets known as super-Earths: Start with a sub-Neptune, then chip away everything that doesn’t look like a super-Earth.

A super-Earth is a rocky planet that’s up to a few times bigger and heavier than Earth. A sub-Neptune is a few times larger than that. It may have a rocky core surrounded by a thick atmosphere, like Neptune, one of the giant planets of our own solar system. Searches have revealed hundreds of examples of both classes of planet.

Astronomers have pondered how the two types form. And some recent studies suggest that super-Earths might form from sub-Neptunes.

The studies show that super-Earths are more common in older star systems than in younger ones. Since the planets in the studies are quite close to their host stars, that could mean that, given time, a star can turn a sub-Neptune into a super-Earth. Travis Berger, a member of one of the study teams, explained how in a press briefing in January.

BERGER: You start off with a sub-Neptune, you hit it with a bunch of high-energy radiation—and lots of it—over billions of years, and eventually you can strip off its atmosphere and make it become a super-Earth.

That might not be the only way to make a super-Earth. But it could be one way to sculpt some of the worlds in other star systems.

Script by Damond Benningfield

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You might think of the planet Kepler-64b as Tatooine-plus. Like the home of Luke Skywalker, the planet orbits both members of a binary — two stars locked in a tight orbit around each other. That gives the planet two sunrises and two sunsets every day.

In the case of Kepler-64b, though, the two stars are bound to another binary. That gives the system four stars in all. So far, Kepler-64b is the only planet known to reside in a four-star system.

One of the stars the planet orbits is bigger, heavier, and brighter than the Sun. The other is smaller, lighter, and much fainter than the Sun. The stars are quite close together, so they orbit each other once every three weeks.

The planet itself is a giant. It orbits the stars at about 60 percent of the distance from Earth to the Sun. That makes the planet quite hot — probably too hot for life.

The other binary consists of a Sun-like star and another feeble star. The pair is separated from the other stars by about a thousand times the Earth-Sun distance. Even at that range, though, it would be bright enough see during the day. And at night, the combined stars would shine about as bright as a full Moon — lighting up the surface of a unique planet.

The Kepler-64 system is several thousand light-years away, in Cygnus. The swan climbs into view by around midnight, and is high in the sky at first light. Kepler-64 is near the intersection of the swan’s body and wings.

Script by Damond Benningfield

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A trip to a super-Earth orbiting a star in Pisces would be super-quick. Under daytime temperatures of more than 5500 degrees Fahrenheit, you’d be vaporized in moments.

K2-141b is about half again as wide as Earth, and five times as heavy. And like Earth, it’s made of rock and metal. It orbits less than a million miles from its sun, K2-141. At that distance, it’s “locked” so that the same hemisphere always faces the star, just as the same hemisphere of the Moon always faces Earth.

A study last year outlined what must be happening on the planet.

Under the never-ending glare of the star, rocks on the dayside would melt. That would form an ocean of molten rock that might be dozens of miles deep. Lava at the top of the ocean would vaporize, forming a thin atmosphere of sodium and compounds made of silicon.

At the “twilight zone” between day and night, winds would blow toward the nightside at thousands of miles per hour. Under the darkness of night, the atmosphere would condense and form clouds of liquid metal, which would then “rain” onto the surface. Currents in the ocean would carry material back around to the dayside, continuing the cycle on this super-hot super-Earth.

Pisces is nudging into view in the east at first light. Tomorrow, it’s above and to the left of the crescent Moon. K2-141 stands above the Moon. But it’s so faint that you need a telescope to see it.

Script by Damond Benningfield

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Rocky planets like Earth are tough. They can survive some pretty harsh conditions. Some have even formed from the debris around exploded stars. And they may form around supermassive black holes, where conditions could be comfortable for life.

Giant black holes inhabit the hearts of most big galaxies, including the Milky Way. Many of the black holes pull in gas and dust, creating a hot disk that spirals around the black hole. The disk produces radiation and winds of charged particles that could be bad news for newly forming planets.

But a recent study says that, under the right circumstances, it’s possible that Earth-like planets could be born around such a black hole. At the right distance, the disk would look the same size as the Sun does in our own sky, and it would provide about the same amount of energy.

That energy might help forge the chemical “building blocks” of life. And it could power photosynthesis in plants. With an especially big black hole, the “habitable zone” might be thousands of light-years wide.

Not surprisingly, there’s a downside to being in that zone. Black holes sometimes produce huge outbursts — enough to sterilize nearby planets. And the odd gravitational effects around a black hole could sling a planet around like a car on a roller-coaster.

Still, scientists aren’t ruling out the possibility that life could inhabit worlds around giant black holes.

Script by Damond Benningfield

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The early morning sky offers up a couple of beautiful sights tomorrow. One is a meteor shower, although you need to be far from city lights to see it. The other is visible from any place with clear skies: a pairing of the Moon and the planet Jupiter.

The Eta Aquariid meteor shower should be at its best over the next couple of nights. It fires up as Earth flies through the orbital path of Comet Halley. Dust grains from the comet plunge into the atmosphere at speeds of up to 150,000 miles per hour. They quickly vaporize, forming the glowing slashes of light known as meteors. Almost all of them are too faint to see from the city, though.

Unfortunately for those of us in the U.S., the shower is best viewed from the southern hemisphere. That’s because its meteors appear to “rain” into the sky from the constellation Aquarius. From North America, it doesn’t rise until the wee hours of the morning. And it scoots quite low across the southern horizon, so we don’t get the full glory of the shower. Instead, we might see a dozen or so meteors per hour at most.

Coincidentally, the planet Jupiter is at the edge of Aquarius right now. It’s low in the southeast at first light, and looks like a brilliant star. Tomorrow, it’ll stand to the upper right of the Moon at first light. The moonlight will wash out the remaining meteors. But the Moon will rise later on Thursday, providing a little extra time to watch the end of the shower.

Script by Damond Benningfield

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The giants of the solar system form a wide, skinny triangle with the Moon in the wee hours of tomorrow. Jupiter, the largest planet, looks like a brilliant star to the left of the Moon. And fainter Saturn, the second-largest planet, is to the upper right of the Moon.

Today, Jupiter is five times farther from the Sun than Earth is, with Saturn almost twice that far. But that probably hasn’t always been the case. When the solar system was young, the planets may have moved much closer to the Sun, then back out again. That migration would have scattered the leftover “building blocks” of the planets — balls of ice and rock — kicking many of them out of the solar system. And a recent study suggested that Jupiter and Saturn could have kicked out another planet.

Calculating what might have happened requires complicated models and lots of computer power. But astronomers can find support for the idea that planets move around by looking at other star systems.

In fact, they’ve been tracking some planets known as “hot Jupiters” for years. They’re giant planets, like Jupiter. But they’re so close to their stars that they orbit in just days, making them quite hot. It’s likely that they were born farther out, then migrated inward. And long-term observations of several of them show that the planets continue to move closer to their stars. That shows that planets don’t always stay where they were born; sometimes, they like to move around.

Script by Damond Benningfield

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