Tag Archives: astronomy

What KIC 8462852 Says About Us

Dyson sphereKIC 8462852. Hardly a household name. But it may be, one day soon, or at least when it garners a more prosaic name. It’s a star and it sits rather forlornly in space in the rightmost edge of the constellation Cygnus, almost 1,500 light years away. And although it’s too dim to be seen by the naked eye, it has caught the attention of astronomers and conspiracy theorists alike, worldwide.

KIC 8462852 is a mature F3-class sun, more massive than the Sun and both brighter, hotter. It’s the kind of sun we usually search for habitable planets around, at least within the range of potential candidates. But it’s been watched for the past six years with growing fascination and wonder. As Science Alert tells us:

It was first discovered by NASA’s Kepler Space Telescope in 2009, and scientists have been tracking the light it emits ever since, along with the light of another 150,000 or so newly discovered stars. They do this because it’s the best way to locate distant planets – slight, periodic dips in a star’s brightness signal the fact that it might have one or more large objects orbiting it in a regular fashion.
These brightness dips are usually very slight, with the stars dimming by less than 1 percent every few days, weeks, or months, depending on the size of the planet’s orbit.

That dimming is usually regular and explicable, and small. Not so with KIC 8462852. Its brightness has dipped inexplicably in large amounts with unnerving regularity, every 750 days, reaching levels of 15% and even 22% reduction of light for between five and 80 days.

Scientists scratch their head and wonder what could be large enough to diminish the light from a bright star by that amount. No planet could ever be that big. And it would have to be an enormous cloud of space junk – an improbable amount in a very tight formation – to do it.

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Chasing storms on Saturn

There’s a beautiful video about the Cassini mission and its images of the storms on Saturn at the New York Times website. It’s amazing to see what images and information science has given us about a planet 886 billion miles (1.4 billion kms) away and its odd collection of rings and 60 moons.

Saturn’s storms

Saturn takes 30 years to orbit the Sun and in January, 2014, began its first spring in 15 years. Until then, the northern hemisphere was shrouded in darkness and the rings tilted away from us. Now the north pole is in sunlight and the magnificent, monstrously large, hexagonal storm at its centre is clearly visible. The video makes it quite an entertaining and awe-inspiring sight.

The hexagonal shape, while unusual, is natural and has been replicated in the laboratory. It is not, as some wingnut conspiracy theorists suggest, a supernatural event, anything to do with aliens or the gates of hell (nor, as uber wingnut David Icke has suggested, is Saturn a giant, artificial broadcasting device… ).

Cassini will be travelling right over the north pole in 2016 in its final – and perhaps most spectacular – mission, for a close-up view of the storm. You can read more about the weird hexagonal storm on the JPL website. The eye of the storm alone in 1,240 miles across (2,000 kms) and the dorm itself is estimated at 60 miles (100kms) deep.

Cassini took seven years to reach Saturn, but that’s a short time compared to New Horizons, which will reach Pluto next July, after a voyage of nine years.

In related news, the spacecraft Rosetta arrived at the comet 67P/Churyumov-Gerasimenko last week, the first spacecraft to rendezvous with a comet. The images sent back so far have been breathtaking. Rosetta is in orbit 62 miles (100 kms) from the comet, but will soon lower to 31 miles (50kms) to prepare for a landing. Rosetta took ten years to reach its target.

All of this is truly exciting, inspirational stuff, isn’t it? Science never ceases to amaze and astound me.

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Doomsday averted (again)

Asteroid 2014 DA14Seventeen thousand miles. Seems like a long way, but it’s less than one tenth the distance from here to the moon, and it’s within the satellite belt. In cosmic terms, it’s frighteningly close. Consider that the Sun is 93 million miles way, and it affects everything on this planet.*

It’s still a miss, though. Asteroid DA14 will race by Earth at 27,700 kPH, February 15. But it won’t hit us. Whew.

You might be able to see it, if you know where to look. You’ll have to be fast, though – it will move VERY quickly across the sky. And you’ll need at least binoculars – even at 13 storeys tall, it won’t be visible to the naked eye.

Wikipedia tells us this chunk of rock called 2012 DA14 is

…a near-Earth asteroid with an estimated diameter of about 45 meters (148 ft) and an estimated mass of about 130,000 metric tons

Some sites say it is 62m wide, but it probably is irregular in size, thus the difference. Even so, 45m is BIG if it hits us; big enough to wipe out a small city. The 1908 Tunguska event was caused by an object also less than 100m and it levelled several hundred square miles of forest. Were it to enter the atmosphere, it could also become an aerial blast like Tungsuka.

Space.com notes:

Asteroid 2012 DA14’s close encounter is also a record-breaking celestial event… An object this large only passes this close to the Earth about once every 40 years, and likely only hits the planet once every 1,200 years…The asteroid will not only pass between Earth and the moon’s orbit, but also fly lower than the ring of geosynchronous communications, weather and navigation satellites that fly high above the planet. Asteroid 2012 DA14 will be 5,000 miles (8,046 km) closer to Earth than those satellites during the flyby.

Pretty close. But a long way from the ISS, which orbits between 330 and 410 kms above the surface.

Read about what an asteroid is here – you’ll also get an interesting comment on challenges to some cosmological ideas about how these bodies formed. If you haven’t been following the recent announcements, several companies have declared their interest in mining these asteroids. The Edmonton Journal noted earlier this month:

It may sound more like science fiction than imminent reality, but two U.S. companies have been outlining plans to harvest asteroids for mineral wealth in what they hope will be a 21st century equivalent of gold and oil rushes.
They intend to deploy small satellites to prospect asteroids, then effectively lasso them, transporting them into Earth’s orbit to harvest precious metals and liquids.
The newest entrant to the fast-developing asteroid mining world is Deep Space Industries, which has just unveiled ambitious plans to send prospecting spacecraft in two years’ time and begin extraction by 2020.
“It is exciting to be present at the beginning of the second space age, led by commercial businesses,” David Gump, Deep Space’s chief executive, told The Sunday Telegraph.

Anyway, it’s not the apocalypse, Friday, but it is an exciting moment for science and might be a seminal moment for space commerce.



* It isn’t a UFO from your favourite imaginary planet, sorry to spoil that for you. It’s a lifeless chunk of rock. Get over it.

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