10 Quick Thoughts about Water on Mars

By Corey S. Powell | September 28, 2015 12:57 pm
Here there be water? Dark streaks on Mars (presented in false color for clarity) indicate likely flows of salty water on the planet. Credit: NASA/JPL-Caltech/Univ. of Arizona

Here there be water? Dark streaks on Mars (presented in false color for clarity) indicate likely flows of salty water on the planet. Credit: NASA/JPL-Caltech/Univ. of Arizona

NASA generated quite a bit of buzz today with the apparent discovery of flowing water on Mars. Now to anybody who follows science news–especially news about space and alien life–those words may sound awfully familiar. It seems like NASA has been discovering water on Mars every year for the last decade. This time really is different, however. For one thing, scientists are talking about water on Mars right now. For another, the evidence is much stronger than it was in past reports; I wrote about some of those earlier speculations here.

Although the news just broke earlier today, there has already been extensive discussion of the results online. I’ve read through the early conversations (so you don’t have to). Here are some of the key things you should know. I’ll start with the bad news, since I always like to get it out of the way first.

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Your BS Detector for Warp Drives, Double Moons, and Other Implausible Claims

By Corey S. Powell | August 27, 2015 4:17 pm
Will Mars appear as large as the full moon? Your innate common sense will tell you this cannot possibly be true. (Credit: Unknown)

Will Mars really appear as large in the sky as the full moon? Your innate common sense is all you need to tell you this cannot possibly be true. (Credit: Unknown)

Today is the day when, according to a widely circulated email/Facebook hoax, Mars will appear as large in the sky as the full moon. In reality, nothing short of the catastrophic disruption of the entire solar system could allow such a thing to happen (and if that were happening, you probably would have heard the news). Still, I have sympathy for those who were taken in by the hoax. We live in an age of amazing space imagery: snapshots of nitrogen glaciers on Pluto, a robot bouncing off a comet, ice moons hovering over the rings of Saturn. If you don’t think too hard about it, one more wild view doesn’t seem so implausible.

The barrage of genuine scientific amazement surely also explains why so many people credulously accept other erroneous or at least misleading stories, such as the ongoing reports that NASA has validated an “impossible space drive”–or, in some variations, that NASA “accidentally created a warp drive.” I’m sympathetic again. After all, NASA really did send an ion-powered spacecraft to the dwarf planet Ceres. That’s pretty wild. Again, if you don’t think too hard about it, why not accept another, even more staggering technological breakthrough?

Some quick online research will usually separate the serious stuff from the hoaxes and the hype, but many people lack the time or even the inclination. What would be truly helpful is a set of basic reality-check tests that anyone can apply: an all-purpose science BS-detector kit that requires little more than getting past that first hurdle of thinking. I’m going to attempt to build one right here. I’d love to hear your ideas as well.

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10 Amazing Things You Should Know About the Perseid Meteor Shower

By Corey S. Powell | August 12, 2015 1:04 pm
Colorful, sputtering Perseid meteor photographed last night by Terry Allshouse near Eustis, Florida, and posted on the Realtime Meteor Gallery.

A colorful, sputtering Perseid meteor was photographed last night by Terry Allshouse near Eustis, Florida, and posted on the Realtime Meteor Gallery. All that from something about the size of a pea!

The most consistently reliable meteor shower—the Perseids—peaks tonight. Under clear, dark, unobstructed skies you might see 60 to 100 meteors an hour. And this year, nature is cooperating: The moon is a thin crescent that does not rise until dawn, meaning that the astronomical sky will remain wonderfully dark all night through. (Clouds are another matter; getting away from buildings, trees, and city lights is all up to you.)

For tips on how to watch the Perseids, read through this helpful viewer’s guide prepared by our friends at Astronomy magazine. That will tell you what you need to know about how to watch. It’s a lot harder to find good information about what you are seeing. That’s why I’m here.

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The Eye-Popping Astonishment of Pluto

By Corey S. Powell | July 19, 2015 9:34 am
Alan Stern reacts to the early images of Pluto and Charon coming in from New Horizons. No further explanation necessary. (Credit: NASA/JHU-APL)

Alan Stern reacts to the early images of Pluto and Charon coming in from New Horizons. No further explanation necessary. (Credit: NASA/JHU-APL)

I spent the past week at Pluto central–aka, the Johns Hopkins University Applied Physics Lab in Laurel, Maryland–watching images and data come in from the New Horizons spacecraft. You don’t need me to tell you how incredible those first views are. They’ve been covered widely in the science media, including right here on this site, and have thoroughly (and gratifyingly) crossed over into the mainstream. I even got a chance to talk about them on Fox News. But there is a lot more to the story than the new landscapes of Pluto, stunning as they may be.

First and foremost, there is the enormous amount of scientific surprise embedded within those images. Alan Stern, the principal investigator and prime mover behind New Horizons, routinely declared that we should all be prepared for surprises when we got a first look at Pluto. What he added, in his quieter moments, is that we should be prepared even for unpleasant surprises. Pluto might look just like Neptune’s moon Triton. Worse, it might be an inert ball of ice, covered with ancient craters and decorated only with dark, carbon-rich discolorations. Of course, that turned out not to be the case. Stern’s eye-popping reaction, shown up above, says it all.

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MORE ABOUT: NASA, New Horizons, Pluto, Stern

The Man Who (Almost) Discovered Pluto…and Also (Almost) Discovered the Expanding Universe

By Corey S. Powell | July 12, 2015 9:33 am
Discovery photos of Pluto, taken by Clyde Tombaugh under Vesto Slipher's direction. (Credit: Lowell Observatory)

Discovery photos of Pluto, taken by Clyde Tombaugh under Vesto Slipher’s direction. Now we know that the unassuming dot at the arrows is an exotic world with five moons. (Credit: Lowell Observatory)

As the New Horizons probe closes in on Pluto–now less than two days away!–there have been a lot of thoughtful articles looking back at the people responsible for the discovery of this remarkable little world. They have focused mostly on Clyde Tombaugh, the man who spotted Pluto amidst a sea of stars in 1930. Some articles have also told the story of Venetia Burney, the 11-year-old girl who gave Pluto its name, or Percival Lowell, whose obsession with finding “Planet X” inspired Tombaugh’s search. In all these stories, though, one name is conspicuously missing: Vesto Slipher.

It was Slipher who initiated the planet search and who directed its outcome. He was probably the first to set eyes on Pluto. He was also a meticulous deep-sky observer who collected the first evidence of the expanding universe, more than a decade before Edwin Hubble’s landmark publication that led to the modern idea of the Big Bang. So why is there no Slipher Space Telescope? Why have you never even heard of him and his connection to Pluto?

Therein lies a tale.

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How New Horizons Survived the 40-Year-Glitch and Made it to Pluto

By Corey S. Powell | July 10, 2015 2:59 pm
Pluto and Charon, the latest view from New Horizons--a mission that nearly didn't happen, over and over. (Credit: NASA/JHU-APL/SWRI)

Pluto and Charon seen by New Horizons from 3.7 million miles. This spectacular view, and the mission that made it possible, nearly didn’t happen–not once, but over and over. (Credit: NASA/JHU-APL/SWRI)

In space exploration, there are a million ways that things can go wrong and just one way that they can go right. When the New Horizons probe skims less than 8,000 miles past the surface of Pluto on July 14, it will happen only because a large team of scientists, engineers, and mission planners managed to eliminate all the wrong and navigate their way to the right, a process that has taken more than 40 years to fully unfold.

The engineers have become so good at fixing problems that most of the time the public has no idea what they are up against—until something goes wrong, as happened to New Horizons last weekend, when a software glitch caused the probe to shut down into “safe” mode. For a moment, this was a news story. Then, once again, the engineers stepped up and solved the problem (caused by an obscure timing flaw in a command sequence sent to the probe in preparation for flyby). Within three days, all was back to normal. As New Horizons principal investigator Alan Stern says, “In terms of science, it won’t change an A-plus even into an A.”

But software problems are hardly the only glitches that nearly derailed the mission to Pluto. Politics and personalities can go wrong, too, and they frequently did.

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White Spots, Lone Mountains, and Other Funny Business on Ceres

By Corey S. Powell | June 30, 2015 10:56 pm
Ceres is a wonderland of puzzles, including the white spots (far right) and enigmatic ridges, crater chains, and flows. (Credit: NASA/JPL/UCLA/MPS/DLR/IDA - Processing Elisabetta Bonora & Marco Faccin)

Ceres is a wonderland of puzzles, including the white spots (far right) and enigmatic ridges, crater chains, and flows. (Credit: NASA/JPL/UCLA/MPS/DLR/IDA; processing Elisabetta Bonora & Marco Faccin)

“The most exciting phrase to hear in science, the one that heralds new discoveries, is not ‘Eureka’ but ‘That’s funny…'” That quote, delivered by the brilliant science writer Isaac Asimov, keeps popping into my head as I look at the remarkable new images of Ceres. NASA’s Dawn spacecraft has been orbiting the dwarf planet since March 6, scrutinizing a landscape that is not quite like anything humans have ever seen before.

One detail on Ceres jumped out almost immediately: a bizarre white spot, drastically brighter than its drab surroundings. As Dawn got closer, the probe’s camera showed that the white spot is actually a patch of at least eight smaller white areas; there are also smaller white spots and extended light-ish splotches scattered across Ceres’s 950-kilometer-wide 590-mile wide globe. What are they? No idea, except not alien landing lights (they don’t show up in the dark). Subsequent images revealed a solitary, 3-mile-high mountain; long ridges and apparent streamers of impact debris; giant frozen surface flows; and craters with unusual distorted, vaguely hexagonal shapes.

The initial scientific reaction to these Ceres images boils down to three simple words that Asimov would well recognize: “That looks funny.”

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MORE ABOUT: Ceres, Dawn, NASA, white spots

Space Junk is a Problem. Is a Laser Cannon the Solution?

By Corey S. Powell | May 20, 2015 4:14 pm


There’s a general rule in media reporting called Betteridge’s Law: Whenever a headline poses a question–especially a sensational one–the answer is “no.” I’m going to break the law this time. An orbiting laser cannon is not only an intriguing technology but, yes, it’s one of the most promising ways to clean up the ever-thickening cloud of dangerous debris surrounding the Earth.

And just to be clear, space junk is a danger. There are about 25,000 human-made objects larger than your fist flying around in orbit, and about half a million pieces bigger than a dime. If you include millimeter-scale shrapnel, the number of rogue bits reaches deep into the millions. Typical speeds in low-Earth orbit are about 30,000 kilometers per hour (18,000 miles per hour), ten times the velocity of a rifle bullet. You see the problem: A little impact can pack a big wallop.

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7 Remarkable Lessons from Messenger’s Mission to Mercury

By Corey S. Powell | May 1, 2015 12:53 am
Final resting place of the Messenger probe on Mercury, where it crash landed at 8,700 miles per hour. Credit: NASA/APL/CIW

Final resting place of the Messenger probe on Mercury, where it crash landed on April 30 while traveling at 8,700 miles per hour. Credit: NASA/APL/CIW

Through most of its life, NASA’s scrappy Messenger probe was something of a unsung hero. The first spacecraft ever to orbit Mercury didn’t have the you-are-there immediacy of a Mars rover, the daredevil appeal of landing on a comet, or the romance of visiting a beautiful ringed planet. But with today’s death–the result of a long-anticipated crash into the planet it studied–we can clearly see what an incredibly successful explorer Messenger was.

Mercury has long been a solar-system enigma. It is not particularly small (roughly halfway in size between Mars and the moon), and it is not particularly far away (third closest planet to Earth after Mars and Venus), but the first planet from the sun is devilishly hard to study. Seen from Earth it hangs low in the sky; from space it hugs so close to the solar glare that the Hubble telescope cannot aim at it. Astronomers were so stymied that they didn’t even know how quickly Mercury rotated until 1965, when they found out, not by looking but by bouncing radar signals off its surface.

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MORE ABOUT: comet, ice, Mercury, Messenger

The Many Resurrections of the Hubble Space Telescope

By Corey S. Powell | April 24, 2015 2:56 pm
Laughing stock: In the 1991 movie "Naked Gun 2 1/2," the Hubble Telescope was depicted as a disaster on par with the Edsel and the Titanic.

Laughing stock: In the 1991 comedy Naked Gun 2 1/2, the Hubble Space Telescope (top right, on the wall) was depicted as a disaster on par with the Edsel, Michael Dukakis, and the Titanic.

If you are old enough to remember news stories from 1990 (or if you are a devoted student of astronomy), you’ll recall that the Hubble Space Telescope was not always regarded as the technological triumph that NASA is loudly celebrating today, on its 25th anniversary. The orbiting observatory debuted as a king-size disaster: the telescope that couldn’t see straight, built with a mirror that was ground perfectly…but perfectly incorrect.

The story of how the error was discovered and ultimately fixed has been told many times, most recently in a beautiful retrospective by my colleague Ian Sample at The Guardian. But today it is hard to appreciate the magnitude of Hubble’s turnaround–the depth of the scientific despair right after launch, and the many resurrections that transformed Hubble into the most famous and productive observatory in  history. Since Hubble may not live to celebrate a 30th anniversary, there is no time like the present to tell the tale.

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MORE ABOUT: Hubble, supernova

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Notes from the far edge of space, astronomy, and physics.

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