Category: Headline Makers

What Makes A Planet A Planet?

Headline Makers, New Research, Science History

I grew up believing that there were nine planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. Then, in 2006 my understanding of the universe was shaken when poor little Pluto was stripped of its classification and labelled just another object in the Kuiper Belt, an area that extends from the orbit of Neptune and contains thousands of icy “objects” with the same consistency as Pluto.

The decision that Pluto was not a planet came in 2006 based on the 2005 discovery of Eris, an object larger than Pluto, in the Kuiper Belt. Pluto and Eris are both considered “dwarf planets.” According to the International Astronomical Union for an object to be a planet it must meet three criteria:

  1. It needs to orbit around the sun (or if part of a different solar system than ours, it needs to orbit around another star)
  2. It needs to have enough gravity to pull itself into a spherical shape
  3. It must be the dominant gravitational body in its orbit (thus any smaller body in its orbit is either consumed or flung away by the object’s gravitational pull – being smaller than Eris, Pluto clearly doesn’t qualify)
Pluto by the Hubble Space Telescope via Wikimedia Commons

But why digress on a five-year old story about a former planet’s rejection? Well, because the issue of what makes something a planet seems like it could again be coming into question. This week the BBC  ran the article “Free-floating planets found with no star in sight” talking about the new discovery of objects in space that are seemingly un-connected to a star. The BBC article is referencing the research “Bound and unbound planets abound” featured in Nature, and as we learned from the Pluto experience, criteria #1 for being classified as a planet is that the object in question needs to orbit a star.

So then what is going on with the new discovery of at least 10 objects the size of Jupiter that don’t orbit a star? The research suggests that objects like this might be so common, they actually outnumber stars 2:1. While the BBC’s article states that researcher are cautious to completely flip our understanding of the universe based on a single study – if true, it would completely flip our understanding of the universe.

The definition of a planet is firmly grounded in the three criteria listed above, so these new objects don’t fit the bill because #1 – orbiting a star is violated. But then, what are they? The answer to that is a little complicated. The BBC’s article doesn’t explain it. So, since I have zero background in astronomy, I did some digging and found Phil Plait’s blog Bad Astronomy for Discover.

According to Plait’s post called “The galaxy may swarm with billions of wandering planets,” the objects talked about in the Nature study either formed like stars or they formed like planets in solar systems (like our own) and got tossed out. Plait favors the latter, saying they are most likely rejects from other solar systems.

He explains that massive planets often form along the outside of a solar system, and then migrate inward toward the center star. This could cause other plants in the path of the migrating planet to undergo changes in their orbit, or even get flung out the solar system completely. It is these planets that get flung out of their solar system by the movement of larger planets that could be the star-less objects featured in the Nature study. The evidence in favor of this theory is the prevalence of large plants that orbit very close to their stars.

So most likely – the objects in question ARE planets, they formed like planets, in a solar system that orbited a star. But, somewhere along the way they got tossed out of their solar system, and thus became free-floating planets.

I’ll be interested to see if there is any kind of distinction as far as name or classification that these rogue planets are given, that identifies that they are different than your typical planet. Lord knows losing Pluto was bad enough, I’m not sure what I’ll do if there is another planetary shake up. Its rough seeing things you learned when you were six get turned on their head. But, it is also incredibly cool how much new information the universe still has to give up. I really love the idea that there could be so many free-floating planets out there waiting to be discovered.

Nuclear Legacy: Chernobyl Turns 25

Environment, Headline Makers, Past Articles, Science History, Technology

The worst nuclear disaster the world has ever known, began with a trial run of an experimental cooling protocol on April 26, 1986. A power surge occurred in reactor #4 at the Chernobyl Nuclear Power Plant, near the town of Pripyat in the Ukraine (then part of the USSR.) An emergency shut down was attempted, but the situation was already out of control. Another power surge – stronger than the first – ruptured the containment vessel through a series of explosions that launched radioactive fuel and core materials into the atmosphere. When the reactor’s graphite moderator was exposed to open air, it ignited in a fire that sent a plume of smoke, ripe with radioactive material into the atmosphere.

Map of Chernobyl’s radioactive fallout

The plume drifted over parts of the former Soviet Union and Europe releasing into the open more radioactive material than the atomic bomb dropped of Hiroshima during World War II. The most effected regions include Belarus, Ukraine and what is now Russia – though radioactive material was detected at elevated levels throughout Europe.

The disaster killed 31 people who either worked at the reactor or were part of the emergency response crew, but the number of people who have been killed as a result of subsequent radiation exposure vary from the World Health Organization’s estimated 4,000 to the Greenpeace estimate of 200,000 or more.

The Soviet Union tried hard to downplay the April 26th fire and explosion back in 1986, but two days later on April 28th workers at the Forsmark Nuclear Power Plant in Sweden 680 miles from Chernobyl detected radioactive particles on their clothes. Sweden’s search for the source of the radioactivity (after it was determined that there was no problem at their plant) led to the conclusion that a serious incident had occurred in the western part of the Soviet Union. Chernobyl become the center of world wide attention.

On the 25th anniversary of the Chernobyl disaster, society is still dealing with the legacy of fear, misinformation, and health effects left by the destroyed power plant. Chernobyl was ranked as a level 7 disaster on the International Nuclear Event Scale (INES,) which is the highest possible ranking. The world is still reeling from March’s Fukushima nuclear disaster in Japan, the only other INES level 7 disaster in history. But Fuskushima is not Chernobyl. Fukushima has not caused the level of death and destruction as Chernobyl – and the plants were of completely different designs.

The nuclear reactors at Chernobyl were made based on a now defunct Soviet design, which had known cooling problems. The plant’s workers were testing a new cooling protocol because it was known that in the event of a power outage the system in place (back up generators, etc.) would not have been able to cool the reactors quickly enough. There has been much speculation about who is to blame for the Chernobyl incident – if it was the reactor design or if it was human error.

Chernobyl as it is today

The first reports out of Chernobyl blamed the workers – reporting that they didn’t have adequate training and experience, that they were operating the plant with key safety systems (like the Emergency Core Cooling System) turned off, and that they knowingly ignored regulations. However, over time the role of these accusations has been downplayed, while flaws in the design of the control rods (part of the cooling system) and the reactors ability to deal with the build up of steam has been blamed for the bulk of the incident.

The initial clean up of Chernobyl was done by “liquidators” who moved the majority of debris into the damaged reactor, which was covered in sand, lead and boric acid dropped from helicopters. A concrete enclosure was built around the damaged reactor – a task that exposed the construction workers to significant amounts of radiation.

In February I did a post on What We Don’t Know about Chernobyl – namely that the site of the damaged reactor has been without a proper containment vessel all these years. The concrete sarcophagus originally erected around the destroyed reactor is still in place, and there are cracks in it. The money was never raised to build a more permanent enclosure.

The Fukushima disaster has brought Chernobyl back into the headlines, and today on its 25th anniversary we have to stop and ask ourselves how our understanding of nuclear power has been influenced and shaped by that April day back in 1986. In the wake of a nuclear disaster many people question whether the science is really safe, but I think the question we should really be asking is whether the science, in human hands, is really safe. It isn’t an issue of nuclear power – it is an issue of what happens when people try to harness nuclear power.

War Journalists: Casualties of Their Trade

Good Writing, Headline Makers, State of Journalism

Its hard to understand why something has the ability to punch you in the figurative gut. Something so far removed from you that it should barely register a reaction. Yet, it steals your breath anyway. That happened to me this week – with a tweet. The offending tweet (from a breaking news thread) said, “Reports: renowned war photojournalists Chris Hondros, Tim Hetherington killed in Libya. Details sketchy; awaiting more.”

I don’t know why this news struck me so very hard. These are not the first journalists to be killed in a war zone – but Tim Hetherington is the first journalist whose work I have studied to be killed so shockingly, and yet so predictably. It registered. It hurt. Not for me personally, it hurt for everyone who knew him. It hurt for the people whose lives he brought to light. It hurt for the stories he won’t get to tell. It hurt because people you admire shouldn’t die. Not like that. At least not in a perfect world. But then again, in a perfect world there wouldn’t be a profession called “War Photojournalist.”

Hetherington is best know for the documentary film Restrepo, which he directed with Sebastian Junger. It was nominated for an Oscar this past winter. I’ve read Junger’s book on the same events as the film – called War, and seen parts, though admittedly not all of Restrepo. It is about the time Junger and Hetherington spent embedded with a group of American soldiers in the Korengal Valley in Afghanistan. My post, Sebastian Junger’s War Zone ruminates on the book and on the topic of war. But looking back on it, I can’t help but feel deeply how little I know about war.

There has been a lot of coverage of Hetherington and Hondros’ deaths, but the People Magazine of it all isn’t the story I hope most people will read to find out about these men, and the circumstances under which they died. Sebastian Junger has a tribute in Vanity Fair written as a personal letter to Hetherington that drips with grief and beauty. Susan Orlean has a post in The New Yorker about Hetherington and what it is to be brave. New York Times war correspondent C.J. Chivers has a post on his personal website, Almost Dawn in Libya: Chris and Tim heading home, that pauses amidst the chaos of tragedy to thank the people and groups that tried so hard to save, and then do right by the fallen photojournalists. These are the stories that I hope people will read. It is a tall order to memorialize the fallen, but these writers give it a damn good try.

Robots on the Front Line

Grad School, Headline Makers, Technology

I’m working on an article about how robots can and more importantly, can not, be designed and programmed to function like humans. In anticipation of this, I’ve noticed that this week robots have been making headlines for their role in the war in Afghanistan. But while useful, robots are no replacement for the ingenuity, decision making, and critical thinking capabilities of real, human soldiers.
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If the war in Afghanistan was fought with light sabers, aliens, and Samuel L. Jackson I think the conflict would be over by now. But alas, the light sabers, aliens and Jedi warriors of Star Wars are figments of a time long long ago in a galaxy far far away. But what about the battle droids seen in the video? A robot war sounds like something you could only see on the silver screen, but new technology being implemented in the Afghan war may be the FIRST STEP (note: ONLY a first step) toward a real conflict that is decided by robotic prowess.
According to U.S. Marine Corps. Lt. Col. Dave Thompson, project manager for the joint project office for robotic systems (hows that for an example of a ridiculous round-about government-given title,) there are more than 2,000 ground robots assisting U.S. troops in the war in Afghanistan. But, while it might be fun to evoke the imagery of the battle droid, engaged in an epic fight, REAL robots serve a very different function.
When we talk about the United States’ “robot ground troops” we are essentially talking about computers that can identify bombs and other dangers. The robots do this in one of two ways A: with a combination of sensors and imaging equipment that relays to the human troops that there is a bomb present , or B: by going into an area ahead of the human troops, so that if there is an explosion, the robot takes the hit instead of the humans. 
Robots are NOT running around in the desert wielding AK-47’s, taking out the Taliban. Let me say that again, robots are NOT actively engaged in battle. They do not fight, at least not in the Star Wars battle droid sense. Instead, America’s robot troops are just another tool in the technological arsenal that the U.S. uses to bolster the abilities of its human troops. 
Much of America’s security and defense technology is classified, so we don’t know EXACTLY what it is used for and how these robots accomplish their tasks. But we do know that they are successful enough for ground troops to be requesting the implementation of more robots. We also have access to some information about the use of robots in war-zones like the iRobot (yes, the makers of the Roomba vacuum) line of products. 
So while the battle droid only exists in a galaxy far far away, that’s not to say that the robots in Afghanistan are not supremely cool and impressive. Take a look at this CNN report on the iRobot technology to see for yourself what our robot troops can do: