Pluto and Planethood

Today NASA's "New Horizons" mission, launched just over 13 months ago, will fly past Jupiter on its way to Pluto. The giant planet will provide a gravitational boost to the spacecraft, helping it reach the edge of our solar system by 2015. Over the past few decades, NASA satellites have visited Mercury, Venus, Mars, Jupiter, Saturn, Uranus, and Neptune -- but this is the first mission ever to visit Pluto. Meanwhile, astronomers have decided that Pluto should no longer be considered a planet.

To the average person, it probably seemed ridiculous when the International Astronomical Union announced last August that Pluto would henceforth be known as a "dwarf planet" -- the prototype of a new class of objects in the outer solar system. It even led to a satirical headline reading "NASA Launches Probe To Inform Pluto Of Demotion". However, there were legitimate scientific developments that compelled astronomers to adopt a new definition of planet -- it was just unfortunate that this new definition removed Pluto from the list.

Starting in 1992, astronomers began to discover many small icy objects outside the orbit of Neptune that appeared similar to comets, but which never came close enough to the Sun to evaporate and develop tails. As time went by and the technologies for detecting these objects improved, surveys began to identify some larger examples. In the last few years, astronomers found several that are comparable in size to Pluto -- and even one that is larger! Theories suggested that there were likely to be hundreds or thousands of such objects in the outer solar system, so classifying them all as new planets could create real problems for school children trying to remember them all.

Since Pluto appeared to be just one of the larger members of this class of objects, it fell victim to the new classification scheme. Like many political decisions, the available choices were limited to bad (define planet in a way that excludes Pluto) or worse (bestow the title of planet on hundreds of new objects). Conspicuously absent was an alternative proposal to adopt a new definition of planet that would avoid such proliferation, while honoring the historical status of Pluto as an exception to the new rule. When the IAU meets again 3 years from now, I suspect that such an alternative will be considered by the astronomers -- with plenty of time to spare before "New Horizons" reaches its final destination.

Killer Asteroid Politics

This past weekend, a group of scientists and former astronauts met in San Francisco to discuss the possibilities for averting disaster if one of the hundreds of known potentially hazardous asteroids were found to be on a collision course with the Earth. They were motivated, in part, by the recent discovery that one such asteroid -- known as "99942 Apophis" -- will skim very close to the Earth in 2029, and has a significant chance of actually hitting the Earth seven years later. The central question is: if precise observations during the 2029 passage reveal that Apophis will hit in 2036, what should we do about it?

You might think that these astronomers are just being alarmist. After all, there have been several recent occasions when the news media report on an asteroid that might hit the Earth -- only to retract the claim a few days later, after additional observations rule out a collision. The primary source of these reports is a list maintained by the Minor Planet Center at the Harvard- Smithsonian Center for Astrophysics. Consider the position of the scientists. They are certainly aware that additional observations will often rule out a future impact -- but if they withhold the early predictions they are accused of a cover-up. So instead they update their predictions continuously, the newspapers report on an uncertain impact, and the astronomers are accused of fear-mongering. It's a no-win situation.

Considering the possible consequences of an asteroid impact, I would rather know about it as far ahead of time as possible. It's similar to the early predictions by meteorologists tracking the path of a hurricane. The uncertainties grow larger as they extrapolate the observations further from the storm's current location -- but the advance warning helps residents of the potentially affected areas to begin preparing for the worst. In the case of Apophis, this might mean placing the entire planet on alert, but at least we would have seven years to devise and execute a plan for avoiding doomsday.

The age of the dinosaurs came to a sudden end when a large asteroid struck near the Yucatan peninsula in the Gulf of Mexico. If humans are smart enough, we can avoid a similar fate.

Budget Uncertainties

More than 4 months into the current fiscal year, the U.S. government still hasn't passed a budget. The administration has already released its budget request for the next fiscal year, which begins in October. This is not the first time we've seen such long delays in the funding of government programs -- including scientific research and development -- and it probably won't be the last. But these annual delays undermine the ability of federal agencies to engage in the long-term planning that could improve the overall efficiency of government.

After the elections in November, the lame-duck Congress passed only 2 of the 11 appropriations bills needed to keep the government running. So, while the Departments of Defense and Homeland Security were fully funded, all other federal programs were asked to continue operating at last year's budget levels through mid-February. The idea was to force the newly elected Congress to spend its first weeks debating the unfinished business of the outgoing Congress. But it didn't work, and in late January the incoming Congress was poised to extend last year's funding levels through the end of this year.

This was a particularly unpleasant prospect for science funding, since several federal agencies (including the National Science Foundation) had been promised significant budget increases this year as part of the American Competitiveness Initiative announced in the State of the Union address in 2006. Without an appropriations bill, this extra funding would simply disappear. Fortunately, last week Congress included a last-minute provision to restore the promised budget increases for several agencies that support scientific research.

A typical grant from the NSF to an individual researcher lasts for 3-5 years, so this effectively sets a minimum planning timescale for the agency. Long annual budget delays create serious inefficiencies in the system -- inflation erodes the value of last year's budget dollar, forcing program cuts to make up any gap, and budget increases that arrive late need to be spent on a shorter timescale. There must be a better way to fund science.

Engineering the Climate

This week the media got a sneak preview of the most recent 5-year study from the Intergovernmental Panel on Climate Change -- a United Nations group of more than 500 scientists from around the globe. The report, which will officially be released this Friday, concludes that "humans have already caused so much damage to the atmosphere that the effects of global warming will last for more than 1,000 years." The good news is: we haven't reached the tipping point yet -- there's still time to reverse the damage we've done and avoid the most severe consequences of climate change.

But some scientists have already started to think about the worst case scenario. What if we don't have the political will to break our addiction to fossil fuels and overconsumption before it's too late? In this case, we might want to consider more drastic measures -- like devising a technological fix, as a last ditch effort to save ourselves.

One such idea, soon to be published in the Journal of the British Interplanetary Society, is to shade the Earth slightly for several decades by creating huge dust clouds in semi-stable orbits near the Moon. The dust could be obtained by deflecting a nearby comet to this region of space and then grinding it up -- but this has the disadvantage of possibly causing the comet to strike the Earth itself and destroy all life as we know it. The other potential source of dust is the Moon. There's plenty of dust there, but we would need to launch it into orbit. This is somewhat easier on the Moon, since the gravity is weaker and there is no atmospheric drag, but it is still a formidable challenge.

To obtain the necessary amount of lunar dust, the author estimates that we would need to launch "about 300 metric tons/s for 10 years" and that "the energy can be derived directly from the Sun". The amount of energy required is about 2% of the current global demand for energy, hundreds of times more solar power capacity than we currently have on Earth -- and we need it on the Moon! If we cannot manufacture solar panels on the Moon, then we would need to launch them from the Earth -- and this would cost about 300 times the current U.S. national debt. This is much more expensive than simply blanketing the Earth with solar panels now -- a technological fix to the climate problem before it gets out of hand.

The Earth from Space

In a live conversation from the International Space Station last night, Indian-American astronaut Sunita Williams told a group of school children in India that "Space is an amazing place for all. Here there are no borders, and the world is very peaceful". Sunita traveled to the ISS aboard the space shuttle Discovery, and plans to work there for the next six months.

The view of a world without borders may be the greatest benefit of making space tourism more accessible to the people of Earth in the future. But with a current price tag of about $20 million, few people can afford the trip. Several entrepreneurs are developing concepts for bringing space travel to the masses, and they are already busy building "spaceports" in places like New Mexico and west Texas. Competition between these companies will help push the price down by a factor of 100, but there are still relatively few people who will be able to afford a $200,000 seat.

Fortunately, an ongoing project by NASA is bringing the view of our planet without borders (or even clouds!) to computer screens around the globe. No doubt you have already seen the impressive composite image of the Earth, pieced together from satellite data obtained at different times and places when there were no clouds to block the view. NASA's "Blue Marble" project is now generating such images every month, so we can watch the surface of the Earth changing over time. At the highest resolution, each pixel in these new images spans just 500 meters on the ground.

Maybe if more people see these images and begin to think of the Earth as a place without borders, we can all live in the peaceful world that Sunita was talking about.

Selling Stellar Seismology

After the successful launch of the French COROT satellite from Kazakhstan, news reports from around the world described the new space telescope as a "planet-seeker" designed to "search for new Earths". These headlines may have surprised some of the European scientists who plan to use observations from COROT to study the interiors of distant stars -- a technique known as asteroseismology. Beyond the headlines, only about 1 in 10 articles even mentioned that COROT would also "probe the mysteries of stellar interiors".

The COROT website features both scientific objectives prominently. In fact, the name COROT is an acronym for "COnvection ROtation and planetary Transits". If you think using only the T from "planetary Transits" is a bit of a cheat, you're right. The mission was originally given its name when it was only designed to do asteroseismology (studying COnvection and ROTation in stars similar to our Sun). Mission scientists added the planet-hunting capability later, since it exploited the same type of observations and attracted political support from a broader cross-section of the scientific community.

The fact that planet-hunting garners more support than asteroseismology is a reflection of its greater appeal among the general public. It also helps explain why the media chose to focus on the search for distant worlds rather than the more abstract goal of probing stellar interiors. About 2 years from now, NASA will launch a slightly larger telescope called Kepler, which is also designed to do both asteroseismology and planet-hunting. Unless stellar seismologists become a bit more media savvy in the meantime, you can count on more headlines about the search for distant Earths.

"Google Sky" coming soon?

This week, NASA announced a strategic partnership with Google to make the agency's massive archive of data more accessible to the public. In the initial phases of the project, the Internet search giant will integrate 3D maps of the moon and Mars into an interface similar to its popular "Google Earth" software, allowing anyone "to experience a virtual flight over the surface of the moon or through the canyons of Mars".

As a simple demonstration of how Google can collaborate fruitfully with space scientists, take a look at the "Google Mars" project, on the web since last March. Working with a group of NASA researchers at Arizona State University, Google adapted their intuitive Maps interface to display optical, infrared and radar data of the red planet. In place of local businesses, the Mars maps include information bubbles marking the locations of major craters, mountains, and the landing sites of robotic spacecraft.

NASA has numerous archives of astronomical data that are already available to the general public, but even some astronomers have a difficult time finding and navigating these websites. For example the Multi-mission Archive, hosted by the Space Telescope Science Institute in Baltimore, allows anyone to download images and other data from the Hubble Space Telescope and many other NASA missions dating back to the 1970's. While the concept is useful (it beats trying to get the data from each mission website individually), the search interface is needlessly complicated and the query results are almost inscrutable. It's not hard to see how Google could make a significant contribution to making these data more accessible.

My own model for a search-friendly archive of astronomical data would be called "Google Sky". Imagine the Google Maps interface populated with the high resolution color images generated by the Sloan Digital Sky Survey (supplemented by the old Palomar Sky Survey to include the entire southern sky). Now imagine that when you search for a specific star or galaxy, the map would zoom into that location and allow you to switch to an infrared or ultraviolet view, just as you can turn on satellite imagery with Google Maps. Finally, the "Find Businesses" feature in the Maps interface would be replaced with "Find Data" -- allowing seamless access to complete archives of ground-based and satellite data that are ready to download and use. It may sound like a dream, but with Google and NASA on the same team, it could soon be a reality.

Misguided Moon Base

Last week NASA announced plans to establish a permanent base on the Moon by the year 2024. You might think astronomers would be among the biggest cheerleaders of such an idea. I can't pretend to speak for all astronomers, but a little history might help you understand the lack of enthusiasm among at least some of my colleagues.

The whole idea of NASA going to the moon again is part of a new vision for space exploration outlined in a speech given by George W. Bush on January 14, 2004. This vision called for a return to the Moon as part of a longer-term plan to prepare for human exploration of Mars. At the time, the scientific community was stunned -- in part because the announcement seemed to come out of nowhere. It certainly wasn't the result of a grassroots effort by the astronomy community. In fact, astronomers had completed their own scientific vision of the future just a few years earlier, and it made no mention of a Moon base.

So where did the President get the idea? The consensus seems to be that, since NASA was planning to decommission the Space Shuttle and end its support of the International Space Station by the end of the decade, aerospace contractors began to wonder where that generous slice of NASA's $15-billion budget would end up. The new vision provided a definite answer, and NASA began to implement it almost immediately.

In its 2005 budget plan, NASA earmarked $12-billion in funding over five years to support the new vision for space exploration, but $11-billion of this total was "reallocated" from existing programs. To astronomers, this means a likely budget cut for research funding (the Office of Space Science, NASA's main source of basic research funding for astronomers, had a $4-billion budget in 2005).

Of course, now that NASA intends to build a base on the Moon there are many scientists with ideas for how to exploit it scientifically. But this is not a good recipe for getting the most science from the taxpayer's dollar -- it is a bunch of astronomers scrambling to recover from the new source of funding what they have lost from the old one.

Welcome to the New Media

Several years ago, a friend of mine from graduate school started a website called starstuff.org, which was designed to bring astronomy news directly from astronomers to interested journalists and members of the general public. The name was motivated by a famous quote from astronomer Carl Sagan on the popular PBS television series, "Cosmos". He said, "we are, all of us, made of star-stuff". This unfiltered news website was a great idea, and I contributed several articles to it. But, for a variety of reasons, it eventually shut down.

It is in the spirit of starstuff.org that I am starting this new blog. I will try to make new posts about once a week, giving an astronomer's perspective on current news from the world of astronomy and about science in general.

My thanks go out to Sara "Star" Johnson of Bloomington, Indiana for letting me take over this blog name. Her blog is now hosted at star.qnarf.com