Voyager 1 Gets Ever Farther Away

Creeping Closer to the “Edge” of the Solar System

The two Voyager spacecraft have always occupied a soft spot in my heart because they were the first ones I ever reported on in my days as a science journalist. They opened up our eyes to what actually exists in the outer solar system around the planets Jupiter, Saturn, Uranus, and Neptune. For the first time, those gas and ice giants became recognizable worlds, with moons and rings and unusual weather patterns.

The Voyagers are on one-way trips out of the Solar System.  Voyager 1 is literally pushing the envelope of the Sun’s influence, currently transiting through a region called the “magnetic highway”. To understand that term, think of the Sun as blowing a bubble of gas out to interstellar space. Like any bubble (or a balloon), it has a thin surface. The region inside the bubble is threaded with the Sun’s magnetic field lines.

Artist’s concept of the Voyager 1 spacecraft’s exploration of a region in the outermost par tof the heliosphere (the bubble blown out by the Sun). In this region solar magnetic field lines (yellow arcs) are piling up and intensifying. The depletion region, where voyager is now, could be the last part of our solar system and once it clears that area, the spacecraft will truly be in interstellar space. Image Credit: NASA/JPL-Caltech

Voyager 1 has been slowly exploring the outermost regions of the bubble. In 2004, it  passed a shockwave known as the “termination shock”. This is where solar wind suddenly slows down and becomes more turbulent. In 2010, Voyager then passed into an area called the “stagnation region” where the outward velocity of the solar wind slowed to zero and sporadically reversed direction.

On Aug. 25, 2012, Voyager 1 entered the depletion region, where the magnetic field acts as a kind of magnetic highway that lets energetic ions from inside the heliosphere escape out, and cosmic rays from interstellar space zoom in. (To learn more about how this region acts as a magnetic highway, click here and read more here about today’s Voyager 1 announcement.)

As Voyager 1 zooms out on its endless journey, eventually it will cross the heliopause—the “skin” of the bubble blown out by the Sun. After that, it’s clear sailing to the next flyby of a celestial object, the star Gliese 445.  However, that won’t happen for about 40,000 years.  Chances are that Voyager 1 will be unable to tell us anything about it (provided we’re still around), since its systems are slowly deteriorating, and astronomers will begin shutting down most of its subsystems in the next few years. Still, it will send signals as long as its power holds out, as it transits interstellar space at the fastest speed relative to the Sun of any human-made object sent to space.

If you’ve never read about the Voyager missions to the outer solar system, they provide quite a tale and one well worth knowing. So, check here and here and here  to learn more about these amazing spacecraft and the discoveries they helped planetary scientists make.

The Astronaut View of Colorado Fires

The Consequences of Beetle Kill, Drought, and Climate Change

Look at this picture for a while. It shows a complex of fires going on southwest of where I live.

Plumes of smoke belie the existence of massive forest and wildfires in southwestern Colorado. Courtesy NASA.

These thick plumes are the last gasps of dead trees and drought-ridden vegetation that only needed one strike of lightning to get started. This is what the fires look like from space. The images were taken by astronauts aboard the International Space Station and show the results of a confluence of beetles, extreme drought, and climate change. (Read more about this confluence in Alan Boyle’s article at NBCNews.com.)

Ther Wild Rose blaze is now fully contained, meaning that there is a line of control all around it.  The West Fork Complex fire continues to chew its way across the landscape, threatening towns and forests.

This mega-blaze started as three smaller fires (started by lightning), and together they consumed approximately 75,000 acres (30,000 hectares) by June 25. The fires were burning in rugged terrain with large amounts of beetle-killed spruce forests. According to the information published with this image by NASA, the West Fork Complex fire was so hot that it spawned numerous pyrocumulus clouds. These are tall, cauliflower-shaped clouds that billowed high above the surface. Pyrocumulus clouds are similar to cumulus clouds, but the heat that forces the air to rise (which leads to cooling and condensation of water vapor) comes from fire instead of sun-warmed ground.

Scientists monitor pyrocumulus clouds closely because the clouds can inject smoke and pollutants high into the atmosphere. As pollutants are dispersed by wind, they can affect air quality over broad areas. As noted by the University Maryland at Baltimore County (UMBC) Smog Blog, smoke from the fire contributed to elevated concentrations of particulate matter over large sections of the eastern United States. We’ve smelled the smoke from this fire over our own home, which is at least a day’s drive away. Last year we had plumes of smoke over much of the state from fires in Arizona and New Mexico, and so in addition to the dangers that fires pose to immediate areas, they also affect life great distances away.

Preliminary observations by the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite indicate the West Fork Complex fire lofted smoke plumes as high as 13.5 kilometers (8.4 miles) up in the atmosphere. Satellite observations also show that smoke from the fire reached European air space by June 24.

This year is a very dry one for the southwestern part of Colorado. All of us who live in or near the mountains are very aware of the fire dangers. Although our area got quite a lot of snow and rain this year, the chances for one lightning strike, one cigarette butt flicked out of a car by an ignorant idiot, or an illegal campfire to do great damage are foremost in our minds. We see the loss of trees to beetle kill.

We also see the changes in the forests and wildlife due to the warmer temperatures and more extreme weather brought on by changes in Earth’s climate.  And, it’s not just forest fires that are a side consequence of climate change. There are people in Oklahoma and Texas and Central Europe, where flooding continues, and Southeast Asia, where monsoon weather is more extreme than usual. THEY also see the effects of climate change. They’re living it first-hand.

The fires I see in this image are just one stark reminder of what we face as our planet’s climate continues to change.  It is time, as President Obama, and many U.S. military leaders and environmental scientists around the world, joined by other world leaders have ALSO said, to confront the issue instead of denying it (in the face of all the evidence). It is time because the people who live in damaged areas and have lost their homes, their livelihoods (and sometimes their lives) around the world are also part of the consequences of climate change. It’s time to get real, people.