Glowing trails seen in the early morning sky over the Marshall Islands (NASA/Jon Grant)
Ball lightning? Spectral orbs? Swamp gas? Early this morning, May 7, these eerie glowing trails were seen in the sky above the Marshall Islands and were captured on camera by NASA photographer John Grant. Of course, if NASA’s involved there has to be a reasonable explanation, right?
For a larger image (and to see what really caused the trails) click below:
Credit: NASA/John Grant
Although it might look like cheesy special effects, these colorful clouds are actually visible trails that were left by two sounding rockets launched from Roi Namur in the Marshall Islands, at 3:39 a.m. EDT on May 7. The rockets were part of the NASA-funded EVEX experiment to study winds and electrical activity in the upper atmosphere.
The red cloud was formed by the release of lithium vapor and the white-and-blue tracer clouds were formed by the release of trimethyl aluminum (TMA). These clouds allowed scientists on the ground from various locations in the Marshall Islands to observe neutral winds in the ionosphere.
“Neutral winds are one of the hardest things to study,” said Doug Rowland, an EVEX team member at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “One can’t physically see the wind, and it is difficult to measure from the ground, so we use the TMA as a tracer.”
Launch of the second EVEX rocket on the morning of May 7. The plume from the first is visible on the left. (NASA/John Grant)
The EVEX (Equatorial Vortex Experiment) rockets were launched 90 seconds apart. By staggering the launches the two rockets were able to gather data simultaneously at two altitudes through the ionosphere.
Beginning about 60 miles (96 km) up, the ionosphere is a crucial layer of charged particles surrounding our planet. This layer serves as the medium through which high frequency radio waves – such as those sent down to the ground by satellites – travel. Governed by Earth’s magnetic field, high-altitude winds, and incoming material and energy from the sun, the ionosphere can be calm at certain times of day and at other times turbulent, disrupting satellite signals.
The EVEX experiment is designed to measure events in two separate regions of the ionosphere to see how they work together to drive it from placid and smooth to violently disturbed. Such information could ultimately lead to the ability to accurately forecast this important aspect of space weather.
A rendering of the Cluster satellite, designed to measure electric fields, which Andre and Cully used to detect low-energy ions high above the Earth. (Credit: European Space Agency)
[/caption]
Thousands of miles above Earth, space weather rules. Here storms of high-energy particles mix the atmosphere, create auroras, challenge satellites and even cause disturbances with electric grids and electronic devices below. It’s a seemingly empty and lonely place – one where a mystery called “cold plasma” has been found in abundance and may well have implications with our connection to the Sun. While it has remained virtually hidden, Swedish researchers have created a new method to measure these cold, charged ions. With evidence of more there than once thought, these new findings may very well give us clues as to what’s happening around other planets and their natural satellites.
“The more you look for low-energy ions, the more you find,” said Mats Andre, a professor of space physics at the Swedish Institute of Space Physics in Uppsala, Sweden, and leader of the research team whose findings have been accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union. “We didn’t know how much was out there. It’s more than even I thought.”
Where does this enigma originate? The low-energy ions begin in the upper portion of our atmosphere called the ionosphere. Here solar energy can strip electrons from molecules, leaving atoms such as oxygen and hydrogen with a positive charge. However, physically finding these ions has been problematic. While researchers knew they existed at altitudes of about 100 kilometers (60 miles), Andre and colleague Chris Cully set their sites higher – at between 20,000 and 100,000 km (12,400 to 60,000 mi). At the edge, the amount of cold ions varies between 50 to 70%… making up most of the mass of space.
However, that’s not the only place cold plasma has been found. According to the research satellite data and calculations, certain high-altitude zones harbor low-energy ions continuously. As far fetched as it may sound, the team has also detected them at altitudes of 100,000 km! According to Andre, discovering so many relatively cool ions in these regions is surprising because there’s so much energy hitting the Earth’s high altitudes from the solar wind – a hot plasma about 1,000 times hotter than what Andre considers cold. Just how cold? “The low-energy ions have an energy that would correspond to about 500,000 degrees Celsius (about one million degrees Fahrenheit) at typical gas densities found on Earth. But because the density of the ions in space is so low, satellites and spacecraft can orbit without bursting into flames.”
A scientist examines one of the European Space Agency's four Cluster satellites, used in a recent Geophysical Research Letters study to measure low-energy ions. (Credit: European Space Agency)
Pinpointing these low-energy ions and measuring how much material is leaving our atmosphere has been an elusive task. Andre’s workshop is a satellite and one of the four European Space Agency CLUSTER spacecraft. It houses a detector created from a fine wire that measures the electronic field between them during satellite rotation. However, when the data was collected, the researchers found a pair of mysteries – strong electric fields in unexpected areas of space and electric fields that didn’t fluctuate evenly.
“To a scientist, it looked pretty ugly,” Andre said. “We tried to figure out what was wrong with the instrument. Then we realized there’s nothing wrong with the instrument.” What they found opened their eyes. Cold plasma was changing the arrangement of the electrical fields surrounding the satellite. This made them realize they could utilize their field measurements to validate the presence of cold plasma. “It’s a clever way of turning the limitations of a spacecraft-based detector into assets,” said Thomas Moore, senior project scientist for NASA’s Magnetospheric Multiscale mission at the Goddard Space Flight Center in Greenbelt, Maryland. He was not involved in the new research.
Through these new techniques, science can measure and map Earth’s cold plasma envelope – and learn more about how both hot and cold plasma change during extreme space weather conditions. This research points towards a better understanding of atmospheres other than our own, too. Currently the new measurements show about a kilogram (two pounds) of cold plasma escapes from Earth’s atmosphere every second, By having a solid figure as a basis for rate of loss, scientists may be able model what became of Mars’ atmosphere – or explain the atmosphere around other planets and moons. It can also aid in more accurate space weather forecasting – even if it doesn’t directly influence the environment itself. It is a key player, even if it doesn’t cause the damage itself. “You may want to know where the low-pressure area is, to predict a storm,” Andre noted.
Modernizing space weather forecasting to where it is similar to ordinary weather forecasting, was “not even remotely possible if you’re missing most of your plasma,” Moore, with NASA, said. Now, with a way to measure cold plasma, the goal of high-quality forecasts is one step closer. “It is stuff we couldn’t see and couldn’t detect, and then suddenly we could measure it,” Moore said of the low-energy ions. “Now you can actually study it and see if it agrees with the theories.”
For his next big plan for the private space industry, Richard Branson is thinking up new ways to excite affluent space tourists: flying them into the biggest lightshow on Earth, the Aurora Borealis. Although the New Mexico Virgin Galactic Spaceport isn’t scheduled for completion until 2010, the British entrepreneur is already planning his next project intended for cruises into the spectacular space phenomenon from an Arctic launchpad.
Located in the far north of Sweden (in the Lapland province), the small town of Kiruna has a long history of space observation and rocket launches. The Arctic location provides the town with unrivalled views of the Aurora Borealis as it erupts overhead. The Auroral lightshow is generated by atmospheric reactions to impacting solar wind particles as they channel along the Earth’s magnetic field and down into the thickening atmospheric gases.
Once a view exclusive only to sounding rockets, this awe inspiring sight may in the future be seen from the inside, and above, by fee-paying space tourists as they are launched into space from a new spaceport, on the site of an existing base called Esrange. Although launching humans into an active aurora holds little scientific interest (if it did, it would have probably been done by now), it does pose some prudent health and safety questions. As Dr Olle Norberg, Esrange’s director, confidently states: “Is there a build-up of charge on the spacecraft? What is the radiation dose that you would receive? Those studies came out saying it is safe to do this.” Phew, that’s a relief.
The chance to actually be inside this magnificent display of light will be an incredible selling point for Virgin Galactic and their SpaceShipTwo flights. As if going into space were not enough, you can see and fly through the atmosphere at it’s most magnificent too.
