Space program might be behind metals found in atmosphere
What’s in our atmosphere? You know about most of it. Gases we breathe and water vapor in the form of humidity and tiny water droplets we see as clouds. Bigger water droplets fall as rain, hail, sleet, or snow depending on the weather and temperature. But there is a lot of other stuff up there, particles mostly from human activity.
The gases of our atmosphere consist of 78% nitrogen and 21% oxygen. There is a smattering of other gases. Our air is .04% carbon dioxide and, unfortunately, increasing. There is also a tiny bit of other gases accounting for .96% of our atmosphere.
Water vapor often condenses into water droplets by sticking to nucleating particles like soot from fires and volcanoes, windblown dust, and sea salt. But other stuff is also up there. Volcanoes and burning fossil fuels release sulfur, which easily combines with other particles in the air creating sulfates.
NASA recently used high-altitude airplanes to get a detailed accounting of what’s in our air. They were surprised to find tiny particles of metals, most of which are in the form of sulfates. The metals they found include some we really don’t want to be breathing, like aluminum, copper, cadmium, tin, and lead. There are also some rarer metals like titanium, hafnium, bismuth, and lithium.
It turns out, these metals are the result of our space program. Every time a spent stage or a dead or failing satellite reenters our atmosphere and burns up, tiny flecks of the metals they are made of float in the upper atmosphere, often to form sulfates with the sulfur droplets in the air.
Fortunately, these metal sulfates rarely get down into the lower atmosphere where we can breathe them in, but just the thought of inhaling them seems unpleasant.
Geminid meteor shower to peak
One of the most active meteor showers occurs each year in mid-December, the Geminid meteor shower. This year, it peaks on the night of Dec. 14-15. Meteor showers occur when small bits of rock and metal that are frozen in the icy body of a comet are released as the heat from the sun slowly melts the surface ice of the comet. The Geminid shower’s parent is an asteroid called Phaethon. It was once a comet, but now, much of its ice is already gone, leaving behind the rocky core.
The Winter Solstice occurs on Dec. 21, marking the shortest day of the year. From then on, until next June, the amount of sunlight increases each day.
Planet Visibility Report
Venus still shines brightly in the predawn sky. Mars has moved into the morning sky to join Venus, but will be hidden in the sun’s glare until late in the month. Mercury sits in the evening sky but never gets far enough from the sun for easily visibility. Jupiter and Saturn are both in the evening sky all month. New moon occurs on Dec. 12, with the full moon on Dec. 26.