Light Pollution: An Unnecessary Expense

We are Losing the Dark

The United States at night. Courtesy NASA/GSFC.
The United States at night. Courtesy NASA/GSFC.

I live in a dark-sky area. Or, mostly dark-sky, since the light pollution from nearby Denver and the Front Range seep over the mountains and blot out the eastern horizon. It used to be that humans had unfettered access to the night sky. Now, we have to try and see the stars through a growing haze of light shining upwards. Why do we shine light UP?  Why light up the sky?  It’s totally unnecessary, particularly when what we want to light up is on the ground, not in the sky. Every year we waste billions of dollars in lighting up the sky. That’s a lot of fossil fuel to be burned and wasted, fuel that could be better used elsewhere.

There are reasons to light things up at night, no question about it. But, the sky isn’t one of those things. And, overuse of light not only costs more money, it affects the health of people and wildlife. Lights at night affect people’s ability to sleep, which is a primary component of good health. There is also growing medical evidence that extra light at night plays a role in a higher risk of breast and prostate cancer in people who are exposed to it. In addition, wildlife suffers from our overweening reliance on sending light UP to the sky. The environmental cost is incredibly high. And, it doesn’t have to be that way. We can learn to use light properly and still maintain safety and security.

ltd_poster_t (1)The solutions to light pollution actually start with each of us:  we have it in our power to make sure our lighting around our homes and in our towns is not facing UP. We can use fully shielded fixtures which actually help save money. We can also properly light ONLY the places that need it. And, if we don’t need the lights on, we can simply turn them off. Saves money and our health.

The International Dark-Sky Association is the world’s premier light pollution mitigation organization and the group has an amazing amount of free information on their web site that anyone can access interested in mitigating light use. One of the things they have is a video that I co-produced for them, called Losing the Dark, available as a free download for planetariums and also as a flat-screen HD for use on computers, kiosks, in auditoriums, classrooms and other venues equipped with a video projector.  In the months since its February 2013 release, the videos have gotten a great deal of attention on IDA’s Youtube channel and also on the Loch Ness Productions Youtube channel. Many planetariums (both fulldome video and classic theaters) have gotten the show.  It’s a six-minute look at light pollution and what we can do to mitigate it.

Recently IDA posted a survey about how people are using the video. If you have downloaded it, they’d love to hear from you about how you use it, and so on. It’s a short, confidential survey and well worth the couple of minutes

Simulating Long-Distance Calls to Mars

MAVEN Undergoes Communications Tests

Last week while I was attending a meeting of planetarium folk in Kansas City, the MAVEN mission went through a series of communications tests at the Kennedy Space Center as engineers continue to prep the spacecraft for its trip to Mars. This is pretty crucial; you don’t want to get all the way to Mars only to find out something happened to the radio comm system. So, part of the launch prep is to test all the systems, including the communications packages.

An artist's conception of the MAVEN mission in orbit around Mars. Courtesy NASA/GSFC.
An artist’s conception of the MAVEN mission in orbit around Mars. Courtesy NASA/GSFC.

MAVEN, which is the latest mission to Mars, is going to the Red Planet to study the upper atmosphere. The other missions we’re familiar with are on the ground (Curiosity, for example) or mapping the planet from orbit (Mars Reconnaissance Orbiter). This one is going to spend its time swooping through parts of the upper atmosphere and gather data about that thin, thin layer of Martian “air” that will tell scientists more about what’s there, how the atmosphere has evolved over time, and try to measure the loss of volatiles (gases) from the uppermost layers. The science mission for MAVEN (which stands for “Mars Atmosphere and Volatile Evolution”) is focused primarily on figuring out which processes allow the top of the atmosphere to escape to space. From that information, scientists will be able to get a better handle on the climate change Mars has undergone since its formation.

It’s pretty clear that Mars was once warmer and somewhat wetter than it is now, and atmospheric escape must have played a huge role in turning Mars into the desert it is today. So, MAVEN will be gathering a lot of data, and sending it back to Earth. That’s why it’s important to have a robust set of comm instruments onboard. During last week’s tests, engineers simulated the distance over which MAVEN’s signals must pass. They beamed test signals to the spacecraft’s low-gain and high-gain antennas and through that practice, treated the instruments as if they were on the 10-month journey to Mars and then on its orbital mission.

 

I found the procedure fascinating to read about, particularly how they simulated “real conditions”. First, the engineers rigged up a way to ramp down the power of the signals by sending them through a series of wiring networks. In essence, they found ways to reduce the signal down to the lowest possible power. Then, the instrument scientists logged into to the system and went through a normal day’s mission commands, as if they were talking to a spacecraft actually at Mars. It was a good practice for everybody, and just the latest in a series of simulations the teams are going through as the November launch date gets nearer.

In “real time”, the spacecraft will gather its data and then send it back to Earth via its onboard radio systems. The signals will be received by the Deep Space Network, and then sent along to the scientists at the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder. From there, the team members in the U.S. and France will get and analyze their data, helping put t0gether a fuller, richer story about Mars and the role its atmosphere plays.

Exploring Science and the Cosmos

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