The past month or so has given us a flyovers by the Space Shuttles Discovery and Enterprise (with associated striking photos), the Hubble Space telescope’s birthday, budget questions over satellites, and proposals to mine asteroids for resources. Typically, my gaze is focused on the earth’s surface or lower atmosphere, but these events have me looking back up for a change and thinking about the role of space in science. However, aspects of this endeavor may be at risk.
My fascination with space
As a kid I grew up with the Space Shuttle. This ranged from highs, such as classroom shuttle launches and dreams of Space Camp (based in part on the movie) to lows such as the Challenger disaster. This was brought in to particular focus as one of our favorite teachers went through the Teacher in Space competition that ultimately went to Christa McAullife. Our small elementary school followed the events very closely, including watching that fateful flight on a classroom TV in 1986. Despite that event, lots of science fiction and an old telescope kept my interest on the skies and beyond.
It was, ironically, when I formalized my interest in science by attending graduate school that I lost sight of the utility in studying what lies beyond our planet. My feeling, at the time, was that there were plenty of pressing and interesting problems on our own home world that deserved our attention and resources. I quickly realized the error in this, again perhaps ironically, when I tried to explain why my rather esoteric research should be of concern to my non-scientist parents. It was then that someone, possibly my PhD advisor, said something along the lines of, “Scientific knowledge is like a vast ocean. The research we’re doing may represent only small buckets into this ocean and we have no idea when or where someone may withdraw our contribution. But it’s enough knowing we’re adding to it and making it available.” Again in the world of limited resources it may not be defensible to make the scientific endeavor that idealistic, but I got the point.
The Hubble space telescope arrives
The Hubble Deep Field image showing thousands of galaxies and looking back to the time just after the Big Bang. How many galaxies can you count? Credit: NASA, ESA, S. Beckwith (STScI) and the HUDF Teamhe
It was also around this time the Hubble space telescope began releasing truly incredible images of space that got my scientific wonder going full speed again and likely others’ as well. The one that leaves me in awe is the Hubble ultra deep field image. The image represents about one-thirteen millionth of the area of the entire sky, contains around 10,000 galaxies and looks back in time to the point just after the Big Bang and initial galaxy formation. But it’s not just about pretty pictures. Over 10,000 scientific journal articles have been published using Hubble data. And in the true spirit of open science virtually anyone can apply for time on Hubble. Just don’t hold your breath on getting it.
Science in (or from) space provides great value to my personal work and that of UCS.
This comes from a wide range of observations of the Earth system from satellites. Satellites provide information that is unique in that they can conduct global measurements in relatively short amounts of time and with repetition over their multiyear lifespans (the satellite passes over a given area on a highly regular basis over and over). In a previous life, some of my work involved the Aura satellite, which is part of a larger series of satellites known as the A-Train.
Aura measures various aspects of atmospheric chemistry. Very high in the atmosphere it measures how the stratospheric ozone hole is changing. Much closer to the surface, it tracks atmospheric pollutants and air quality with public health impacts and how changing chemistry in the atmosphere affects climate. Other satellites provide information on the global water cycle, properties of clouds, the amount of solar radiation Earth receives, changes in land use, and many others. Two of the most interesting, in my opinion, are the GRACE satellites that measure changes in Earth’s gravitational field. This is done by accurately measuring the distance between two satellites that depends on the underlying gravitational field. Among other applications this has been used to measure ice loss in Greenland and of perhaps more immediate concern depletion of groundwater basins.
Artist's depiction of the A-Train series of satellites. Some satellites carry multiple instruments. The approximate viewing areas of the instruments are shown. Credit: NASA
One very important aspect of obtaining long-term satellite data important for climate trends is ensuring that the older satellite and its replacement are both in orbit at the same time, so any offsets or discrepancies between the two can be accounted for. The overlapping measurements ensure that the data record can be extended with the new satellite. Continued funding for these satellites then becomes critical, but recent news is not promising. This is problematic for not only the existing satellite fleet and potential replacements, but also for satellites providing new types of measurements such as the Orbiting Carbon Observatory (OCO), which would produce a global map of sources and sinks of carbon dioxide and how they change over time with a high degree of accuracy. Delays are already happening with this, however.
Science from space is costly and not without some failure (for instance, see the original OCO satellite). But investing in it not only is investing in the scientific endeavor and the vast amount of information and breakthroughs that can provide. It is also a pathway via a spectacular image or two to a sense of wonderment not only about our universe (or multiverse depending on your perspective), but maybe more importantly to a renewed sense of wonderment about our own planet. At least that is the case for me.