As astronomers, we study the solar system, galaxy, and universe, and the extraordinary images and discoveries that we share instill a sense of awe and wonder.
Research indicates that awe can trigger empathy and enhanced collective concern. And so, while revealing the uniqueness, wonder and fragility of Earth, the astronomical perspective can also nurture its stewardship and care.
The first, taken from the International Space Station 350 kilometers above Earth, shows the day-night boundary and the thin layer that is our delicate atmosphere.
The second was snapped by the Apollo 11 crew from lunar orbit in 1969—385,000 kilometers from Earth. Revealing the loneliness and fragility of our planet, this photo helped propel the environmental movement.
The third was taken by the Voyager 1 spacecraft in 1990—6.5 billion miles from Earth. From this distance, Earth is just a point, coincidentally lying in a scattered ray of light from the Sun.
“Look again at that dot. That’s here. That’s us. On it, everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every “superstar,” every “supreme leader,” every saint and sinner in the history of our species lived there — on a mote of dust, suspended in a sunbeam.
The Earth is the only world known to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment the Earth is where we make our stand. “
The fundamental papers describing the effect of CO2 on the atmosphere are accessible to astronomers. We study radiative transfer and we understand how the thermal balance works in planetary atmospheres like our own. By reading, reflecting, and interacting with researchers on the front lines of climate research, we are cultivating a level of expertise that allows us to accurately communicate climate science with the added perspective we have as astronomers.
View our climate communication resources to develop your climate communication skills.
We would like to take a moment to clear up a misconception that our own research (and the excitement that surrounds it) has created: the notion that transporting humanity from Earth to destinations in space might be a viable way to cope with a degraded ecology on Earth. This is not possible in the immediate future.
The temperature on the surface of Venus is about 850°F (450°C). This high temperature cannot be explained simply because Venus is closer to the Sun than the Earth. The searing temperature of Venus is proof that the greenhouse effect is real. Venus has a thick atmosphere made almost entirely of carbon dioxide, a greenhouse gas. Venus is often called our sister planet, because it is about the same size as the Earth and just a little closer to the Sun. The lessons from Venus are that more greenhouse gases mean higher temperatures, and planets that appear to be Earth-like from great distances are not necessarily habitable worlds.
Billions of years ago, the conditions on Mars were warm enough that there was liquid water on its surface, meaning the conditions may have been suitable for life. While the climate of Mars changed for natural reasons, it serves as a stark reminder that there is no guarantee a planet will remain habitable.
It was from studying the atmosphere of Venus that scientists first learned that chlorofluorocarbons (CFCs) are damaging the Earth’s ozone layer. Nations soon came together to ban the use of CFCs, and our ozone layer is slowly healing.
Astronomers have discovered over four thousand planets orbiting around other stars. None of them are places where we could live. And even if they were habitable they are much too far away for us to travel. Mars at its closest is four light minutes away, and we still lack the ability to send a single person there. The nearest star is over four light years away! Using current technology, that would take over 6,000 years for a spaceship to reach!
When you take a step back and view Earth from space, you begin to comprehend that, in the scheme of things, it is little more than a tiny point of light surrounded by either vast emptiness, unlivable temperatures, or violent cosmic processes beyond our comprehension. And yet, on that tiny point of light, every creature that ever lived, every human you have ever known, has found refuge. Visiting in person scale models of our solar system, like this one, can help us understand our cosmic place. And nurturing a cosmic perspective of our own existence can help us recognize the critical importance of caring for our only home.